基于比例阀门的精密气压控制方法研究

Study on Precision Pneumatic Pressure Control Method Using Proportional Valves

对精密气压控制方法进行了研究,应用气动比例阀门作为压力产生的执行机构,采用模拟和数字PID双闭环反馈控制,采用硅压阻模拟传感器和数字石英谐振传感器的双传感器结构,对系统控制结构进行设计,实现了气体压力的精密控制,压力输出准确度为0.02%,控制稳定性达0.003%。系统压力产生速度快、没有压力过冲,控制精度高,稳定性好。该系统为压力参数的自动检定提供了精密压力基准源,可以实现压力表、压力变送器和压力传感器的自动检定校准。

An automatic precision pneumatic pressure control method is introduced, the control methods are analogy--numeric PID doub- le closed--loop feedback, two pneumatic proportional valves are used as parts of pressure control. A double pressure sensor structure with a normal Si--Pressure--Resistor pressure sensor as analogy control and a digital crystal pressure sensor as digital control has been developed. The gas pressure can be controlled precisely, the accuracy is up to 0.02%, and its control stability is about 0. 003%. The process of pressure generation is rapid, accurate and no visible overshot. It provides a standard source for pressure automatic verification, it can be used to automatically or semi-- automatically calibrate pressure gauges, pressure transducers and pressure sensors.