feat(bringup): add robot_ns to sim_robot.launch.py

README.md

@@ -174,6 +174,11 @@ its previews.
 `sim.launch.py` is `world.launch.py` (Gazebo with the world) and `sim_robot.launch.py` (the simulated robot with the
 same localization, SLAM and navigation as the real one) together, with RViz and joystick teleop; tools such as the
 GUI start them one by one.
+In a simulation shared by several robots each one is started with `sim_robot.launch.py robot_ns:=<name>`: the name
+is given to the model, its Gazebo topics and its controller manager. The topics of the controller manager move under
+`/<name>` too (`robot_description`, `joint_states`, `diff_drive_controller/cmd_vel`, `diff_drive_controller/odom`), so
+`robot_ns` works only with what runs the shared simulation and bridges them (the arena of the KPI Rover hub);
+with `load_controllers:=false` it also loads the controllers.
 
 Keyboard control (second zellij pane):
 ```bash

src/platform/kpi_rover_bringup/config/gz_bridge.yaml

@@ -1,16 +1,16 @@
-- ros_topic_name: "clock"
-  gz_topic_name: "clock"
+- ros_topic_name: "/clock"
+  gz_topic_name: "/clock"
   ros_type_name: "rosgraph_msgs/msg/Clock"
   gz_type_name: "gz.msgs.Clock"
   direction: GZ_TO_ROS
 
-- ros_topic_name: "scan"
+- ros_topic_name: "/scan"
   gz_topic_name: "scan"
   ros_type_name: "sensor_msgs/msg/LaserScan"
   gz_type_name: "gz.msgs.LaserScan"
   direction: GZ_TO_ROS
 
-- ros_topic_name: "imu_broadcaster/imu"
+- ros_topic_name: "/imu_broadcaster/imu"
   gz_topic_name: "imu_broadcaster/imu"
   ros_type_name: "sensor_msgs/msg/Imu"
   gz_type_name: "gz.msgs.IMU"

src/platform/kpi_rover_bringup/config/kpi_rover_controllers.yaml

@@ -1,4 +1,4 @@
-controller_manager:
+/**/controller_manager:
   ros__parameters:
   # TODO Return back normal rate. It was decrised for debugging
     update_rate: 30 
@@ -12,7 +12,7 @@ controller_manager:
     imu_broadcaster:
       type: imu_sensor_broadcaster/IMUSensorBroadcaster
 
-diff_drive_controller:
+/**/diff_drive_controller:
   ros__parameters:
     left_wheel_names: ["front_left_wheel_joint", "rear_left_wheel_joint"]
     right_wheel_names: ["front_right_wheel_joint", "rear_right_wheel_joint"]
@@ -28,12 +28,14 @@ diff_drive_controller:
     publish_wheel_tf: true
     publish_cmd: true 
     enable_odom_tf: false
+    # The frames stay odom, base_footprint in a namespace too (robot_ns of sim_robot.launch.py)
+    tf_frame_prefix_enable: false
 
     position_feedback: true
     linear:
       x: {min_velocity: -1.0, max_velocity: 1.0}
 
-imu_broadcaster:
+/**/imu_broadcaster:
   ros__parameters:
     sensor_name: "imu"
     frame_id:  "imu_link"

src/platform/kpi_rover_bringup/launch/sim_robot.launch.py

@@ -3,7 +3,7 @@
 from launch.conditions import IfCondition
 from launch.event_handlers import OnProcessExit
 from launch.launch_description_sources import PythonLaunchDescriptionSource
-from launch.substitutions import LaunchConfiguration, PathJoinSubstitution
+from launch.substitutions import LaunchConfiguration, PathJoinSubstitution, PythonExpression
 from launch_ros.actions import Node
 from launch_ros.substitutions import FindPackageShare
 
@@ -17,6 +17,7 @@ def generate_launch_description():
     y_pose = LaunchConfiguration('y_pose')
     z_pose = LaunchConfiguration('z_pose')
     yaw_pose = LaunchConfiguration('yaw_pose')
+    robot_ns = LaunchConfiguration('robot_ns')
 
     declared_arguments = [
         DeclareLaunchArgument(
@@ -32,6 +33,14 @@ def generate_launch_description():
         DeclareLaunchArgument(
             'nav', default_value='true',
             description='Start Nav2 (handles the RViz 2D Goal Pose)'),
+        DeclareLaunchArgument(
+            'robot_ns', default_value='',
+            description='Name of the robot in a simulation shared by several robots: its model, '
+                        'Gazebo topics and controller manager. The controller manager topics move under it '
+                        'and need a bridge from what runs the shared simulation'),
+        DeclareLaunchArgument(
+            'load_controllers', default_value='true',
+            description='Load the controllers; false when something else loads them'),
     ]
 
     # robot_state_publisher with the sim_mode URDF (gz_ros2_control plugin)
@@ -42,14 +51,15 @@ def generate_launch_description():
             'use_sim_time': 'true',
             'sim_mode': 'true',
             'wheel_radius': wheel_radius,
+            'robot_ns': robot_ns,
         }.items(),
     )
 
     spawn_robot = Node(
         package='ros_gz_sim',
         executable='create',
         arguments=[
-            '-name', 'kpi_rover',
