Research On The Electro-hydraulic Servo Test Bed Of The Hydraulic Damper

The tests of hydraulic damper are one of the important methods to detect the various technical parameters of damper. The test bed of electro-hydraulic servo could provide a powerful means for these tests. The structure design and the performance of the measurement and control system of the test bed will have a direct impact on the actual testing results.According to the performance parameters of hydraulic damper needed to be tested, this paper confirms that the test bed should have two functions, namely force loading and position controlling, so as to meet the requirements of testing properties of hydraulic damper with low resistance and speed locking and loading impact. Through the piecewise linearization of characteristics of the damper and the corresponding simplification of the mathematical models of the servo control components, the specific linear mathematical models of the hydraulic servo systems of force and position control are established. The frequency domain method is adopted to analyze the two control systems, and the parameters of the Conventional PID controller has been set by adjusting the systems according to its principles and characteristics.The simulation studies on the mathematical models of the electro-hydraulic servo testing system of hydraulic damper have been done. It can be seen that Conventional PID controller has both advantages and disadvantages in this system by the results of simulation. Exactly speaking, Conventional PID controller has a preferable control effect for the situation where damping coefficient of the damper keep unchanged. However, when damping coefficient of the damper change within a certain range, the control performance of the Conventional PID controller is not very satisfactory, worse still, it is likely to make the system unstable. On the basis of the Conventional PID controller, the fuzzy adaptive PID controller by exerting the principles of fuzzy control is assembled. It can be seen from the simulation results that fuzzy adaptive PID controller has a preferable control effect for both the situations where damping coefficient of the damper keep unchanged and where they change within a certain range; thereby it embodies its outstanding performance, and the wide prospect of its application in the electro-hydraulic servo testing system of hydraulic damper.Test results show that the overall design of the test bed is reasonable. Fuzzy adaptive PID controller has good controlling quality. Thus it can provide the manufacture and production of hydraulic damper with the necessary equipment of test and detection.