Study Of Dynamic Characteristics On Hydraulic Cylinder Control System For Underground Mining Loader's Manipulator

A model for this article is domestic underground mining loader. Through establishing the mathematical model of hydraulic cylinder system of working device, the transfer function is obtained and the stability of hydraulic cylinder system is verified based on the drawing of the open-loop bode diagram. Building a three-dimensional model of mechanical structure for work device by Pro/Engineer, main parameters of mechanical part of hydraulic cylinder control system is obtained and an AMESim model of mechanical structure is established, then An AMESim model of hydraulic system is established. Through simulating cylinder control system by AMESim, draws the displacement response curves of hydraulic cylinder.The results study that the problems of cylinder control system are slow displacement response, large amount of overshoot and oscillation, long lag time, in the working condition of compound action. These problems can affect the safety, service life and work efficiency of the machine.According to the above problems, combining with of parameters the model and applying PID control strategy, the closed loop control system of hydraulic cylinder is established. Through simulating PID control system by AMESim, displacement response curves are obtained. The results study that displacement response significantly speeds up, overshoot and lag time significantly are reduced, except for in condition of large change loading. Analysis of the reason is that adaptability of PID controller which is difficult to cope with the large change of loading is bad.The paper comes up with the method of fuzzy PID control and fuzzy PID controller is designed, simulating the model of fuzzy PID controller with the co-simulation method of Matlab/Simulink and AMESim. The results study that in the operation condition of the hydraulic cylinder in large load change, the overshoot and time lag are significantly reduced, the work efficiency is improved. The fuzzy PID controller improves the adaptability and robustness of cylinder control system for underground mining loader.