During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive...During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive distance)to a moving target as quickly as possible,resulting in the extended minimum-time intercept problem(EMTIP).Existing research has primarily focused on the zero-distance intercept problem,MTIP,establishing the necessary or sufficient conditions for MTIP optimality,and utilizing analytic algorithms,such as root-finding algorithms,to calculate the optimal solutions.However,these approaches depend heavily on the properties of the analytic algorithm,making them inapplicable when problem settings change,such as in the case of a positive effective range or complicated target motions outside uniform rectilinear motion.In this study,an approach employing a high-accuracy and quality-guaranteed mixed-integer piecewise-linear program(QG-PWL)is proposed for the EMTIP.This program can accommodate different effective interception ranges and complicated target motions(variable velocity or complicated trajectories).The high accuracy and quality guarantees of QG-PWL originate from elegant strategies such as piecewise linearization and other developed operation strategies.The approximate error in the intercept path length is proved to be bounded to h^(2)/(4√2),where h is the piecewise length.展开更多
面对多障碍、大尺寸障碍、狭窄通道等特殊环境下的USV路径规划问题,快速扩展随机树算法(rapidly-exploring random trees,RRT)存在采样基数大、规划成功率低、规划路径曲折等缺点。基于双延迟深度确定性策略梯度(twin delayed deep dete...面对多障碍、大尺寸障碍、狭窄通道等特殊环境下的USV路径规划问题,快速扩展随机树算法(rapidly-exploring random trees,RRT)存在采样基数大、规划成功率低、规划路径曲折等缺点。基于双延迟深度确定性策略梯度(twin delayed deep deterministic policy gradient,TD3)提出一种全局路径规划算法(TD3-RRT)。结合RRT算法与深度强化学习建立USV路径搜索模型,利用前视探测感知环境以自适应调整扩展步长,通过策略网络输出路径搜索方向,解决RRT算法扩展盲目的问题;改进后见经验回放策略,通过重选虚拟目标、双经验回放池采样等策略以增强复杂环境下路径搜索能力;通过奖励函数提高规划路径质量,加快路径搜索速度。实验结果表明:不同环境下TD3-RRT相比当前主流算法能够有效提高规划成功率,优化转向角度、路径长度和规划时间,证明了改进算法能有效加快路径搜索速度并提高路径质量,且对不同环境具有良好适应性。展开更多
As the problem of surface garbage pollution becomes more serious,it is necessary to improve the efficiency of garbage inspection and picking rather than traditional manual methods.Due to lightness,Unmanned Aerial Vehi...As the problem of surface garbage pollution becomes more serious,it is necessary to improve the efficiency of garbage inspection and picking rather than traditional manual methods.Due to lightness,Unmanned Aerial Vehicles(UAVs)can traverse the entire water surface in a short time through their flight field of view.In addition,Unmanned Surface Vessels(USVs)can provide battery replacement and pick up garbage.In this paper,we innovatively establish a system framework for the collaboration between UAV and USVs,and develop an automatic water cleaning strategy.First,on the basis of the partition principle,we propose a collaborative coverage path algorithm based on UAV off-site takeoff and landing to achieve global inspection.Second,we design a task scheduling and assignment algorithm for USVs to balance the garbage loads based on the particle swarm optimization algorithm.Finally,based on the swarm intelligence algorithm,we also design an autonomous obstacle avoidance path planning algorithm for USVs to realize autonomous navigation and collaborative cleaning.The system can simultaneously perform inspection and clearance tasks under certain constraints.The simulation results show that the proposed algorithms have higher generality and flexibility while effectively improving computational efficiency and reducing actual cleaning costs compared with other schemes.展开更多
基金supported by the National Natural Sci‐ence Foundation of China(Grant No.62306325)。
文摘During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive distance)to a moving target as quickly as possible,resulting in the extended minimum-time intercept problem(EMTIP).Existing research has primarily focused on the zero-distance intercept problem,MTIP,establishing the necessary or sufficient conditions for MTIP optimality,and utilizing analytic algorithms,such as root-finding algorithms,to calculate the optimal solutions.However,these approaches depend heavily on the properties of the analytic algorithm,making them inapplicable when problem settings change,such as in the case of a positive effective range or complicated target motions outside uniform rectilinear motion.In this study,an approach employing a high-accuracy and quality-guaranteed mixed-integer piecewise-linear program(QG-PWL)is proposed for the EMTIP.This program can accommodate different effective interception ranges and complicated target motions(variable velocity or complicated trajectories).The high accuracy and quality guarantees of QG-PWL originate from elegant strategies such as piecewise linearization and other developed operation strategies.The approximate error in the intercept path length is proved to be bounded to h^(2)/(4√2),where h is the piecewise length.
