Vehicle-mounted manhole cover detection method based on arc-point combination

Abstract

The invention discloses a vehicle-mounted manhole cover detection method based on arc-point combination. The method comprises the following steps that images shot by an automobile data recorder are converted into grey-scale images, and an edge extraction algorithm and a thinning algorithm are used for contour extracting and thinning; according to connectivity and regional relationships among points, the contour is broken off from cross points, segmental arcs are classified according to concavity and convexity of each segmental arc, and linear segments and small segmental arcs are removed; candidate segmental arcs are divided into groups, arcs which meet quadrant constraint and central constraint are classified, and a central point position is determined by central point constraint; points are selected from segmental arcs in different quadrants and least square fit of an ellipse is carried out; false removal and screening are conducted on a fitted ellipse, and the position of a manhole cover is judged. According to the vehicle-mounted manhole cover detection method based on the arc-point combination, segmental arc processing is used as preprocessing of the point fitting, most of the irrelevant interference is removed at the complicated road background, the probability of invalid random sampling is excluded, and the detection speed of road surface manhole covers is improved.

Description

【Technical field】 [0001] The invention relates to a method for detecting manhole covers in the field of assisted driving, in particular to a vehicle-mounted manhole cover detection method based on arc-point combination. 【Background technique】 [0002] In recent years, incidents of injuries to people and vehicles caused by the loss of manhole covers on the road surface have occurred frequently, but the detection and research on manhole covers at home and abroad have not been in place in time. Most of the existing improvement measures focus on real-time supervision of smart devices installed on manhole covers, or Increase the frequency of inspections by increasing personnel input. The vehicle-mounted anti-collision warning system that is widely used at this stage can only detect and warn pedestrians and vehicles, but is powerless for manhole covers that are installed almost flush with the ground. For drivers, it is an urgent need for safe driving to grasp the condition of the...

AI Technical Summary

Problems solved by technology

The first three methods start from the point of view of point operation. When the background is single and the interference is less, the algorithm fitting speed is faster, but as the number of points in the image increases, the invalid sampling increases sharply, and the processing takes a long time; based on the arc The segment segmentation and aggregation method uses the arc segment as the basic unit of operation, which has strong noise resistance and fast processing speed, but the implementation process is cumbersome. Discreteness determines that it is impossible for us to obtain accurate tangent values, and the approximation of multiple tangents makes the fitting process prone to large errors

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