电液比例阀用控制器的设计

Design of Controller Used by Electro-Hydraulic Proportional Valve

在分析电液比例阀静态特性的基础上,设计了控制器的硬件电路,提出了一种利用PWM信号产生阶跃信号的新方法,通过PWM信号占空比的阶梯式变化解决了被控系统压力或速度的无冲击过渡,有利于简化硬件电路。同时,给比例电磁铁施加一定的颤振信号和先导电流可以改善阀心的动态性能并减小流量死区。根据晶体管参数随温度变化会引起温度漂移的缺点,对传统的功率放大电路进行了改进,在一定程度上抑制了温度漂移。经过在线仿真和实物实验,验证了控制器的硬件电路设计的有效性和正确性,提高了其精度和稳定性。

Based on analysis of static characteristic of electro-hydraulic proportional valve, the article designs hardware circuit of the controller, proposes a new method of generating step signal using PWM .By changing gradually duty cycle of PWM signal,it solves no-impact transition of the controlled system＇s pressure or speed and simplifies hardware circuit. Meanwhile, the dynamic characteristics of proportional valve can be improved by superposing certain dithers to the coil of proportional valve ,and flow dead zone can be reduced by exerting certain initial current. According to the disadvantage of temperature drift that can be caused by the transistor parameters＇s change,it improves the traditional power amplifier circuit, to a certain extent, suppress the temperature drift. By on-line simulation and material object＇s test, it verifies its validity and correctness of hardware circuit design of the controller, and improves its accuracy and stability.