共查询到17条相似文献，搜索用时 781 毫秒
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UUV 集群在执行大范围搜索任务时分配方案的优劣对于提高任务执行效率至关重要。研究解决 UUV 集群同时进行多区域搜索中的任务分配问题,使得全部区域搜索完成时长最小。针对传统匈牙利算法无法高效解决不平衡任务分配的问题,提出一种改进匈牙利多轮分配算法。该算法通过多轮任务分配,实现空闲 UUV 高效利用和目标区域合理分配,通过在代价函数中引入边际代价和保守估计时长,大大减小了全部区域搜索完成时长。仿真实验结果表明：提出的算法相比传统匈牙利算法能够合理分配空闲 UUV,提高分配效率。此外,相较于仅采用搜索时长为代价函数,在代价函数中引入边际代价和保守估计时长能够针对耗时长的区域最大限度缩短搜索时长,保证随着 UUV 数量的增加,全部区域搜索完成时长单调递减。 相似文献
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针对无人水下航行器（Autonomous Underwater Vehicle,AUV）运动约束多,传统遗传算法的路径寻优效率低、收敛速度慢等问题,提出了一种改进遗传算法的 AUV 路径规划方法。该算法选用栅格法构建环境,使用路径长度、平滑度和危险区域作为评价函数。改进遗传算法种群初始化过程,引入周围点栅格提高收敛速度,同时结合灾变思想避免群体陷入局部最优解。该算法根据 AUV 最大转角的约束条件,设计了 AUV 平滑过程和删除过程,避免了 AUV 航行出现急停急转。仿真及湖上试验结果表明：改进遗传算法相比传统遗传算法,路径长度减少 11.4%,收敛速度加快 20.0%,且收敛路径满足 AUV 航行约束要求。 相似文献
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为解决传统海图抽选存在的主观性高和抽选效率低的问题,尝试将图论中的Floyd算法应用到海图抽选问题中,通过在无向图多路径数据结构中对Floyd算法进行加速改进,提出了一种基于无向图Floyd加速模型的海图抽选方法。该方法通过对网络图及算法进行优化,实现了抽选海图航路覆盖范围的最大化和抽选海图数量的最小化,并将时间复杂度降至O(1/2(n)(n-1)~2);通过利用基于等价点数组的最短路径集算法,实现了同等海图数量前提下的不同海图选取方案。最后通过实验验证了上述模型在海图选取中的可行性和优越性。 相似文献
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当前关于使用蚁群算法解决载人潜水器路径规划问题的研究,往往只注重路径的长度和算法收敛速度,容易忽略路径点与障碍物之间的距离和路径的平滑度等要素。载人潜水器过于靠近障碍物航行时容易产生碰撞;按照不平滑路径行驶时,频繁地转向会降低航行效率。为解决这些问题,受人工势场法启发,文中在蚁群算法的概率选择环节引入障碍物惩罚因子φ和转向惩罚因子ψ,对路径点的选择加以限制。仿真测试表明,相比于传统蚁群算法和Dijkstra算法,该算法规划的路径与障碍物之间保持安全距离且转向次数更少,因此载人潜水器按照此路径航行时,安全性和航行效率更高。 相似文献
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合成孔径雷达在海洋环境监测和海洋研究中扮演着越来越重要的角色。受其成像机制的影响，合成孔径雷达图像总是受到斑点噪声的污染。斑点噪声的存在会增大目标识别、跟踪和分类的难度，也会降低雷达信号的信噪比。合成孔径雷达海洋图像具有一些特殊的性质：海洋现象在雷达图像中主要呈现为条带状或斑块状的结构。这些条带状或斑块状的结构呈现出高度的自相似性或信息冗余。非局部平均方法能够衡量图像中不同图像块之间纹理结构的相似性，并利用图像的自相似性对图像进行去噪。但非局部平均去燥方法存在计算量巨大、计算耗时长的缺点，这几乎限制了其实际应用。本文采用一种自适应方法将雷达图像中的像素点区分为纹理区像素点和平坦区像素点。对纹理区像素点，采用较大的相似窗和搜索窗，对平坦区像素点，采用较小的相似窗和搜索窗，从而提高计算速度。进一步，本文基于计算统一设备并行架构（CUDA）技术，利用计算机图形处理器（GPU）对前述算法进行并行加速。与经典非局部平均算法相比，加速后算法的计算效率提高了200倍。 相似文献
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In order to reduce the total resistance of a hull, an optimization framework for the bulbous bow optimization was presented. The total resistance in calm water was selected as the objective function, and the overset mesh technique was used for mesh generation. RANS method was used to calculate the total resistance of the hull. In order to improve the efficiency and smoothness of the geometric reconstruction, the arbitrary shape deformation (ASD) technique was introduced to change the shape of the bulbous bow. To improve the global search ability of the particle swarm optimization (PSO) algorithm, an improved particle swarm optimization (IPSO) algorithm was proposed to set up the optimization model. After a series of optimization analyses, the optimal hull form was found. It can be concluded that the simulation based design framework built in this paper is a promising method for bulbous bow optimization. 相似文献
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针对海洋环境下自主水下机器人（AUV）的路径规划问题,提出了一种基于框架四叉树的改进量子粒子群算法（QPSO）,首先使用框架四叉树的方法对障碍物建模,该方法提高了建模的精度且对后续算法的效率也有极大的改进,之后设计改进的量子粒子群算法,并且结合水下环境的特殊性设计适应度函数,综合考虑航线路径长度、偏转角度以及海流影响,使得算法可以在水下环境中寻得能耗最短的解路径。最后通过仿真试验验证,相比于传统的栅格法和粒子群算法,改进量子粒子群算法的运算时间更短,收敛速度更快,其独特的适应度函数可以使AUV能更好适应水下多变的环境,且能利用海流设计能耗更小的路径,具有很大的实用价值。 相似文献
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An improved particle swarm optimization algorithm with harmony strategy for the location of critical slip surface of slopes 总被引：1，自引：0，他引：1
