Research of laser velocity measurement technology based on fast cross-correlation method with transfer function

Laser measurement was the main method for velocity measurement of the moving objects such as conveyor belt and hot rolled steel plate. In order to improve measurement accuracy and response speed, system transfer correlation analysis velocity measurement technology was proposed. System transfer function of two signals between transmitter and receiver was calculated. Theoretical verification and experimental analysis were carried out by correlation analysis. The results show that, relative error is less than 0.1%. Laser velocity measurement system is constructed by correlation analysis of system transfer function instead of demodulation circuit to simplify signal conditioning circuit and reduce the uncertainty caused by circuit part. Fast correlation analysis is realized by cross-power spectral function method and transfer function of the system is obtained in frequency domain to improve the response speed of the system. By reasonably setting the distance between transmitters, sampling integration improves the measurement signal-to-noise ratio and reduces environmental uncertainty. The uncertainty of measurement is less than 0.2%. This research has certain guiding significance for the real-time measurement of conveyor belt speed.