Research on Speed Measurement Signal Denoising Processing of Laser Doppler Vibrometer

Speed is an important parameter to reflect the quality of products and equipment, and it plays an important role to monitor and diagnose its operating status by measuring speed. The laser Doppler vibrometer measures the speed with the advantages of non-contact measurement, high sensitivity, small non-linear error and fast dynamic response, and can measure motor speed more accurately. However, the speed data during the measurement process contains a lot of noise, so the measurement data must be denoised. This paper introduces the principle of measuring motor speed with a surface laser Doppler vibrometer, and builts the speed measurement experimental system. The improved wavelet basis denoising threshold algorithm is designed, and the speed measurement data are processed by the improved wavelet basis denoising threshold algorithm and the Kalman filtering algorithm, and the measurement data noise is filtered out, the measurement accuracy is improved. The results show that the average square root value after Kalman filter is closer to the motor rated speed value, the variance is small, the relative error is small, and the denoising effect is better.