Tiltrotor VTOL Control Issues
I’m a college student and a beginner trying to control a tiltwing aircraft using PX4 Pro v1.16.0 with the Generic tiltrotor VTOL frame in QGroundControl.
I’m trying to use the ailerons for yaw control during hover, which requires yaw-roll mixing. However, I haven’t been successful. I thought the aileron servos would respond by applying roll and yaw scales, but they don’t move. Strangely, they sometimes start working if I reduce the value of the rudder servo. Is this a trade-off? I really need help.
Also, the sticks are too sensitive. The servos move to their maximum position even with just a slight stick input. Please help!
Out of the box the generic tiltrotor VTOL doesn’t mix yaw into the ailerons in hover – PX4 mainly uses differential thrust for yaw. If you want yaw-roll mixing, you’ll need to edit the mixer file (in ROMFS/px4fmu_common/mixers/) or use Control Allocation in newer PX4 versions.The ailerons moving only when you reduce rudder scale suggests a control allocation trade-off – rudder is prioritized. Try adjusting the mixer weights.
For the very sensitive stick response:
- Re-check RC calibration in QGC
- Tune down FW_R_* / FW_Y_* gains
- Add expo on your transmitter.