Research On Dynamic Characteristics And Control Method Based On Hydraulic Servo Test Bench

During tramcar’s running, its wheel hub reducer usually suffered the cyclical pressure result in fatigue damage. Therefore, it needs high performance of wheel hub reducer. In order to detect the performance of the wheel hub reducer, we need a fatigue test bench. It can provide sine wave, triangle wave, square wave and random wave, which can imitate different road loading system.With the continuous development of hydraulic technology, people pay much more attention to dynamic performance of the bench. Such as, how to increase control precision, reduce the hydraulic shock, and improve system dynamic quality, etc. Therefore, it is necessary for us to have a study of the dynamic characteristics of test bench. Specific research contents and results are as follows:Firstly, according to the technical requirements, puts forward the design scheme of hydraulic servo test bench, formulate schematic diagram of the hydraulic, carry out the calculation and selection of the hydraulic system components.Secondly, established the power bond model of hydraulic system and hydraulic components based on the power bond graph method, and the pilot operated relief valve are analyzed in detail, then built the simulation model by20-sim software. Compare the simulation results and experimental results, confirmed the correctness of the mathematical model of the hydraulic servo test bench and the pilot operated relief valve.Thirdly, through the simulation analysis of the model, some important influence factors of the dynamic characteristics are discussed, such as system pressure, hydraulic pipeline parameters, load stiffness, the accumulator and cylinder leakage coefficient, revealed the influence regular of these parameters on the system dynamic characteristics. As well, the analysis and research on dynamic performance of the pilot operated relief valve has carried on.Lastly, because of different frequency and different amplitude of the input signal, conventional PID values must often change to get better output signal. And also can’t reach the ideal control precision. So the fuzzy adaptive PID control was adopted. The simulation results show that application of fuzzy adaptive PID control is better than conventional PID in improving control precision, and the PID parameters are automatically updated.This paper researched on the dynamic characteristics and the control accuracy based on a hydraulic servo test bench. Provide theoretical support for designing and improving the hydraulic servo test bench, and has a guiding significance for improving the dynamic performance and the control accuracy of the test bench system.