传递函数快速相关法的激光测速技术研究

激光技术测量是实现传送带、热轧钢板等运动物体测速的主要手段,为了改善测量精度和响应速度,提出系统传递相关分析测速技术。采用计算发射端和接收端之间两路信号的系统传递函数进行相关性分析的方法,进行了理论验证和实验分析,得到了相对误差小于0.1%的实验结果。结果表明,利用系统传递函数相关分析构建激光测速系统,代替解调电路,简化信号调理电路,可降低电路部分引起的不确定度;互功率谱函数法实现快速相关分析和频域求得系统传递函数,可提高系统响应速度;合理设置发射端间距,取样积分提高测量信噪比,降低环境引起的不确定度,测量不确定度小于0.2%。该研究对传送带速率的实时测量有一定指导意义。

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.