Hello, I have built a large symmetrical 8 kg payload co-axial octacopter UAV. Upon testing the drone seems to have little yaw authority in the CCW direction. I researched online but couldn’t find how the PX4 controller handles the yaw rotation.
From my understanding in the pair that is involved with the desired yaw direction the upper motor speeds up while the lower motor slows down in order to provide the counter-torque for the yaw of the vehicle. In this manner, each arm keeps the same overall vertical thrust and a net torque is produced. Is this correct ? Can you provide any details about how the yaw controller works in an octacopter co-axial configuration ?
Will a small cant angle (tilt towards the yaw direction) in the motors help in creating more control authority ? From my point of view the up and down motors of each arm should have opposite angles so that the component of the thrust vector between doesnt get cancelled by the one of the adjacent arm. Any advice on that matter would be helpful !
PID tuning will also be needed to make the yaw gains more aggressive I suppose.
This is the longest log I have. The yaw seems awfully underactuated. There is also a lot of noise on the pitch and roll graphs. I didn’t do a sensor calibration before the flight, as I have done it in the same place a month ago. This seems to have worsened the behaviour of the drone. The pixhawk is soft mounted, should i try to hard mount it onto the frame (Pixhawk 6x). Any reply about the details of the yaw controller in the coaxial configuration ? Maybe, someone with experience in PX4 flight control architecture can help !
Message me on Discord (