基于光电传感技术的薄层水流流速测量系统构建与试验

为减小染色法测量坡面水流流速的误差,提高染色法测量准确度,根据染色示踪剂在水中扩散引起颜色发生变化的特性,结合漫反射型模拟量光电颜色传感器和数据采集卡采集信号,通过小波变换对信号进行去噪,研发一种基于光电传感技术的薄层水流流速测量系统。以流量法为参照,确定该系统传感器最优数据采集距离为0.6～0.8 m;传感器数据采集距离为0.7 m时,该系统测量数据最小相对误差仅为0.48%,变异系数15%。相比染色法,该系统与流量法拟合的决定系数在0.90以上,大于染色法的决定系数0.75。表明薄层水流流速测量系统优于染色法,可以用坡面薄层水流试验研究中。

Construction and Experiment of Shallow Flow Velocity Measurement System Based on Photoelectric Sensor Technology

In order to reduce the staining method of slope flow velocity measurement error, improve the dyeing method of measurement accuracy, according to the characteristics of color change caused by the diffusion of dye tracer in water, a shallow water flow velocity measurement system based on photoelectric sensor technology was developed by combining diffuse reflection analog photoelectric color sensor and data acquisition card to collect signals, and wavelet transform was used to denoise the signal. Taking the discharge method as a reference, the optimal data acquisition distance of the sensor of the system was determined to be 0.6~0.8 m. When the sensor data acquisition distance was 0.7 m, the minimum relative error of the measured data of the system was only 0.48%, and the coefficient of variation was less than 15%. Compared with the dye tracing technique, the fitting coefficient of the system and the discharge method was more than 0.90, which is greater than the dye tracing technique''s coefficient of 0.75. The results show that the measuring system is superior to the dye tracing technique and can be used in the experimental study of shallow overland flows.