基于图像处理技术的输电线路异物检测研究

发布时间：2018-06-02 18:24

本文选题：关键帧提取 + 背景运动补偿　；参考：《东北电力大学》2017年硕士论文

【摘要】：我国经济正在飞速发展,国内对于电力的需求也急速增长,高压线是电力供应的保障,但是高压线常年暴露于野外环境,常有异物悬挂在输电线路上,导致坠线的危害,严重影响居民的正常生活和企业的安全生产。传统人工巡线的方式耗时耗力,并且受到地理环境和气候变化的严重制约;然而飞行器巡线可以在远距离和复杂环境中准确地进行电力安全检测,该技术集飞行器控制和图像处理技术为一体,使用机载摄像头收集航拍视频,并通过图像技术分析航拍视频,从而检测高压线的运行状态,飞行器航拍方式能够自动检测线路运行状态,同时有效提高异物检测的准确性。本文针对输电线路悬挂异物的问题,采用目标检测技术分析输电线路的航拍视频,达到自动标注并准确跟踪异物的目的。首先提取输电线路航拍视频的关键帧,依据视频中背景信息复杂但是变化缓慢的特点,采用渐变镜头边缘检测算法提取关键帧,通过预估漂移区域法改进双阈值镜头检测算法,达到保留视频中关键信息的目的;其次在背景补偿方面,使用投影法估计背景的运动量,采用预测器来改进投影法,达到快速并准确估计背景运动量的目的,从而弥补相邻帧间背景的偏差量;再次使用三帧差法检测异物,使用二维交叉熵法改进阈值分割技术,并通过概率密度函数精简异物区域,利用八连通区域法标注异物区域,达到准确检测并标注异物区域的目的;最终通过提取ORB特征点跟踪输电线路异物,以参考帧中异物区域为基础,使用Mean-Shift算子预估当前帧中异物区域,提取两帧中异物区域的ORB特征点,通过PROMATCH算子改进汉明距离,达到准确跟踪输电线路异物的目的。本文采用预估漂移区域和双阈值法结合来检测关键帧,能够有效剔除视频中冗余帧,在保证所选帧中包含主要内容的同时,减少系统计算量;在背景运动补偿中采用最小二乘预测器,可以改变灰度投影法逐帧搜索的弊端,提高背景运动量的计算效率;在运动目标检测方面使用二维交叉熵阈值法,能够增加异物区域的完整度,并且减少非异物区域的影响;在异物跟踪中采用ORB算子,有效缩短特征点间匹配时间。由实验分析可知,本文可实现异物的检测、跟踪操作。
[Abstract]:China's economy is developing rapidly, and the domestic demand for electricity is also growing rapidly. The high-voltage line is the guarantee of power supply, but the high-voltage line is exposed to the field environment all the year round, and foreign bodies are often hung on the transmission line, which results in the harm of falling line. Seriously affect the normal life of residents and safe production of enterprises. The traditional manual inspection method is time-consuming and labor-intensive, and is severely restricted by geographical environment and climate change. However, aircraft patrol can accurately detect electric power security in long distance and complex environment. The technology integrates the aircraft control and image processing technology, uses the airborne camera to collect aerial video, and analyzes the aerial video through the image technology, so as to detect the running state of the high-voltage line. Aerial photography can automatically detect the running state of the line and improve the accuracy of foreign body detection. In this paper, aiming at the problem of transmission line hanging foreign body, the target detection technology is used to analyze the aerial video of transmission line, and the purpose of automatic marking and accurate tracking of foreign body is achieved. Firstly, the key frame of transmission line aerial video is extracted. According to the characteristics of complex background information but slow change in the video, the edge detection algorithm of gradient shot is used to extract the key frame, and the dual threshold shot detection algorithm is improved by predictive drift region method. Secondly, in the aspect of background compensation, the projective method is used to estimate the motion of the background, and the projector is used to improve the projection method, so that the background motion can be estimated quickly and accurately. In order to make up for the deviation between adjacent frames, three frame difference method is used to detect foreign body again, two dimensional cross entropy method is used to improve threshold segmentation technology, and the probability density function is used to simplify foreign body region, and eight connected region method is used to mark foreign body region. Finally, by extracting the ORB feature points to track the foreign bodies in the transmission line, and based on the foreign body region in the reference frame, the foreign body region in the current frame is estimated by using the Mean-Shift operator. The ORB feature points of the foreign body region in the two frames are extracted, and the hamming distance is improved by the PROMATCH operator to track the foreign body in the transmission line accurately. In this paper, the combination of predictive drift region and double threshold method is used to detect the key frames, which can effectively eliminate the redundant frames in the video, while ensuring that the selected frames contain the main contents while reducing the system computation. In background motion compensation, the least square predictor can change the disadvantage of the gray projection method to search frame by frame, and improve the computational efficiency of background motion, and the two-dimensional cross entropy threshold method is used in moving object detection. It can increase the integrity of the foreign body region and reduce the influence of the non-foreign body region, and the ORB operator can effectively shorten the matching time between the feature points in the foreign body tracking. According to the experimental analysis, the detection and tracking of foreign bodies can be realized in this paper.
【学位授予单位】：东北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP391.41;TM755

【参考文献】