基于机器视觉的装载机装卸动作时间测量系统

Loading and unloading action time measurement system of loader based on machine vision

针对目前测量装载机装卸动作时间过程中存在的测量效率低、误差大的问题,设计了一种基于机器视觉的装载机装卸动作时间测量系统。首先对采集到的装载机装卸运动视频序列图像进行图像预处理,再利用形状模板匹配结合运动预测在图像中找寻铲斗并获取其质心像素点坐标,建立装载机铲斗运动轨迹,然后定位装卸动作的4个运动阶段的轨迹分界点确定每个阶段各自的起止帧及其帧数,最后利用帧率将帧数换算成时间进行计算,实现装载机装卸动作时间的自动测量。实验结果表明,该系统对装载机装卸动作时间测量偏差小于0.5 s,测量结果稳定有效;并且通过运动预测对铲斗位置进行估计的方法,使形状模板匹配的匹配耗时缩短了16.45%。

Aiming at the problems of low measuring efficiency and large error in the current process of measuring loader loading and unloading action time,a measuring system of loader loading and unloading action time based on machine vision is designed.Firstly,the video image sequence of loader loading and unloading motion is preprocessed,and then the shape template matching and motion prediction are used to find the position of the bucket in the image and obtain the center of mass pixel coordinates of the bucket.The motion track of loader bucket is established by using the pixel coordinates of the bucket's center of mass.Then,the trajectory dividing points of the four loading and unloading motion stages are located,and the starting and ending frames and their frame numbers of the four motion stages are determined by using the trajectory dividing points.Finally,the frame number of the start frame and the end frame is converted into time by frame rate for calculation,so as to realize the automatic measurement of the loading and unloading action time of the loader.The experimental results show that the measured deviations of the measuring system for the loading and unloading action time of the loader is less than 0.5 s,the measuring results is stable and effective.On the other hand,because motion prediction is used to estimate the bucket position,the time consumption for shape template matching is reduced by 16.45%.