变形信号中突变点的检测

Singularity detection of deformation signal

变形监测获得的信号含有噪声、变形信号和突变信号(信号的奇异性).信号在突变处的小波变换模极大值不随尺度的增加而变化,而在白噪声处的模极大值随尺度的增加而减小.根据这一规律,分析了变形监测信号突变点在卷积型小波变换下的特征及小波函数的选取,给出了用小波变换模极大值进行突变点定位、奇异度检测,根据突变点的奇异程度确定突变的的强度,检测变形信号的突变点.

The observed signal of deformation monitoring includes noise, deformation signal and abrupt changing signal （singularity signal）. Wavelet transform modulus maximum at sin- gular points of signal keeps conctant with the increased scale but the value at white noise points will decrease. Based on the different behaviors between the signal and the noise, how to choose wavelet basis and the feature of singularity point being transformed by convolution wavelet are analyzed. The method for positioning the transient point and detecting the degree of singularity, and, the method for determing the intensity of abrupt change are povided in the paper.