MIMO Robust Servo Controller Design Based on Internal Model Principle Using Polynomial Differential Operator

Abstract

This paper proposes a controller design method for the multi-input multi-output robust servo system based on the internal model principle using polynomial differential operator. To do this task, the followings are done. Firstly, the basic idea of internal model principle is described. Secondly, the extended system by operating the polynomial differential operator to a given system with disturbance under the given conditions of reference and disturbance expressed into polynomial differential equation form and an output error is introduced. Thirdly, the controllability checking of the extended systems is done. Fourthly, a state feedback law is obtained by solving the pole assignment problem with all the poles of the extended system. Fifthly, a full observer is designed to estimate unknown states. Sixthly, the proposed control method is applied to a four steering wheel vehicle. Simulation results show that the proposed method can successfully make the system with a step and ramp type of disturbance track three references such as step, ramp and parabola types.