An Integral Framework of Task Assignment and Path Planning for Multiple Unmanned Aerial Vehicles in Dynamic Environments

In this paper, a hierarchical framework for task assignment and path planning of multiple unmanned aerial vehicles (UAVs) in a dynamic environment is presented. For multi-agent scenarios in dynamic environments, a candidate algorithm should be able to replan for a new path to perform the updated tasks without any collision with obstacles or other agents during the mission. In this paper, we propose an intersection-based algorithm for path generation and a negotiation-based algorithm for task assignment since these algorithms are able to generate admissible paths at a smaller computing cost. The path planning algorithm is also augmented with a potential field-based trajectory replanner, which solves for a detouring trajectory around other agents or pop-up obstacles. For validation, test scenarios for multiple UAVs to perform cooperative missions in dynamic environments are considered. The proposed algorithms are implemented on a fixed-wing UAVs testbed in outdoor environment and showed satisfactory performance to accomplish the mission in the presence of static and pop-up obstacles and other agents.     

Imperialist Competitive Algorithm for AUV Path Planning in a Variable Ocean

An imperialist competitive algorithm (ICA) is introduced for solving the optimal path planning problem for autonomous underwater vehicles (AUVs) operating in turbulent, cluttered, and uncertain environments. ICA is a new sociopolitically inspired global search metaheuristic based on a form of competition between “imperialist” forces and opposing colonies. In this study, ICA is applied to optimize the coordinates of a set of control points for generating a curved spline path. The ICA-based path planner is tested to find an optimal trajectory for an AUV navigating through a variable ocean environment in the presence of an irregularly shaped underwater terrain. The genetic algorithm (GA) and quantum-behaved particle swarm optimization (QPSO) are described and evaluated with the ICA for the path optimization problem. Simulation results show that the proposed ICA approach is able to obtain a more optimized trajectory than the GA- or QPSO-based methods. Monte Carlo simulations demonstrate the robustness and superiority of the proposed ICA scheme compared with the GA and QPSO schemes.     

Reactive Path Planning in a Dynamic Environment

This paper deals with the problem of path planning in a dynamic environment, where the workspace is cluttered with unpredictably moving objects. The concept of the virtual plane is introduced and used to create reactive kinematic-based navigation laws. A virtual plane is an invertible transformation equivalent to the workspace, which is constructed by using a local observer. This results in important simplifications of the collision detection process. Based on the virtual plane, it is possible to determine the intervals of the linear velocity and the paths that lead to collisions with moving obstacles and then derive a dynamic window for the velocity and the orientation to navigate the robot safely. The speed of the robot and the orientation angle are controlled independently using simple collision cones and collision windows constructed from the virtual plane. The robot's path is controlled using kinematic-based navigation laws that depend on navigation parameters. These parameters are tuned in real time to adjust the path of the robot. Simulation is used to illustrate collision detection and path planning.      

High-Speed Environment Representation Scheme for Dynamic Path Planning

This paper presents an efficient approach to represent the environment, which can be used to facilitate dynamic path planning in robot navigation systems. The environment is modelled by first defining a 'virtual rectangle' to represent an environment that avoids unwanted obstacles. The obstacles within the environment are then represented as convex polygons to generate the required visibility graph. The devised techniques lend well for hardware porting and thus highly suited to high-speed generation of the visibility graph. It has been demonstrated that efficient dynamic path planning can be realised by generating the 'virtual rectangle' on the fly such that only the environment needed to facilitate onward traversal can be identified. Finally, the proposed algorithms lend well for high-speed computations as they facilitate a high-degree of parallelism at the architecture level.     

面向未知环境的机器人动态路径规划算法研究

针对未知地图环境下侦察巡检机器人路径规划算法存在的运算耗时较高、响应慢等问题,提出一种适用于未知地图信息情况下的动态路径规划方法及避障策略.首先,改进跳点搜索算法的关键点生成方法,针对大地图动态环境下的搜索需求提出"指定动态跳点"策略;其次,针对"指定动态跳点"策略在凹型障碍物内不易脱离等问题,提出"重搜索"策略;最后...     

