We are working on a quadcopter with tiltrotors and Im exploring full body pitch control, where the drone can rotate from 0° to near 90° nose-up while minimizing horizontal drift.
Current PX4 tiltrotor implementations, such as the Prisma PX4 tilting multirotor repo, allow tilting the rotors to bias thrust and fly tilted, however it doesn’t seem that they can independently pitch the body to large angles.
Has anyone previously attempted or acheived this kind of full-body pitch control with a quadcopter or multirotor setup? Any guidance, references would be appreciated.
Current Approach : We implemented a module where a knob on the Remote Controller directly controls the desired pitch angle of the drone in a custom airframe.
The knob sets a pitch setpoint.
We read the actual pitch from the Flight Controller via QGC.
The module computes the error between actual pitch and the setpoint
The servos controlling the tiltrotors then attempt to stabilise the vehicle at the commanded pitch based on whether it overshot / undershot the angle
Problem / Limitation
The QGC / PX4 parameter we subscribe to always tries to maintain horizontal orientation.
When the servos attempt to pitch the body, the flight controller fights back, preventing the drone from holding large pitch angles, even though our servo logic is correct.
Using a PX4-supported tiltrotor airframe as a base, we observed that changes to the pitch setpoint had no effect on our servos during bench testing.
Any ideas, prior work, or guidance on achieving this type of control would be much appreciated.
P.S. We are using an NXP MR-VMU-RT1176 Flight Controller.
