A study on high accuracy discrete-time sliding mode control

Official URL: http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/4061663/4061664/04061730.pdf?isnumber=4061664&prod=CNF&arnumber=4061730&arSt=355&ared=360&arAuthor=Asif+Sabanovic%3B+Khalid+Abidi%3B+Meltem+Elitas

In this paper a Discrete-Time Sliding-Mode based controller design for high accuracy motion control systems is presented. The controller is designed for a general SISO system with nonlinearity and external disturbance. Closed-Loop behavior of the general system with the proposed control and Lyapunov stability is shown and the error of the closed loop system is proven to be within an o(T2). The proposed controller is applied to a stage driven by a piezo drive that is known to suffer from hysteresis nonlinearity in the control gain. Proposed SMC controller is proven to offer chattering-free motion and rejection of the disturbances represented by hysteresis and the time variation of the piezo drive parameters. As a separate idea to enhance the accuracy of the closed loop system a combination of disturbance rejection method and the SMC controller is explored and its effectiveness is experimentally demonstrated. Closed-loop experiments are presented using PID controller with and without disturbance compensation and Sliding-Mode Controller with and without disturbance compensation for the purpose of comparison.