动态不确定环境下多目标路径规划方法

提出一种在动态不确定环境下求解多目标问题时快速调整移动路径的方法.首先提出采用逆向多目标启发式搜索进行全局规划,求解问题的最优路径集合;然后提出动态多目标路径规划方法,先根据当前观测进行全局规划,在移动过程中探测到不一致的环境信息时,通过对先前搜索中部分信息的重用,在全局规划的基础上进行增量重规划,调整当前状态与目标状...     

实时任务优先级动态分配策略

现有大多数方法都是根据任务的截止期、空闲时间或者价值(密度)来确定任务的优先级,很少综合分析以上各个因素对任务优先级的影响.论文研究任务价值密度和紧迫性的变化特征,提出优先级的动态分派策略DPA,该策略可通过参数p与q来调节任务价值密度与紧迫性对任务优先级影响的程度,从而满足不同应用需求.最后,仿真实验结果显示,应用DPA策略的基于优先级的调度可以提高系统累积价值收益,降低任务截止期错失率.     

面向未知环境及动态障碍的人工势场路径规划算法

实际战场环境错综复杂,很多隐蔽、动态的障碍无法通过高空手段预先探测得知,因而对智能体执行任务的安全性产生威胁.针对未知且障碍形态多样的战场环境,以躲避动、静障碍,追踪目标为研究对象,提出一种面向未知环境及动态障碍的改进人工势场(Artificial Potential Field,APF)路径规划算法.在该算法中,智能...     

动态灾害环境下多对多物资配送路径规划方法

动态灾害环境下多对多物资配送路径规划问题具有重大的现实意义,它需要在路径规划的同时应对路网环境随时间的变化,并找到不同应急物资储备点、配送点之间的最佳对应关系,同时保证求解的时效性和成功率.目前的静态预案规划方法(SPO)和动态路径规划方法(DPO)难以确保动态灾害环境下求解效果的理论最优性,甚至可能导致部分配送点不能...     

动态环境下多重A算法的机器人路径规划方法

传统的A*算法仅适用于全局的静态环境,在求解路径规划问题时存在搜索效率低,路径不平滑等不足.针对这些问题,进行了以下改进:优化全局路径节点,引入删除冗余点准则与新增节点准则,使得全局路径更加平滑,更符合机器人运动学规律;结合滚动窗口法的思想,在每个滚动窗口内进行局部路径规划,首先根据前一步的节点信息确定局部子目标区域,...     

动态复杂环境下的机器人路径规划蚂蚁预测算法

研究了一种新颖的动态复杂不确定环境下的机器人路径规划方法和动态避障码蚁预测算法.该方法模拟蚂蚁的觅食行为,由多组蚂蚁采用最近邻居搜索策略和趋近导向函数相互协作完成全局最优路径的搜索.在此基础上用虚拟蚂蚁完成与动态障碍物碰撞的预测,并用蚁群算法进行避障局部规划.理论和仿真实验结果均表明,即使在障碍物非常复杂的地理环境,用文中算法也能迅速规划出优化路径,且能安全避碰.     

Market-Based Task Assignment for Cooperative Timing Missions in Dynamic Environments

New market-based decentralized algorithms are proposed for the task assignment of multiple unmanned aerial vehicles in dynamic environments with a limited communication range. In particular, a cooperative timing mission that cannot be performed by a single vehicle is considered. The baseline algorithms for a connected network are extended to deal with time-varying network topology including isolated subnetworks due to a limited communication range. The mathematical convergence and scalability analyses show that the proposed algorithms have a polynomial time complexity, and numerical simulation results support the scalability of the proposed algorithm in terms of the runtime and communication burden. The performance of the proposed algorithms is demonstrated via Monte Carlo simulations for the scenario of the suppression of enemy air defenses.     

Job Shop型制造系统任务分配和能力规划问题的并行优化

在排队理论基础上,建立了Job Shop型制造系统任务分配和能力规划并行优化问题的数学模型,提出了解决这一问题的遗传算法,数值实验表明这一算法是有效的.     

