Adaptive Terminal Sliding-Mode Control for Servo Systems with Inertia Variations

Inertia variations in servo systems greatly affect the control performance. This paper presents an adaptive terminal sliding-mode controller to deal with the problem. Instead of using traditional mathematics model, a characteristic model, which has more advantages in describing time-varying dynamics, is adopted to describe the servo system with inertia variations. The parameters of characteristic model are identified by the recursive least squares algorithm. Then, an adaptive terminal sliding-mode controller is designed based on the characteristic model. Theoretical analysis proves that the quasi-sliding mode is reached in finite steps. Simulation results demonstrate the improvement of tracking performance of the proposed controller.