Robust Predictive Control of Electro-mechanical Servo System

In this work, the output tracking predictive controller is robustified by using an Extended State Observer (ESO). The predictive controller formulation needs availability of accurate mathematical model of the plant. Further, implementation of the controller requires measurement of output derivatives. In this work the ESO is employed to address the issues. The ESO simultaneously estimate the output derivatives and uncertainty. The estimated uncertainty is used to robustify the predictive controller designed for the nominal system. Closed loop stability of the overall system is established. The notable feature of the proposed design is that it neither requires accurate plant model nor any information about the uncertainty. To demonstrate the effectiveness, numerical simulation results of the proposed approach as applied to the servo motion control problem are presented and it is shown that the ESO based predictive controller offers improved performance.