共查询到19条相似文献,搜索用时 171 毫秒
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水下连接器的对接作业是水下工程作业的重要环节,针对目前依靠摄像机传回视频进行作业过程中存在的操作难度大、依赖操作员经验的问题,设计基于双目视觉的水下连接器位姿测量方法。该方法首先根据水下连接器的颜色特征确定检测范围,之后在检测范围中以水下连接器为模板进行初步定位,然后根据水下连接器端面的成像特点检测椭圆特征,并进行双目匹配获得相关三维点坐标,最后计算得出水下连接器的位姿。实验表明,该方法位置测量平均误差1.3%,姿态测量平均误差3.5°,可以较好地为水下连接器对接作业提供参考。 相似文献
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声纳浮标网络可用于对潜艇等水下目标进行定位。针对声纳浮标节点的特性,提出一种新的时间加权质心算法。新的时间加权质心算法将各个节点探测的信号强度反映到节点发送探测信息的等待时间中,利用等待时间的长短对各节点位置进行加权,因此权重体现了各节点到目标的距离,提高了目标定位精度,而通信量与一般质心算法相同。仿真结果验证了算法的有效性。 相似文献
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为了解决以双目视觉为主导的自主式水下机器人(AUV)对接回收过程中出现的单一摄像机遭受遮挡或因水下环境特殊而发生故障的问题,提出一种基于单双目切换的AUV视觉定位方法。该方法通过自适应阈值法区分图像中的光源与背景,通过中心加权质心检测法提取光源中心,并以光源中心点数量为判定条件选取单目或双目视觉定位,添加水体折射参数提高定位精度。试验结果显示,采用该方法的定位耗时相比以往减少约70%,定位结果输出稳定,对接精度在允许范围内。该方法在AUV回收对接过程中通过牺牲部分定位精度来提高对接的实时性和鲁棒性,保障AUV成功对接回收。 相似文献
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自主式水下机器人(AUV)具有自主导航、自主避碰和自主作业能力,光视觉信息获取与处理算法是AUV进行水下作业的重要内容和关键技术。本文着重叙述水下三维目标信息的获取过程和图象常用算法,最后给出试验结果,以说明研究工作的有效性和成果的实用性。 相似文献
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WU Xiao-guang SHI Zhong-kun 《船舶与海洋工程学报》2006,5(2):36-41
1Introduction Sonarself noiseisakeyfactorinfluencingthehiding capabilityofanunderwatervehicleanddetectioncapa bilityofsonar.Decreasingsonarself noisehasimpor tanteffectonenhancingtheprobabilityofsonardetec tionandbattleeffectivenessofunderwatervehicle.An … 相似文献
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Toshihiro Maki Hayato Mizushima Tamaki Ura Takashi Sakamaki Masao Yanagisawa 《Journal of Marine Science and Technology》2012,17(3):330-339
Underwater jacket structures or support legs of on-water platforms, such as ports and oil rigs, need to be periodically inspected for maintenance, environmental monitoring, and security reasons. Autonomous underwater vehicles (AUVs) can potentially make these tasks more inexpensive and reliable compared to conventional methods that involve the use of divers and remotely operated vehicles. This paper proposes a robust and practical self-localization method for an underwater vehicle navigating around jacket structures, where the performance of conventional acoustic positioning suffers from multipath degradation. The key idea is to stochastically update the vehicle??s horizontal position and heading relative to the structures using two types of perceptional sensors, sonar and camera, assuming that the configuration of the structure is known. The performance of the method was verified with tank experiments using a jacket mock-up and the AUV Tri-Dog 1. 相似文献
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The effective method of the recognition of underwater complex objects in sonar image is to segment sonar image into target, shadow and sea-bottom reverberation regions and then extract the edge of the object. Because of the time-varying and space-varying characters of underwater acoustics environment, the sonar images have poor quality and serious speckle noise, so traditional image segmentation is unable to achieve precise segmentation. In the paper, the image segmentation process based on MRF (Markov random field) model is studied, and a practical method of estimating model parameters is proposed. Through analyzing the impact of chosen model parameters, a sonar imagery segmentation algorithm based on fixed parameters' MRF model is proposed. Both of the segmentation effect and the low computing load are gained. By applying the algorithm to the synthesized texture image and actual side-scan sonar image, the algorithm can be achieved with precise segmentation result. 相似文献
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水下声呐图像目标检测问题是一项重要而困难的工作,采用滑动窗计算图像中各像素点处邻域像素灰度的统计量,利用最大熵图像分割算法确定检测阈值,并利用均值、标准差、偏态和峰度等统计量对算法进行了仿真验证,对声呐图像中的目标回波区和阴影区域均可实现较好的检测效果。结果表明,该方法具有原理简单、运算效率高、实时性好等特点,具有较强的工程应用价值。 相似文献