Design Of Electric Servo-cylinder Loading System Based On LADRC

Electric servo-cylinder loading system is widely used in engineering machinery,pressure test equipment,aerospace and other fields because of its compact structure,fast response,strong anti-overload ability and small space occupation.With the development of science and technology,the servo cylinder is also developing towards the direction of heavy load and high precision.This project is commissioned by the Institute of seismic engineering of Dalian University of technology to develop a servo cylinder loading system with STM32 as the control core.The research methods and contents of this paper mainly include the following aspects:First,this paper analyzes and arranges the research status of the electric servo-cylinder control system at home and abroad by referring to the relevant literature,including the research on clearance compensation,output lag algorithm,etc.;discusses the structure of electric servo-cylinder and related control theory,and demonstrates the feasibility of using electric servo-cylinder as loading equipment.Next,the overall control scheme with single-chip microcomputer and electric servocylinder as the core is put forward in this paper.According to the control performance of the control system,the selection of the single-chip microcomputer and the design of the relevant peripheral hardware circuits are completed.The selection of other important parts has been done.Then,the paper discusses the causes of the reverse gap,introduces the common mathematical model of the reverse clearance,establishes the mathematical model of the AC servo motor,and the methods of eliminating the gap,establishes the mathematical model of the AC servo motor,and completes the modeling work of the whole loading test system.Combined with the classic PID controller,the closed-loop control is realized after building the MATLAB/Simulink simulation model.The advantages and disadvantages of the PID control and the stability of the control system are analyzed,which will provide a reference for the subsequent control algorithm's optimization.Finally,a linear active disturbance-rejection controller(LADRC)is proposed to solve the complex problems of nonlinear reverse error and reverse clearance in the electric servo cylinder loading system.The controller has the advantages of good anti-interference performance and fast dynamic response.According to the requirements of the geotechnical experiment,by means of simulation,it is verified that the linear ADRC has better position tracking performance and shorter output lag time compared with the classical PID controller,which could reduce the reverse error.