Research On Electro-hydraulic Load Simulator Systemof Springload

For General elastic load, the load elastic stiffness value is positive. But, there is acertain type of variable elastic load has both positive stiffness and negative stiffness. Forload simulator, no matter what its loading system or the bearing system is closely relatedto the load displacement. when the system has variable elastic load, the system willappear essentially unstable because of load stiffness transform into negative. This kind ofvariable elastic load effect of the system with its changes in the size of the stiffness valueand stiffness values of positive and negative change. These effects make the system willnot be able to keep consistent response speed and precision, even unstable.Based on the load simulator of variable elastic load in the experimental. Analyzethe stability and response characteristics on the load simulator system which is containsof variable elastic load. And add compensation block to optimize system, to solve theloss of system stability and system features is beyond the scope of work requirements.Summarized as follows：1Respectively overview the basic theory of force control system and position,and analyze the relationship and transformation of force control system and positioncontrol system.2According to the Load simulator model that the experiment is required,respectively established the mathematical model of the elastic load generator and loaddevice, and obtain the main parameters of the system through design and calculation.3Establishing simulation model is built based on the system mathematic model,and carries on the digital simulation using MATLAB Simulink toolbox, analyzed theinfluence of different position and load stiffness on the system to control accuracy,response speed and stability, and verified the accuracy of the mathematical model by thesimulation value.4According to the problem the negative stiffness makes the loss of systemstability, under the goal of the system response time is consistent, by joining systematic compensation and correction system makes the system recover stable and make thesystem feature meet the requirements of the job.This paper studied the characteristics of the elastic stiffness can be plus or minusalternates alternately on load simulator, focusing on instability problem when the systemload stiffness changes in the elastic load, in order to improve the system response speedand control precision and guarantee the stability of system, which uses comprehensivecorrection strategy mechanical compensation system and of PID control, provides a newsolution for solve the system instability of variable elastic load.