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计算机工程 ›› 2024, Vol. 50 ›› Issue (2): 113-121. doi: 10.19678/j.issn.1000-3428.0067238

• 人工智能与模式识别 • 上一篇    下一篇

基于全景视觉的无人船水面障碍物检测方法

周金涛, 高迪驹*(), 刘志全   

  1. 上海海事大学航运技术与控制工程交通运输行业重点实验室, 上海 201306
  • 收稿日期:2023-03-22 出版日期:2024-02-15 发布日期:2023-07-10
  • 通讯作者: 高迪驹
  • 基金资助:
    国家自然科学基金(52001197)

Detection Method of Water-Surface Obstacles for Unmanned Ships Based on Panoramic Vision

Jintao ZHOU, Diju GAO*(), Zhiquan LIU   

  1. Key Laboratory of Transport Industry of Marine Technology and Control Engineering, Shanghai Maritime University, Shanghai 201306, China
  • Received:2023-03-22 Online:2024-02-15 Published:2023-07-10
  • Contact: Diju GAO

摘要:

无人船航行时水面障碍物检测因视角不足,导致漏检或误检,同时为满足无人船安全正常作业的需求,提出基于全景视觉的无人船水面障碍物目标检测方法。与传统的单目和双目视觉相比,全景视觉具有水平方向大视场监控的优点。基于多目全景视觉系统获得待拼接图像,在加速稳健特征(SURF)算法的基础上进行图像配准,引入k维树来构建数据索引,实现搜索空间级分类并进行快速匹配。通过M估计样本一致算法对匹配点进行优化,剔除误匹配点。对于图像融合中重叠区域出现的拼接缝隙或重影问题,设计一种基于圆弧函数的加权融合算法。提出改进的水面障碍物目标检测模型DS-YOLOv5s,将拼接好的全景图像作为训练好的模型作为输入,从而检测目标障碍物。实验结果表明,改进后的SURF算法与SURF算法相比特征点的匹配正确率提高11.47个百分点,在匹配时间上比SURF、RANSAC算法缩短5.83 s,DS-YOLOv5s模型的mAP@0.5达到95.7%,检测速度为51帧/s,符合实时目标检测标准。

关键词: 全景视觉, 图像拼接, 无人船, 改进YOLOv5, 目标检测

Abstract:

During the navigation of an unmanned ship, an inadequate perspective may cause obstacles on the water-surface to be missed.To enable the safe and normal operation of unmanned ships, this study proposes a panoramic vision-based method for the detection of water-surface obstacles.Panoramic vision is employed because it has the advantage of horizontal large-field monitoring, in contrast to traditional monocular and binocular vision. In the proposed approach, a multi-camera panoramic vision system acquires an image to be stitched.The Speeded-Up Robust Feature(SURF) algorithm then performs image registration. A k-dimensional tree constructs a data index, facilitating search-space level classification and fast matching.The M-estimation-based sample consensus algorithm optimizes the matching points and eliminates the mismatched points.A specifically designed arc function-based weighted fusion algorithm stitches the gaps and overcomes ghosting in the overlapping areas during image fusion. Finally, this study proposes an improved water-surface obstacle target detection model DS-YOLOv5s. This model takes the stitched panoramic image as input to detect target obstacles. In experiment, the improved SURF algorithm improved the feature-point matching accuracy by 11.47 percentage points compared to the SURF algorithm, and shorten the matching time by 5.83 seconds compared to the SURF, RANSAC algorithm. The DS-YOLOv5s model mAP@0.5 reached 95.7%, with a detection speed of 51 frames/s, conforming to real-time object detection standards.

Key words: panoramic vision, image stitching, unmanned ship, improved YOLOv5, target detection