The determination of optimal values for three parameters required in the original particle swarm optimization algorithm is very difficult.It is proposed that two new parameters simulating the harmony search strategy can be adopted instead of the three parameters which are required in the original particle swarm optimization algorithm to update the positions of all the particles.The improved particle swarm optimization is used in the location of the critical slip surface of soil slope,and it is found that the improved particle swarm optimization algorithm is insensitive to the two parameters while the original particle swarm optimization algorithm can be sensitive to its three parameters. 相似文献
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An effective path planning or route planning algorithm is essential for guiding unmanned surface vehicles (USVs) between way points or along a trajectory. The A* algorithm is one of the most efficient algorithms for calculating a safe route with the shortest distance cost. However, the route generated by the conventional A* algorithm is constrained by the resolution of the map and it may not be compatible with the non-holonomic constraint of the USV. In this paper an improved A* algorithm has been proposed and applied to the Springer USV. A new path smoothing process with three path smoothers has been developed to improve the performance of the generated route, reducing unnecessary ‘jags’, having no redundant waypoints and offering a more continuous route. Both simulation and experimental results show that the smoothed A* algorithm outperforms the conventional algorithm in both sparse and cluttered environments that have been uniformly rasterised. It has been demonstrated that the proposed improved A* route planning algorithm can be applied to the Springer USV providing promising results when tracking trajectories. 相似文献
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A trajectory-cell based method was proposed for unmanned surface vehicle (USV) motion planning to combine the expression of the dynamic constraints and the discretization of the search space. The dynamic constraints were expressed by the USV trajectories produced by the mathematical model. The search space was performed by the discretization rules with the consideration of the path continuity, the search convenience and the maneuvering simplification. Therefore, the trajectory-cells were the discretized trajectories, which made the search space meet the USV dynamic constraints, and guaranteed the final spliced path continuous. After abstracting the characteristics of those cells, the available waypoints and headings were represented as the search indexes. Finally, a trajectory-cell based path searching strategy was proposed by determining the cost function of the A* algorithm. The results showed that the proposed algorithm can plan a practical motion path for the USV. 相似文献
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考虑深水S型铺设中离散均布托辊对上弯段管道的支撑作用,提出了管道铺设形态和内力的分段解析求解方法,通过迭代搜索算法确定管道最佳反弯点和升离点的位置,结合刚性悬链线理论和欧拉梁弯曲理论,推导了管道的变形和内力的解析表达式。依据所建立的分段解析方法编制了相应的数值计算程序,以某3 000 m水深铺设12英寸管道为例,计算了管道形态和内力响应,与商用有限元软件的数值分析结果进行对比,表明了分段解析方法的准确性和有效性。建立的方法具有较高的计算效率,为进一步开展S型铺设参数的优化或可靠性研究提供了有力的手段。 相似文献