ROS 2 Lyrical lab 08 · 2–3 hours

ros2_control and diagnostics

Connect a simulated arm to controller_manager, command a trajectory and record evidence.

Before you start

Lab 07 complete
Industrial Robots access for model-specific work

Files you will touch

src/training_arm_description/urdf/training_arm.ros2_control.xacro
src/training_arm_bringup/config/controllers.yaml

Step 1

Set up

sudo apt install ros-lyrical-ros2-control ros-lyrical-ros2-controllers
ros2 control list_hardware_interfaces
ros2 control list_controllers

Step 2

Create the file

controller_manager:
  ros__parameters:
    update_rate: 100
    joint_state_broadcaster:
      type: joint_state_broadcaster/JointStateBroadcaster
    arm_controller:
      type: joint_trajectory_controller/JointTrajectoryController

Step 3

Build, run and inspect

ros2 run controller_manager spawner joint_state_broadcaster
ros2 run controller_manager spawner arm_controller
ros2 control list_controllers
ros2 bag record /joint_states /arm_controller/controller_state

Proof that it works

Both controllers report active
Command and state interfaces are claimed correctly
The bag records joint state and controller state topics

Recovery notes

Use mock hardware until stop, limit and recovery behavior are proven.
A robot_description change requires restarting controller_manager; live URDF reload is not supported.

ros2_control controller manager