融合激光扫描与机器视觉的煤流量测量研究

Coal flow measurement based on laser scanning and machine vision

煤矿主运输系统煤流量监测是煤矿运输智能化的重要环节,可实现运输系统节能降耗,提高矿井原煤运输的效率和安全性。文章研究了融合激光扫描与机器视觉的输送带煤流量测量方法,与传统接触式测量相比可快速精准地获得煤流的截面全轮廓信息。分析了像素点在图像平面与物理空间内对应点的几何映射关系,通过相机标定实验获得图像系统的转换系数,通过数字图像滤波增强等手段提高采集图像的清晰度,采用图像分割算法对激光光斑条纹的有效区域进行分割,利用图像膨胀操作算法修复激光光斑图像中的断点,进而拟合出光斑区域的边缘骨架轮廓,计算提取激光光斑条纹中心线。采用黎曼和法计算每一幅图像中煤流表面上的激光光斑变形轮廓面积,根据实验系统中激光器的投射角度反求带式输送机上方煤流截面积,最终结合带式输送机速度和图像采集帧率等参数计算获得煤流量信息。

Coal flow monitoring in the main coal transportation system is an important part in the intelligent transportation of coal mines, which can bring down energy consumption, and enhance the efficiency and safety of the coal transportation system. A coal flow measurement method is proposed for belt conveyor based on laser scanning and machine vision. Compared with traditional contact measurement, it can quickly and accurately obtain the full cross-sectional profile information of coal flow. The geometrical mapping relationship between pixel points in the image plane and the corresponding points in the physical space is studied. The conversion coefficient of the image system is obtained through camera calibration experiments, and the definition of the captured image is improved by means of digital image filtering and enhancement. The image segmentation algorithm is used to segment the effective area of the laser spot fringe. The breakpoint in the laser spot image is repaired by the image expansion operation algorithm, then the edge skeleton contour of the spot area is fitted, and the center line of the laser spot fringe is calculated and extracted. The Riemann sum method is used to calculate the deformed contour area of the laser spot on the surface of the coal flow in each image, and the cross-sectional area of the coal flow above the belt conveyor is reversed according to the projection angle of the laser in the experimental system, and finally, the coal flow information is calculated and obtained combining with parameters such as belt speed and image acquisition frame rate.