一种压力传感器单故障实时诊断方法研究

Method Research of a kind of Pressure Sensor’s Real Time Single Fault Diagnosis

摘要:

研究对象为容式变极距型液位压力传感器,分析了传感器测量电路的工作原理与特性；故障诊断首先用压力变化率判断测量电路故障存在性；再得到额定输入信号下电路电桥输出信号和运算放大器输出这两个检测信号的表达式,各表达式均以电路相关元件为自变量,因不同元件发生数值漂移故障时,对检测信号的影响趋势各不相同,使得精确到元件的故障定位得以实现；确定故障位置后将正常元件值代入检测信号表达式联立方程组求解,以实现精确到元件的故障定值；仿真显示该故障诊断方法所求得故障值非常接近真实故障值。

Abstract:

The capacitor style and electrode distance variance liquid level pressure sensor is talked about.Analyze the operation principle and the features of the sensor’s measuring circuit. Fault diagnosis uses the change rate of the pressure to judge the existence of the measure circuit fault at first. Make the bridge output signal and the operational amplifier output signal as the two detection signals. Then two detection signals’ expressions in rated input are acquired.The expressions’ arguments are all circuit elements.Since different elements can influence the detection signals differently in their numerical drift fault severally, the fault location accurate to single element can be realized.Substitute the value of the normal elements value into the detection signals’ expressions to simultaneous and solve the equations.Thus realize the fault evaluation accurate to single element.The simulation shows the value of the fault diagnosis is very close to the true value.