Electric Control System Research And Design Of The Hydraulic Servo-shimmy Testing Machine For Elastic Shaft's Test

Hydraulic servo-swing vibration testing machine is a important equipment to test materials,which could provide a strong guarantee to study the performance of flexible shaft. Based on the the core components which is called force (motion) converted mechanism, the electric control system of the testing machine whose maximum out-torque was 30000N·m was self-designed. The testing machine was used to test high torque flexible shaft,and then the material properties parameters will be obtained. To ensure the testing machine can meet the technical requirements of high torque output and high control accuracy, hydraulic servo-control technology was designed. Hydraulic system, and related hardware and software of electrical control system were used for power source for the system.A special structure that the servo control system and data acquisition systems were independent was designed for the testing machine's electrical control system, and then a DSP servo controller was designed and made for the system to complete the closed loop servo valve servo control and fault protection. The PCI data acquisition card was added to the tester data acquisition system to test high-speed data acquisition and reading, so, the test data acquisition rate also increased significantly. IPC and the servo controller was connected by the serial port for data communications, meanwhile, the test data acquisition and data processing were handled by the computer.When flexible shaft parts were tested, the load characteristics was changing in the large scale, meanwhile, the pre-test manual parameter tuning of the actual situation is more complicated. To solve these problems to guarantee the control precision and improve anti-interference ability, a parameter self-tuning fuzzy PID control (Fuzzy-PID) algorithm which could be used in this testing machine after compared the algorithm of traditional PID control and fuzzy logic control. The algorithm is discussed emphatically in this paper. A mathematical model simulation and hardware-in-the-loop simulation were designed respectively to verify its effectiveness by using the MATLAB/Simulink toolbox, and then the Fuzzy-PID algorithm was compiled and loaded into DSP high speed servo-controller. Measurement and control program was programmed by Visual C++ programming tools on the industrial personal computer. The testing process could be monitored by the computer's real-time system, and the test data could be displayed and stored easily. Some software and hardware anti-interference measures were used, and then the testing machine can satisfy the requirements of accuracy of 0.5%.