基于数字图像处理的液位测量系统的研究与实现

Measurement System of Liquid Level Based on Digital Image Processing

基础设备的数字化是智慧电厂发展的基本要求。为实现基地式液位仪表的远程监视与自动读数,提出了一种基于数字图像处理的液位测量系统。图像处理算法包括颜色阈值分割、改进的Canny边缘检测、模板匹配,并提出窗口搜索峰值检测算法,分别对采集图像进行仪表定位、液位分界面提取、数字识别和摄像头自标定,从而实现液位图像的数字化。同时,该测量系统具有自适应中值滤波、直方图分析和透视失真自矫正功能,增强了测量的抗干扰性和自适应性。经实验室试验,测量系统的有很好的准确性,能维持原有仪表的精度等级。

The digitalization of basic equipment is the basic requirement for the development of intelligent power plants. In orderto realize remote monitoring and automatic reading of base type liquid level meters,a liquid level measuring system based ondigital image processing is proposed. Image processing algorithms include color threshold segmentation,improved Canny edgedetection and template matching and window search peak detection,which is new proposed. Instrument location,level interfaceextraction,digital recognition and camera selfcalibration are respectively performed on the captured images,finally realizingthe digitization of liquid level image. At the same time,the system has the function of adaptive median filtering,histogramconcavity analysis and perspective distortion selfcorrection,improving its noise resistance and adaptive performance. Aslaboratory tested,the measurement system has good accuracy and can maintain the accuracy level of the original instrument.