Design On Digital Controller Of Electro-hydraulic Proportional Relief Valve

Electro-hydraulic proportional relief valve is an important pressure control component in the hydraulic system. With the growing breadth of electro-hydraulic proportional technical applications. It puts forward higher requirements to valve control system. efficient, intelligent, network technology has become the developmenttrend.However,the starting of field is late in domestic. The technology is urgent to promote and improve. Based on this, we designed a digital controller of electro-hydraulic proportional relief valve, designed to improve control effect and improve the cost-efficacy, and lay the foundation for the engineering practice.Firstly, the structure of the pilot proportional relief valve was analyzed, and to understand how it works in the article.then, the mathematical model was established on the valve block. Finally, the static and dynamic simulation to each module and the whole system were realized in Matlab/Simulink. Comprehensived current situation of domestic and foreign literatures and market, a needs analysis is conducted to the digital controller, and the overall scheme of digital controller of proportional relief valve was designed.Combined with control features of proportional relief valve and requirements of industrial control. The hardware circuit of the controller was designed included digital control roof and analog drive backplane. Digital board based on AT91R40008processor, building control system, analog board supply power module, serial port module, acquisition module, driving module, A/D conversion module, feedback regulation module etc.The TLE7242G control chip was adopted in driver module. simplified the peripheral hardware design.High frequency PWM superposition of independent flutter and current closed-loop control mode was achieved. At the same time,the Nucleus PLUS operating system was transplanted on the AT91R40008processor, the overall planning of the system was made using the idea of modularization.Meanwhile, The application program of control system is compiled.The main module includes monitoring module, data acquisition module, SPI communication module, serial communication module, signal processing module, PID control module.It built a experimental platform to test the proportional relief valve and its controller based on Rexroth TS-DS4. The testing of the system was made, at the same time The digital controller of independent design was debugged in the experimental stage, System debugging experimental verification, the controller is able to achieve the basic control functions to stabilize the work, Control effect is better.