共查询到20条相似文献,搜索用时 15 毫秒
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火场烟雾弥漫、能见度低,消防队员很难准确定位并找寻到合适的撤离路径.文中使用人机协作在火场中建立动态三角网基础上,以网络节点为参考点为消防员规划撤离路线.该方案使用基于相似函数的证据理论对火场中各节点采集的烟雾浓度、温度、氧气浓度进行数据融合,并确定节点位置的安全等级;引入预测机制,可以预测短时间内前进路径中节点位置的安全等级的变化.根据安全等级变化,剔除网络中危险节点,使用基于路程换算的A算法计算实时最短的安全路径.通过数据分析表明,该方案能更好的适应火场环境多变的特点. 相似文献
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In many wireless sensor network (WSN) applications, the location of a sensor node is crucial for determining where the event or situation of interest occurred. Therefore, localization is one of the critical challenges in WSNs. Mobile anchor node assisted localization (MANAL) is one of the promising solutions for the localization of statically deployed sensors. The main problem in MANAL localization is that the path planning of the mobile anchor (MA) node should be done so that the localization error in the network will be minimal and that all unknown nodes in the network are covered. This paper proposes a new path planning approach called nested hexagons curves (NHexCurves) for MANAL. NHexCurves guarantees that it will receive messages from at least three non-collinear anchors to locate all unknown nodes in the network. The proposed model has compared six different path planning schemes in the literature using weighted centroid localization (WCL). In these comparisons, first of all, localization errors of the models are compared using some statistical concepts. Second, the variation of the localization error according to parameters such as resolution (R) and the standard deviation of noise (σ) is observed. Then, with similar approaches, the standard deviation of errors, localization ratio, scalability performances, and finally, path lengths of the models are examined. The simulation results show that the NHexCurves static path planning model proposed in this study stands out compared to other models with high localization error and localization ratio performance, especially at low resolutions, due to its path design. At the same time, the lowest error values according to σ are obtained with the proposed model among all models considered. 相似文献
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Michael Logothetis George Kokkinakis 《International Journal of Communication Systems》1995,8(2):143-153
Periodical performance evaluation and adaptive resource assignment, already proposed as performance-oriented management, seems to be the most suitable strategy for network planning under demand uncertainty. In this paper, we exploit the inherent capability of ATM networks to rearrange dynamically the already installed resources, and propose performance-oriented management combined with virtual path bandwidth (VPB) control for the planning of the extensions of bandwidth capacities of virtual paths (VPs) and transmission links of the network. We define a large network optimization problem and solve it by a rigorous, analytical procedure. The optimization model comprises specific requirements of the network-planning problem and a bandwidth distribution scheme ensuring network reliability. We reveal the efficiency of the proposed scheme by applying it on a model network, considering two realistic case-studies of network-traffic evolution. We show that in the presence of VPB control: (a) the initial distribution of the total bandwidth to VPs is of no importance, since it can be adaptively rearranged according to the offered traffic, (b) the network is well used and bandwidth investment could be saved, and (c) whenever additional bandwidth must be installed in VPs which have an unanticipated bad grade-of-service, time savings result. We present the network performance in detail, in figures, and compare this with the performance of the network in the absence of VPB control. 相似文献
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This research suggests a methodology to optimize Elman neural network based on improved slime mould algorithm(ISMA) to anticipate the aero optical imaging deviation. The improved Tent chaotic sequence is added to the SMA to initialize the population to accelerate the algorithm’s speed of convergence. Additionally, an improved random opposition-based learning was added to further enhance the algorithm’s performance in addressing problems that the SMA has such as weak convergence ability in the la... 相似文献
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RRT算法是一种能够处理障碍物和差分约束的问题的算法,被广泛应用于移动机器人的路径规划.针对于基本RRT算法存在的随机性较大和所求解路径非最优等问题,需要对其进行改进从而优化性能与运行效率.本文主要采用双向RRT算法融合人工势场法的方案进行改进后的路径规划,然后借助Dijkstra算法进一步处理所求解的路径,以寻求路径的最优解.仿真结果表明,本方案可以减少基本RRT算法随机性的影响,提高移动机器人路径规划的效率. 相似文献
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当移动机器人具有有限的计算能力时,Bug算法是最简单有效的路径规划算法,适用于环境地图未知或环境快速变化的情况,这些算法从机器人传感器,如激光雷达传感器来获得的本地信息和全局目标信息,以朝向目标的直线运动和沿着障碍的边界运动这两种简单的运动方式来到达目标点。文章对此展开了分析。 相似文献
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自主移动机器人在室内环境中的导航取得了重大进展,然而地图构建精度较差且路径规划欠佳,限制了这类机器人的实际应用。为了解决这些问题,提出了一种基于引导搜索的路径规划算法,即引力双向快速搜索随机树算法(GBI RRT),该算法采用目标偏差抽样,有效地引导节点走向目标,减少无效搜索。为了进一步提高导航效率,又提出了一种消除低质量节点,提高路径曲率的路径重组策略,为了验证上述方法的有效性,将其集成到一个基于ROS系统的移动机器人中,并在仿真和真实环境实验中进行了评估。结果表明,GBI RRT在各种室内环境下的性能均优于现有算法。 相似文献
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《现代电子技术》2016,(16):55-57
对数控加工中的孔群加工路径规划优化方法进行研究。将孔群的加工路径规划问题与典型旅行商问题进行类比,建立刀具空行程最短的数学模型和适应度函数。针对常规混合算法不能够将两种算法进行融合,只是单纯叠加,无法在最佳时机进行算法转化,使得算法混合优势不够明显等问题,该文对混合算法进行改进。使用遗传算法得到若干优化解,并将其变成初始信息素从而改成初始信息素偏低问题。使用动态转移代替静态转移法将遗传算法切换到蚁群算法。算法后期,信息素更新方法使用动态挥发系数法,对交叉变异概率使用信息素和适应度进行动态调节,交叉变异位置使用信息素和启发信息决定。以一种机械零件的孔群加工为例,对研究的混合算法的加工路径规划优化方法进行实例分析,结果表明相比常规混合算法,该文研究的混合算法具有更高的求解精度和优化效果。 相似文献
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路径规划问题是地理信息系统(GIS)研究领域中的关键内容之一,最短路径的寻找更是热点问题。在数据量较大时,传统前K条最短路径算法效率较低,且不能解决某些实际需求下规划K条差异较大的路径问题。在Dijkstra算法的基础上,引入有利度与重复度的概念,通过对路径结果重复度的检测以及由有利度的改变所引起的图的变化,循环寻找当前图中的最短路径,从而实现了多条差异路径的规划。在上述算法的基础上,对野外区域中带状区域的有利度及重复度进行控制,解决了传统前K条最短路径算法难以满足野外区域多条差异路径规划的问题。 相似文献
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The problem of multi-point path planning is a NP-hard problem,which is equivalent to finding the shortest path of a starting point and some specific node.Aiming at the problem of multi-point path planning,a retrospective ant colony-particle swarm optimization algorithm was proposed.This algorithm used Floyd-Warshall to transform the graph and combined ant colony algorithm and particle swarm algorithm to find the shortest path.The experimental results show that this algorithm can find the precise solution under small data,at the same time,under a large amount of data,can be better than the maximum minimum ant colony algorithm and genetic algorithm. 相似文献