面向障碍速度不确定性的无人艇动态避碰  

Dynamic collision avoidance for unmanned surface vessels under the uncertainty of obstacle velocity

作　　者：瞿栋[1] 彭艳[1] 蒲华燕 罗均[1] 黄承义[2] 柯俊[1] QU Dong;PENG Yan;PU Huayan;LUO Jun;HUANG Chengyi;KE Jun(School of Mechatronic Engineering and Automation,Shanghai University,Shanghai 200444,China;North Sea Engineering Survey and Research Institute,State Oceanic Administration,Qingdao 266061,Shandong,China)

机构地区：[1]上海大学机电工程与自动化学院,上海200444 [2]国家海洋局北海海洋工程勘察研究院,山东青岛266061

出　　处：《上海大学学报（自然科学版）》2019年第5期655-667,共13页Journal of Shanghai University:Natural Science Edition

基　　金：国家重点研发计划资助项目(2017YFC0806700);国家自然科学基金资助项目(61673254);上海市科研计划资助项目(17DZ1205001)

摘　　要：避碰稳定性直接关乎无人艇航行安全,传感器对障碍速度观测的不确定性会导致避碰策略出现跳动,严重降低避碰稳定性.提出不确定性条件下的速度障碍(uncertain velocityobstacle, UVO)算法,在碰撞风险评估中采用自适应阈值的最近会遇点(closest point ofapproach, CPA)法,基于国际海事避碰规则(International Regulations for Preventing Collisions at Sea,COLREGS)建立边界缓冲区,从宏观上提升避碰过程的稳定性.为了减少无人艇避碰角度的变化次数,在无人艇的速度空间中对不确定性条件下的速度障碍(velocity obstacle,VO)区进行建模,并采用梯度下降法在代价空间进行局部寻优,从微观上提升避碰策略的稳定性.在仿真平台下进行UVO算法和VO算法的对比实验,结果表明UVO 算法的避碰策略跳动次数、避碰成功率和最近会遇距离3项指标均优于VO算法.在实艇海试中进行了对遇、交叉、追越等典型会遇场景的避碰实验,无人艇均能安全避过运动目标.实验结果证明了UVO算法具有较好稳定性和安全性.The stability of collision avoidance is directly relate to the safety of unmanned surface vehicle (USV). However, the uncertainty of perception about the velocity of moving obstacles seriously undermine the stability of collision avoidance. Thus, an uncertain velocity obstacle (UVO) method is proposed to solve this problem. In order to improve the stability of collision avoidance at the macro level, an adaptive threshold-based closest point of approach (CPA) is adopted to assess collision risk while a boundary buffer is used to calculate the type of International Regulations for Preventing Collisions at Sea (COLREGS). To prevent changes in collision avoidance strategy, the UVO is modeled in velocity space of the USV, and a gradient descent method is used to determine local optimization of the cost function. Contrast experiments in simulation platform between UVO and VO indicate that the UVO has better performance on three indicators: strategy changes, success rate, and safe distance. Typical encounters such as head-on, crossing, and overtaking are conducted in sea trials. The USV successfully avoids each moving obstacle in the experiment. The results demonstrate the stability and safety of the UVO method.

关 键 词：无人艇 动态避碰 速度不确定性 速度障碍 碰撞风险评估 

分 类 号：TP242.6[自动化与计算机技术—检测技术与自动化装置]