The Research On The Control System Of Electro-hydraulic Servo Fatigue Loading Machine

During tank's moving, the rubber in the tracked board is suffered the cyclical pressure, rally, torque. It is very easy to fatigue ineffective because of the cyclical power. Therefore, it needs high performance of rubber. In order to test the performance of rubber, we need a fatigue testing machine. This machine must have high-precision, high response, as well as large loading system, and it can provide sine wave, square wave, triangle wave, combination wave, random road spectrum, which can imitate different road loading system. It is possible for electro-hydraulic servo system to realize the testing machine.Judging from the current situation in our country, electro-hydraulic servo fatigue testing machine mainly rely on imports, and domestic research progress is mainly embodied in the mechanical and hydraulic parts. The research on actuator and controller has little progress. Even though, it has some progress, there are at an experimental stage, and almost have none sophisticated products. Therefore, the aim to my subject is setting up a platform of fatigue testing machine, which is mature, stable, and focused on the development of hydraulic servo system and computer control systems.Based on discussing the characteristics of electro-hydraulic servo fatigue loading machine and the development of machine at home and abroad, the article designs the hydraulic control systems and computer control systems of the machine. For the difference between electro-hydraulic position servo loop and electro-hydraulic pressure servo loop, we put forward a strategy, which is controlled by both the digital PID and analog PID, in order to ensure the high-precision, high response of machine, and take the cost-effective into account.At the same time, the article sets up the equation between load pressure and load flow of power agency, based on the overall program of electro-hydraulic servo system. In this basis, it makes the theoretical analysis of valve-cylinder system and establishes its mathematical model, and calculates the transfer function of output displacement and load pressure. Finally, we use MATLAB to make dynamic simulation and correction to system, and according to simulation results to design and select the servo amplifier.Waveform output and data acquisition are achieved by high-performance D/A and A/D card. In the data collection process, in order to resolve the contradictions between high-speed data acquisition and low-speed data processing, we adopt a multi-threaded technology. At the same time, in order to ensure the data continuous, large-capacity collection, we adopt a multi-level cache technology. By this way, the accuracy and response speed of the machine are ensured.The successful development of fatigue loading machine makes up for the domestic blank in the fatigue loading machine of tracked board, and improves the level of rubber testing, and plays an important role in promoting the country's national defense construction.