feat: add lms-nav2-gazebo-simulator module

2026-07-28 10:35:22 +09:00
commit 0db91a16b8
160 changed files with 275895 additions and 0 deletions
@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.8)
+project(nav2_turtlebot_simulator)
+
+find_package(ament_cmake REQUIRED)
+
+install(DIRECTORY launch worlds DESTINATION share/${PROJECT_NAME})
+
+ament_package()
@@ -0,0 +1,133 @@
+import os
+import tempfile
+import xml.etree.ElementTree as ET
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument, IncludeLaunchDescription, OpaqueFunction
+from launch.conditions import IfCondition
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def create_flat_house_world(gazebo_dir):
+    """Create a texture-free copy of the house model while retaining its mesh hierarchy."""
+    world_path = os.path.join(gazebo_dir, 'worlds', 'turtlebot3_house.world')
+    model_path = os.path.join(gazebo_dir, 'models', 'turtlebot3_house', 'model.sdf')
+    flat_models_dir = os.path.join(tempfile.gettempdir(), 'nav2_flat_models')
+    flat_model_dir = os.path.join(flat_models_dir, 'turtlebot3_house_flat')
+    os.makedirs(flat_model_dir, exist_ok=True)
+
+    house_model_tree = ET.parse(model_path)
+    house_model = house_model_tree.getroot()
+    house_model.attrib['name'] = 'turtlebot3_house_flat'
+
+    for visual in house_model.findall('.//visual'):
+        material = visual.find('material')
+        if material is None:
+            material = ET.SubElement(visual, 'material')
+
+        for script in material.findall('script'):
+            material.remove(script)
+
+        for name, value in (
+            ('ambient', '0.62 0.67 0.76 1'),
+            ('diffuse', '0.62 0.67 0.76 1'),
+            ('specular', '0.05 0.05 0.05 1'),
+        ):
+            color = material.find(name)
+            if color is None:
+                color = ET.SubElement(material, name)
+            color.text = value
+
+        shadows = visual.find('cast_shadows')
+        if shadows is None:
+            shadows = ET.SubElement(visual, 'cast_shadows')
+        shadows.text = 'false'
+
+    # ElementTree serializes Gazebo's frame='' as frame="", which is invalid SDF.
+    for element in house_model.iter():
+        if element.attrib.get('frame') == '':
+            del element.attrib['frame']
+
+    house_model_tree.write(
+        os.path.join(flat_model_dir, 'model.sdf'),
+        encoding='utf-8',
+        xml_declaration=True,
+    )
+    with open(os.path.join(flat_model_dir, 'model.config'), 'w', encoding='utf-8') as config:
+        config.write(
+            '<model><name>turtlebot3_house_flat</name>'
+            '<version>1.0</version><sdf version="1.6">model.sdf</sdf></model>'
+        )
+
+    with open(world_path, 'r', encoding='utf-8') as source:
+        flat_world = source.read().replace('model://turtlebot3_house', 'model://turtlebot3_house_flat')
+
+    flat_world_path = os.path.join(tempfile.gettempdir(), 'nav2_turtlebot3_house_flat.world')
+    with open(flat_world_path, 'w', encoding='utf-8') as destination:
+        destination.write(flat_world)
+
+    existing_model_path = os.environ.get('GAZEBO_MODEL_PATH', '')
+    os.environ['GAZEBO_MODEL_PATH'] = os.pathsep.join(
+        part for part in (flat_models_dir, existing_model_path) if part
+    )
+    return flat_world_path
+
+
+def launch_gazebo(context):
+    gazebo_dir = get_package_share_directory('turtlebot3_gazebo')
+    simulator_dir = get_package_share_directory('nav2_turtlebot_simulator')
+    gazebo_ros_dir = get_package_share_directory('gazebo_ros')
+    world = LaunchConfiguration('world').perform(context)
+    render_mode = LaunchConfiguration('render_mode').perform(context).strip().lower()
+
+    if render_mode not in {'flat', 'full'}:
+        raise RuntimeError('render_mode must be either flat or full')
+
+    if world == 'turtlebot3_house.world' and render_mode == 'flat':
+        world_path = create_flat_house_world(gazebo_dir)
+    else:
+        world_path = os.path.join(
+            simulator_dir if world == 'empty_world.world' else gazebo_dir,
+            'worlds',
+            world,
+        )
+    return [
+        IncludeLaunchDescription(
+            PythonLaunchDescriptionSource(os.path.join(gazebo_ros_dir, 'launch', 'gzserver.launch.py')),
+            launch_arguments={
+                'world': world_path,
+                'extra_gazebo_args': '-slibgazebo_ros_state.so',
+            }.items(),
+        ),
+        Node(
+            package='gazebo_ros',
+            executable='spawn_entity.py',
+            arguments=[
+                '-entity', 'turtlebot3_burger_3d_lidar',
+                '-file', os.path.join(gazebo_dir, 'models', 'turtlebot3_burger', 'model.sdf'),
+                '-x', LaunchConfiguration('x_pose').perform(context),
+                '-y', LaunchConfiguration('y_pose').perform(context),
+                '-z', '0.01',
+            ],
+            output='screen',
+        ),
+    ]
+
+
+def generate_launch_description():
+    gazebo_ros_dir = get_package_share_directory('gazebo_ros')
+    return LaunchDescription([
+        DeclareLaunchArgument('gui', default_value='false'),
+        DeclareLaunchArgument('world', default_value='turtlebot3_world.world'),
+        DeclareLaunchArgument('render_mode', default_value='flat'),
+        DeclareLaunchArgument('x_pose', default_value='-2.0'),
+        DeclareLaunchArgument('y_pose', default_value='-0.5'),
+        OpaqueFunction(function=launch_gazebo),
+        IncludeLaunchDescription(
+            PythonLaunchDescriptionSource(os.path.join(gazebo_ros_dir, 'launch', 'gzclient.launch.py')),
+            condition=IfCondition(LaunchConfiguration('gui')),
+        ),
+    ])
@@ -0,0 +1,14 @@
+<?xml version="1.0"?>
+<package format="3">
+  <name>nav2_turtlebot_simulator</name>
+  <version>1.0.0</version>
+  <description>Headless Gazebo and TurtleBot3 Burger startup for the Nav2 lab.</description>
+  <maintainer email="platform@autonomystudio.net">Autonomy Studio</maintainer>
+  <license>Apache-2.0</license>
+  <buildtool_depend>ament_cmake</buildtool_depend>
+  <exec_depend>gazebo_ros</exec_depend>
+  <exec_depend>launch</exec_depend>
+  <exec_depend>launch_ros</exec_depend>
+  <exec_depend>turtlebot3_gazebo</exec_depend>
+  <export><build_type>ament_cmake</build_type></export>
+</package>
@@ -0,0 +1,11 @@
+<?xml version="1.0"?>
+<sdf version="1.6">
+  <world name="empty_world">
+    <include><uri>model://ground_plane</uri></include>
+    <include><uri>model://sun</uri></include>
+    <physics type="ode">
+      <real_time_update_rate>1000.0</real_time_update_rate>
+      <max_step_size>0.001</max_step_size>
+    </physics>
+  </world>
+</sdf>
@@ -0,0 +1,187 @@
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Changelog for package turtlebot3_gazebo
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+2.3.8 (2025-07-10)
+------------------
+* None
+
+2.3.6 (2025-06-19)
+------------------
+* None
+
+2.3.4 (2025-05-28)
+------------------
+* None
+
+2.3.0 (2025-02-17)
+------------------
+* Added multi-robot launch functionality
+* Updated robot mesh in Gazebo and RViz
+* Added launch file for TurtleBot3 Autorace 2020
+* Added plugins to the models of Autorace 2020
+* Contributors: Hyungyu Kim
+
+2.2.6 (2022-05-26)
+------------------
+* ROS 2 Humble Hawksbill supported
+* Contributors: Will Son
+
+2.2.5 (2021-08-25)
+------------------
+* Release for ROS 2 Rolling
+* Contributors: Will Son
+
+2.2.4 (2021-06-14)
+------------------
+* Release for ROS 2 Galactic
+* Separate world and robot models(#162)
+* Clean up unncessary files
+* Use turtlebot3_common mesh modeling
+* Independent turtlebot3_simulations package
+* Contributors: Joep Tool, Will Son
+
+2.2.3 (2021-04-12)
+------------------
+* Update required keyword arguments
+* Clear up exec_depend
+* Fix Waffle Pi wheel inertia
+* Contributors: ruffsl, Will Son
+
+2.2.2 (2021-02-24)
+------------------
+* Remove shared objects built in older version
+* Contributors: Will Son
+
+2.2.1 (2021-01-13)
+------------------
+* Eloquent Elusor EOL
+* Add missing imu joint in sdf
+* Append Gazebo model path
+* Portable fix, launch description revise
+* Ament lint applied
+* Contributors: minwoominwoominwoo7, Rayman, seanyen, ashe kim, Will Son
+
+2.2.0 (2020-06-29)
+------------------
+* TurtleBot3 Drive node implementation
+* Additional Gazebo maps added
+* argument tags in the sdf file replaced with remapping tags
+* Low polygon 3D modeling applied for simulation
+* Contributors: Ryan Shim, Mikael Arguedas, Will Son
+
+2.1.0 (2019-09-10)
+------------------
+* Added turtlebot3_house and related world, model files
+* Contributors: Ryan Shim
+
+2.0.1 (2019-09-05)
+------------------
+* Modified dependency packages
+* Modified launch directory
+* Added a launch file for robot state publisher
+* Contributors: Darby Lim, Pyo
+
+2.0.0 (2019-08-20)
+------------------
+* Supported ROS 2 Dashing Diademata
+* Updated the CHANGELOG and version to release binary packages
+* Contributors: Darby Lim, Pyo
+
+1.3.0 (2020-06-29)
+------------------
+* Turtlebot3 Autorace 2020 implemented
+* Remove the plugin_path from gazebo_ros export
+* Remove *nix path separator
+* Contributors: Ashe Kim, Ben Wolsieffer, Sean Yen
+
+1.2.0 (2019-01-22)
+------------------
+* moved <scene> into <world> `#65 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/65>`_
+* modified ML stage
+* delete unused param
+* update algorithm and modified variable more clearly
+* Contributors: Darby Lim, Gilbert, Louise Poubel, Pyo
+
+1.1.0 (2018-07-20)
+------------------
+* modified uri path
+* modified autorace
+* delete remap
+* Contributors: Darby Lim, Gilbert, Pyo
+
+1.0.2 (2018-06-01)
+------------------
+* added mission.launch modified model.sdf
+* deleted turtlebot3's gazebo plugins
+* modified autorace gazebo
+* merged pull request `#53 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/53>`_ `#52 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/52>`_ `#51 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/51>`_ `#50 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/50>`_ `#49 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/49>`_
+* Contributors: Gilbert, Darby Lim, Pyo
+
+1.0.1 (2018-05-30)
+------------------
+* resolving dependency issues:
+  http://build.ros.org/job/Kbin_dj_dJ64__turtlebot3_gazebo__debian_jessie_amd64__binary/2/
+* Contributors: Pyo
+
+1.0.0 (2018-05-29)
+------------------
+* added world for turtlebot3_autorace
+* added world for turtlebot3_machine_learning
+* merged pull request `#46 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/46>`_ from AuTURBO/develop
+  add turtlebot3_autorace world'
+* merged pull request `#48 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/48>`_ `#47 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/47>`_ `#44 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/44>`_ `#42 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/42>`_ `#41 <https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/41>`_
+* Contributors: Darby Lim, Gilbert, hyunoklee, Pyo
+
+0.2.4 (2018-03-14)
+------------------
+* None
+
+0.2.3 (2018-03-14)
+------------------
+* solved DuplicateVersionsException error
+* Contributors: Pyo
+
+0.2.2 (2018-03-14)
+------------------
+* None
+
+0.2.1 (2018-03-14)
+------------------
+* added worlds for gazebo and turtlebot3
+* Contributors: Darby Lim
+
+0.2.0 (2018-03-13)
+------------------
+* added slam with multiple tb3
+* added multi example
+* added turtlebot3_house
+* modified cmake file
+* modified spwn model name
+* modified multi slam param
