fix: publish MKMini lidar transform for SLAM

src/nav2_turtlebot_simulator/launch/simulator.launch.py

@@ -368,11 +368,23 @@ def launch_gazebo(context):
         entity_name = 'mkmini_gazebo'
         model_directory = os.path.join(simulator_dir, 'models')
         model_path = os.path.join(model_directory, 'mkmini_gazebo', 'model.sdf')
-        # Keep the default spawn point proportional to the expanded MKMini map.
-        if spawn_x == '-2.0' and spawn_y == '-0.5':
-            spawn_x = str(-2.0 * MKMINI_WORLD_SPACING_SCALE)
-            spawn_y = str(-0.5 * MKMINI_WORLD_SPACING_SCALE)
-        static_transforms = []
+        # The world obstacles are spread out for MKMini, but the original
+        # TurtleBot spawn is already inside the navigable centre of that map.
+        # Scaling it as well placed the robot against the generated map edge.
+        # Gazebo's fixed joint does not reliably publish this transform to the
+        # separate SLAM container. Publish the sensor mounting point explicitly.
+        static_transforms = [
+            Node(
+                package='tf2_ros',
+                executable='static_transform_publisher',
+                name='mkmini_lidar_tf',
+                arguments=[
+                    '--x', '0', '--y', '0', '--z', '0.6',
+                    '--roll', '0', '--pitch', '0', '--yaw', '0',
+                    '--frame-id', 'base_link', '--child-frame-id', 'os_lidar',
+                ],
+            ),
+        ]
     else:
         raise RuntimeError('platform must be turtlebot3 or mkmini')