The Research On Vehicle Leaf-spring Performance And Durability Test Rig Based On Hydraulic Servo Drive

As a kind of test equipment, the electro-hydraulic servo fatigue testing machine has been applied in many fields, such as engineering machinery, plane, automobile and so on. Moreover, it plays an important role in material test, development of new materials, product design, and supervision of product quality control. In addition, it colligates high technique like latter-day closed loop servo, digital display, electro-mechanical integration and computer, so it possesses very strong interdiscipline and difficult to design. With the development of technology, people pay more attention to the electro-hydraulic servo fatigue testing and more claim to the dynamic fatigue test.Though the research on leaf-spring performance and durability test Rig has been carried out for many years, most of the test rigs can’t unify the performance test and the durability test. What’s more, the method of loading always being mechanical, which lead to the loading waveform lacks of variation and convenience.The thesis designs a new mechanical construction, which can meet the requirement about the unity of the performance test and the durability test. And provide a loading way with many waveform, all that can improve the test rig’s combination property. Base on the construction of the test rig, design the theory drawing of the hydraulic system, calculate relevant parameter, carry on component selection, and finish the design of loading system-hydraulic cylinder with proportional servo valve of the test rig. With the model of the valve-controlled asymmetrical cylinder, the system transfer function is built and the system stability is analyzed. thought the research about system control policy, the self-adaptive fuzzy PID controller base on PLC is designed. By the research on MATLAB simulation, the control effect by different control method is compared, and the availability and advantage of the self-adaptive fuzzy PID control is verified.Finally,the control strategy of the Test Rig has been proved feasible again by the entire machine’s test on the control effect.