Circuit Design And Simulation Of Proportional Valve Controller Based On CAN-BUS

Electrohydraulic proportional control technology has developed rapidly in recent 30 years. Proportional solenoid responds to input voltage signal, makes spool motion, then changes aera of orifice and finally let the flow rate is proportional to the input control voltage. Among electrohydraulic proportional control technology, proportion controller is one of the main research fields, which is used to support current and adjusted to proportion flow valve using open-loop or closed-loop control. So far, At home and abroad, no matter analogue or digital proportion controller, whose price is expensive. Based on the present condition, and according to extensive research for function and characteristics of proportion controller at home and abroad, this paper designs a high performance and high reliability digital proportion controller based on LPC2290 microprocessor.This paper firstly analyzes the structure and characteristics of proportional flow valve, then the mathematical model of which is gived. Next LPC2290 microprocessor is selected as the core chip, PWM power amplifier circuit, valve level measurement circuit, power transformation circuit, A/D and D/A conversion circuit, UART serial interface communication circuit and CAN-BUS interface circuit is expanded. This paper uses Multisim software to simulate the power module, PWM power amplifier module and valve level measurement module. The results show that the designed circuit can meet the design requirements.The software design of digital proportional controller is based onμc/OS-ⅡReal-time operating system. The software is divided to data acquisition and filtering module, A/D conversion module, Serial interface communication module and CAN-BUS communication module. This paper has gived their task and design flow chart to facilitate the subsequent code writing work.