Research On Control Algorithm Of Load Simulation System Of Oil Film Bearing Test Rig

Oil-film bearing is one of special sliding bearing,with incomparable advantages over other types of bearing.It has the characteristics of high degree of lubrication,small coefficient of friction and strong carrying capacity etc.Oil-film bearing is widely used in metallurgy,military,wind power and other industries.As an effective means to verify theoretical derivation and numerical simulation,the experimental research on oil-film bearing is necessary for the development of oil-film bearing technology.Improving the running accuracy of key parts of the test equipment and optimizing the performance of the test equipment can effectively improve the simulation accuracy of the running situation of the oil film bearing.It also could promote the theoretical innovation of the oil film bearing and the development of production technology.The oil-film bearing test rig established by our school can simulate the usage of oil-film bearing in actual factories through artificial simulated load and rotation law.The corresponding experimental data are extracted from it.In order to accurately simulate the bearing load,the control accuracy of the corresponding load simulation system must be guaranteed.Intelligent control technology as the development direction in the industrial control field is an important means to improve the performance of test rig.Therefore,it is an important task to integrate the original hardware and advanced control algorithm.Furthermore we can improve the performance of existing equipment and meet the needs of deeper theoretical research.The research content of this paper is as follows:First,the oil film bearing test bench belongs to the multi-field coupling system.The oil film bearing test rig is a typical electro-hydraulic coupling control system.The theoretical transfer function model of the load simulation system is obtained by analyzing the working principle of the existing equipment and the electrohydraulic control theory.Secondly,Considering the system model contains some unknown parameters,it is impossible to directly establish an accurate theoretical model.Therefore,we realize the approximate estimation of the mathematical model by parameter identification.In this paper,ARMAX model is used for system parameter identification.The collected input and output signals are identified by MATLAB parameter identification toolbox.Thirdly,the various definition of fractional calculus,calculating tool function and discretization method are discussed.The numerical implementation of fractional PID controller on computer is given.Furthermore,the simulation module is established.By MATLAB/SIMULINK software,fractional PID and classical PID controller are simulated in time domain and frequency domain.Fourthly,the influence of five parameters in fractional PID controller on the control effect is analyzed completely.The controller was designed and optimized based on ITAE performance index by selecting appropriate method of parameter optimization.By using MATLAB/SIMULINK software two PID algorithm in the time domain and frequency domain were researched The simulation results are analyzed and discussed.