+* modified camera position
+* modified folder name
+* Contributors: Darby Lim
+
+0.1.7 (2017-08-16)
+------------------
+* renamed missed the install rule (worlds -> models)
+* Contributors: Darby Lim, Tully Foote
+
+0.1.6 (2017-08-14)
+------------------
+* modified folder name and model path
+* updated rviz and add static tf publisher for depth camera
+* Contributors: Darby Lim
+
+0.1.5 (2017-06-09)
+------------------
+* modified make files for dependencies
+* updated turtlebot3 sim
+* updated world config
+* Contributors: Darby Lim
+
+0.1.4 (2017-05-23)
+------------------
+* added as new meta-packages and version update (0.1.4)
+* Contributors: Darby Lim, Pyo
@@ -0,0 +1,96 @@
+################################################################################
+# Set minimum required version of cmake, project name and compile options
+################################################################################
+cmake_minimum_required(VERSION 3.5)
+project(turtlebot3_gazebo)
+
+if(NOT CMAKE_CXX_STANDARD)
+  set(CMAKE_CXX_STANDARD 17)
+endif()
+
+if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  add_compile_options(-Wall -Wextra -Wpedantic)
+endif()
+
+if(MSVC)
+  add_compile_definitions(_USE_MATH_DEFINES)
+endif()
+
+################################################################################
+# Find ament packages and libraries for ament and system dependencies
+################################################################################
+find_package(ament_cmake REQUIRED)
+find_package(gazebo REQUIRED)
+find_package(gazebo_ros_pkgs REQUIRED)
+find_package(geometry_msgs REQUIRED)
+find_package(nav_msgs REQUIRED)
+find_package(rclcpp REQUIRED)
+find_package(sensor_msgs REQUIRED)
+find_package(tf2 REQUIRED)
+
+################################################################################
+# Build
+################################################################################
+link_directories(
+  ${GAZEBO_LIBRARY_DIRS}
+)
+
+include_directories(
+  include
+  ${GAZEBO_INCLUDE_DIRS}
+)
+
+set(dependencies
+  "geometry_msgs"
+  "nav_msgs"
+  "rclcpp"
+  "sensor_msgs"
+  "tf2"
+)
+
+set(EXEC_NAME "turtlebot3_drive")
+
+add_executable(${EXEC_NAME} src/turtlebot3_drive.cpp)
+ament_target_dependencies(${EXEC_NAME} ${dependencies})
+
+add_library(traffic_light_plugin SHARED src/traffic_light_plugin.cpp)
+target_link_libraries(traffic_light_plugin ${GAZEBO_LIBRARIES})
+
+add_library(traffic_bar_plugin SHARED src/traffic_bar_plugin.cpp)
+target_link_libraries(traffic_bar_plugin ${GAZEBO_LIBRARIES})
+
+add_library(obstacle1 SHARED src/obstacle1.cpp)
+target_link_libraries(obstacle1 ${GAZEBO_LIBRARIES})
+
+add_library(obstacle2 SHARED src/obstacle2.cpp)
+target_link_libraries(obstacle2 ${GAZEBO_LIBRARIES})
+
+add_library(obstacles SHARED src/obstacles.cpp)
+target_link_libraries(obstacles ${GAZEBO_LIBRARIES})
+
+################################################################################
+# Install
+################################################################################
+install(TARGETS ${EXEC_NAME}
+  DESTINATION lib/${PROJECT_NAME}
+)
+
+install(DIRECTORY launch models rviz worlds
+  DESTINATION share/${PROJECT_NAME}/
+)
+
+install(DIRECTORY include/
+  DESTINATION include/
+)
+
+################################################################################
+# Macro for ament package
+################################################################################
+ament_export_include_directories(include)
+ament_export_dependencies(gazebo_ros_pkgs)
+ament_export_dependencies(geometry_msgs)
+ament_export_dependencies(nav_msgs)
+ament_export_dependencies(rclcpp)
+ament_export_dependencies(sensor_msgs)
+ament_export_dependencies(tf2)
+ament_package()
@@ -0,0 +1,38 @@
+// Copyright 2012 Open Source Robotics Foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Author: Ryan Shim
+
+#ifndef TURTLEBOT3_GAZEBO__OBSTACLE1_HPP_
+#define TURTLEBOT3_GAZEBO__OBSTACLE1_HPP_
+
+#include <ignition/math.hh>
+#include <gazebo/common/common.hh>
+#include <gazebo/gazebo.hh>
+#include <gazebo/physics/physics.hh>
+
+namespace gazebo
+{
+class Obstacle1 : public ModelPlugin
+{
+public:
+  void Load(physics::ModelPtr _parent, sdf::ElementPtr /*_sdf*/) override;
+
+private:
+  physics::ModelPtr model;
+  event::ConnectionPtr updateConnection;
+};
+GZ_REGISTER_MODEL_PLUGIN(Obstacle1);
+}  // namespace gazebo
+#endif  // TURTLEBOT3_GAZEBO__OBSTACLE1_HPP_
@@ -0,0 +1,39 @@
+// Copyright 2012 Open Source Robotics Foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Author: Ryan Shim
+
+#ifndef TURTLEBOT3_GAZEBO__OBSTACLE2_HPP_
+#define TURTLEBOT3_GAZEBO__OBSTACLE2_HPP_
+
+#include <ignition/math.hh>
+#include <gazebo/common/common.hh>
+#include <gazebo/gazebo.hh>
+#include <gazebo/physics/physics.hh>
+
+namespace gazebo
+{
+class Obstacle2 : public ModelPlugin
+{
+public:
+  Obstacle2() = default;
+  void Load(physics::ModelPtr _parent, sdf::ElementPtr /*_sdf*/) override;
+
+private:
+  physics::ModelPtr model;
+  event::ConnectionPtr updateConnection;
+};
+GZ_REGISTER_MODEL_PLUGIN(Obstacle2);
+}  // namespace gazebo
+#endif  // TURTLEBOT3_GAZEBO__OBSTACLE2_HPP_
@@ -0,0 +1,41 @@
+// Copyright 2012 Open Source Robotics Foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Author: Ryan Shim
+
+#ifndef TURTLEBOT3_GAZEBO__OBSTACLES_HPP_
+#define TURTLEBOT3_GAZEBO__OBSTACLES_HPP_
+
+#include <ignition/math.hh>
+#include <gazebo/common/common.hh>
+#include <gazebo/gazebo.hh>
+#include <gazebo/physics/physics.hh>
+
+#define PI 3.141592
+
+namespace gazebo
+{
+class Obstacles : public ModelPlugin
+{
+public:
+  Obstacles() = default;
+  void Load(physics::ModelPtr _parent, sdf::ElementPtr /*_sdf*/) override;
+
+private:
+  physics::ModelPtr model;
+  event::ConnectionPtr updateConnection;
+};
+GZ_REGISTER_MODEL_PLUGIN(Obstacles);
+}  // namespace gazebo
+#endif  // TURTLEBOT3_GAZEBO__OBSTACLES_HPP_
@@ -0,0 +1,45 @@
+// Copyright 2025 ROBOTIS CO., LTD.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Author: Hyungyu Kim
+
+#ifndef TURTLEBOT3_GAZEBO__TRAFFIC_BAR_PLUGIN_HPP_
+#define TURTLEBOT3_GAZEBO__TRAFFIC_BAR_PLUGIN_HPP_
+
+#include <gazebo/gazebo.hh>
+#include <gazebo/physics/physics.hh>
+
+namespace gazebo
+{
+class TrafficBar : public ModelPlugin
+{
+public:
+  TrafficBar();
+  void Load(physics::ModelPtr _model, sdf::ElementPtr _sdf) override;
+  void OnUpdate();
+
+private:
+  double traffic_cycle;
+  int status;
+
+  common::Time last_time;
+  event::ConnectionPtr update_connection;
+  ignition::math::Pose3d down_pose;
+  ignition::math::Pose3d up_pose;
+  physics::ModelPtr model;
+  physics::WorldPtr world;
+};
+GZ_REGISTER_MODEL_PLUGIN(TrafficBar);
+}  // namespace gazebo
+#endif  // TURTLEBOT3_GAZEBO__TRAFFIC_BAR_PLUGIN_HPP_
@@ -0,0 +1,53 @@
+// Copyright 2025 ROBOTIS CO., LTD.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Author: Hyungyu Kim
+
+#ifndef TURTLEBOT3_GAZEBO__TRAFFIC_LIGHT_PLUGIN_HPP_
+#define TURTLEBOT3_GAZEBO__TRAFFIC_LIGHT_PLUGIN_HPP_
+
+#include <string>
+#include <vector>
+
+#include <gazebo/gazebo.hh>
+#include <gazebo/physics/physics.hh>
+
+namespace gazebo
+{
+class TrafficLight : public ModelPlugin
+{
+public:
+  TrafficLight();
+  ~TrafficLight();
+
+  void Load(physics::ModelPtr _model, sdf::ElementPtr _sdf) override;
+  void OnUpdate();
+
+private:
+  double traffic_cycle;
+  int status;
+  std::vector<std::string> textures;
+
+  common::Time last_time;
+  event::ConnectionPtr update_connection;
+  gazebo::transport::NodePtr node;
+  gazebo::msgs::Visual msg;
+  gazebo::transport::PublisherPtr visPub;
+  physics::ModelPtr model;
+  physics::WorldPtr world;
+};
+GZ_REGISTER_MODEL_PLUGIN(TrafficLight);
+}  // namespace gazebo
+
+#endif  // TURTLEBOT3_GAZEBO__TRAFFIC_LIGHT_PLUGIN_HPP_
@@ -0,0 +1,70 @@
+// Copyright 2019 ROBOTIS CO., LTD.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Authors: Taehun Lim (Darby), Ryan Shim
+
+#ifndef TURTLEBOT3_GAZEBO__TURTLEBOT3_DRIVE_HPP_
+#define TURTLEBOT3_GAZEBO__TURTLEBOT3_DRIVE_HPP_
+
+#include <tf2/LinearMath/Matrix3x3.h>
+#include <tf2/LinearMath/Quaternion.h>
+#include <geometry_msgs/msg/twist.hpp>
+#include <nav_msgs/msg/odometry.hpp>
+#include <rclcpp/rclcpp.hpp>
+#include <sensor_msgs/msg/laser_scan.hpp>
+
+#define DEG2RAD (M_PI / 180.0)
+#define RAD2DEG (180.0 / M_PI)
+
+#define CENTER 0
+#define LEFT   1
+#define RIGHT  2
+
+#define LINEAR_VELOCITY  0.3
+#define ANGULAR_VELOCITY 1.5
+
+#define GET_TB3_DIRECTION 0
+#define TB3_DRIVE_FORWARD 1
+#define TB3_RIGHT_TURN    2
+#define TB3_LEFT_TURN     3
+
+class Turtlebot3Drive : public rclcpp::Node
+{
+public:
+  Turtlebot3Drive();
+  ~Turtlebot3Drive();
+
+private:
+  // ROS topic publishers
+  rclcpp::Publisher<geometry_msgs::msg::Twist>::SharedPtr cmd_vel_pub_;
+
+  // ROS topic subscribers
+  rclcpp::Subscription<sensor_msgs::msg::LaserScan>::SharedPtr scan_sub_;
+  rclcpp::Subscription<nav_msgs::msg::Odometry>::SharedPtr odom_sub_;
+
+  // Variables
+  double robot_pose_;
+  double prev_robot_pose_;
+  double scan_data_[3];
+
+  // ROS timer
+  rclcpp::TimerBase::SharedPtr update_timer_;
+
+  // Function prototypes
+  void update_callback();
+  void update_cmd_vel(double linear, double angular);
+  void scan_callback(const sensor_msgs::msg::LaserScan::SharedPtr msg);
+  void odom_callback(const nav_msgs::msg::Odometry::SharedPtr msg);
+};
+#endif  // TURTLEBOT3_GAZEBO__TURTLEBOT3_DRIVE_HPP_
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+
+
+def generate_launch_description():
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    x_pose = LaunchConfiguration('x_pose', default='0.0')
+    y_pose = LaunchConfiguration('y_pose', default='0.0')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'empty_world.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+        ),
+        launch_arguments={'use_sim_time': use_sim_time}.items()
+    )
+
+    spawn_turtlebot_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'spawn_turtlebot3.launch.py')
+        ),
+        launch_arguments={
+            'x_pose': x_pose,
+            'y_pose': y_pose
+        }.items()
+    )
+
+    ld = LaunchDescription()
+
+    # Add the commands to the launch description
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(robot_state_publisher_cmd)
+    ld.add_action(spawn_turtlebot_cmd)
+
+    return ld
@@ -0,0 +1,137 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool, HyunGyu Kim
+
+import os
+import xml.etree.ElementTree as ET
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import GroupAction
+from launch.actions import IncludeLaunchDescription
+from launch.actions import RegisterEventHandler
+from launch.event_handlers import OnShutdown
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import PushRosNamespace
+
+
+def generate_launch_description():
+    TURTLEBOT3_MODEL = os.environ['TURTLEBOT3_MODEL']
+
+    number_of_robots = 4
+    namespace = 'TB3'
+    pose = [[-2, -0.5], [0.5, -2], [2, 0.5], [-0.5, 2]]
+    model_folder = 'turtlebot3_' + TURTLEBOT3_MODEL
+    urdf_path = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'models',
+        model_folder,
+        'model.sdf'
+    )
+    save_path = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'models',
+        model_folder,
+        'tmp'
+    )
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='false')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'turtlebot3_world.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd_list = []
+
+    for count in range(number_of_robots):
+        robot_state_publisher_cmd_list.append(
+            IncludeLaunchDescription(
+                PythonLaunchDescriptionSource(
