Research Of The Digital Variable Pump System Controlled By High-speed Switching Valve Based On Neural Net

Hydraulic pump is one of the most significant components in hydraulic system, and it’s also the heart of hydraulic control system, its performance will impact on the static and dynamic characteristics of actuating elements and the control feature of hydraulic system immediately. With the development of advanced technology, the request of the engineering application of hydraulic transmission to hydraulic element is getting higher and higher. The traditional hydraulic pump control system can’t realize the digital intelligent control, the response speed and dynamic property of the components are poor, and it is sensitive to oil pollution, so it can not meet the requirements of modern engineering applications.Digital intelligence is a very important developing direction and tendency of hydraulic controlling technology in the modern world, and in the era of rapid progress of computer, the development of hydraulic components have already shifted to digital from analog, and the development of traditional hydraulic control also towards to intelligent control constantly. It’s a new type digital hydraulic system which output flow of hydraulic pump are controlled by digital hydraulic control valve, and it has a strong anti-pollution, excellent reproducibility, convenience of connecting with computer, low price and many other advantages.A kind of piston pump digital variable system based on the combination of CMAC neural network and PID control is presented in this paper, which is mainly consisted of the neural network controller, the pressure and displacement sensor, the high-speed switching valve, the axial plunger pump and other components. The system’s dynamic and static characteristics of high-speed switching valve were improved by the intelligent controller of PWM signal, and the control of all parts of this system were optimized automatically and intelligently according to the requirements, so as to realize the intellectualized control of hydraulic digital pump control system.The research status and development of high-speed switching valve and control technology of digital variable pump, and the composition of digital pump control system were reviewed in this paper firstly. This paper designed a kind of controller based on neural net algorithm in order to improve the defects and shortages of existing hydraulic pump system, and the variable displacement mechanism of pump could be adjusted and changed as moving speed and position of the piston cylinder by controlling the PWM duty cycle of high-speed switching valve, and then change the pressure difference between two cavities piston cylinders, realize the control of output flow and pressure of axial piston pump. The controlling system was emulated by the software of MATLAB and SIMULINK, and the simulations reveal that the control effect and stability of this system can meet the requirement of working. The mathematical model of digital variable pump was built by software of AMESim, and the co-simulation was present with SIMULINK and AMESim, and the analysis showed that this system has good stability and dynamic property. A kind of intelligent microcomputer chip based on the control of CMAC neural network and traditional PID were eventually presented in order to realize the integration scheme of digital pump and controller, and the mechatronics integration of digital variable pump system.