Cooperative path planning is an important area in fixed-wing UAV swarm.However,avoiding multiple timevarying obstacles and avoiding local optimum are two challenges for existing approaches in a dynamic environment.Fir...Cooperative path planning is an important area in fixed-wing UAV swarm.However,avoiding multiple timevarying obstacles and avoiding local optimum are two challenges for existing approaches in a dynamic environment.Firstly,a normalized artificial potential field optimization is proposed by reconstructing a novel function with anisotropy in each dimension,which can make the flight speed of a fixed UAV swarm independent of the repulsive/attractive gain coefficient and avoid trapping into local optimization and local oscillation.Then,taking into account minimum velocity and turning angular velocity of fixed-wing UAV swarm,a strategy of decomposing target vector to avoid moving obstacles and pop-up threats is proposed.Finally,several simulations are carried out to illustrate superiority and effectiveness.展开更多
A novel method was designed to solve reinforcement learning problems with artificial potential field.Firstly a reinforcement learning problem was transferred to a path planning problem by using artificial potential fi...A novel method was designed to solve reinforcement learning problems with artificial potential field.Firstly a reinforcement learning problem was transferred to a path planning problem by using artificial potential field(APF),which was a very appropriate method to model a reinforcement learning problem.Secondly,a new APF algorithm was proposed to overcome the local minimum problem in the potential field methods with a virtual water-flow concept.The performance of this new method was tested by a gridworld problem named as key and door maze.The experimental results show that within 45 trials,good and deterministic policies are found in almost all simulations.In comparison with WIERING's HQ-learning system which needs 20 000 trials for stable solution,the proposed new method can obtain optimal and stable policy far more quickly than HQ-learning.Therefore,the new method is simple and effective to give an optimal solution to the reinforcement learning problem.展开更多
针对复杂输电环境下机械臂多目标点路径规划效率低、路径代价高的问题,提出了基于改进的人工势场引导的知情快速扩展随机树算法(improved artificial potential field-informed rapidly-exploring random trees star,IAPF-IRRT^(*))来...针对复杂输电环境下机械臂多目标点路径规划效率低、路径代价高的问题,提出了基于改进的人工势场引导的知情快速扩展随机树算法(improved artificial potential field-informed rapidly-exploring random trees star,IAPF-IRRT^(*))来提升路径规划的性能。首先引入长方体斥力场模型改进传统人工势场中球形斥力场模型,建立输电环境下复杂障碍物的斥力场。然后采用位置均匀分布的椭球域改进IAPF-IRRT*算法中的椭圆域,避免复杂输电环境下采样点出现局部冗余,提高搜索效率。最后引入三角寻优法优化路径中的冗余节点并结合三次样条插曲线对路径平滑处理。在三维简单、三维复杂和复杂输电环境这三组不同复杂程度的障碍物地图上进行验证,其结果表明:IAPF-IRRT*算法与标准RRT、RRT*算法相比,时间效率分别提升了44.8%~83.8%、68.3%~95.2%、26.5%~71.8%;路径代价分别降低了15.5%~35.0%、14.1%~35.3%、31.5%~43.5%;路径中的节点数量分别减少了75.6%~78.8%、75.0%~78.0%、70.4%~72.0%。展开更多
为解决传统人工势场法(APF)进行水面无人艇路径规划时出现局部最小和路径不平滑的问题,对斥力系数进行动态调整并引入逃逸力。为使水面无人艇在动态避碰中按国际海上避碰规则(international regulations for preventing collisions at s...为解决传统人工势场法(APF)进行水面无人艇路径规划时出现局部最小和路径不平滑的问题,对斥力系数进行动态调整并引入逃逸力。为使水面无人艇在动态避碰中按国际海上避碰规则(international regulations for preventing collisions at sea,COLREGS)航行,结合无人艇性能制定了无人艇的避碰规则,并引入转向力。通过Matlab对静态未知障碍物的仿真实验,验证改进APF算法能解决局部最小问题且规划的路径更加安全平滑。通过对动态未知障碍物4种典型局面的仿真实验表明,改进APF算法在复杂环境下也能引导无人艇在符合避碰规则的前提下对多个动态障碍进行安全规避。展开更多
文摘Cooperative path planning is an important area in fixed-wing UAV swarm.However,avoiding multiple timevarying obstacles and avoiding local optimum are two challenges for existing approaches in a dynamic environment.Firstly,a normalized artificial potential field optimization is proposed by reconstructing a novel function with anisotropy in each dimension,which can make the flight speed of a fixed UAV swarm independent of the repulsive/attractive gain coefficient and avoid trapping into local optimization and local oscillation.Then,taking into account minimum velocity and turning angular velocity of fixed-wing UAV swarm,a strategy of decomposing target vector to avoid moving obstacles and pop-up threats is proposed.Finally,several simulations are carried out to illustrate superiority and effectiveness.
基金Projects(30270496,60075019,60575012)supported by the National Natural Science Foundation of China
文摘A novel method was designed to solve reinforcement learning problems with artificial potential field.Firstly a reinforcement learning problem was transferred to a path planning problem by using artificial potential field(APF),which was a very appropriate method to model a reinforcement learning problem.Secondly,a new APF algorithm was proposed to overcome the local minimum problem in the potential field methods with a virtual water-flow concept.The performance of this new method was tested by a gridworld problem named as key and door maze.The experimental results show that within 45 trials,good and deterministic policies are found in almost all simulations.In comparison with WIERING's HQ-learning system which needs 20 000 trials for stable solution,the proposed new method can obtain optimal and stable policy far more quickly than HQ-learning.Therefore,the new method is simple and effective to give an optimal solution to the reinforcement learning problem.
文摘针对复杂输电环境下机械臂多目标点路径规划效率低、路径代价高的问题,提出了基于改进的人工势场引导的知情快速扩展随机树算法(improved artificial potential field-informed rapidly-exploring random trees star,IAPF-IRRT^(*))来提升路径规划的性能。首先引入长方体斥力场模型改进传统人工势场中球形斥力场模型,建立输电环境下复杂障碍物的斥力场。然后采用位置均匀分布的椭球域改进IAPF-IRRT*算法中的椭圆域,避免复杂输电环境下采样点出现局部冗余,提高搜索效率。最后引入三角寻优法优化路径中的冗余节点并结合三次样条插曲线对路径平滑处理。在三维简单、三维复杂和复杂输电环境这三组不同复杂程度的障碍物地图上进行验证,其结果表明:IAPF-IRRT*算法与标准RRT、RRT*算法相比,时间效率分别提升了44.8%~83.8%、68.3%~95.2%、26.5%~71.8%;路径代价分别降低了15.5%~35.0%、14.1%~35.3%、31.5%~43.5%;路径中的节点数量分别减少了75.6%~78.8%、75.0%~78.0%、70.4%~72.0%。
文摘为解决传统人工势场法(APF)进行水面无人艇路径规划时出现局部最小和路径不平滑的问题,对斥力系数进行动态调整并引入逃逸力。为使水面无人艇在动态避碰中按国际海上避碰规则(international regulations for preventing collisions at sea,COLREGS)航行,结合无人艇性能制定了无人艇的避碰规则,并引入转向力。通过Matlab对静态未知障碍物的仿真实验,验证改进APF算法能解决局部最小问题且规划的路径更加安全平滑。通过对动态未知障碍物4种典型局面的仿真实验表明,改进APF算法在复杂环境下也能引导无人艇在符合避碰规则的前提下对多个动态障碍进行安全规避。
