基于霍夫变换及相似度检测的圆形表计检测方法

Circular meter detection method based on Hough and similarity detection

变电站巡检机器人沿巡检道路行走进行设备巡检,停在预定的监控位置,调用云台预置位将监测仪器对准被监测设备,可见光检测仪器通过光学变焦获取比例适当的清晰图片。由于机器人导航定位精度、行进姿态偏差和云台预置位定位精度等误差的综合影响,导致每次巡检时同一观测目标的成像位置在整幅图像视野中的位置有较大偏差。霍夫圆检测作为常用的圆形检测方法可以很好地检测图像中的圆形,但是搜索区域、搜索半径等参数设置需要人为反复试验才能取得良好的检测效果,因此不适合于背景复杂且圆形大小未知的变电站图像。文章将霍夫圆检测和感知哈希相似度算法相结合,从霍夫圆检测结果当中,筛选出与基准图圆形表相似的现场圆形表计,定位出圆形表计所在位置,从而计算出圆形表与其在基准图的位置偏差,通过云台扭转实现表计二次对准。

Substation inspection robot walks along the inspection road to carry out equipment inspection,stops at the scheduled monitoring position,calls the PTZ preset position to align the monitoring instrument with the monitored equipment,and the visible light detection instrument obtains a clear picture with appropriate proportion through optical zoom.Due to the combined effects of robot navigation positioning accuracy,travel attitude deviation and PTZ preset position accuracy,the position of the same observation target at each inspection has a large deviation in the position of the entire image field of view.Hough circle detection,as a common method of circle detection,can detect the circle in the image very well.However,in order to achieve good detection results,the parameters such as search area and search radius must be a value obtained by many human experiments,so it is not suitable for images in transformer substation with complex background and unknown circle size.In this paper,Hough circle detection and perceptual Hash similarity algorithm are combined.From many results of Hough circle detection,the target meter similar to the circular meter in the reference image is selected,and its location is obtained.Then the position deviations between the circular meter and the one in reference image are calculated,and the second alignment of the meter is realized by turning the platform.