+                    os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+                ),
+                launch_arguments={
+                    'use_sim_time': use_sim_time,
+                    'frame_prefix': f'{namespace}_{count+1}'
+                    }.items()
+            )
+        )
+
+    spawn_turtlebot_cmd_list = []
+
+    for count in range(number_of_robots):
+        tree = ET.parse(urdf_path)
+        root = tree.getroot()
+        for odom_frame_tag in root.iter('odometry_frame'):
+            odom_frame_tag.text = f'{namespace}_{count+1}/odom'
+        for base_frame_tag in root.iter('robot_base_frame'):
+            base_frame_tag.text = f'{namespace}_{count+1}/base_footprint'
+        for scan_frame_tag in root.iter('frame_name'):
+            scan_frame_tag.text = f'{namespace}_{count+1}/base_scan'
+        urdf_modified = ET.tostring(tree.getroot(), encoding='unicode')
+        urdf_modified = '<?xml version="1.0" ?>\n'+urdf_modified
+        with open(f'{save_path}{count+1}.sdf', 'w') as file:
+            file.write(urdf_modified)
+
+        spawn_turtlebot_cmd_list.append(
+            IncludeLaunchDescription(
+                PythonLaunchDescriptionSource(
+                    os.path.join(launch_file_dir, 'multi_spawn_turtlebot3.launch.py')
+                ),
+                launch_arguments={
+                        'x_pose': str(pose[count][0]),
+                        'y_pose': str(pose[count][1]),
+                        'robot_name': f'{TURTLEBOT3_MODEL}_{count+1}',
+                        'namespace': f'{namespace}_{count+1}',
+                        'sdf_path': f'{save_path}{count+1}.sdf'
+                }.items()
+            )
+        )
+
+    ld = LaunchDescription()
+    # Add the commands to the launch description
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(RegisterEventHandler(
+        OnShutdown(
+            on_shutdown=lambda event,
+            context: [os.remove(f'{save_path}{count+1}.sdf') for count in range(number_of_robots)]
+        )
+    ))
+    for count, spawn_turtlebot_cmd in enumerate(spawn_turtlebot_cmd_list, start=1):
+        ld.add_action(GroupAction([PushRosNamespace(f'{namespace}_{count}'),
+                                  robot_state_publisher_cmd_list[count-1],
+                                  spawn_turtlebot_cmd]))
+
+    return ld
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+# Copyright 2019 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: HyunGyu Kim
+
+import os
+
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    TURTLEBOT3_MODEL = os.environ['TURTLEBOT3_MODEL']
+
+    x_pose = LaunchConfiguration('x_pose', default='0.0')
+    y_pose = LaunchConfiguration('y_pose', default='0.0')
+    robot_name = LaunchConfiguration('robot_name', default=TURTLEBOT3_MODEL)
+    namespace = LaunchConfiguration('namespace', default='')
+    sdf_path = LaunchConfiguration('sdf_path', default='')
+
+    declare_x_position_cmd = DeclareLaunchArgument(
+        'x_pose', default_value='0.0',
+        description='Specify namespace of the robot')
+
+    declare_y_position_cmd = DeclareLaunchArgument(
+        'y_pose', default_value='0.0',
+        description='Specify namespace of the robot')
+    start_gazebo_ros_spawner_cmd = Node(
+        package='gazebo_ros',
+        executable='spawn_entity.py',
+        arguments=[
+            '-entity', robot_name,
+            '-file', sdf_path,
+            '-x', x_pose,
+            '-y', y_pose,
+            '-z', '0.01',
+            '-robot_namespace', namespace
+        ],
+        output='screen',
+    )
+
+    ld = LaunchDescription()
+    ld.add_action(declare_x_position_cmd)
+    ld.add_action(declare_y_position_cmd)
+    ld.add_action(start_gazebo_ros_spawner_cmd)
+    return ld
@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Darby Lim
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.substitutions import LaunchConfiguration
+from launch.substitutions import PythonExpression
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    TURTLEBOT3_MODEL = os.environ['TURTLEBOT3_MODEL']
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    urdf_file_name = 'turtlebot3_' + TURTLEBOT3_MODEL + '.urdf'
+    frame_prefix = LaunchConfiguration('frame_prefix', default='')
+
+    print('urdf_file_name : {}'.format(urdf_file_name))
+
+    urdf_path = os.path.join(
+        get_package_share_directory('turtlebot3_description'),
+        'urdf',
+        urdf_file_name)
+
+    with open(urdf_path, 'r') as infp:
+        robot_desc = infp.read()
+
+    return LaunchDescription([
+        DeclareLaunchArgument(
+            'use_sim_time',
+            default_value='false',
+            description='Use simulation (Gazebo) clock if true'),
+        Node(
+            package='robot_state_publisher',
+            executable='robot_state_publisher',
+            name='robot_state_publisher',
+            output='screen',
+            parameters=[{
+                'use_sim_time': use_sim_time,
+                'robot_description': robot_desc,
+                'frame_prefix': PythonExpression(["'", frame_prefix, "/'"])
+            }],
+        ),
+    ])
@@ -0,0 +1,70 @@
+# Copyright 2019 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    # Get the urdf file
+    TURTLEBOT3_MODEL = os.environ['TURTLEBOT3_MODEL']
+    model_folder = 'turtlebot3_' + TURTLEBOT3_MODEL
+    urdf_path = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'models',
+        model_folder,
+        'model.sdf'
+    )
+
+    # Launch configuration variables specific to simulation
+    x_pose = LaunchConfiguration('x_pose', default='0.0')
+    y_pose = LaunchConfiguration('y_pose', default='0.0')
+
+    # Declare the launch arguments
+    declare_x_position_cmd = DeclareLaunchArgument(
+        'x_pose', default_value='0.0',
+        description='Specify namespace of the robot')
+
+    declare_y_position_cmd = DeclareLaunchArgument(
+        'y_pose', default_value='0.0',
+        description='Specify namespace of the robot')
+
+    start_gazebo_ros_spawner_cmd = Node(
+        package='gazebo_ros',
+        executable='spawn_entity.py',
+        arguments=[
+            '-entity', TURTLEBOT3_MODEL,
+            '-file', urdf_path,
+            '-x', x_pose,
+            '-y', y_pose,
+            '-z', '0.01'
+        ],
+        output='screen',
+    )
+
+    ld = LaunchDescription()
+
+    # Declare the launch options
+    ld.add_action(declare_x_position_cmd)
+    ld.add_action(declare_y_position_cmd)
+
+    # Add any conditioned actions
+    ld.add_action(start_gazebo_ros_spawner_cmd)
+
+    return ld
@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool, Hyungyu Kim
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+
+
+def generate_launch_description():
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    x_pose = LaunchConfiguration('x_pose', default='0.8')
+    y_pose = LaunchConfiguration('y_pose', default='-1.747')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'turtlebot3_autorace_2020.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+        ),
+        launch_arguments={'use_sim_time': use_sim_time}.items()
+    )
+
+    spawn_turtlebot_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'spawn_turtlebot3.launch.py')
+        ),
+        launch_arguments={
+            'x_pose': x_pose,
+            'y_pose': y_pose
+        }.items()
+    )
+
+    ld = LaunchDescription()
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(robot_state_publisher_cmd)
+    ld.add_action(spawn_turtlebot_cmd)
+    return ld
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+
+
+def generate_launch_description():
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    x_pose = LaunchConfiguration('x_pose', default='0.0')
+    y_pose = LaunchConfiguration('y_pose', default='0.0')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'turtlebot3_dqn_stage1.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+        ),
+        launch_arguments={'use_sim_time': use_sim_time}.items()
+    )
+
+    spawn_turtlebot_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'spawn_turtlebot3.launch.py')
+        ),
+        launch_arguments={
+            'x_pose': x_pose,
+            'y_pose': y_pose
+        }.items()
+    )
+
+    ld = LaunchDescription()
+
+    # Add the commands to the launch description
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(robot_state_publisher_cmd)
+    ld.add_action(spawn_turtlebot_cmd)
+
+    return ld
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+
+
+def generate_launch_description():
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    x_pose = LaunchConfiguration('x_pose', default='0.0')
+    y_pose = LaunchConfiguration('y_pose', default='0.0')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'turtlebot3_dqn_stage2.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+        ),
+        launch_arguments={'use_sim_time': use_sim_time}.items()
+    )
+
+    spawn_turtlebot_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'spawn_turtlebot3.launch.py')
+        ),
+        launch_arguments={
+            'x_pose': x_pose,
+            'y_pose': y_pose
+        }.items()
+    )
+
+    ld = LaunchDescription()
+
+    # Add the commands to the launch description
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(robot_state_publisher_cmd)
+    ld.add_action(spawn_turtlebot_cmd)
+
+    return ld
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+
+
+def generate_launch_description():
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    x_pose = LaunchConfiguration('x_pose', default='0.0')
+    y_pose = LaunchConfiguration('y_pose', default='0.0')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'turtlebot3_dqn_stage3.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+        ),
+        launch_arguments={'use_sim_time': use_sim_time}.items()
+    )
+
+    spawn_turtlebot_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'spawn_turtlebot3.launch.py')
+        ),
+        launch_arguments={
+            'x_pose': x_pose,
+            'y_pose': y_pose
+        }.items()
+    )
+
+    ld = LaunchDescription()
+
+    # Add the commands to the launch description
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(robot_state_publisher_cmd)
+    ld.add_action(spawn_turtlebot_cmd)
+
+    return ld
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+
+
+def generate_launch_description():
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    x_pose = LaunchConfiguration('x_pose', default='0.0')
+    y_pose = LaunchConfiguration('y_pose', default='0.0')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'turtlebot3_dqn_stage4.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+        ),
+        launch_arguments={'use_sim_time': use_sim_time}.items()
+    )
+
+    spawn_turtlebot_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'spawn_turtlebot3.launch.py')
+        ),
+        launch_arguments={
+            'x_pose': x_pose,
+            'y_pose': y_pose
+        }.items()
+    )
+
+    ld = LaunchDescription()
+
+    # Add the commands to the launch description
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(robot_state_publisher_cmd)
+    ld.add_action(spawn_turtlebot_cmd)
+
+    return ld
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+
+
+def generate_launch_description():
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    x_pose = LaunchConfiguration('x_pose', default='-2.0')
