Attitude control of 3-DOF helicopter based on Iterative Learning Control

Tracking control problems of the elevation and travel angles are investigated for 3-DOF (three degree of freedom) helicopter in this paper. By combining the normal PID controller based on LQR (linear quadratic regulator) and PID-type Iterative Learning Control, a new mixed controller is proposed for 3-DOF helicopter to achieve higher tracking accuracy. Compared with the normal PID controller based on LQR, the mixed controller can achieve better asymptotic converging effect for the control of the elevation and travel angles of 3-DOF helicopter. By the relatively small times of iteration, the system achieves quite high tracing accuracy under the mixed controller.