Electro-hydraulic proportional control system of hydraulic machine

• 1、School of Automation Science and Electrical Engineering , Beihang University
• 2、School of Automation Science and Electrical Engineering , Beihang University, Beijing 100191

Abstract：Hydraulic machine is a pilot production equipment, it is used to suppress explosive forming in this project. In order to improve the quality of molding products, it requirs that the loading force, displacement and speed can be controlled and measured; Not only to maintain a constant load force, but also to maintain a constant speed of load displacement; And the load precision should achieve a test-machine level. In this paper, electro-hydraulic proportional technology is adopt to realize the constant load force control, the constant speed control and displacement control in the adjustment process. In the system, a telescopic hydraulic cylinder is used as actuator, electro-hydraulic proportional valve as signal transformation component, PLC and IPC as control core, and the working status of machine is monitored and controlled via the HMI interface. Integration and networking of monitoring and management of the machine is achieved through the industrial Ethernet. The mathematical model of the position closed-loop is established and the analysed by comparing the performance of the model before and after PID correction in this article. Conventional PID algorithm is adopt in the actual closed-loop, by adjusting the PID parameters online, the process control achieved a good result, the control system met the design requirments.

Keywords： Electro-hydraulic proportional technology hydraulic machine PLC HMI industrial process control