一种基于IMM的分布式扩展目标跟踪算法
Distributed Tracking of Extended Objects Based on IMM
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摘要: 随着传感器分辨率的提高,将目标视为一个质点可能导致大量信息的丢失,传统点目标跟踪模型不再适用。而扩展目标跟踪算法不仅考虑了目标的运动状态(如位置、速度和加速度),还考虑了目标的扩展状态(如形状、大小和方向等),可获得更准确且完整的目标状态估计。近年来,利用随机矩阵跟踪扩展目标的方法颇受欢迎。实际场景中扩展目标运动复杂多变,可能导致其运动状态和扩展发生突变。多模型算法,如交互多模型(Interactive Multiple Model, IMM)算法,是一种有效的机动目标跟踪方法。本文考虑利用传感器网络以分布式算法实现机动扩展目标的跟踪问题。本文提出了一种基于扩散策略的分布式机动扩展目标跟踪算法,其中,采用随机矩阵法对扩展目标进行建模。该算法拓展了IMM框架,以描述不同扩展特性的扩展目标在不同过程噪声下的运动特性,并进一步研究了一种减小通信量的分布式局部扩散策略。具体地说,在该算法中,每个节点基于IMM框架跟踪机动扩展目标,并采用加权Kullback-Leibler平均实现IMM框架中的数据融合。此外,应用本文所提出的局部扩散策略,每个节点仅与邻居节点交换部分中间估计值,以实现较低通信负担的有效的分布式扩展目标跟踪。仿真实验结果表明,本文所提的基于局部扩散策略的分布式机动扩展目标跟踪算法能够有效地跟踪机动扩展目标,且具有相对较低的网络通信负担。Abstract: With the increasing sensor resolution capabilities (such as the phased array radar), obtaining multiple measurements from an object body is possible; therefore, treating an object as a point mass becomes less valid as it would result in a potentially significant loss of information. In this case, the traditional methods for tracking an object cannot be applied directly. In contrast, extended object tracking algorithms, which consider not only the kinematic state (such as the position, velocity, and acceleration of the extended object) but also the extension (such as the shape, size, and orientation of the extended object), could provide more accurate, reliable, and comprehensive estimates of the extended object’s state. Recently, using a random matrix for extended object tracking has gained popularity. In practice, the state of the extended object is generally complex. When an extended object maneuvers, both the kinematic state and the extension may undergo abrupt changes. Multiple model approaches, such as the interactive multiple model (IMM), are well-known candidates for significantly improving overall tracking performance if the extended object switches between maneuvering and non-maneuvering behavior. In this study, we considered tracking a maneuvering extended object based on the distributed network. We proposed a distributed maneuvering extended object tracking algorithm based on the diffusion strategy, where the random matrix method is utilized to model the extension of the extended object. We expanded the IMM framework to describe the motion characteristics of the extended object with different extension characteristics under different process noises and further developed a communication-cost-effective partial diffusion strategy. Specifically, each node in the distributed network would track the maneuvering extended object based on the IMM method, where the model data would be fused using the weighted Kullback-Leibler average (KLA) method. Additionally, utilizing the partial diffusion strategy, each node would only share partial intermediate estimates with its neighbors during each iteration, which would markedly reduce the communication burden among nodes at the cost of moderate or even slight performance loss. Illustrative simulations validate that the proposed algorithm based on a partial diffusion strategy can effectively track the maneuvering extended object, incurring a relatively lower network communication burden.