Quadcopter PID Tuning for Altitude Hold/Position Hold along Z axis

Question

Good day, I have just finished tuning the Pitch and Roll PID's. I did this by setting the throttle such that the quad is weightless. I did the tuning of each axes separately.

I would just like to ask what is the best way to tune the PID for maintaining an altitude setpoint.

Is it best to turn off the Pitch and Roll PID controllers while tuning the altitude PID or is it best to have them already active while tuning the latter controller?

I am going to use a cascaded PID controller using the Velocity along the z-axis calculated from the accelerometer output for the inner PID loop (150Hz) and the altitude measurement of the HC-SRO4 ultrasonic sensor (20Hz) for the outer PID loop.

Answer 1

Currently I am performing my research on that, and in my case I decided to tune all the PIDs. Angles of the quadrotor tend to zero, while altitude controller tend to the objective height. That's habitual in bibliography.

In my particular simulations on the computer, PD parameters were enough and all the controllers adapted the same Proportional and Derivative parameters.