结合LSTM的强化学习动态环境路径规划算法

在路径规划领域已经涌现出了诸多的优秀的经典算法,但这些传统方法往往基于静态环境,对于动态可变环境缺乏处理能力.本文提出一种结合LSTM强化学习动态环境路径规划算法.首先,本文以环境图像作为输入,最大限度了保证了原始的信息来源.而后构建了自动编码器用来对环境图像进行特征降维,降低了整体模型的复杂程度.最后采用深度强化学习...     

复杂环境中煤矿智能机器人巡检路径动态规划

在复杂开采环境下,煤矿智能机器人往往出现移动路径规划不准确、规划效率低和规划延迟等问题.因此,提出了一种巡检路径的动态规划算法,并对传统的动态窗口算法进行了改进.将智能机器人的移速限制空间转换成二维坐标空间,通过膜间通信及内部粒子更新规则来更新粒子,使机器人以最优速度、最佳路径进行巡检.仿真结果表明,这种算法优化了机器...     

足球机器人动态路径规划方法研究

针对机器人足球系统的高度实时性、不确定性,提出了一种基于统计预测的路径规划方法,该方法考虑到障碍物的速度大小和方向的不确定性,用数学统计的方法对障碍物的运动进行建模;机器人在运动过程中,根据得到的环境信息在机器视觉范围内建立预测窗口和避障窗口,在预测窗口内,机器人根据障碍物的信息建立障碍物的预测区域,在避障窗口内,机器人根据自身的位置与障碍物的预测区域,分别调用切线法或滚动窗口法进行路径规划;该方法属于局部路径规划方法,机器人在移动过程中需要不断更新环境信息来进行避障.     

一种改进的未知动态环境下机器人混合路径规划方法

动态未知环境下的机器人路径规划是机器人导航领域的重要课题之一,采用传统的方法求解并不理想。针对这个问题,提出一种改进的机器人混合路径规划方法。首先利用改进的文化基因算法规划出较优的全局路径,指引机器人沿着全局路径行走,然后根据传感器探测到的局部环境信息,利用Morphin算法进行局部路径实时规划,使机器人有效地躲避动态障碍物。仿真实验表明,该算法在未知动态路径规划中具有良好的效果。     

虚拟场景自动漫游的路径规划算法

采用机器人学中的运动规划算法得到大致路径,并对路径进行数次优化得到最终路径．用户无需直接控制位置与视角,仅需给出目标点,系统就会自动地完成整个漫游;漫游过程中摄像机不会与物体发生碰撞,并且给出的画面符合一些基本的美学原则．该算法基于场景的层次分解,并采用了高效的路径平滑与视角规划方法,使得整个规划过程需要的时间非常少,提高了算法的实用性．     

IMMAS算法在复杂环境下路径规划中的应用

移动机器人路径规划是机器人学的一个重要研究领域.文章将改进的MMAS蚁群算法引入路径规划,在栅格法建模的基础上,改进初始蚁群设置,使用可变的终点定义,终合考虑可选点与终点的距离、可选点的被访问次数以及各可选路径上的信息素强度来设计启发式因子,使用奖励机制更新信息素,动态确定最大最小信息素范围,建立了一种新型优化算法.仿真结果表明,利用改进的MMAS算法,可充分发挥蚁群算法的优越性,并减小了陷入停滞状态的可能性,快速搜索到最优解.     

物联网环境下的助盲寻物机器人动态路径规划

近年来,盲人及低视力患者日益增多,世界上针对盲人及低视力患者的科研开发日渐普遍,基于RFID助盲语音寻物机器人是为了解决盲人家居寻物不便而开发的一款嵌入式产品。系统以盲人生活空间作为参考,构建虚拟仿真地图,并在寻径过程中实时监测现实环境更新仿真地图,动态规划寻径算法。参考Dijkstra算法与A Star算法,构建栅格法实现局部最优路径规划;参考蚁群算法构建出路径存储修正算法,与环路修正算法一起对栅格法进行修正和补充,逐步实现对全局最优路径的规划。降低了存储空间和提高了寻径效率,减少物理实现所需要功耗与实践,准确而且高效为盲人规划出最优前进路径,并引导盲人到达寻物点。