1 Feedforward Control of an Autonomous Helicopter using Trim Inputs

In this paper, a feedforward control strategy augmented to an existing feedback controller is demonstrated for an autonomous helicopter. The sole purpose of the feedforward controller is to assist the feedback loop in rejecting wind disturbances based on wind velocity measurements made onboard the helicopter. The feedforward control actions are obtained through trimming of the helicopter model subjected to a simulated wind, while a linear quadratic regulator (LQR) is implemented as the feedback controller. Based on simulations performed using mathematical model of the Bergen Industrial Twin autonomous helicopter with various wind velocity measurements, the feasibility of this approach for wind disturbance rejection is verified. Nomenclature ݀ ൌ external disturbance ݎ ൌ reference input ݕ ൌ plant output ܥff ൌ feedforward controller ܥfb ൌ feedback controlle