Control performance improvement for QTW UAV by using feedforward gains

This paper examines the effectiveness of Feed-Forward (FF) gains in Control Augmentation System (CAS) of Quad Tilt Wing (QTW) Unmanned Aerial Vehicle (UAV) “McART3”. We have already designed CAS for McART3 with only Proportional and Integral (PI) feedback controllers, and have demonstrated its capability of Vertical Take-Off and Landing (VTOL) as well as high speed cruise; however, pilot comments in flight tests indicate that handling quality is not satisfactory and needs improvement. We therefore examine the effectiveness of FF gains in this note, and their usefulness to suppress overshoot, particularly in longitudinal motions, is confirmed by numerical simulations. However, in flight tests, neither apparent improvement of command tracking performance nor pilot rating improvement appears.