Control of a Coaxial Helicopter with Center of Gravity Steering

This paper shows roll and pitch feedback control on a coaxial mini helicopter equipped with a center of gravity steering mechanism. The helicopter carries a minimal set of sensors to measure yaw rate, distance to ground and roll and pitch angle. While yaw rate and distance to ground control are already realized on the helicopter, roll and pitch control including the necessary signal filtering are newly developed for the system. Additionally, two feedforward compensations for the distance to ground control are introduced. Flight data shows the performance of the attitude control subjected to external disturbances, and the improvements achieved by the two compensations in distance to ground control.