Adaptive Flocking Control with a Minority of Informed Agents

In this paper, we address the flocking problem of multiple dynamic mobile agents with a virtual leader in a dynamic proximity network. To avoid fragmentation, we propose a novel flocking algorithm that consists of both an adaptive controller for followers and a feedback controller for the virtual leader. Based on our algorithm, all agents in the group can form a network, maintain connectivity, and track the virtual leader, even when only a minority of agents have access to the information of the virtual leader. Finally, several convincing simulation results are provided that demonstrate 2‐D flocking of a group of agents using the proposed algorithm.     

Coverage tracking control for multiple cooperative agents

In this article, we consider coverage problem of a moving target by multiple mobile agents. The mobile agents with global sensing areas and limited actuation region are designed to track down a target with estimation error with the help of flocking and coverage. In order to capture the target, its location and velocity are first estimated. With observer-based estimation combined with flocking control, respectively, the group of agents can catch the target by a coverage tracking policy in finite time.     

基于蜂拥控制的移动传感器网络目标跟踪算法

针对移动传感器网络中的目标跟踪问题, 以及现有控制策略在保持网络拓扑结构连通性和降低能量消耗方面存在的不足, 提出一种基于蜂拥控制的移动传感器网络目标跟踪算法. 首先, 利用网络中部分节点检测目标, 并使用卡尔曼一致性滤波算法估计目标的状态, 在获得比较精确的估计状态的同时降低能量消耗; 然后, 在蜂拥控制下传感器网络始终保持拓扑结构连通性和目标对网络可见, 同时避免节点之间发生碰撞. 仿真结果验证了所提出算法的有效性.

     

融合局部自适应追踪的多目标牵制蜂拥算法

针对以往的多智能体蜂拥控制算法在考虑单个目标追踪情形时不具普适性,以及现有的多目标蜂拥控制都是基于全局目标信息来进行集中式协调控制,而非基于局部目标信息下的分布式协调控制的问题,提出一种融合局部自适应检测机制的分布式协同牵制蜂拥算法。首先,算法在分离、聚合、速度匹配和引导反馈的基础上,引入局部自适应追踪策略,实现智能体的局部动态跟随运动;其次,受牵制思想启发,根据节点影响力指数评估算法选取m个信息个体分别向m个目标进行多目标追踪,起到模拟外部信息的作用,不同的信息个体会由于局部自适应检测机制间接地引领周围局部个体向不同目标进行追踪;最后,设计一类新的聚集和排斥势能函数,实现相同目标智能体的聚集,以及不同目标智能体的避碰,具有可调参数少和效率高的优势。通过三维仿真实验验证了算法的多目标追踪可行性和有效性。     

六足机器人动态目标检测与跟踪系统研究

动态目标检测与目标跟踪是图像领域的热点研究问题,为研究其在移动机器人领域的应用价值,设计了六足机器人动态目标检测与跟踪系统。针对非刚体运动目标容易被检测为多个分散区域的问题提出区域合并算法,并通过对称匹配、自适应外点滤除对运动背景进行精确补偿,最终基于背景补偿法实现对运动目标的精确检测。研究了基于KCF（Kernel Correlation Filter）的目标跟踪算法在六足机器人平台上的应用,设计了自适应跟踪算法实现六足机器人对运动目标的角度跟踪。将运动目标检测及跟踪算法应用于六足机器人系统。实验表明,在六足机器人移动过程中,系统可对运动目标进行精确检测与跟踪。     

基于神经网络的不确定移动机器人鲁棒自适应跟踪控制

针对含运动学未知参数以及动力学模型不确定的非完整轮式移动机器人轨迹跟踪问题,基于Radical Basis Function(径向基函数)神经网络,提出了一种鲁棒自适应控制器.首先,考虑移动机器人运动学参数未知的情况,提出了一种含自适应参数的运动学控制器,用以补偿参数不确定性导致的系统误差;其次,利用神经网络控制技术,对于机器人在移动中动力学模型不确定问题,提出了一种具有鲁棒性的动力学控制器,使得移动机器人可以在不知道具体动力学模型的情况下跟踪到目标轨迹;最后利用Lyapunov稳定性理论证明了整个系统的稳定性.通过数值仿真验证了所设计的控制器的可行性.     

