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1.
    
Multi‐agent formations have been recently the subject of many studies. An important operational challenge, largely unaddressed in the literature, is to ensure that functionality of the formation is retained should agents be lost through misadventure, mission reassignment, and so on. In the context of sensor networks, it is also important to allow for the loss of multiple sensors as the low quality of sensor hardware, common unattended implementations, and so on makes it a common issue. In this paper, we address these issues by proposing information structures that are tolerant to the loss of multiple agents. Using graph theory (and more specifically rigidity theory), we characterize several properties of such formations/networks in a unified framework: We characterize the k‐vertex rigidity property of the underling graph of such formations. This is performed by deriving a set of useful conditions that can form a guideline for designing agent‐loss‐tolerant formations. We elaborate the study by characterizing robust formations with the optimal number of control links. We also propose a set of operations preserving the tolerance to multiple agent losses in such formations. These operations provide flexibility in designing the formations in terms of several designing parameters (e.g., geometry, diameter, and max degree). Especially in the case of formations, the ability to handle controller adjustments in a distributed way is important, and the paper addresses this issue for a number of the robustness problems considered. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

2.
    
Multiagent formation control may proceed by ensuring that designated pairs of agents maintain a specified distance between each other, in order that the overall shape of the formation can be preserved while it translates or rotates. A minimally rigid formation is one in which loss of any one such constraint or link means that individual agent motions can occur, which do not preserve the shape of the formation. Recognizing that real‐world formations may suffer link loss and even agent loss, this paper presents a systematic approach to defining a measure for redundant or nonminimal rigidity, which is the property that formation shape will still be preserved in the face of loss of a certain designated number of distance constraints or formation agents. Most of the results are concerned with advancing a deterministic measure, but this paper also indicates circumstances under which a statistical measure may be relevant. For illustration, the paper analyses a number of standard formations to establish their levels of redundancy. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

3.
针对两个节点集合,提出了一组可定位性条件.可定位性条件包含两部分:两个集合之间需要的连接边的数目,以及如何布置这些连接边.本文将每组节点和它们的内部连接边刻画成一个距离图.两个节点集合之间的可定位性判定等同于两个融合图的全局刚性测试.针对两个融合图的可定位性,给出了一系列的充要条件.  相似文献   

4.
针对分布式 MDS-MAP 算法的不足,提出了一种基于图刚性理论的无线传感器定位新算法 MDS-MAP (GR)。算法利用图的刚性理论,确定网络中的所有刚性子区域,然后利用合并定理将刚性子区域进行扩展,最后对合并得到的刚性区域利用 MDS-MAP 算法和锚节点实现网络中节点的大规模定位。算法尽可能对刚性区域进行合并,节省了执行 MDS-MAP 算法的次数,提高了执行效率。通过在不同拓扑结构的无线传感器网络中进行了仿真实验,说明了提出的算法能有效定位不同半径下网络中90%以上的节点,另外,新方法比现有方法在定位成功率上提高了4%~5%,并且定位精度提高了2%~3.5%左右。算法适用于大规模无线传感器网络中的快速定位。  相似文献   

5.
无线传感器网络定位理论和算法   总被引:2,自引:0,他引:2       下载免费PDF全文
定位技术作为网络协议和应用的基础,已经成为无线传感器网络重要的支撑技术,是传感器网络研究的核心问题之一.系统地总结了近年来定位理论和算法的最新研究进展.全面阐述了定位问题的形式化定义、定位问题复杂度分析、基于刚性理论的定位理论和定位问题可计算性研究的最新成果.通过对定位理论的研究可以更好地揭示定位技术的本质,回答很多定位技术相关的基本问题.此外,还深入分析了近年来典型的定位算法,介绍每种算法的设计思想,分析其适用范围和不足.最后给出定位理论和定位算法未来的研究方向.  相似文献   

6.
The objective of this paper is to design distributed control algorithms for a multi-agent system such that a rigid formation can be achieved asymptotically and the agents can finally move with a desired velocity. In particular, it is assumed that the formation is not necessarily minimally rigid, and the desired velocity is available to only a subset of the agents. Estimators are constructed for the agents to estimate the desired velocity, which are further used to design the control inputs of the agents. The proposed control algorithms consist of a formation acquisition term which depends on a potential function and the rigidity matrix, and a velocity estimation term. To deal with non-minimal rigidity, the centre manifold theorem is exploited to prove the stability of the resulting system. Simulation results are also provided to show the effectiveness of the proposed control algorithms.  相似文献   

