In this paper, a sliding mode based self-tuning PID controller is proposed for uncertain second order systems. While developing the controller, it is assumed that the system model has a part which contains nonlinear terms similar to PID structure which is a new approach in the literature. The controller and update rules for controller parameters are obtained from Lyapunov stability analysis. The proposed controller with update rule is experienced on an experimental 2-DOF helicopter which is also known as Twin-Rotor Multi-Input Multi-Output System (TRMS). From experiments, it was seen that the PID parameter update rules run satisfactorily and, in parallel with this, the controller achieved the control objective by providing the system track the desired trajectory.
Self-Tuning PID controller, Sliding mode controller; Second order systems