基于预测的动态分簇目标跟踪算法

在保证高跟踪准确度的基础上,降低节点的能耗,延长网络的寿命是目标跟踪的核心问题。为此,提出了一种基于预测的动态分簇目标跟踪算法Pre-DC。该算法首先建立动态的簇结构,然后利用粒子滤波算法实现簇对目标的跟踪,最后根据预测误差大小动态地更新簇结构。这样不仅降低了跟踪簇的能量消耗,同时也提高了跟踪精确度。仿真结果表明,算法在参与跟踪节点较少的情况下,能获得很好的目标跟踪精度。     

无线传感器网络目标跟踪算法的研究

研究传感器网络目标跟踪精度问题,跟踪目标的运动轨迹具有时变性,是一种非线性、非高斯问题,传统跟踪算法解决非线性问题时具有局限性,导致目标跟踪精度不高。为提高目标跟踪精度,将不受非线性、非高斯问题限制的粒子滤波算法引入到无线传感器网络目标跟踪应用中,并对基本粒子滤波算法的缺陷进行改进。仿真结果表明,改进粒子滤波算法提高了粒子利用效率,不仅提高了目标跟踪的精度,跟踪性能更好,并适合于目标跟踪的精度和实时性要求,为设计网络系统提供了参考。     

基于MLP和SPSO的机器人行为选择与运动控制方法

针对传统行为选择机制(ASM)不能很好地做出控制决策的问题,提出一种基于多层感知(MLP)前馈神经网络的ASM,并将其应用到移动机器人目标跟踪中。首先,根据具体应用场景预定义多个机器人行为。然后,根据机器人配备的图像和红外传感器获得的目标位置和障碍物信息,通过MLP神经网络从预定义行为中选择出所需执行的行为。另外,为了构造最优的MLP模型,采用一种简化粒子群算法(SPSO)来优化网络权值参数。机器人目标跟踪仿真的结果表明,提出的ASM能够准确选择出合适的行为,实现了控制机器人跟踪目标移动且能够避开各种障碍物。     

The multi‐iterative closest point tracker: An online algorithm for tracking multiple interacting targets

We describe and evaluate a greedy detection‐based algorithm for tracking a variable number of dynamic targets online. The algorithm leverages the well‐known iterative closest point (ICP) algorithm for aligning target models with target detections. The approach differs from trackers that seek globally optimal solutions because it treats the problem as a set of individual tracking problems. The method works for multiple targets by sequentially matching models to detections, and then removing detections from further consideration once models have been matched to them. This allows targets to pass close to one another with reduced risks of tracking failure due to “hijacking,'' or track merging. There has been significant previous work in this area, but we believe our approach addresses a number of tracking problems simultaneously that have only been addressed separately before. The algorithm is evaluated using four to eight laser range finders in three settings: quantitatively for a basketball game with 10 people and a 25‐person social behavior experiment, and qualitatively for a full‐scale soccer game. We also provide qualitative results using video to track ants in a captive habitat. During all the experiments, agents enter and leave the scene, so the number of targets to track varies with time. With eight laser range finders running, the system can locate and track targets at sensor frame rate 37.5 Hz on commodity computing hardware. Our evaluation shows that the tracking system correctly detects each track over 98% of the time. © 2012 Wiley Periodicals, Inc.     

基于扩展Kalman滤波的空基多平台多传感器数据配准和目标跟踪算法

本文研究基于扩展Kalman滤波和多个空中移动平台的多传感器数据配准与目标跟踪问题.文中首先给出了空中移动平台传感器数据配准几何坐标转换算法;接着将目标运动模型和传感器配准误差模型组合在同一个状态方程中,然后利用扩展Kalman滤波方程进行估计.Monte-Carlo仿真表明,该方法能同时有效地估计目标运动状态和传感器配准误差.     

On collaborative tracking of a target group using binary proximity sensors

In order to track multiple targets in a wireless sensor network, existing work has mostly focused on tracking the trajectories of each individual target that can be identified. However, such algorithms are often ineffective to handle a large number of targets—identifying each of them is too hard due to the fact that the targets usually move together and their locations may also be close to each other. This paper investigates the problem of tracking a group of targets when their motions are correlated. Specifically, we propose a family of algorithms for collaborative tracking with the help of binary proximity sensors. More specifically, our contributions include a fault-tolerant target group detection algorithm, two target group localization algorithms, and dynamic reporter node selection and redeployment control algorithms. Furthermore, we explore the fundamental limit on the accuracy of localizing a target group.     

Improved clustering algorithms for target tracking in wireless sensor networks

In recent years, there has been a growing interest in wireless sensor networks because of their potential usage in a wide variety of applications such as remote environmental monitoring and target tracking. Target tracking is a typical and substantial application of wireless sensor networks. Generally, target tracking aims basically at estimating the location of the target while it is moving within an area of interest and consequently report it to the base station in a timely manner. However, achieving a high accuracy of tracking together with energy efficiency in target tracking algorithms is extremely challenging. In this article, we propose two algorithms to enhance the adaptive-head clustering algorithm, formerly lunched, namely, the improved adaptive-head and improved prediction-based adaptive head. Particularly, the first algorithm uses dynamic clustering to achieve impressive tracking quality and energy efficiency through optimally choosing the cluster head that participates in the tracking process. On the other hand, the second algorithm incorporates a prediction mechanism to the first proposed algorithm. Our proposed algorithms are simulated using Matlab considering various network conditions. Simulation results show that our proposed algorithms can accurately track a target, even when random moving speeds are considered and consume much less energy, when compared with the previous algorithm for target tracking, which in turn prolong the network lifetime much more.     

