Research On A Daptive Sliding Mode Control Of Electro-hydraulic Servo Fatigue Testing Machine Based On RBFNN

In the enterprises and colleges,the amount of old test equipment is large,and with the development of science and technology and the higher requirements for the performance of test equipment,these test equipments are facing elimination due to the backward performance of the control system.Compared with the procurement of new test equipment,the upgrade of the control system of the equipment that is still available in the hardware of these mainframes can not only avoid waste of equipment and save research funding.The research object of this paper is an Instron 1343 250kN electro-hydraulic servo fatigue testing machine produced in the 1980s.Due to its age,its control system is no longer available.It is necessary to design a control system for it to complete the fatigue test.In order to solve the problem of the fatigue tester control system adapting to different performance,size and shape parameters,this paper designs a control algorithm with parameter adaptive ability for its electro-hydraulic servo position control system,so that the fatigue test machine can adapt to the unknown parameters in its electrohydraulic servo system.The main research contents of the paper include:(1)The principle and composition of the fatigue testing machine control system are analyzed.The hardware of the control system is selected.The mathematical model of the actuator of the fatigue testing machine control system is established by using the mechanism analysis method.The position control is applied to the two actual working conditions.The mathematical model is analyzed,the main parameters of the model are determined and the stability of the model is analyzed,and the necessity of designing the control algorithm is given by simulation.(2)The RBFNN is used to compensate the uncertain parameters in the mathematical model of the fatigue testing machine.An adaptive sliding mode control based on the RBFNN compensation is designed and simulated in Simulink.The simulation results verify the effectiveness of the control algorithm.(3)The embedded control program of CompactRIO controller was developed by using model-based design method.The human-computer interaction software platform of position control was designed by LabVIEW.And using LabVIEW to carry out hardware-in-the-loop simulation experiments on the correctness of controller compilation and controller effectiveness.(4)The experimental preparation work was completed,and the parameter determination experiment was carried out on the effective working area of the hydraulic cylinder of the fatigue testing machine.The experimental research on the two specimens with different shape and shape parameters was carried out to verify the effectiveness of the designed control algorithm.The design of the fatigue testing machine control system has important reference value and significance for the development of the functional module of the fatigue testing machine and the upgrading and reconstruction of similar equipment.