+    y_pose = LaunchConfiguration('y_pose', default='-0.5')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'turtlebot3_house.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+        ),
+        launch_arguments={'use_sim_time': use_sim_time}.items()
+    )
+
+    spawn_turtlebot_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'spawn_turtlebot3.launch.py')
+        ),
+        launch_arguments={
+            'x_pose': x_pose,
+            'y_pose': y_pose
+        }.items()
+    )
+
+    ld = LaunchDescription()
+
+    # Add the commands to the launch description
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(robot_state_publisher_cmd)
+    ld.add_action(spawn_turtlebot_cmd)
+
+    return ld
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+#
+# Copyright 2019 ROBOTIS CO., LTD.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Authors: Joep Tool
+
+import os
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+from launch.substitutions import LaunchConfiguration
+
+
+def generate_launch_description():
+    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
+    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
+
+    use_sim_time = LaunchConfiguration('use_sim_time', default='true')
+    x_pose = LaunchConfiguration('x_pose', default='-2.0')
+    y_pose = LaunchConfiguration('y_pose', default='-0.5')
+
+    world = os.path.join(
+        get_package_share_directory('turtlebot3_gazebo'),
+        'worlds',
+        'turtlebot3_world.world'
+    )
+
+    gzserver_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
+        ),
+        launch_arguments={'world': world}.items()
+    )
+
+    gzclient_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
+        )
+    )
+
+    robot_state_publisher_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'robot_state_publisher.launch.py')
+        ),
+        launch_arguments={'use_sim_time': use_sim_time}.items()
+    )
+
+    spawn_turtlebot_cmd = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource(
+            os.path.join(launch_file_dir, 'spawn_turtlebot3.launch.py')
+        ),
+        launch_arguments={
+            'x_pose': x_pose,
+            'y_pose': y_pose
+        }.items()
+    )
+
+    ld = LaunchDescription()
+
+    # Add the commands to the launch description
+    ld.add_action(gzserver_cmd)
+    ld.add_action(gzclient_cmd)
+    ld.add_action(robot_state_publisher_cmd)
+    ld.add_action(spawn_turtlebot_cmd)
+
+    return ld
@@ -0,0 +1,14 @@
+material checker
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture checker.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>checker</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Gilbert</name>
+    <email>kkjong@robotis.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="checker">
+    <static>true</static>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.02 1 1</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.02 1 1</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/checker/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/checker/materials/textures</uri>
+            <name>checker</name>
+          </script>
+        </material>
+      </visual>
+    </link>
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material course
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture course.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>course</name>
+  <version>1.0</version>
+  <sdf version="1.6">model.sdf</sdf>
+  <author>
+    <name>Gilbert</name>
+    <email>kkjong@robotis.com</email>
+  </author>
+
+  <description>
+    A simple textured ground plane
+  </description>
+</model>
+
@@ -0,0 +1,41 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="course">
+    <static>true</static>
+    <link name="course_link">
+      <collision name="course_collision">
+        <geometry>
+          <plane>
+            <normal>0 0 1</normal>
+            <size>4 4</size>
+          </plane>
+        </geometry>
+        <surface>
+          <friction>
+            <ode>
+              <mu>100</mu>
+              <mu2>50</mu2>
+            </ode>
+          </friction>
+        </surface>
+      </collision>
+      <visual name="course_visual">
+        <cast_shadows>false</cast_shadows>
+        <geometry>
+	        <plane>
+            <normal>0 0 1</normal>
+            <size>4 4</size>
+          </plane>
+        </geometry>
+	      <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/course/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/course/materials/textures</uri>
+            <name>course</name>
+          </script>
+        </material>
+      </visual>
+    </link>
+  </model>
+</sdf>
+
@@ -0,0 +1,14 @@
+material traffic_bar
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_bar.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_bar</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+    <name>Hyungyu Kim</name>
+    <email>kimhg@robotis.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,32 @@
+<?xml version='1.0'?>
+<sdf version="1.6">
+  <model name="traffic_bar">
+    <static>false</static>
+    <link name="traffic_bar">
+        <pose> 0 0 0 0 0 0</pose>
+        <collision name="collision">
+          <geometry>
+            <box>
+              <size>0.3 0.02 0.05</size>
+            </box>
+         </geometry>
+        </collision>
+        <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.3 0.02 0.05</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_bar/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_bar/materials/textures</uri>
+            <name>traffic_bar</name>
+          </script>
+        </material>
+      </visual>
+    </link>
+    <plugin name="traffic_bar_plugin" filename="libtraffic_bar_plugin.so">
+    </plugin>   
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_construction
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_construction.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_construction</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_construction">
+    <static>true</static>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_construction/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_construction/materials/textures</uri>
+            <name>traffic_construction</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_intersection
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_intersection.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_intersection</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_intersection">
+    <static>true</static>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_intersection/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_intersection/materials/textures</uri>
+            <name>traffic_intersection</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_left
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_left.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_left</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_left">
+    <static>true</static>
+    <link name="box">
+      <pose>1.08 -0.838 0.125 0 -0 -1.57</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_left/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_left/materials/textures</uri>
+            <name>traffic_left</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,41 @@
+material traffic_light_red
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_light_red.png
+      }
+    }
+  }
+}
+
+material traffic_light_green
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_light_green.png
+      }
+    }
+  }
+}
+
+material traffic_light_yellow
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_light_yellow.png
+      }
+    }
+  }
+}
@@ -0,0 +1,13 @@
+<?xml version="1.0" ?>
+<model>
+    <name>traffic_light</name>
+    <version>1.0</version>
+    <sdf version="1.6">model.sdf</sdf>
+    <author>
+        <name>Ashekim</name>
+        <email>ashekim@robotis.com</email>
+        <name>Hyungyu Kim</name>
+        <email>kimhg@robotis.com</email>
+    </author>
+    <description>The traffic light.</description>
+</model>
@@ -0,0 +1,32 @@
+<?xml version='1.0'?>
+<sdf version='1.6'>
+  <model name='traffic_light'>
+    <link name='traffic_light'>
+      <pose>0 0 0 0 0 0</pose>
+      <collision name='collision'>
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>   
+      </collision>
+      <visual name='visual'>
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_light/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_light/materials/textures</uri>
+            <name>traffic_light_red</name>
+          </script>
+        </material>
+      </visual>
+    </link>
+    <plugin name="traffic_light_plugin" filename="libtraffic_light_plugin.so">
+    </plugin>
+    <static>1</static>
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_noentry
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_noentry.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_noentry</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_noentry">
+    <static>true</static>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_noentry/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_noentry/materials/textures</uri>
+            <name>traffic_noentry</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_parking
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_parking.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_parking</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_parking">
+    <static>true</static>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_parking/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_parking/materials/textures</uri>
+            <name>traffic_parking</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_pl_left
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_pl_left.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_pl_left</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_pl_left">
+    <static>true</static>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_pl_left/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_pl_left/materials/textures</uri>
+            <name>traffic_pl_left</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_right
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_right.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_right</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_right">
+    <static>true</static>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_right/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_right/materials/textures</uri>
+            <name>traffic_right</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_stop
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture traffic_stop.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_stop</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Gilbert</name>
+    <email>kkjong@robotis.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_stop">
+    <static>true</static>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_stop/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_stop/materials/textures</uri>
+            <name>traffic_stop</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,14 @@
+material traffic_tunnel
+{
+  technique
+  {
+    pass
+    {
+      texture_unit
+      {
+        texture tunnel.png
+      }
+    }
+  }
+}
+
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>traffic_tunnel</name>
+  <version>1.0</version>
+  <sdf version='1.6'>model.sdf</sdf>
+
+  <author>
+    <name>Hyunok Lee</name>
+    <email>hyunokhyunok@naver.com</email>
+  </author>
+
+  <description>
+    Model with links of simple shapes and texture applied.