一种基于区域分裂与合并的势博弈网络拓扑控制算法

现有无线传感器网络拓扑控制算法在传感器节点部署密集或稀疏区域存在网络拓扑链路冗余、个别节点负载过重、瓶颈节点和网络生命周期短等问题。针对这些问题,提出一种基于区域分裂与合并的势博弈网络拓扑控制算法,该算法首先划分目标区域并随机抛洒传感器节点,在每个子区域内进行博弈并选出簇首节点,利用区域分裂与合并思想,在节点密集区域进行分割再博弈,防止部分节点负载过大,在节点稀疏区域利用权重链路进行合并,防止出现瓶颈节点以保障网络连通;然后对所有簇首节点实施二次势博弈生成簇首拓扑结构连接各子区域。仿真结果表明,该算法能够有效缓解节点负载,均衡节点能耗,延长网络生命周期。     

Robust visual tracking control system of a mobile robot based on a dual-Jacobian visual interaction model

This paper presents a novel design of a robust visual tracking control system, which consists of a visual tracking controller and a visual state estimator. This system facilitates human–robot interaction of a unicycle-modeled mobile robot equipped with a tilt camera. Based on a novel dual-Jacobian visual interaction model, a robust visual tracking controller is proposed to track a dynamic moving target. The proposed controller not only possesses some degree of robustness against the system model uncertainties, but also tracks the target without its 3D velocity information. The visual state estimator aims to estimate the optimal system state and target image velocity, which is used by the visual tracking controller. To achieve this, a self-tuning Kalman filter is proposed to estimate interesting parameters and to overcome the temporary occlusion problem. Furthermore, because the proposed method is fully working in the image space, the computational complexity and the sensor/camera modeling errors can be reduced. Experimental results validate the effectiveness of the proposed method, in terms of tracking performance, system convergence, and robustness.     

无线传感器网络分布式多目标跟踪算法研究

由于无线传感器网络的资源有限,集中式多目标跟踪算法在无线传感器网络多目标跟踪中受到限制.在无线声学传感器网络下,基于动态分簇结构,提出了一种分布式多目标跟踪算法.每个传感器的测量为来自单个目标或多个目标的声音信号和环境噪声的叠加.在跟踪过程中,每个目标对应于一个粒子滤波,当目标之间的距离较远时,进行单目标跟踪.当目标之...     

Bearings only single-sensor target tracking using Gaussian mixtures

This paper presents a new approach for single sensor tracking using passive bearings only measurements. Gaussian mixture measurement presentation, together with a track splitting algorithm, allow space-time integration of the target position uncertainty with a simple algorithm. The bearings-only measurements are incorporated into track as they arrive using a dynamic bank of linear Kalman filters. While this approach is applicable to the case with the target detection, data association and multitarget issues, this paper concentrates on the target trajectory estimation using associated measurements. A simulation study demonstrates the benefits of this approach.     

无线传感器网络下移动扩散源追踪算法

与移动瞬时源追踪相比,移动扩散源追踪相对困难.本文分析了移动扩散源扩散过程,给出了离散化浓度场模型.将连续线源目标追踪问题转化为离散点源目标追踪的次优问题,提出了一种离散化移动扩散源追踪算法.在该算法中,先采用约束最小二乘方法估计目标实时位置、到达时间等相关参数,并进一步采用仅针对位置序列的Sage-Husa卡尔曼滤波方法优化位置估计.该算法克服了一般基于动态序列的追踪方法无法直接应用于离散移动扩散源追踪问题的不足.在仿真实验中,分别在匀速率平滑曲线运动与变速非平滑曲线运动的情形下进行追踪实验,分析了追踪精度与采样间隔以及观测节点密度的关系.仿真结果说明了提出的移动扩散源追踪算法的有效性.     

空基多平台多传感器时间空间数据配准与目标跟踪

研究多个空中移动平台的时间空间数据配准与目标跟踪问题.首先给出空中移动平台传感器数据空间配准几何坐标转换算法;然后采用最小二乘法对多传感器异步测量数据进行时间配准;最后将目标的运动模型和传感器配准误差模型组合在同一个状态方程中,利用扩展Kalman滤波方程进行估计.Monte-Carlo仿真表明,该方法能同时有效地估计目标运动状态和传感器配准误差,比传统配准方法具有更快的收敛速度和更高的精度.     

一种目标监测的移动传感器网络覆盖分布式优化算法

针对移动传感器网络中目标监测的节点部署问题,为保证在无覆盖漏洞的同时减少覆盖冗余,以六边形棋盘结构(HTL)为网络的目标部署结构,提出一种基于群集控制的分布式部署算法.该方法只需目标的相对方向和邻居节点的相对位置、速度信息,可不依赖于通信.仿真结果表明,所提出的算法对静止和运动目标均有效,与基于虚拟力的算法相比所需信息更少,部署更均匀,对HTL的逼近效果更好,覆盖更优.