[bicycle_steering_controller] Wrong command return

[metanav]

Why does the bicycle_steering_controller return the traction command as angular speed of the rear virtual wheel? I expect it to return linear velocity along with steering angle.

https://github.com/ros-controls/ros2_controllers/blob/master/steering_controllers_library/src/steering_odometry.cpp#L286-L290

$ ros2 topic pub /bicycle_steering_controller/reference  \ 
geometry_msgs/msg/TwistStamped "{twist: {linear: {x: 0.2}, angular: {z: 0.01}}}"

As shown below the linear_velocity_command is 3.2 that is 0.2 /0.0625 (linear.x / wheel_radius).

$ ros2 topic echo /bicycle_steering_controller/controller_state
header:
  stamp:
    sec: 1748972977
    nanosec: 107514147
  frame_id: odom
traction_wheels_position: []
traction_wheels_velocity:
- 3.2
steer_positions:
- 0.016098609122644516
linear_velocity_command:
- 3.2
steering_angle_command:
- 0.016098609122644516

If the wheels angular velocity is intended then the above message is misleading.

The documentation mentions:

Command interfaces [(https://control.ros.org/iron/doc/ros2_controllers/steering_controllers_library/doc/userdoc.html#command-interfaces)
If parameter front_steering == true
<front_wheels_names[i]>/position double, in rad
<rear_wheels_names[i]>/velocity double, in m/s

[christophfroehlich]

From the comment in the message I'd say that the intention was to publish the command with the same unit as sent to the hardware
https://github.com/ros-controls/control_msgs/blob/323c96d6d8d98faa3799ba90a369d6c49a1c2b75/control_msgs/msg/SteeringControllerStatus.msg#L5

I agree that the msg field name is misleading, as well as the docs are wrong.