Nonlinear feedforward control for wind disturbance rejection on autonomous helicopter

This paper presents the design and verification of a model based nonlinear feedforward controller for vertical and horizontal wind disturbance rejection on autonomous helicopters. The feedforward control is based on a helicopter model that is derived using a number of carefully chosen simplifications to make it suitable for the purpose. The model is inverted for the calculation of rotor collective and cyclic pitch angles given the wind disturbance. The control strategy is then applied on a small helicopter in a controlled wind environment and the effectiveness and advantage of the feedforward controller is demonstrated through flight tests.