气动薄膜调节阀控制气体压力的建模与仿真

Modeling of Linear System for Air Pressure Control by Using Pneumatic Diaphram Valve

针对航空产品测试台中常见的一类控制对象,气动薄膜调节阀控制气体压力进行分析与建模;首先由气动薄膜调节阀的动态方程得到一个以静摩擦力为约束条件的含扰动的线性系统模型,然后在理想气体条件下讨论管道中流动气体压力的动态模型,以工程实际为基础提出系统静态解的假设,通过引入参数摄动,写出它的含摄动参数的线性方程;综合这两个系统,提出了一个含不确定性的线性系统模型,并证明这个系统在忽略不确定性时是能控并且能观的,对一个工程问题进行仿真分析表明,阀芯扰动是导致PI算法控制精度变差的重要原因,同时也说明建模结论具有工程上的实用性。

A pneumatic diaphram valve was depicted as a linear system model with disturbance when it satisfied the condition of static friction. A nonlinear differential equation expressed the pressure of ideal gas flow in a pipe. Based on engineering practice, the hypothesis of static solution of the equation was put forward. Considered the hypothesis and parameters perturbation, the pressure of ideal gas flow in a pipe was described as a linear system model with perturbation parameters. According to these models and satisfying given conditions, the plants of air pressure control by using pneumantic diaphram valve is described as a model of linear system containing uncertainty. The system is controllable and observable when ignoring the uncertainty. Using these conclusions, a simulated analysis of a engineering problem indicates that the consequence is of practical significance.