A Novel Strategy to Improve the Performance of Speed And the Currentloopsfor Servo Control

Abstract

The classical PI controllers are widely used in servo speed-loop and current-loop control structures because of their simple algorithm and stability.The corresponding PI control parametersaffect the performance of the loop responses.We always expect to expedite the response by improving Kp,but too largeKp will not only improve the speed and current responses but also bring oscillations and overshoots; thus the value of Kp is limited.The paper presents a new method to reduce the oscillations and overshoots for speed and current loops by means of low-order observers. The observers are used to extract the oscillation signals as compensation.The principle of the proposed method is explained and the rules of important controller parameters are described.Simulation and experiments are conducted to prove the advantage of the proposed strategy.Both the results have verifiedthe validity of the new strategy.