+  </description>
+</model>
@@ -0,0 +1,30 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="traffic_tunnel">
+    <pose>0 0 0.125 0 0 0</pose>
+    <link name="box">
+      <pose>0 0 0 0 0 0</pose>
+      <collision name="collision">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+      </collision>
+      <visual name="visual">
+        <geometry>
+          <box>
+            <size>0.12 0.025 0.25</size>
+          </box>
+        </geometry>
+        <material>
+          <script>
+            <uri>model://turtlebot3_autorace_2020/traffic_tunnel/materials/scripts</uri>
+            <uri>model://turtlebot3_autorace_2020/traffic_tunnel/materials/textures</uri>
+            <name>traffic_tunnel</name>
+          </script>
+        </material>
+      </visual>
+    </link>    
+  </model>
+</sdf>
@@ -0,0 +1,408 @@
+<?xml version="1.0" ?>
+<sdf version="1.4">
+  <model name="turtlebot3_burger">
+    <pose>0.0 0.0 0.0 0.0 0.0 0.0</pose>
+
+    <link name="base_footprint"/>
+
+    <link name="base_link">
+
+      <inertial>
+        <pose>-0.032 0 0.070 0 0 0</pose>
+        <inertia>
+          <ixx>7.2397393e-01</ixx>
+          <ixy>4.686399e-10</ixy>
+          <ixz>-1.09525703e-08</ixz>
+          <iyy>7.2397393e-01</iyy>
+          <iyz>2.8582649e-09</iyz>
+          <izz>6.53050163e-01</izz>
+        </inertia>
+        <mass>8.2573504e-01</mass>
+      </inertial>
+
+      <collision name="base_collision">
+        <pose>-0.032 0 0.070 0 0 0</pose>
+        <geometry>
+          <box>
+            <size>0.140 0.140 0.140</size>
+          </box>
+        </geometry>
+      </collision>
+
+      <visual name="base_visual">
+        <pose>-0.032 0 0 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/burger_base.dae</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+      </visual>
+    </link>
+
+    <link name="imu_link">
+      <sensor name="tb3_imu" type="imu">
+        <always_on>true</always_on>
+        <update_rate>200</update_rate>
+        <imu>
+          <angular_velocity>
+            <x>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </x>
+            <y>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </y>
+            <z>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </z>
+          </angular_velocity>
+          <linear_acceleration>
+            <x>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </x>
+            <y>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </y>
+            <z>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </z>
+          </linear_acceleration>
+        </imu>
+        <plugin name="turtlebot3_imu" filename="libgazebo_ros_imu_sensor.so">
+          <ros>
+            <!-- <namespace>/tb3</namespace> -->
+            <remapping>~/out:=imu</remapping>
+          </ros>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="base_scan">
+      <inertial>
+        <pose>-0.020 0 0.161 0 0 0</pose>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+        <mass>0.114</mass>
+      </inertial>
+
+      <collision name="lidar_sensor_collision">
+        <pose>-0.020 0 0.161 0 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.0508</radius>
+            <length>0.055</length>
+          </cylinder>
+        </geometry>
+      </collision>
+
+      <visual name="lidar_sensor_visual">
+        <pose>-0.032 0 0.171 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/lds.dae</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+      </visual>
+
+      <sensor name="hls_lfcd_lds" type="ray">
+        <always_on>true</always_on>
+        <visualize>true</visualize>
+        <pose>-0.032 0 0.171 0 0 0</pose>
+        <update_rate>5</update_rate>
+        <ray>
+          <scan>
+            <horizontal>
+              <samples>360</samples>
+              <resolution>1.000000</resolution>
+              <min_angle>0.000000</min_angle>
+              <max_angle>6.280000</max_angle>
+            </horizontal>
+          </scan>
+          <range>
+            <min>0.120000</min>
+            <max>3.5</max>
+            <resolution>0.015000</resolution>
+          </range>
+          <noise>
+            <type>gaussian</type>
+            <mean>0.0</mean>
+            <stddev>0.01</stddev>
+          </noise>
+        </ray>
+        <plugin name="turtlebot3_laserscan" filename="libgazebo_ros_ray_sensor.so">
+          <ros>
+            <!-- <namespace>/tb3</namespace> -->
+            <remapping>~/out:=scan</remapping>
+          </ros>
+          <output_type>sensor_msgs/LaserScan</output_type>
+          <frame_name>base_scan</frame_name>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="wheel_left_link">
+
+      <inertial>
+        <pose>0 0.08 0.023 -1.57 0 0</pose>
+        <inertia>
+          <ixx>1.8158194e-03</ixx>
+          <ixy>-9.3392e-12</ixy>
+          <ixz>1.04909e-11</ixz>
+          <iyy>3.2922126e-03</iyy>
+          <iyz>5.75694e-11</iyz>
+          <izz>1.8158194e-03</izz>
+        </inertia>
+        <mass>2.8498940e-02</mass>
+      </inertial>
+
+      <collision name="wheel_left_collision">
+        <pose>0 0.08 0.023 -1.57 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.033</radius>
+            <length>0.018</length>
+          </cylinder>
+        </geometry>
+        <surface>
+          <!-- This friction pamareter don't contain reliable data!! -->
+          <friction>
+            <ode>
+              <mu>100000.0</mu>
+              <mu2>100000.0</mu2>
+              <fdir1>0 0 0</fdir1>
+              <slip1>0.0</slip1>
+              <slip2>0.0</slip2>
+            </ode>
+          </friction>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+
+      <visual name="wheel_left_visual">
+        <pose>0 0.08 0.023 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/tire.dae</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+      </visual>
+    </link>
+
+    <link name="wheel_right_link">
+
+      <inertial>
+        <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+        <inertia>
+          <ixx>1.8158194e-03</ixx>
+          <ixy>-9.3392e-12</ixy>
+          <ixz>1.04909e-11</ixz>
+          <iyy>3.2922126e-03</iyy>
+          <iyz>5.75694e-11</iyz>
+          <izz>1.8158194e-03</izz>
+        </inertia>
+        <mass>2.8498940e-02</mass>
+      </inertial>
+
+      <collision name="wheel_right_collision">
+        <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.033</radius>
+            <length>0.018</length>
+          </cylinder>
+        </geometry>
+        <surface>
+          <!-- This friction pamareter don't contain reliable data!! -->
+          <friction>
+            <ode>
+              <mu>100000.0</mu>
+              <mu2>100000.0</mu2>
+              <fdir1>0 0 0</fdir1>
+              <slip1>0.0</slip1>
+              <slip2>0.0</slip2>
+            </ode>
+          </friction>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+
+      <visual name="wheel_right_visual">
+        <pose>0.0 -0.08 0.023 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/tire.dae</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+      </visual>
+    </link>
+
+    <link name='caster_back_link'>
+      <pose>-0.081 0 -0.004 -1.57 0 0</pose>
+      <inertial>
+        <mass>0.005</mass>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+      </inertial>
+      <collision name='collision'>
+        <geometry>
+          <sphere>
+            <radius>0.005000</radius>
+          </sphere>
+        </geometry>
+        <surface>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+    </link>
+
+    <joint name="base_joint" type="fixed">
+      <parent>base_footprint</parent>
+      <child>base_link</child>
+      <pose>0.0 0.0 0.010 0 0 0</pose>
+    </joint>
+
+    <joint name="wheel_left_joint" type="revolute">
+      <parent>base_link</parent>
+      <child>wheel_left_link</child>
+      <pose>0.0 0.08 0.023 -1.57 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="wheel_right_joint" type="revolute">
+      <parent>base_link</parent>
+      <child>wheel_right_link</child>
+      <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name='caster_back_joint' type='ball'>
+      <parent>base_link</parent>
+      <child>caster_back_link</child>
+    </joint>
+
+    <joint name="imu_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>imu_link</child>
+      <pose>-0.032 0 0.068 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="lidar_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>base_scan</child>
+      <pose>-0.032 0 0.171 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <plugin name="turtlebot3_diff_drive" filename="libgazebo_ros_diff_drive.so">
+
+      <ros>
+        <!-- <namespace>/tb3</namespace> -->
+      </ros>
+
+      <update_rate>30</update_rate>
+
+      <!-- wheels -->
+      <left_joint>wheel_left_joint</left_joint>
+      <right_joint>wheel_right_joint</right_joint>
+
+      <!-- kinematics -->
+      <wheel_separation>0.160</wheel_separation>
+      <wheel_diameter>0.066</wheel_diameter>
+
+      <!-- limits -->
+      <max_wheel_torque>20</max_wheel_torque>
+      <max_wheel_acceleration>1.0</max_wheel_acceleration>
+
+      <command_topic>cmd_vel</command_topic>
+
+      <!-- output -->
+      <publish_odom>true</publish_odom>
+      <publish_odom_tf>true</publish_odom_tf>
+      <publish_wheel_tf>false</publish_wheel_tf>
+
+      <odometry_topic>odom</odometry_topic>
+      <odometry_frame>odom</odometry_frame>
+      <robot_base_frame>base_footprint</robot_base_frame>
+
+    </plugin>
+
+    <plugin name="turtlebot3_joint_state" filename="libgazebo_ros_joint_state_publisher.so">
+      <ros>
+        <!-- <namespace>/tb3</namespace> -->
+        <remapping>~/out:=joint_states</remapping>
+      </ros>
+      <update_rate>30</update_rate>
+      <joint_name>wheel_left_joint</joint_name>
+      <joint_name>wheel_right_joint</joint_name>
+    </plugin>      
+  </model>
+</sdf>
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>TurtleBot3(Burger)</name>
+  <version>2.0</version>
+  <sdf version="1.4">model-1_4.sdf</sdf>
+  <sdf version="1.5">model.sdf</sdf>
+
+  <author>
+    <name>Taehun Lim(Darby)</name>
+    <email>thlim@robotis.com</email>
+  </author>
+
+  <description>
+    TurtleBot3 Burger
+  </description>
+</model>
@@ -0,0 +1,467 @@
+<?xml version="1.0" ?>
+<sdf version="1.5">
+  <model name="turtlebot3_burger">
+    <pose>0.0 0.0 0.0 0.0 0.0 0.0</pose>
+
+    <link name="base_footprint"/>
+
+    <link name="base_link">
+
+      <inertial>
+        <pose>-0.032 0 0.070 0 0 0</pose>
+        <inertia>
+          <ixx>7.2397393e-01</ixx>
+          <ixy>4.686399e-10</ixy>
+          <ixz>-1.09525703e-08</ixz>
+          <iyy>7.2397393e-01</iyy>
+          <iyz>2.8582649e-09</iyz>
+          <izz>6.53050163e-01</izz>
+        </inertia>
+        <mass>8.2573504e-01</mass>
+      </inertial>
+
+      <collision name="base_collision">
+        <pose>-0.032 0 0.070 0 0 0</pose>
+        <geometry>
