For the mobile robot path planning under the complex environment,ant colony optimization with artificial potential field based on grid map is proposed to avoid traditional ant colony algorithm's poor convergence a...For the mobile robot path planning under the complex environment,ant colony optimization with artificial potential field based on grid map is proposed to avoid traditional ant colony algorithm's poor convergence and local optimum.Firstly,the pheromone updating mechanism of ant colony is designed by a hybrid strategy of global map updating and local grids updating.Then,some angles between the vectors of artificial potential field and the orientations of current grid are introduced to calculate the visibility of eight-neighbor cells of cellular automata,which are adopted as ant colony's inspiring factor to calculate the transition probability based on the pseudo-random transition rule cellular automata.Finally,mobile robot dynamic path planning and the simulation experiments are completed by this algorithm,and the experimental results show that the method is feasible and effective.展开更多
This article presents information on the study of the flora of Uzbekistan based on grid system mapping. The urban flora of the city of Bukhara was researched in it. As a result of research, the territory of Bukhara ci...This article presents information on the study of the flora of Uzbekistan based on grid system mapping. The urban flora of the city of Bukhara was researched in it. As a result of research, the territory of Bukhara city was divided into 85 indexes based on 1 × 1 km<sup>2</sup> grid mapping system. The diversity and density of species in the indexes are determined. The influence of anthropogenic factors on the diversity of species in the indexes is determined.展开更多
在基于视觉的即时定位与建图(Simultaneous Localization and Mapping,SLAM)中,RTAB-Map是一个比较经典的解决方案,它包含有鲁棒的视觉里程计,同时也提供稠密点云地图、2D占据栅格地图和Octomap(3D占据栅格地图)三种地图构建形式。但稠...在基于视觉的即时定位与建图(Simultaneous Localization and Mapping,SLAM)中,RTAB-Map是一个比较经典的解决方案,它包含有鲁棒的视觉里程计,同时也提供稠密点云地图、2D占据栅格地图和Octomap(3D占据栅格地图)三种地图构建形式。但稠密点云地图数据量大,无法适用于机器人导航;2D占据栅格地图虽数据量小,但无法反映复杂地形特征,一般只用于室内扫地机器人导航;Octomap能较好地反映三维空间内障碍物的信息,多用于无人机的导航,但对于地面移动机器人来说存在信息冗余。为RTAB-Map扩展了2.5D高程栅格地图构建模块,这种地图可以很好地反映地形环境特征,且地图所占用存储空间更小,更能充分利用移动机器人有限的存储和计算资源。展开更多
针对多无人艇编队避障问题,对静态避障的路径消耗问题进行建模分析,在动态避障时提出一种偏置人工势场法使策略符合艇群国际海上避碰规则(swarm International Regulations for Preventing Collisions at Sea,sCOLREGS)。本方法首先对...针对多无人艇编队避障问题,对静态避障的路径消耗问题进行建模分析,在动态避障时提出一种偏置人工势场法使策略符合艇群国际海上避碰规则(swarm International Regulations for Preventing Collisions at Sea,sCOLREGS)。本方法首先对传统人工势场法进行改进,定义符合艇群会遇态势判断需求的sCOLREGS,通过速度障碍法实时判断碰撞风险,然后利用偏置斥力区域的改进人工势场法实现对规则的遵守。仿真实验表明,本文方法在障碍物与编队大小相当时可显著减少避障路程,在确保避障实时性的同时,较好地遵守了国际海上避碰规则相关条例。研究结论可为海面无人艇集群安全航行提供参考。展开更多
