Rover Offboard: rover_speed_setpoint / rover_rate_setpoint

PX4 Autopilot
1

Hi everyone,
I’m trying to control a PX4 v1.17 rover in Offboard via ROS 2. Offboard mode is accepted, the vehicle arms, failsafe is not triggered, and my rover setpoint topics are being received — but the rover does not actuate (wheels don’t spin). Also, internal uORB throttle/steering setpoints don’t appear to be produced.

Setup / context

  • PX4: v1.17

  • Vehicle type: rover

  • ROS 2: publishing setpoints continuously (about 50 Hz)

What is being published from ROS 2

These topics are streaming:

  • /fmu/in/offboard_control_mode

    • velocity = true

  • /fmu/in/rover_speed_setpoint

    • speed_body_x ≈ 0.86

  • /fmu/in/rover_rate_setpoint

    • yaw_rate_setpoint ≈ -0.18

What PX4 sees (MAVLink console)

Using listener on PX4:

  • listener rover_speed_setpoint → updates normally

  • listener rover_rate_setpoint → updates normally

But:

  • listener rover_throttle_setpoint → prints only the topic header (no data / no updates)

  • listener rover_steering_setpoint → same (header only)

So it looks like PX4 receives rover_speed_setpoint and rover_rate_setpoint, but it does not generate/update rover_throttle_setpoint / rover_steering_setpoint, and there’s no actual actuation.

Vehicle state

Commander reports:

  • Armed

  • navigation mode: Offboard

  • failsafe: no

Failsafe flags snapshot during the session:

    • global_position_invalid: true

    • home_position_invalid: true

    • manual_control_signal_lost: true
      These might be acceptable for rover offboard, but I’m not sure if any of them blocks rover actuation / throttle output.

Question

  1. What conditions must be met for PX4 rover Offboard to translate rover_speed_setpoint + rover_rate_setpoint into rover_throttle_setpoint + rover_steering_setpoint?

  2. Are there specific PX4 parameters (rover, safety, offboard, navigator, actuator mapping) that can prevent throttle/steering setpoints from being generated even when offboard is accepted?

  3. What logs / uORB topics should I check to see why throttle/steering are not produced? (I can provide a .ulg log if needed.)

Any advice on what to inspect next would be appreciated.

2

Hi, have you tried using an external mode (see here) instead of the legacy “Offboard” mode? External modes get more testing and offer a cleaner API than “Offboard”. It’s still offboard in the sense that part of the controller is running on the ROS side and not PX4.

3

May I ask if you have resolved this issue? I am encountering the same problem and it is very troubling.