Design And Research Of Passive Hydraulic Loading System

The loading system is divided into active loading and passive loading.Compared with the active loading,the passively input force input signal is generated during the movement of the load,the load itself has its own motion rule and is not controlled by the loading system.In the passive hydraulic loading system,when the electro-hydraulic proportional relief valve is used as the pressure control element of the system to loaded with a small load,the loading stability is poor and the loading effect is not good.Based on this,a new loading method is proposed in the paper,in other words,using an electrohydraulic servo valve as the pressure control element of the loading system to achieve stable loading of small loads.Firstly,the paper analyzes the basic components and principles of a passive hydraulic loading system,and the loading mode of the electro-hydraulic proportional overflow valve as the pressure control element and the loading principle of the loading mode with the electro-hydraulic servo valve as the pressure control element are analyzed respectively.And the advantages and disadvantages of these two loading methods are compared.Secondly,a passive hydraulic loading system was designed on the basis of selecting the loading method.The optimal matching analysis is performed on the system.The main parameters of the required components in the system are calculated based on the analysis results,and the model of the component is determined based on the calculated values.In addition,the control principle of passive hydraulic loading is analyzed.Using the linearization analysis method,the mathematical model of the system is deduced.Based on the deduced mathematical model,the dynamic characteristics of the loading system are simulated and analyzed.Finally,in order to improve the control performance of the loading system,according to the characteristics of passive hydraulic loading,a PID controller is added to the forward channel of the loading system.The simulation analysis shows that the control performance of the loading system is improved after adding PID.