针对无人机在高密度障碍物的城市环境飞行中路径规划实时性难以满足的问题,在A^(*)算法基础上结合跳点搜索(Jump Point Search, JPS)策略,提出一种Jump A^(*)(JA^(*))算法。将A^(*)算法进行三维扩展,并提出了一种三维对角距离精确表示...针对无人机在高密度障碍物的城市环境飞行中路径规划实时性难以满足的问题,在A^(*)算法基础上结合跳点搜索(Jump Point Search, JPS)策略,提出一种Jump A^(*)(JA^(*))算法。将A^(*)算法进行三维扩展,并提出了一种三维对角距离精确表示了实际路径代价,缩短了搜索时间。在二维JPS策略的基础上拓展得到了三维JPS策略,代替了A^(*)算法中的几何邻居扩展,大大减少了扩展结点数。对障碍物密度0.1~0.4的复杂三维栅格地图进行了路径规划仿真。仿真结果表明,JA^(*)算法相较于A^(*)算法,在高密度多障碍物的近地城市环境下,路径长度几乎不变,评估节点数大幅度减小,搜索速度具有显著提升。展开更多
基金National Natural Science Foundation of China(No.61373110)the Science-Technology Project of Wuhan,China(No.2014010101010005)
文摘For the mobile robot path planning under the complex environment,ant colony optimization with artificial potential field based on grid map is proposed to avoid traditional ant colony algorithm's poor convergence and local optimum.Firstly,the pheromone updating mechanism of ant colony is designed by a hybrid strategy of global map updating and local grids updating.Then,some angles between the vectors of artificial potential field and the orientations of current grid are introduced to calculate the visibility of eight-neighbor cells of cellular automata,which are adopted as ant colony's inspiring factor to calculate the transition probability based on the pseudo-random transition rule cellular automata.Finally,mobile robot dynamic path planning and the simulation experiments are completed by this algorithm,and the experimental results show that the method is feasible and effective.
文摘This article presents information on the study of the flora of Uzbekistan based on grid system mapping. The urban flora of the city of Bukhara was researched in it. As a result of research, the territory of Bukhara city was divided into 85 indexes based on 1 × 1 km<sup>2</sup> grid mapping system. The diversity and density of species in the indexes are determined. The influence of anthropogenic factors on the diversity of species in the indexes is determined.
文摘在基于视觉的即时定位与建图(Simultaneous Localization and Mapping,SLAM)中,RTAB-Map是一个比较经典的解决方案,它包含有鲁棒的视觉里程计,同时也提供稠密点云地图、2D占据栅格地图和Octomap(3D占据栅格地图)三种地图构建形式。但稠密点云地图数据量大,无法适用于机器人导航;2D占据栅格地图虽数据量小,但无法反映复杂地形特征,一般只用于室内扫地机器人导航;Octomap能较好地反映三维空间内障碍物的信息,多用于无人机的导航,但对于地面移动机器人来说存在信息冗余。为RTAB-Map扩展了2.5D高程栅格地图构建模块,这种地图可以很好地反映地形环境特征,且地图所占用存储空间更小,更能充分利用移动机器人有限的存储和计算资源。
文摘针对多无人艇编队避障问题,对静态避障的路径消耗问题进行建模分析,在动态避障时提出一种偏置人工势场法使策略符合艇群国际海上避碰规则(swarm International Regulations for Preventing Collisions at Sea,sCOLREGS)。本方法首先对传统人工势场法进行改进,定义符合艇群会遇态势判断需求的sCOLREGS,通过速度障碍法实时判断碰撞风险,然后利用偏置斥力区域的改进人工势场法实现对规则的遵守。仿真实验表明,本文方法在障碍物与编队大小相当时可显著减少避障路程,在确保避障实时性的同时,较好地遵守了国际海上避碰规则相关条例。研究结论可为海面无人艇集群安全航行提供参考。
文摘针对无人机在高密度障碍物的城市环境飞行中路径规划实时性难以满足的问题,在A^(*)算法基础上结合跳点搜索(Jump Point Search, JPS)策略,提出一种Jump A^(*)(JA^(*))算法。将A^(*)算法进行三维扩展,并提出了一种三维对角距离精确表示了实际路径代价,缩短了搜索时间。在二维JPS策略的基础上拓展得到了三维JPS策略,代替了A^(*)算法中的几何邻居扩展,大大减少了扩展结点数。对障碍物密度0.1~0.4的复杂三维栅格地图进行了路径规划仿真。仿真结果表明,JA^(*)算法相较于A^(*)算法,在高密度多障碍物的近地城市环境下,路径长度几乎不变,评估节点数大幅度减小,搜索速度具有显著提升。