文摘面对多障碍、大尺寸障碍、狭窄通道等特殊环境下的USV路径规划问题,快速扩展随机树算法(rapidly-exploring random trees,RRT)存在采样基数大、规划成功率低、规划路径曲折等缺点。基于双延迟深度确定性策略梯度(twin delayed deep deterministic policy gradient,TD3)提出一种全局路径规划算法(TD3-RRT)。结合RRT算法与深度强化学习建立USV路径搜索模型,利用前视探测感知环境以自适应调整扩展步长,通过策略网络输出路径搜索方向,解决RRT算法扩展盲目的问题;改进后见经验回放策略,通过重选虚拟目标、双经验回放池采样等策略以增强复杂环境下路径搜索能力;通过奖励函数提高规划路径质量,加快路径搜索速度。实验结果表明:不同环境下TD3-RRT相比当前主流算法能够有效提高规划成功率,优化转向角度、路径长度和规划时间,证明了改进算法能有效加快路径搜索速度并提高路径质量,且对不同环境具有良好适应性。
基金supported in part by the National Natural Science Foundation of China under Grants 62071189,62201220 and 62171189by the Key Research and Development Program of Hubei Province under Grant 2021BAA026 and 2020BAB120。
文摘As the problem of surface garbage pollution becomes more serious,it is necessary to improve the efficiency of garbage inspection and picking rather than traditional manual methods.Due to lightness,Unmanned Aerial Vehicles(UAVs)can traverse the entire water surface in a short time through their flight field of view.In addition,Unmanned Surface Vessels(USVs)can provide battery replacement and pick up garbage.In this paper,we innovatively establish a system framework for the collaboration between UAV and USVs,and develop an automatic water cleaning strategy.First,on the basis of the partition principle,we propose a collaborative coverage path algorithm based on UAV off-site takeoff and landing to achieve global inspection.Second,we design a task scheduling and assignment algorithm for USVs to balance the garbage loads based on the particle swarm optimization algorithm.Finally,based on the swarm intelligence algorithm,we also design an autonomous obstacle avoidance path planning algorithm for USVs to realize autonomous navigation and collaborative cleaning.The system can simultaneously perform inspection and clearance tasks under certain constraints.The simulation results show that the proposed algorithms have higher generality and flexibility while effectively improving computational efficiency and reducing actual cleaning costs compared with other schemes.
文摘由于海洋环境复杂多变,为了保障海员安全,全面提高海洋水域治理能力,近年来水面无人艇(unmanned surface vehicle,USV)的话题热度逐渐升高。USV路径规划能力是其关键技术之一,是其智能化的重要体现。随着船用雷达的逐步发展,现已成为保障船舶安全航行必不可少的一环。本文针对船用雷达图中USV的路径规划问题,将快速扩展随机树(Rapidly-exploring Random Trees,RRT)算法,对其进行改进并应用于USV路径规划问题,再与经典RRT算法进行比较。实验结果表明,改进后的RRT算法比经典RRT算法的路径长度更短,更平滑,证明改进后的RRT算法可以更有效的完成USV的路径规划。
