Research On Control Strategy And Characteristics Of Friction Type Electrohydraulic Load Simulator

Electro-hydraulic load simulator is a loop simulation device of various groundforce or torque, its performance of loading directly reflects the Degree of precision toApproaching the actual load power and load torque. The better loading performance ofelectro-hydraulic load simulator is, the more accurate testing of high-precisionequipment is. Electro-hydraulic load simulator has been widely used in a variety ofdevices in our life for testing, the higher quality of electro-hydraulic load simulatorperformance are largely needed because of the development of technology, therefore,the study of load simulator for improving the performance has important practicalsignificance for the Civilian and defense.The traditional electro-hydraulic load simulator is a typical passive force controlsystem, the active motion of tested object could make the loader which is connectedtogether solidly produce a strong disturbance, resulting in forced flow between cavitiesof loading motor., and produces the so-called extra force. extra force changescontinuously when the loaded equipment move actively, as long as tested object move,it always exists, and can be large According to strength of the motion characteristics,ithas a seriously affect on the loading performance of electro-hydraulic load simulator.Through the ages, though many scholars study the method of suppressing or eliminatingextra torque in the aspect of structure and control, the results of implementation isunsatisfactory.The electro-hydraulic load simulator studied in this paper changes the traditionalloading program and adopts the theory of friction torque load, which is based on a newidea,so there is no interaction between the movement of the device loaded and thetroque of the loader, and extra torque is eliminated. Because this program is justproposed, technology is not mature. In this paper, we focus on further confirmation ofthis program’s feasibility and some existing problems, verify that loader based onfriction torque compared to conventional load simulator better performance.This paper does the corresponding research based on summarizing previous studiesabout traditional load simulator and combining the characteristics of the new method offriction torque load. Firstly, in order to make preparation for the theoretical analysis, itis very necessary to build detailed mathematical model of this electro-hydraulic loadsimulator for hydraulic valve-controlled asymmetric cylinder and friction; Secondly, onthe basis of existing experimental prototype, we can obtain the actual system modelusing system identification, which provides accurate models for settings actualcontroller parameter; Thirdly, analyzing the problems caused by the introduction of friction load by theory simulation made by related software and measuring the impact ofthese problems on the loading performance; Improving the system accuracy andanti-jamming capability by using ADRC, based on the characteristics of the system andthe problems it has brought; to load simulation analysis of this control strategy toimprove the performance of the system load degree; The last but not the least,verifythe effect that this approach has on eliminating excess force with the help of xPCreal-time simulation platform and LabVIEW control interface, while applying thecontrol strategy to this electro-hydraulic load simulator prototype to verify itseffectiveness in improving the control performance.