Design and Realization of Position Controller Based on Characteristic Model for Servo Systems with Large Inertia Ratio

An adaptive sliding mode controller (ASMC) based on characteristic model is designed to overcome the detrimental effect of large inertia ratio and large-range varying inertia in high accuracy servo systems. The servo system discrete characteristic model is established and adopted for the controller designed instead of using the traditional mechanism model. The recursive least square (RLS) algorithm is used to identify time-varying parameters in characteristic model. The position controller is constituted by an adaptive equivalent controller based on identification parameters and an improved sliding mode controller, and the stability of the closed-loop system is analyzed. The experimental results show that the proposed controller can adapt to large-range varying inertia, and improve the dynamic performance and steady-state precision of servo systems.