共查询到18条相似文献,搜索用时 125 毫秒
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在介绍常用的ZigBee定位算法——接收信号强度指示算法(RSSI)和加权质心定位算法特点的基础上,分析常用算法定位误差产生的原因.针对此,提出改进的RSSI算法——几何测量算法,并将几何算法应用于CC2430无线单片机,对其定位节点进行设计和实现.仿真表明:改进后的算法定位精度提高约3%. 相似文献
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一种改进的ZigBee无线传感器网络定位算法及应用 总被引:1,自引:0,他引:1
在介绍常用的ZigBee定位算法——接收信号强度指示算法(RSSI)和加权质心定位算法特点的基础上,分析常用算法定位误差产生的原因。针对此,提出改进的RSSI算法——几何测量算法,并将几何算法应用于CC2430无线单片机,对其定位节点进行设计和实现。仿真表明:改进后的算法定位精度提高约3%。 相似文献
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针对无线传感网络中RSSI信号波动的问题,分析了环境因素对其的影响,在MICAz节点平台基础上,验证了距离、天线方位、节点高度和发射功率对信号产生的波动大小。通过对实验数据的处理,绘制出RSSI信号的波动曲线以及随各因素变化的拟合曲线。实验结果对基于RSSI的节点定位、跟踪方面的研究提供实践依据。 相似文献
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介绍了一种基于无线传感器网络技术,以CC2430为核心的井下瓦斯监测点定位方法。提出利用分簇方法进行井下数据传输,并利用CC2430中内置的RSSI指示器功能结合加权质心算法来解决瓦斯监测节点的定位问题。 相似文献
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针对无线传感器网络DV-Hop定位算法测距误差大的问题,提出了一种最佳信标节点选择算法。该算法充分考虑了信标节点的位置分布对定位精度的影响,并在算法中加入了跳距误差修正算法,进一步提高了定位精度。最后,利用Matlab进行仿真实验,结果表明:与现有DV-Hop算法相比,改进算法减少了测距误差,提高了定位精度。 相似文献
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针对移动机器人SLAM建图过程中用到的A*算法遍寻节点较多、路径规划时间较长、规划出的路径距离较长的问题,提出在二维栅格地图的基础上使用A*算法结合跳点搜索法和启发神经网络模型.跳点搜索法可以减少遍寻节点数量,启发神经网络可以缩短遍寻节点时间,将这3个算法结合构建成一个新的算法.MATLAB实验验证结果表明:结合后的优... 相似文献
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针对凝汽器真空故障诊断的不确定性和复杂性,提出一种基于模糊粗糙集和事例推理的凝汽器故障诊断新方法。首先,运用模糊粗糙集属性约简方法对故障特征进行约简和权重分配,不仅提取了反映故障的主要特征量,降低了特征变量之间的非线性相关性,而且避免了人的主观性对权重分配的影响。然后,在分析凝汽器真空故障特征的基础上,建立凝汽器真空故障树,以约简特征作为条件对故障树根节点进行归纳检索,有效地减少了候选事例的数量,再通过最近邻法检索故障树叶节点,对凝汽器真空故障进行智能定位。通过对汽轮机凝汽器历史故障特征数据集仿真,验证了该方法的有效性。 相似文献
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An adaptive algorithm suitable for reconstructing a distribution when knowing only a small number of its moments is presented. This method elaborates on a previous technique presented in John et al. (2007), but leads to many advantages compared with the original algorithm. The so-called “finite moment problem” arises in many fields of science, but is particularly important for particulate flows in chemical engineering. Up to now, there is no well-established algorithm available to solve this problem. The examples considered in this work come from crystallization processes. For such applications, it is of crucial interest to reconstruct the particle size distributions (PSD) knowing only a small number of its moments, obtained mostly from numerical simulations or from advanced experiments, but without any a priori knowledge concerning the shape of this PSD. This was already possible in many cases with the original algorithm of John et al. (2007), but complex shapes could not be identified appropriately. The key of the advanced algorithm is the adaptive criterion for positioning dynamically the nodes in an appropriate manner. It turns out that the adaptive algorithm shows considerable improvements in the reconstruction of distributions with a quickly changing curvature or for non-smooth distributions. Since such configurations are quite often found in practice, the new algorithm is more widely applicable compared with the original method. 相似文献
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为了实时掌握井下人员的分布及作业情况,通过利用Wi—Fi无线通信技术,提出了定位系统的总体设计方案和软件设计方案,实现了对井下人员的实时定位、考勤、轨迹跟踪、查询等功能。该系统的运用可以保障井下井上的信息及时准确沟通,精确定位井下人员位置,对煤矿安全生产发挥有重要作用。 相似文献
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塑料注射充模过程流动分析的隐式控制体积法 总被引:4,自引:3,他引:1
为了改善充模过程流动分析隐式方法的迭代过程,提出了一种基于界面更新的隐式方法。该方法只对已注满结点进行求解,然后更新界面结点的体积函数以便决定是否要更新界面。计算表明了隐式方法性能良好,计算速度比显式方法有量级程度的改进。 相似文献
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An interface‐update‐based implicit algorithm for mold filling simulation of liquid composite molding
In this article, a new implicit numerical algorithm has been presented for mold filling simulation in liquid composite molding process. The new implicit numerical algorithm is based on the update of flow interface to track flow front for each time step. Nodes of mesh are divided into three groups, i.e. filled nodes, interface nodes (or partially filled nodes), and empty nodes. Governing equations of filled nodes are solved to obtain pressure distribution; filling fractions of interface nodes are checked to determine if any node is needed to be added to filled nodes or be removed from filled nodes. The local LU factorization solver and preconditioned conjugated gradient iterative solver were employed to investigate the new implicit algorithm. Case studies demonstrated the performance of the proposed implicit algorithm. The new implicit algorithm reduced the computational complexity to below 2.0 power order of problem sizes. POLYM. COMPOS., 27:271–281, 2006. © 2006 Society of Plastics Engineers. 相似文献