Fixed Wing HITL with Gazebo

PX4 Autopilot Airplanes (Fixed Wing)
#1

I have a Fixed Wing model built in Gazebo to use with HITL in a Pixhawk 5x. If I select the HILStar (Xplane) while the Pixhawk has the original firmware PX4 Pro Stable Release v1.12.3 it works well, the motors move in the simulation. If I make a new firmware using
make px4_fmu-v5x_default
and I uploaded through QGC the motors don’t respond, even when I select the same HILStar.

Something I noticed is that when using the custom firmware sometimes I cannot see the topic /gazebo/command/motor_speed
in gazebo and I just see
/gazebo/command/.

Something else is that this folder:
PX4-Autopilot/build/px4_sitl_default/build_gazebo
does not exist in this folder:
PX4-Autopilot/build/px4_fmu-v5x_default
I wonder if I missing something when I make px4_fmu-v5x_default

Also before starting the HITL simulation I tried the following:
~/PX4-Autopilot$ DONT_RUN=1 make px4_fmu-v5x_default gazebo
but I get this error:

ninja: error: unknown target 'gazebo', did you mean 'geo'?
make: *** [Makefile:230: px4_fmu-v5x_default] Error 1

Since my model needs two independent ailerons, basically I could just modify the HILStar mixer or add a new airframe, but this needs a new firmware to be uploaded which is giving the problem.

I would greatly appreciate some suggestion or some workaround.

1 Like
#2

Hi, did you enable HITL as discussed in Hardware in the Loop Simulation \(HITL\) | PX4 User Guide ?

Note, make px4_fmu-v5x_default should be all you need to do for building (or just take the default). Indeed even the enabling HITL probably shouldn’t be needed if you select the HIL target

#3

Hi @hamishwillee, thanks for your reply.

Yes, I can go back and forward uploading to the Pixhawk the Stable_Release_v1.12.3 and px4_fmu-v5x_default.px4 and HITL only works with the Stable_Release.

Actually, to narrow it down further, the same situation happens with the default airframes. For example if I select standard_vtol_hitl gazebo model with the HIL Standard VTOL QuadPlane it works well with Stable Release but not when upload a new firmware to the Pixhawk.

It seems like when the new firmware is generated, something related with Gazebo is missing.

#4

There shouldn’t be anything related to gazebo in the firmware “specifically” as I understand it.

@dagar Can you advise on this HITL query?