Reference mode control for a helicopter with time-varying disturbance

In this paper, the problem of reference mode based flight control is investigated for a linear helicopter system with time-varying disturbance. The time-varying disturbance is considered, which consists of multiple common time-varying disturbances. Firstly, a disturbance observer is designed to estimated the unknown disturbance. Then, combining with the method of reference mode control, a disturbance-observer-based-controller is designed such that the helicopter dynamic could asymptotically track the desired signal of reference mode. Finally, the proposed control method is applied to the flight control of linear helicopter, and the effectiveness of the designed controller is confirmed by the simulation results.