7.
杨旭  陈朋朋  牛强  胡东海 《软件学报》2016,27(S1):28-35
为提高节点定位精度并减少能量耗费,提出一种基于航拍图像处理的节点识别与定位算法.该算法主要思想是将基于深度学习模型的图像识别技术应用到节点识别与定位中.首先通过一个携带GPS的航拍器在节点部署区域自主采集节点图像,利用图像识别技术精确识别定位航拍器所拍摄节点,然后利用贝叶斯平均模型为已识别节点匹配节点编号.最后,将被定位节点升级为锚节点,结合经典定位算法确定未被拍摄的节点位置.通过大量的仿真证明了该算法的有效性.此外,利用25 Micaz节点和一个航拍器进行了实验,实验结果表明,该算法具有较好的鲁棒性、扩展性及定位精度,与传统定位算法相比定位精度提高约10%~30%.  相似文献   

8.
    
We study the local asymptotic stability of undirected formations of single‐integrator and double‐integrator modeled agents based on interagent distance control. First, we show that n‐dimensional undirected formations of single‐integrator modeled agents are locally asymptotically stable under a gradient control law. The stability analysis in this paper reveals that the local asymptotic stability does not require the infinitesimal rigidity of the formations. Second, on the basis of the topological equivalence of a dissipative Hamiltonian system and a gradient system, we show that the local asymptotic stability of undirected formations of double‐integrator modeled agents in n‐dimensional space is achieved under a gradient‐like control law. Simulation results support the validity of the stability analysis. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

9.
节点定位是无线传感器网络中的关键性问题,大多数定位方法无法评估每个节点的定位精度。该文提出一种无需测距的定位算法,将传感器节点的真实位置限定于一个区域中,使用该区域的面积评估传感器节点的位置精确度,利用网络中的非凸约束提高定位精度。仿真结果表明,在使用非凸约束的情况下,对于节点总数为250,20%为已知位置节点的传感器网络来说,90%的节点能较好地被定位。  相似文献   

10.
This article considers the design of a formation control for multivehicle systems that uses only local information. The control is derived from a potential function based on an undirected infinitesimally rigid graph that specifies the target formation. A potential function is obtained from the graph, from which a gradient control is derived. Under this controller the target formation becomes a manifold of equilibria for the multivehicle system. It is shown that infinitesimal rigidity is a sufficient condition for local asymptotical stability of the equilibrium manifold. A complete study of the stability of the regular polygon formation is presented and results for directed graphs are presented as well. Finally, the controller is validated experimentally.  相似文献   

11.
    
In this paper, decentralized methods of optimally rigid graphs generation for formation control are researched. The notion of optimally rigid graph is first defined in this paper to describe a special kind of rigid graphs. The optimally rigid graphs can be used to decrease the topology complexity of graphs while maintaining their shapes. To minimize the communication complexity of formations, we study the theory of optimally rigid formation generation. First, four important propositions are presented to demonstrate the feasibility of using a decentralized method to generate optimally rigid graphs. Then, a formation algorithm for multi-agent systems based on these propositions is proposed. At last, some simulation examples are given to show the efficiency of the proposed algorithm.  相似文献   

12.
    
The Internet is playing an important role in information retrieval, and additionally industrial process manipulation. This paper describes an approach to writing requirements specifications for Internet-based control systems, from which architectures can be derived. The requirements specifications developed are described in terms of a functional model, which is then extended to form an information architecture. Distinct from the functional model, the information architecture provides an indication as to the architectural structure of subsequently developed Internet-based control systems. Three general control structures are generated from the analysis of an information architecture. An integrated-distributed architecture is derived as an ideal implementation, in which a control system is linked to the Internet at all levels of a control system hierarchy.  相似文献   

13.
论文提出了一种基于事件的方案来实现三维空间多智能体系统的方位定位. 依赖方位角刚度设计了一种事件触发的定位方法, 该方法在少数个体方位角已知的前提下, 可以对集群网络中所有个体进行定位. 为了保障方法的有效性, 利用输入到状态的稳定原理, 得到了上述闭环控制系统的稳定性条件, 并且理论保证Zeno行为不发生. 最后, 通过二维和三维的数值仿真验证了所提出的多智能体系统事件触发定位控制方案的有效性.  相似文献   