+          <box>
+            <size>0.140 0.140 0.140</size>
+          </box>
+        </geometry>
+      </collision>
+
+      <visual name="base_visual">
+        <pose>-0.032 0 0 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/bases/burger_base.stl</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+        <material>
+          <ambient>0.3 0.3 0.3 1.0</ambient>
+          <diffuse>0.3 0.3 0.3 1.0</diffuse>
+        </material>
+      </visual>
+    </link>
+
+    <link name="imu_link">
+      <sensor name="tb3_imu" type="imu">
+        <always_on>true</always_on>
+        <update_rate>200</update_rate>
+        <imu>
+          <angular_velocity>
+            <x>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </x>
+            <y>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </y>
+            <z>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </z>
+          </angular_velocity>
+          <linear_acceleration>
+            <x>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </x>
+            <y>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </y>
+            <z>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </z>
+          </linear_acceleration>
+        </imu>
+        <plugin name="turtlebot3_imu" filename="libgazebo_ros_imu_sensor.so">
+          <ros>
+            <!-- <namespace>/tb3</namespace> -->
+            <remapping>~/out:=imu</remapping>
+          </ros>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="base_scan">
+      <inertial>
+        <pose>-0.020 0 0.161 0 0 0</pose>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+        <mass>0.114</mass>
+      </inertial>
+
+      <collision name="lidar_sensor_collision">
+        <pose>-0.020 0 0.161 0 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.0508</radius>
+            <length>0.055</length>
+          </cylinder>
+        </geometry>
+      </collision>
+
+      <visual name="lidar_sensor_visual">
+        <pose>-0.032 0 0.171 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/sensors/lds.stl</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+        <material>
+          <ambient>0.2 0.2 0.2 1.0</ambient>
+          <diffuse>0.2 0.2 0.2 1.0</diffuse>
+        </material>
+      </visual>
+
+      <sensor name="hls_lfcd_lds" type="ray">
+        <always_on>true</always_on>
+        <visualize>true</visualize>
+        <pose>-0.032 0 0.171 0 0 0</pose>
+        <update_rate>5</update_rate>
+        <ray>
+          <scan>
+            <horizontal>
+              <samples>360</samples>
+              <resolution>1.000000</resolution>
+              <min_angle>0.000000</min_angle>
+              <max_angle>6.280000</max_angle>
+            </horizontal>
+          </scan>
+          <range>
+            <min>0.120000</min>
+            <max>3.5</max>
+            <resolution>0.015000</resolution>
+          </range>
+          <noise>
+            <type>gaussian</type>
+            <mean>0.0</mean>
+            <stddev>0.01</stddev>
+          </noise>
+        </ray>
+        <plugin name="turtlebot3_laserscan" filename="libgazebo_ros_ray_sensor.so">
+          <ros>
+            <!-- <namespace>/tb3</namespace> -->
+            <remapping>~/out:=scan</remapping>
+          </ros>
+          <output_type>sensor_msgs/LaserScan</output_type>
+          <frame_name>base_scan</frame_name>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="velodyne_link">
+      <pose>0 0 0.24 0 0 0</pose>
+      <inertial>
+        <mass>0.12</mass>
+        <inertia>
+          <ixx>0.00012</ixx>
+          <iyy>0.00012</iyy>
+          <izz>0.00012</izz>
+        </inertia>
+      </inertial>
+      <visual name="velodyne_visual">
+        <geometry><cylinder><radius>0.035</radius><length>0.055</length></cylinder></geometry>
+        <material><ambient>0.08 0.08 0.08 1</ambient><diffuse>0.12 0.12 0.12 1</diffuse></material>
+      </visual>
+      <collision name="velodyne_collision">
+        <geometry><cylinder><radius>0.035</radius><length>0.055</length></cylinder></geometry>
+      </collision>
+      <sensor name="velodyne_3d" type="ray">
+        <always_on>true</always_on>
+        <visualize>false</visualize>
+        <update_rate>10</update_rate>
+        <ray>
+          <scan>
+            <horizontal><samples>720</samples><resolution>1</resolution><min_angle>-3.141593</min_angle><max_angle>3.141593</max_angle></horizontal>
+            <vertical><samples>16</samples><resolution>1</resolution><min_angle>-0.261799</min_angle><max_angle>0.261799</max_angle></vertical>
+          </scan>
+          <range><min>0.20</min><max>20.0</max><resolution>0.01</resolution></range>
+          <noise><type>gaussian</type><mean>0.0</mean><stddev>0.01</stddev></noise>
+        </ray>
+        <plugin name="velodyne_3d_ros" filename="libgazebo_ros_ray_sensor.so">
+          <ros><remapping>~/out:=raw/lidar</remapping></ros>
+          <output_type>sensor_msgs/PointCloud2</output_type>
+          <frame_name>velodyne_link</frame_name>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="wheel_left_link">
+
+      <inertial>
+        <pose>0 0.08 0.023 -1.57 0 0</pose>
+        <inertia>
+          <ixx>1.8158194e-03</ixx>
+          <ixy>-9.3392e-12</ixy>
+          <ixz>1.04909e-11</ixz>
+          <iyy>3.2922126e-03</iyy>
+          <iyz>5.75694e-11</iyz>
+          <izz>1.8158194e-03</izz>
+        </inertia>
+        <mass>2.8498940e-02</mass>
+      </inertial>
+
+      <collision name="wheel_left_collision">
+        <pose>0 0.08 0.023 -1.57 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.033</radius>
+            <length>0.018</length>
+          </cylinder>
+        </geometry>
+        <surface>
+          <!-- This friction pamareter don't contain reliable data!! -->
+          <friction>
+            <ode>
+              <mu>100000.0</mu>
+              <mu2>100000.0</mu2>
+              <fdir1>0 0 0</fdir1>
+              <slip1>0.0</slip1>
+              <slip2>0.0</slip2>
+            </ode>
+          </friction>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+
+      <visual name="wheel_left_visual">
+        <pose>0 0.08 0.023 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/wheels/left_tire.stl</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+        <material>
+          <ambient>0.2 0.2 0.2 1.0</ambient>
+          <diffuse>0.2 0.2 0.2 1.0</diffuse>
+        </material>
+      </visual>
+    </link>
+
+    <link name="wheel_right_link">
+
+      <inertial>
+        <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+        <inertia>
+          <ixx>1.8158194e-03</ixx>
+          <ixy>-9.3392e-12</ixy>
+          <ixz>1.04909e-11</ixz>
+          <iyy>3.2922126e-03</iyy>
+          <iyz>5.75694e-11</iyz>
+          <izz>1.8158194e-03</izz>
+        </inertia>
+        <mass>2.8498940e-02</mass>
+      </inertial>
+
+      <collision name="wheel_right_collision">
+        <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.033</radius>
+            <length>0.018</length>
+          </cylinder>
+        </geometry>
+        <surface>
+          <!-- This friction pamareter don't contain reliable data!! -->
+          <friction>
+            <ode>
+              <mu>100000.0</mu>
+              <mu2>100000.0</mu2>
+              <fdir1>0 0 0</fdir1>
+              <slip1>0.0</slip1>
+              <slip2>0.0</slip2>
+            </ode>
+          </friction>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+
+      <visual name="wheel_right_visual">
+        <pose>0.0 -0.08 0.023 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/wheels/right_tire.stl</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+        <material>
+          <ambient>0.2 0.2 0.2 1.0</ambient>
+          <diffuse>0.2 0.2 0.2 1.0</diffuse>
+        </material>
+      </visual>
+    </link>
+
+    <link name='caster_back_link'>
+      <pose>-0.081 0 -0.004 -1.57 0 0</pose>
+      <inertial>
+        <mass>0.005</mass>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+      </inertial>
+      <collision name='collision'>
+        <geometry>
+          <sphere>
+            <radius>0.005000</radius>
+          </sphere>
+        </geometry>
+        <surface>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+    </link>
+
+    <joint name="base_joint" type="fixed">
+      <parent>base_footprint</parent>
+      <child>base_link</child>
+      <pose>0.0 0.0 0.010 0 0 0</pose>
+    </joint>
+
+    <joint name="wheel_left_joint" type="revolute">
+      <parent>base_link</parent>
+      <child>wheel_left_link</child>
+      <pose>0.0 0.08 0.023 -1.57 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="wheel_right_joint" type="revolute">
+      <parent>base_link</parent>
+      <child>wheel_right_link</child>
+      <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name='caster_back_joint' type='ball'>
+      <parent>base_link</parent>
+      <child>caster_back_link</child>
+    </joint>
+
+    <joint name="imu_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>imu_link</child>
+      <pose>-0.032 0 0.068 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="lidar_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>base_scan</child>
+      <pose>-0.032 0 0.171 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="velodyne_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>velodyne_link</child>
+      <pose>0 0 0.24 0 0 0</pose>
+    </joint>
+
+    <plugin name="turtlebot3_diff_drive" filename="libgazebo_ros_diff_drive.so">
+
+      <ros>
+        <!-- <namespace>/tb3</namespace> -->
+      </ros>
+
+      <update_rate>30</update_rate>
+
+      <!-- wheels -->
+      <left_joint>wheel_left_joint</left_joint>
+      <right_joint>wheel_right_joint</right_joint>
+
+      <!-- kinematics -->
+      <wheel_separation>0.160</wheel_separation>
+      <wheel_diameter>0.066</wheel_diameter>
+
+      <!-- limits -->
+      <max_wheel_torque>20</max_wheel_torque>
+      <max_wheel_acceleration>1.0</max_wheel_acceleration>
+
+      <command_topic>cmd_vel</command_topic>
+
+      <!-- output -->
+      <publish_odom>true</publish_odom>
+      <publish_odom_tf>true</publish_odom_tf>
+      <publish_wheel_tf>false</publish_wheel_tf>
+
+      <odometry_topic>odom</odometry_topic>
+      <odometry_frame>odom</odometry_frame>
+      <robot_base_frame>base_footprint</robot_base_frame>
+
+    </plugin>
+
+    <plugin name="turtlebot3_joint_state" filename="libgazebo_ros_joint_state_publisher.so">
+      <ros>
+        <!-- <namespace>/tb3</namespace> -->
+        <remapping>~/out:=joint_states</remapping>
+      </ros>
+      <update_rate>30</update_rate>
+      <joint_name>wheel_left_joint</joint_name>
+      <joint_name>wheel_right_joint</joint_name>
+    </plugin>      
+  </model>
+</sdf>
@@ -0,0 +1,408 @@
+<?xml version="1.0" ?>
+<sdf version="1.4">
+  <model name="turtlebot3_burger">
+    <pose>0.0 0.0 0.0 0.0 0.0 0.0</pose>
+
+    <link name="base_footprint"/>
+
