改进中值递推算法在流阻仪测试信号滤波中的运用

Application of improved median recursion method in filter of flow resistance meter test signal

流阻测试仪器体积从大改进成小后,紧密型的布置使得电子元件相互干扰和设备内部气流波动较大,造成测试系统稳定性变差。通过对干扰原因的诊断,运用简单的滤波方法使测试失真度较大。根据上述问题,运用中值算法限阀有效值原理消除脉冲信号,递推平均算法消除流阻仪进气的周期性变化和真空泵振动干扰,由平均绝对误差和均方误差定义算法最优值,降低数据输入低通滤波后的失真度。实验结果表明,运用改进中值递推算法的测试系统有更好的稳定性,但测试系统响应速度较慢。改进中值递推算法能有效消除周期性、脉冲和抖动干扰信号,适用于对测试稳定性与测试精度要求高但测试实时性要求较低的静态测试系统。

After the size of the instrument to test the flow resistance is reduced from large to small,its tight arrangement leads to the signal interference of the electronic components and the airflow fluctuation of the equipment is large in the equipment.This phenomenon causes the stability of the test system to deteriorate.Through the diagnosis of interference causes,the simple filtering method makes the test accuracy poor.Through the summary of various problems.Firstly,the median algorithm is used to eliminate the pulse signal.Then the recursive averaging algorithm is used to eliminate the periodic variation of the intake system and the vibration interference of the vacuum pump.Furthermore,the mean absolute error and mean square error are used to define the optimal value of the algorithm.Finally,the data distortion before low-pass filter processing will be reduced.The experimental results show that the test system using the improved median recursion method has better stability,but its response speed is slow.The improved median recursion method can effectively eliminate the interference signals of periodicity,pulse and dither.The static testing system that it applies to has high requirements for testing stability and testing progress,but low requirements for real-time testing.