14.
节点定位是无线传感器网络实际应用中的关键问题,为了提高定位精度,提出了一种基于测距和改进灰狼优化的无线传感器网络定位算法。本文提出了一种用三个信标节点坐标估计未知节点坐标的定位数学模型,通过该模型完成未知节点初步定位估计,将其作为基于对数递减策略的灰狼优化算法的初始值,通过改进灰狼优化算法寻优获取未知节点的优化坐标。仿真结果显示:通过与已有相关定位算法相比较,本文所提出的算法定位精度更高,并且具有对测距误差鲁棒性强的优点。  相似文献   

15.
鲁棒容错控制系统设计   总被引:32,自引:3,他引:32       下载免费PDF全文
本文考虑了观测器状态反馈控制系统的容错控制问题,提出了一种对传感器失效具有完整性的控制器设计方法,进而讨论了存在参数摄动的情况,给出了鲁棒容错控制器的设计步骤并用设计实例及仿真结果验证了该方法的有效性。  相似文献   

16.
在复杂环境下, 网络呈现出三维分布、链路非确定、应用场景异构、部署区域非结构化等新特点, 传统的定位技术已无法适用。不规则的网络形状很可能导致不准确的传感器节点定位结果, 从而导致定位误差较大。提出一种基于三角划分和MDS的3D节点定位算法。首先, 基于三角划分的方法将不规则的3D网络模型分解为若干个较规则的三角区域; 其次, 在每一个三角区域上采用改进的MDS算法对节点进行定位, 从而建立起局部相对位置地图; 最后, 合并三角子区域, 建立起整个网络全局的位置地图。实验结果表明, 该算法有效地提高了定位精度, 具有一定的实用意义。  相似文献   

17.
无线传感器网络节点定位系统与算法的研究和发展   总被引:22,自引:0,他引:22  
介绍了无线传感器网络节点定位的概念和原理,节点定位计算的一般过程.讨论了传感器网络各种定位系统常用的测距技术与节点定位计算的基本方法,对几种典型的定位算法进行了定性比较.介绍了节点定位系统与算法的最新发展,对传感器网络节点定位系统和算法进行了必要的总结和概括.  相似文献   

18.
针对基于图论的同时定位与制图中,非线性约束方程组维数随机器人运行距离和时间的增加而不断增大的问题,提出一种基于信息增益的图精简算法.该算法通过评估精简前后特征点信息矩阵相对变化,删除观测信息量小于给定阈值的机器人位姿及相应的观测,达到显著简化优化问题的目的.根据测量球形协方差矩阵假设,给出了信息增益的精确和近似计算方法.通过恢复性图剪枝方法,确保图精简过程中的连通性.蒙特卡洛仿真和开源实验数据计算结果表明,在不引入明显的优化误差前提下,该方法可实现位姿和特征点90%的精简,显著提高图优化效率.  相似文献   

19.
    
This article presents a new method to solve a dynamic sensor fusion problem. We consider a large number of remote sensors which measure a common Gauss–Markov process. Each sensor encodes and transmits its measurement to a data fusion center through a resource restricted communication network. The communication cost incurred by a given sensor is quantified as the expected bitrate from the sensor to the fusion center. We propose an approach that attempts to minimize a weighted sum of these communication costs subject to a constraint on the state estimation error at the fusion center. We formulate the problem as a difference-of-convex program and apply the convex-concave procedure (CCP) to obtain a heuristic solution. We consider a 1D heat transfer model and a model for 2D target tracking by a drone swarm for numerical studies. Through these simulations, we observe that our proposed approach has a tendency to assign zero data rate to unnecessary sensors indicating that our approach is sparsity-promoting, and an effective sensor selection heuristic.  相似文献   

20.
一种面向无线传感器网络相对定位的分簇算法   总被引:2,自引:0,他引:2  
测距误差累积是影响无线传感器网络相对定位算法性能的主要因素之一;网络分簇是降低这一误差的有效手段。针对相对定位特点;基于典型分簇算法——OK(Overlapped K-hop);提出EOK(Enhanced Overlapped K-hop)分簇算法。EOK算法改进了OK算法的簇头节点选择机制;提出邻居簇头节点合并机制;使得节点分簇更加符合定位应用需要。仿真实验表明;相比OK算法;采用EOK算法产生的节点簇数量更少、节点簇分布更均匀;在多数网络条件下具有更低的算法通信开销。  相似文献   

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