Research on Double-axis Electro-hydraulic Proportional Loading Control System with Intelligent Dual-PID for Membrane Materials

摘要

Membrane material is one kind of special material with nonlinear feature. Its mechanical characteristic is so complicated and anisotropic that the performance is quite different between the single-axis loading and the double-axis loading. So the experimental results with the single-axis loading will usually lead to unexpected results. With the development and widely application of membrane materials, the double-axis property experiment plays an increasingly important role all around the world. Considering the situation mentioned above, a double-axis electro-hydraulic proportional loading control system with intelligent dual-PID is proposed in this paper, which controls four cylinders respectively with the help of four electro-hydraulic proportional directional valves. The cylinders provide pulling force to membrane material directly under the control of electro-hydraulic proportional directional valves. And the opening of each electro-hydraulic proportional directional valve is adjusted by intelligent dual-PID according to the pulling force as well as the position of cylinder. The simulation model of double-axis electro-hydraulic proportional loading control system with intelligent dual-PID is built and an intelligent dual-PID algorithm is also designed in this paper. The simulation and experiments show that the double-axis electro-hydraulic proportional loading control system with intelligent dual-PID can fulfill the loading precision requirement of double-axis membrane material experiment.