Direct Actuator Control Rover PX4 v1.15

Hi community:)

I am working on a boat project and want to use the rover differential drive solution from PX4 in PX4 v1.15 (for SITL) and v1.15.4 for hardware implementation (px4_fmu-v6x_rover).
Next to Mission Mode, I want to use the Offboard Mode for more precise navigation for a docking maneuver.
I can control the motors via /fmu/in/actuator_motors for DDS. That works fine for a Generic Quadcopter configuration (latest firmware v1.15.4 motor 1 & 2 of my boat configured as motors of the quadcopter, motor 3 & 4 assigned to empty PWM slots).
However, when I use the same script on the rover-firmware, the motors start jerking instead of spinning. Interestingly, the same happens in simulation. Here, I listened to the topics for my boat in gazebo and next to the actual commands that correspond to my offboard script, commands with zero thrust are sent.

I haven’t tested the setup for Mission Mode on the real hardware. However, in simulation the problem does not occur (Even though the boat starts moving backwards - I fix this by inverting the motors, run it, stop it, and invert the motors again - maybe also somebody can help me here).

I want to gain control over the motors. Both, Mavros and DDS-bridging would be fine for me (in mavros sending /mavros/actuator_control is not recognized by the system at all).

Best regards,
Erik

1 Like