Research on Electric Servo Loading System Based on Disturbance Observer

Abstract

A novel double-loop control approach for reducing excess torque of the servo loading system based on disturbance observer is proposed.The mathematical model of the loading system is established by mechanism theory and the reasons causing the excess torque are analyzed, the nominal model and disturbance weighting function are determined based on an approximate method. Dis-turbance observer based the inner loop controller is designed by H ∞ mixed sensitivity method and the external-loop controller is designed as the classical PID contro ller. Both the simulation and experi-ments results show that disturbance observer is feasible and effectiv e to eliminate the excess torque, accuracy of the loading system is improved.