+    <link name="base_link">
+
+      <inertial>
+        <pose>-0.032 0 0.070 0 0 0</pose>
+        <inertia>
+          <ixx>7.2397393e-01</ixx>
+          <ixy>4.686399e-10</ixy>
+          <ixz>-1.09525703e-08</ixz>
+          <iyy>7.2397393e-01</iyy>
+          <iyz>2.8582649e-09</iyz>
+          <izz>6.53050163e-01</izz>
+        </inertia>
+        <mass>8.2573504e-01</mass>
+      </inertial>
+
+      <collision name="base_collision">
+        <pose>-0.032 0 0.070 0 0 0</pose>
+        <geometry>
+          <box>
+            <size>0.140 0.140 0.140</size>
+          </box>
+        </geometry>
+      </collision>
+
+      <visual name="base_visual">
+        <pose>-0.032 0 0 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/burger_base.dae</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+      </visual>
+    </link>
+
+    <link name="imu_link">
+      <sensor name="tb3_imu" type="imu">
+        <always_on>true</always_on>
+        <update_rate>200</update_rate>
+        <imu>
+          <angular_velocity>
+            <x>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </x>
+            <y>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </y>
+            <z>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </z>
+          </angular_velocity>
+          <linear_acceleration>
+            <x>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </x>
+            <y>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </y>
+            <z>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </z>
+          </linear_acceleration>
+        </imu>
+        <plugin name="turtlebot3_imu" filename="libgazebo_ros_imu_sensor.so">
+          <ros>
+            <!-- <namespace>/tb3</namespace> -->
+            <remapping>~/out:=imu</remapping>
+          </ros>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="base_scan">
+      <inertial>
+        <pose>-0.020 0 0.161 0 0 0</pose>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+        <mass>0.114</mass>
+      </inertial>
+
+      <collision name="lidar_sensor_collision">
+        <pose>-0.020 0 0.161 0 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.0508</radius>
+            <length>0.055</length>
+          </cylinder>
+        </geometry>
+      </collision>
+
+      <visual name="lidar_sensor_visual">
+        <pose>-0.032 0 0.171 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/lds.dae</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+      </visual>
+
+      <sensor name="hls_lfcd_lds" type="ray">
+        <always_on>true</always_on>
+        <visualize>true</visualize>
+        <pose>-0.032 0 0.171 0 0 0</pose>
+        <update_rate>5</update_rate>
+        <ray>
+          <scan>
+            <horizontal>
+              <samples>360</samples>
+              <resolution>1.000000</resolution>
+              <min_angle>0.000000</min_angle>
+              <max_angle>6.280000</max_angle>
+            </horizontal>
+          </scan>
+          <range>
+            <min>0.120000</min>
+            <max>3.5</max>
+            <resolution>0.015000</resolution>
+          </range>
+          <noise>
+            <type>gaussian</type>
+            <mean>0.0</mean>
+            <stddev>0.01</stddev>
+          </noise>
+        </ray>
+        <plugin name="turtlebot3_laserscan" filename="libgazebo_ros_ray_sensor.so">
+          <ros>
+            <!-- <namespace>/tb3</namespace> -->
+            <remapping>~/out:=scan</remapping>
+          </ros>
+          <output_type>sensor_msgs/LaserScan</output_type>
+          <frame_name>base_scan</frame_name>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="wheel_left_link">
+
+      <inertial>
+        <pose>0 0.08 0.023 -1.57 0 0</pose>
+        <inertia>
+          <ixx>1.8158194e-03</ixx>
+          <ixy>-9.3392e-12</ixy>
+          <ixz>1.04909e-11</ixz>
+          <iyy>3.2922126e-03</iyy>
+          <iyz>5.75694e-11</iyz>
+          <izz>1.8158194e-03</izz>
+        </inertia>
+        <mass>2.8498940e-02</mass>
+      </inertial>
+
+      <collision name="wheel_left_collision">
+        <pose>0 0.08 0.023 -1.57 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.033</radius>
+            <length>0.018</length>
+          </cylinder>
+        </geometry>
+        <surface>
+          <!-- This friction pamareter don't contain reliable data!! -->
+          <friction>
+            <ode>
+              <mu>100000.0</mu>
+              <mu2>100000.0</mu2>
+              <fdir1>0 0 0</fdir1>
+              <slip1>0.0</slip1>
+              <slip2>0.0</slip2>
+            </ode>
+          </friction>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+
+      <visual name="wheel_left_visual">
+        <pose>0 0.08 0.023 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/tire.dae</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+      </visual>
+    </link>
+
+    <link name="wheel_right_link">
+
+      <inertial>
+        <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+        <inertia>
+          <ixx>1.8158194e-03</ixx>
+          <ixy>-9.3392e-12</ixy>
+          <ixz>1.04909e-11</ixz>
+          <iyy>3.2922126e-03</iyy>
+          <iyz>5.75694e-11</iyz>
+          <izz>1.8158194e-03</izz>
+        </inertia>
+        <mass>2.8498940e-02</mass>
+      </inertial>
+
+      <collision name="wheel_right_collision">
+        <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.033</radius>
+            <length>0.018</length>
+          </cylinder>
+        </geometry>
+        <surface>
+          <!-- This friction pamareter don't contain reliable data!! -->
+          <friction>
+            <ode>
+              <mu>100000.0</mu>
+              <mu2>100000.0</mu2>
+              <fdir1>0 0 0</fdir1>
+              <slip1>0.0</slip1>
+              <slip2>0.0</slip2>
+            </ode>
+          </friction>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+
+      <visual name="wheel_right_visual">
+        <pose>0.0 -0.08 0.023 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/tire.dae</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+      </visual>
+    </link>
+
+    <link name='caster_back_link'>
+      <pose>-0.081 0 -0.004 -1.57 0 0</pose>
+      <inertial>
+        <mass>0.005</mass>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+      </inertial>
+      <collision name='collision'>
+        <geometry>
+          <sphere>
+            <radius>0.005000</radius>
+          </sphere>
+        </geometry>
+        <surface>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+    </link>
+
+    <joint name="base_joint" type="fixed">
+      <parent>base_footprint</parent>
+      <child>base_link</child>
+      <pose>0.0 0.0 0.010 0 0 0</pose>
+    </joint>
+
+    <joint name="wheel_left_joint" type="revolute">
+      <parent>base_link</parent>
+      <child>wheel_left_link</child>
+      <pose>0.0 0.08 0.023 -1.57 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="wheel_right_joint" type="revolute">
+      <parent>base_link</parent>
+      <child>wheel_right_link</child>
+      <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name='caster_back_joint' type='ball'>
+      <parent>base_link</parent>
+      <child>caster_back_link</child>
+    </joint>
+
+    <joint name="imu_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>imu_link</child>
+      <pose>-0.032 0 0.068 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="lidar_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>base_scan</child>
+      <pose>-0.032 0 0.171 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <plugin name="turtlebot3_diff_drive" filename="libgazebo_ros_diff_drive.so">
+
+      <ros>
+        <!-- <namespace>/tb3</namespace> -->
+      </ros>
+
+      <update_rate>30</update_rate>
+
+      <!-- wheels -->
+      <left_joint>wheel_left_joint</left_joint>
+      <right_joint>wheel_right_joint</right_joint>
+
+      <!-- kinematics -->
+      <wheel_separation>0.160</wheel_separation>
+      <wheel_diameter>0.066</wheel_diameter>
+
+      <!-- limits -->
+      <max_wheel_torque>20</max_wheel_torque>
+      <max_wheel_acceleration>1.0</max_wheel_acceleration>
+
+      <command_topic>cmd_vel</command_topic>
+
+      <!-- output -->
+      <publish_odom>true</publish_odom>
+      <publish_odom_tf>true</publish_odom_tf>
+      <publish_wheel_tf>false</publish_wheel_tf>
+
+      <odometry_topic>odom</odometry_topic>
+      <odometry_frame>odom</odometry_frame>
+      <robot_base_frame>base_footprint</robot_base_frame>
+
+    </plugin>
+
+    <plugin name="turtlebot3_joint_state" filename="libgazebo_ros_joint_state_publisher.so">
+      <ros>
+        <!-- <namespace>/tb3</namespace> -->
+        <remapping>~/out:=joint_states</remapping>
+      </ros>
+      <update_rate>30</update_rate>
+      <joint_name>wheel_left_joint</joint_name>
+      <joint_name>wheel_right_joint</joint_name>
+    </plugin>      
+  </model>
+</sdf>
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+
+<model>
+  <name>TurtleBot3(Burger_cam)</name>
+  <version>2.0</version>
+  <sdf version="1.4">model-1_4.sdf</sdf>
+  <sdf version="1.6">model.sdf</sdf>
+
+  <author>
+    <name>Taehun Lim(Darby)</name>
+    <name>Hyungyu Kim</name>
+    <email>thlim@robotis.com</email>
+    <email>kimhg@robotis.com</email>
+  </author>
+
+  <description>
+    TurtleBot3 Burger
+  </description>
+</model>
@@ -0,0 +1,495 @@
+<?xml version="1.0" ?>
+<sdf version="1.6">
+  <model name="turtlebot3_burger_cam">
+    <pose>0.0 0.0 0.0 0.0 0.0 0.0</pose>
+
+    <link name="base_footprint"/>
+
+    <link name="base_link">
+
+      <inertial>
+        <pose>-0.032 0 0.070 0 0 0</pose>
+        <inertia>
+          <ixx>7.2397393e-01</ixx>
+          <ixy>4.686399e-10</ixy>
+          <ixz>-1.09525703e-08</ixz>
+          <iyy>7.2397393e-01</iyy>
+          <iyz>2.8582649e-09</iyz>
+          <izz>6.53050163e-01</izz>
+        </inertia>
+        <mass>8.2573504e-01</mass>
+      </inertial>
+
+      <collision name="base_collision">
+        <pose>-0.032 0 0.070 0 0 0</pose>
+        <geometry>
+          <box>
+            <size>0.140 0.140 0.140</size>
+          </box>
+        </geometry>
+      </collision>
+
+      <visual name="base_visual">
+        <pose>-0.032 0 0 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/bases/burger_base.stl</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+        <material>
+          <ambient>0.3 0.3 0.3 1.0</ambient>
+          <diffuse>0.3 0.3 0.3 1.0</diffuse>
+        </material>
+      </visual>
+    </link>
+
+    <link name="imu_link">
+      <sensor name="tb3_imu" type="imu">
+        <always_on>true</always_on>
+        <update_rate>200</update_rate>
+        <imu>
+          <angular_velocity>
+            <x>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </x>
+            <y>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </y>
+            <z>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>2e-4</stddev>