+            '-name', PythonExpression(["'", robot_ns, "' or 'kpi_rover'"]),
             '-topic', 'robot_description',
             '-x', x_pose,
             '-y', y_pose,
@@ -59,19 +69,22 @@ def generate_launch_description():
         output='screen',
     )
 
+    # Relative Gazebo topics of the config get the namespace (<robot_ns>/scan), the ROS topics don't
     gz_bridge = Node(
         package='ros_gz_bridge',
         executable='parameter_bridge',
+        namespace=robot_ns,
         parameters=[{
             'config_file': PathJoinSubstitution([pkg_bringup, 'config', 'gz_bridge.yaml']),
+            'expand_gz_topic_names': True,
         }],
         output='screen',
     )
 
     joint_state_broadcaster = Node(
         package='controller_manager',
         executable='spawner',
-        arguments=['joint_state_broadcaster', '--switch-timeout', '60'],
+        arguments=['joint_state_broadcaster', '-c', [robot_ns, '/controller_manager'], '--switch-timeout', '60'],
         output='screen',
     )
 
@@ -80,6 +93,7 @@ def generate_launch_description():
         executable='spawner',
         arguments=[
             'diff_drive_controller',
+            '-c', [robot_ns, '/controller_manager'],
             '--switch-timeout', '60',
             '--controller-ros-args', '-r /diff_drive_controller/odom:=/odom',
         ],
@@ -90,7 +104,7 @@ def generate_launch_description():
     spawn_controllers = RegisterEventHandler(OnProcessExit(
         target_action=spawn_robot,
         on_exit=[joint_state_broadcaster, diff_drive_controller],
-    ))
+    ), condition=IfCondition(LaunchConfiguration('load_controllers')))
 
     # Turns unstamped /cmd_vel (Nav2, teleop_twist_keyboard) into the stamped input of the controller
     twist_stamper = Node(

src/platform/kpi_rover_description/launch/description.launch.py

@@ -16,6 +16,7 @@ def generate_launch_description():
     serial_device = LaunchConfiguration('serial_device')
     baud_rate = LaunchConfiguration('baud_rate')
     wheel_radius = LaunchConfiguration('wheel_radius')
+    robot_ns = LaunchConfiguration('robot_ns')
 
     pkg_share = FindPackageShare('kpi_rover_description')
 
@@ -28,7 +29,8 @@ def generate_launch_description():
         ' sim_mode:=', sim_mode,
         ' serial_device:=', serial_device,
         ' baud_rate:=', baud_rate,
-        ' wheel_radius:=', wheel_radius
+        ' wheel_radius:=', wheel_radius,
+        ' robot_ns:=', robot_ns
     ])
 
     # Launch!
@@ -53,6 +55,10 @@ def generate_launch_description():
             'wheel_radius',
             default_value='0.034',
             description='Wheel radius in meters'),
+        DeclareLaunchArgument(
+            'robot_ns',
+            default_value='',
+            description='Name of the robot in a simulation shared by several robots (Gazebo topics, controller manager)'),
 
         Node(
             package='robot_state_publisher',

src/platform/kpi_rover_description/urdf/imu.xacro

@@ -12,7 +12,7 @@
         <sensor type="imu" name="imu">
             <always_on>1</always_on>
             <visualize>false</visualize>
-            <topic>/imu_broadcaster/imu</topic>
+            <topic>$(arg robot_ns)/imu_broadcaster/imu</topic>
             <gz_frame_id>imu_link</gz_frame_id>
         </sensor>
     </gazebo>

src/platform/kpi_rover_description/urdf/lidar.xacro

@@ -36,7 +36,7 @@
     <gazebo reference="laser_frame">
         <sensor name="gpu_lidar" type="gpu_lidar">
         <update_rate>30</update_rate>
-        <topic>scan</topic>
+        <topic>$(arg robot_ns)/scan</topic>
         <gz_frame_id>laser_frame</gz_frame_id>
         <lidar>
             <scan>

src/platform/kpi_rover_description/urdf/robot.urdf.xacro

@@ -6,6 +6,8 @@
     <xacro:arg name="baud_rate" default="921600"/>
     <xacro:arg name="encoder_ticks_per_rev" default="1320"/>
     <xacro:arg name="wheel_radius" default="0.034"/>
+    <!-- Name of the robot in a simulation shared by several robots (Gazebo topics, controller manager namespace) -->
+    <xacro:arg name="robot_ns" default=""/>
 
     <xacro:include filename="materials.xacro" />
     <xacro:include filename="inertia.xacro" />

src/platform/kpi_rover_description/urdf/ros2_control.xacro

@@ -56,6 +56,7 @@
             <!-- Joint state publisher -->
             <plugin filename="gz_ros2_control-system" name="gz_ros2_control::GazeboSimROS2ControlPlugin">
             <parameters>$(find kpi_rover_bringup)/config/kpi_rover_controllers.yaml</parameters>
+            <ros><namespace>$(arg robot_ns)</namespace></ros>
             </plugin>
         </gazebo>
     </xacro:if>