基于小波变换的外测设备动态精度评估方法

A Measurement Equipment Dynamic Precision Evaluating Method Based on Wavelet Transform

为了解决传统的变量差分法或最小二乘拟合残差方法评估外测设备动态精度引入模型误差问题,提出了基于小波变换的外测设备动态精度评估方法。对残差序列的小波基函数选择及系统误差和随机误差分离技术进行了理论分析,并应用某设备的残差序列数据实验验证,取得了基于小波变换和变量差分方法的残差信号系统误差与随机误差以及设备精度指标。结果表明:基于小波变换评估外测设备动态精度无模型误差,计算的设备精度指标符合设备测量特性,基于变量差分的评估方法将模型误差引入到设备综合误差上,导致设备误差变大,影响精度评定的准确性。通过对比分析,更加证明了基于小波变换的外测设备动态精度评估方法的科学、准确。

A measurement equipment dynamic precision evaluating method based on wavelet transform is presented to solve a model error resulted from traditional methods.Technique of separating system error and random error and choice of wavelet basis function are analyzed theoretically.System error and random error are obtained by methods based on wavelet transform and variable differential.The results show that there is no model error in this method which could accord with measurement equipment characteristic,but the variable differential method could produce model error which could degrade the measurement equipment accuracy.