Research On Loading System Of High Pressure Oil Cylinder Test Rig

With the development of information technology and electronic technology, the system combined with electronic control, digital control and hydraulic systems reflects more and more advantages compared with purely hydraulic control system. This paper designs a high-pressure cylinder loading system combined with digital control and hydraulic proportional systems in conjunction with internship experience.Referring to the related national standards of cylinder test, this paper summarizes the test method of the cylinder and makes the overall plan of the high pressure cylinder rig. Then, the test bench hydraulic system is designed and the right model of the working station that used constant pressure is selected. This paper also designs a boost circuit and calculates the pressure-ratio of the pressure-cylinder. And then the boost circuit is simulated based on the AMESim. In the end of this part, this paper optimizes the key factors of control precision that influenced the test bench.This paper summarizes the loading control scheme that used electro-hydraulic proportional overflow valve through analyzing these three common loading ways. Then, it draws the total overall transfer function of the loading system through building the mathematical model of electro-hydraulic proportional loading system. Lastly, this paper conducts time and frequency domain analysis for loading system based on MATLAB and draws the step response and BODE diagrams of the system.This paper also summarizes the computer control system theory and designs the digital PID control program on the basis of the static and dynamic characteristics of the system. The algorithm of this digital PID control program uses a digital integral separation PID control algorithm. In the end of this part, it simulates the digital PID control algorithm on the basis of MATLAB / Simulink.This paper conducts the field test of high pressure cylinder test bench and record the test data, while the test data is fitted in MATALAB and compared with the theoretical curve. Then it can get that the loading system meet the design requirements. Lastly, this paper validates the rationality of the test system and hydraulic loading system and provides a reference for the design and development of the other experimental devices.