Marine Object Detection And Tracking Of USV Based On Visual System

The ocean is main channel of world trade. There is a great of natural resource. It isalways the first security defence of one country as well. More and more attention has beenpaid to develop marine equipment and improve the ability of ocean exploitation andcontrolling by our country and many west countries. As a kind of surface unmanned vehicle,USV involves vehicle structure, hydromechanics, computer science, robotic vision, automaticcontrol and other areas. Therefore, the research on USV is significant in both theoretical andpractical aspects.Object detection and tracking of marine image sequences based on visual sensor ismainly discussed in this paper, aiming at a certain USV “XL-USV”. Effective informationsuch as sea line and object position can be obtained through image processing and it isnecessary for USV to prevent collision and carry out tasks autonomously. The detailedcontents are as following:(1) Give a brief overview to the development of USV and the applications status of USVbased on environment perception equipment in and out of the country. Summerize theresearch of marine image processing including sea line detection and objection detection andobject tracking technology.(2) Typical feature of marine image is analyzed. Image enhancing methods and imagesmoothing methods are studied combining with those features. A practic method is present torestore the demaged image with noise such as exposures and reflections.(3) The background characteristic of marine image sequences captured during USVmoving is analyzed. The form of sea line displayed in dynamic sence is summarized. Afeasible method is proposed to detect sea-line which is not only appropriate for sea-skybackground but also for offshore background. The problem of moving USV detecting the sealine adaptively is solved.(4) The form of object distribution in marine image sequences is analyzed. TraditionalMean-shift segmentation is improved for this special segmenting condition. Meanwhile, agradient information fusion method is used to locate objects in the light of embossment,which is a tool of Photoshop software. The problem of moving USV locating object quicklyand exactly is solved.(5) Surface object tracking methods is discussed. Classic tracking approach such as Mean-shift searching mode and Kalman filter prediction mode is employed in object trackingof marine images. Advantages of these two methods are taken into account and two frames ofprediction and searching modes is constructed to track objects. They release the problem oftracking velocity and tracking size.(6) The system architecture and environmental perception system of XL-USV isintroduced. The visual perception simulation platform of USV is built. Processing flow istested on the platform. The data communication between visual system and path-planning andcontrolling system is smooth. During sea test, the visual perception system is embedded in thereal USV to help it avoid obstacle and move autonomously. It is validated that the processingflow is robust and effective.