+              </noise>
+            </z>
+          </angular_velocity>
+          <linear_acceleration>
+            <x>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </x>
+            <y>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </y>
+            <z>
+              <noise type="gaussian">
+                <mean>0.0</mean>
+                <stddev>1.7e-2</stddev>
+              </noise>
+            </z>
+          </linear_acceleration>
+        </imu>
+        <plugin name="turtlebot3_imu" filename="libgazebo_ros_imu_sensor.so">
+          <ros>
+            <!-- <namespace>/tb3</namespace> -->
+            <remapping>~/out:=imu</remapping>
+          </ros>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="base_scan">
+      <inertial>
+        <pose>-0.020 0 0.161 0 0 0</pose>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+        <mass>0.114</mass>
+      </inertial>
+
+      <collision name="lidar_sensor_collision">
+        <pose>-0.020 0 0.161 0 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.0508</radius>
+            <length>0.055</length>
+          </cylinder>
+        </geometry>
+      </collision>
+
+      <visual name="lidar_sensor_visual">
+        <pose>-0.032 0 0.171 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/sensors/lds.stl</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+        <material>
+          <ambient>0.2 0.2 0.2 1.0</ambient>
+          <diffuse>0.2 0.2 0.2 1.0</diffuse>
+        </material>
+      </visual>
+
+      <sensor name="hls_lfcd_lds" type="ray">
+        <always_on>true</always_on>
+        <visualize>false</visualize>
+        <pose>-0.032 0 0.171 0 0 0</pose>
+        <update_rate>5</update_rate>
+        <ray>
+          <scan>
+            <horizontal>
+              <samples>360</samples>
+              <resolution>1.000000</resolution>
+              <min_angle>0.000000</min_angle>
+              <max_angle>6.280000</max_angle>
+            </horizontal>
+          </scan>
+          <range>
+            <min>0.120000</min>
+            <max>3.5</max>
+            <resolution>0.015000</resolution>
+          </range>
+          <noise>
+            <type>gaussian</type>
+            <mean>0.0</mean>
+            <stddev>0.01</stddev>
+          </noise>
+        </ray>
+        <plugin name="turtlebot3_laserscan" filename="libgazebo_ros_ray_sensor.so">
+          <ros>
+            <!-- <namespace>/tb3</namespace> -->
+            <remapping>~/out:=scan</remapping>
+          </ros>
+          <output_type>sensor_msgs/LaserScan</output_type>
+          <frame_name>base_scan</frame_name>
+        </plugin>
+      </sensor>
+    </link>
+
+    <link name="wheel_left_link">
+
+      <inertial>
+        <pose>0 0.08 0.023 -1.57 0 0</pose>
+        <inertia>
+          <ixx>1.8158194e-03</ixx>
+          <ixy>-9.3392e-12</ixy>
+          <ixz>1.04909e-11</ixz>
+          <iyy>3.2922126e-03</iyy>
+          <iyz>5.75694e-11</iyz>
+          <izz>1.8158194e-03</izz>
+        </inertia>
+        <mass>2.8498940e-02</mass>
+      </inertial>
+
+      <collision name="wheel_left_collision">
+        <pose>0 0.08 0.023 -1.57 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.033</radius>
+            <length>0.018</length>
+          </cylinder>
+        </geometry>
+        <surface>
+          <!-- This friction pamareter don't contain reliable data!! -->
+          <friction>
+            <ode>
+              <mu>100000.0</mu>
+              <mu2>100000.0</mu2>
+              <fdir1>0 0 0</fdir1>
+              <slip1>0.0</slip1>
+              <slip2>0.0</slip2>
+            </ode>
+          </friction>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+
+      <visual name="wheel_left_visual">
+        <pose>0 0.08 0.023 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/wheels/left_tire.stl</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+        <material>
+          <ambient>0.2 0.2 0.2 1.0</ambient>
+          <diffuse>0.2 0.2 0.2 1.0</diffuse>
+        </material>
+      </visual>
+    </link>
+
+    <link name="wheel_right_link">
+
+      <inertial>
+        <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+        <inertia>
+          <ixx>1.8158194e-03</ixx>
+          <ixy>-9.3392e-12</ixy>
+          <ixz>1.04909e-11</ixz>
+          <iyy>3.2922126e-03</iyy>
+          <iyz>5.75694e-11</iyz>
+          <izz>1.8158194e-03</izz>
+        </inertia>
+        <mass>2.8498940e-02</mass>
+      </inertial>
+
+      <collision name="wheel_right_collision">
+        <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+        <geometry>
+          <cylinder>
+            <radius>0.033</radius>
+            <length>0.018</length>
+          </cylinder>
+        </geometry>
+        <surface>
+          <!-- This friction pamareter don't contain reliable data!! -->
+          <friction>
+            <ode>
+              <mu>100000.0</mu>
+              <mu2>100000.0</mu2>
+              <fdir1>0 0 0</fdir1>
+              <slip1>0.0</slip1>
+              <slip2>0.0</slip2>
+            </ode>
+          </friction>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+
+      <visual name="wheel_right_visual">
+        <pose>0.0 -0.08 0.023 0 0 0</pose>
+        <geometry>
+          <mesh>
+            <uri>model://turtlebot3_common/meshes/wheels/right_tire.stl</uri>
+            <scale>0.001 0.001 0.001</scale>
+          </mesh>
+        </geometry>
+        <material>
+          <ambient>0.2 0.2 0.2 1.0</ambient>
+          <diffuse>0.2 0.2 0.2 1.0</diffuse>
+        </material>
+      </visual>
+    </link>
+
+    <link name='caster_back_link'>
+      <pose>-0.081 0 -0.004 -1.57 0 0</pose>
+      <inertial>
+        <mass>0.005</mass>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+      </inertial>
+      <collision name='collision'>
+        <geometry>
+          <sphere>
+            <radius>0.005000</radius>
+          </sphere>
+        </geometry>
+        <surface>
+          <contact>
+            <ode>
+              <soft_cfm>0</soft_cfm>
+              <soft_erp>0.2</soft_erp>
+              <kp>1e+5</kp>
+              <kd>1</kd>
+              <max_vel>0.01</max_vel>
+              <min_depth>0.001</min_depth>
+            </ode>
+          </contact>
+        </surface>
+      </collision>
+    </link>
+
+    <link name="camera_link">
+      <inertial>
+        <pose>0.076 0.0 0.093 0 0 0</pose>
+        <inertia>
+          <ixx>0.001</ixx>
+          <ixy>0.000</ixy>
+          <ixz>0.000</ixz>
+          <iyy>0.001</iyy>
+          <iyz>0.000</iyz>
+          <izz>0.001</izz>
+        </inertia>
+        <mass>0.035</mass>
+      </inertial>
+
+      <pose>0.076 0.0 0.093 0 0 0</pose>
+      <sensor name="camera" type="wideanglecamera">
+        <always_on>true</always_on>
+        <visualize>true</visualize>
+        <update_rate>30</update_rate>
+        <camera name="picam">
+          <horizontal_fov>3.183</horizontal_fov>
+          <image>
+            <width>320</width>
+            <height>240</height>
+            <format>R8G8B8</format>
+          </image>
+          <clip>
+            <near>0.03</near>
+            <far>100</far>
+          </clip>
+          <lens>
+            <type>custom</type>
+            <custom_function>
+              <c1>1.05</c1>
+              <c2>4</c2>
+              <f>1.0</f>
+              <fun>tan</fun>
+            </custom_function>
+            <scale_to_hfov>true</scale_to_hfov>
+            <cutoff_angle>3.1415</cutoff_angle>
+            <env_texture_size>512</env_texture_size>
+          </lens>
+        </camera>
+        <plugin name="camera_driver" filename="libgazebo_ros_camera.so">
+          <alwaysOn>true</alwaysOn>
+          <updateRate>30.0</updateRate>
+          <cameraName>camera</cameraName>
+          <frameName>camera_link</frameName>
+          <imageTopicName>image_raw</imageTopicName>
+          <cameraInfoTopicName>camera_info</cameraInfoTopicName>
+          <hackBaseline>0.07</hackBaseline>
+          <distortionK1>0.0</distortionK1>
+          <distortionK2>0.0</distortionK2>
+          <distortionK3>0.0</distortionK3>
+          <distortionT1>0.0</distortionT1>
+          <distortionT2>0.0</distortionT2>
+          <ros>
+          </ros>
+        </plugin>
+      </sensor>
+    </link>
+
+    <joint name="base_joint" type="fixed">
+      <parent>base_footprint</parent>
+      <child>base_link</child>
+      <pose>0.0 0.0 0.010 0 0 0</pose>
+    </joint>
+
+    <joint name="wheel_left_joint" type="revolute">
+      <parent>base_link</parent>
+      <child>wheel_left_link</child>
+      <pose>0.0 0.08 0.023 -1.57 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="wheel_right_joint" type="revolute">
+      <parent>base_link</parent>
+      <child>wheel_right_link</child>
+      <pose>0.0 -0.08 0.023 -1.57 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name='caster_back_joint' type='ball'>
+      <parent>base_link</parent>
+      <child>caster_back_link</child>
+    </joint>
+
+    <joint name="imu_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>imu_link</child>
+      <pose>-0.032 0 0.068 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="lidar_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>base_scan</child>
+      <pose>-0.032 0 0.171 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <joint name="camera_joint" type="fixed">
+      <parent>base_link</parent>
+      <child>camera_link</child>
+      <pose>0.040 -0.000 0.110 0 0 0</pose>
+      <axis>
+        <xyz>0 0 1</xyz>
+      </axis>
+    </joint>
+
+    <plugin name="turtlebot3_diff_drive" filename="libgazebo_ros_diff_drive.so">
+
+      <ros>
+        <!-- <namespace>/tb3</namespace> -->
+      </ros>
+
+      <update_rate>30</update_rate>
+
+      <!-- wheels -->
+      <left_joint>wheel_left_joint</left_joint>
+      <right_joint>wheel_right_joint</right_joint>
+
+      <!-- kinematics -->
+      <wheel_separation>0.160</wheel_separation>
+      <wheel_diameter>0.066</wheel_diameter>
+
+      <!-- limits -->
+      <max_wheel_torque>20</max_wheel_torque>
+      <max_wheel_acceleration>1.0</max_wheel_acceleration>
+
+      <command_topic>cmd_vel</command_topic>
+
+      <!-- output -->
+      <publish_odom>true</publish_odom>
+      <publish_odom_tf>true</publish_odom_tf>
+      <publish_wheel_tf>false</publish_wheel_tf>
+
+      <odometry_topic>odom</odometry_topic>
+      <odometry_frame>odom</odometry_frame>
+      <robot_base_frame>base_footprint</robot_base_frame>
+
+    </plugin>
+
+    <plugin name="turtlebot3_joint_state" filename="libgazebo_ros_joint_state_publisher.so">
+      <ros>
+        <!-- <namespace>/tb3</namespace> -->
+        <remapping>~/out:=joint_states</remapping>
+      </ros>
+      <update_rate>30</update_rate>
+      <joint_name>wheel_left_joint</joint_name>
+      <joint_name>wheel_right_joint</joint_name>
+    </plugin>
+  </model>
+</sdf>
--- a/Show More
+++ b/Show More