PX4/Firmware — pull request #1049 by DrTon (2014-06-09 09:26:14+00:00)
Title: mc_pos_control, mc_att_control: feed forward attitude rates

One interesting idea about improving position controller performance. Feeding forward attitude rates (we can calculate them with high precision) allows to reduce offset between attitude setpoint and actual setpoint on slow attitude setpoint changes, makes sence for loiter and arriving to waypoint. HIL tests show that D component in velocity controller not needed anymore, i.e. we have -1 parameter and more accurate model of control.

I want to make position controller homogeneous for XY and Z axes, because only difference is that on hovering we have external force vector only along Z. But for fast flight we have also significant air drag forces, so we should have no difference between XY and Z. As result we will have common P and VEL_P / VEL_I parameters for all axes.

Tested in HIL, not tested in flight yet.