Trajectory tracking control of unmanned helicopters by using adaptive dynamic surface approach

As the existing unmanned helicopter models are of high order and great load change, a control method based on the adaptive dynamic surface approach is proposed. In this method, first, one-order linear filters are used to estimate the time derivatives of virtual control signals, thus significantly simplifying the design of the controller. Then, an on-line adaptive law is used to estimate the helicopter mass, thus guaranteeing the stability of the closed-loop system with variable load. Finally, the semi-global uniform bound of tracking errors is proved based on the Lyapunov stability theory. Simulated results indicate that the proposed method is effective and feasible.