Research On Position Resonance Suppression Technique Of Servo Motor Based On Active Disturbance Rejection Control

Servo systems are widely applied in situations where high accuracy,reliability and sustainability are required,such as rolling mills,CNC machines,printing equipments,robots and production lines.Elastic couplings are prevalent in servo systems,however,that such elastic couplings will introduce vibration in servo systems.When vibration frequency lies within the working bandwidth,the servo system will produce much noise,mechanical parts will wear heavily,control accuracy will deterior,the scrap rate will rise,and accidents may happen if no special actions are taken to handle such vibration.Thus,the suppression of vibration in servo systems is necessary.Most servo systems can be modeled as two-inertia systems or their combinations.Therefore,it's important to research into the mechanism and suppression methods of the vibration of two-inertia systems.In this dissertation,detailed study is given on the mechanism and suppression methods of the vibration of the two-inertia system model.By applying modified Active Disturbance Rejection Control(ADRC)algorithm on the position loop,the robustness of the whole servo system is improved,and the vibration is suppressed.The structure of this dissertation is organized as follows:Firstly,the servo system is modeled as a two-inertia system connected by coupling with stiffness and damping.According to the working principle of the two-inertia system model,dynamics of the servo system is analyzed,and the mechanism of vibration is fully studied.Also,how different factors influencing the vibration are studied.Secondly,a modified ADRC suppression method based on the information provided by the position sensor of the motor is proposed.Firstly,a brief introduction on ADRC and its structure is given,and adapted to fit with the two-inertia system model.Secondly,the stability and control performance of this method is analyzed.Finally,simulation study is done,which showed the effectiveness of the proposed method.Thirdly,the experimental platform is built,and a motor drive based on ARM processor is used to test the performance of the control algorithm.Different suppression methods are tested.Performance of notch filter based methods and the proposed method are carefully studied and compared in situations with and without disturbance.The effectiveness and feasibility of proposed method is verified by the experiment.