Cooperative Estimation for Coordinated Target Tracking in a Cluttered Environment

Wireless Sensor Network (WSN) is a new technology integrated with communications, embedded technology, and network functions; having capability of real-time collecting, communicating, and sensing, for which dynamic target locating and tracking is its critical task, as well as a basic element in its commercial and military application such as battlefield information accessing and traffic monitoring. Sensor target tracking is the technology of target location estimate based on measurements from corresponding sensors. An inaccurate estimated location may very easily lead to target tracking failure which reduces the reliability and stability of the target tracking [1]. Experts and scholars have done a lot of researches to solve problems exited in wireless sensor target tracking, and many new tracking algorithms have been proposed, among which tracking algorithms such as target contrail-fitting, linear prediction, Kalman filter, unscented Kalman filter(UKF) and particle filter[2] are most common applied. Sikdar, with his partners, has proposed target location tracking algorithm based on linear sensor which is proved better than conventional contrail fitting algorithm in its effects. Zhang Xiaoping , with his partners, has proposed WSN target tracking algorithm through modeling for quadratic polynomial motions which has improved target tracking accuracy[3]. However, there is a problem in common: all the algorithms above assume the tracking target contrail-fittings being in linear motion, while the actual contrail fitting is of uncertainty and variability, and the estimated accuracy can hardly be improved after being to a certain level. In this condition, the tracking error of the above algorithms can be greater [4]. Kalman filter algorithm can be applied for weakly nonlinear models, but for strongly nonlinear models, Unscented Kalman Filter algorithm can be better. Kalman filter work well in cases based on model-linear and Gaussian noise, thus its estimated accuracy is not that ideal [5, 6]. Particle filter algorithm is based on optimal regression Bayesian filtering algorithm in Monte Carlo simulation, which can accurately estimate the any distribution state with only a small amount of mobile anchor nodes. PF algorithm has distinguished advantages in processing non-linear, non-Gaussian cases [7]. However, in PF application process after several iterations, diversified degradation of the particles will occur, which is likely to lead a target tracking loss, thus further affect WSN target tracking accuracy [8]. In order to solve the diversified degradation of the particles in Particle Filter algorithm, this paper Research on the Target Tracking Algorithm for Wireless Sensor Network Based on Improved Particle Filter Liang Peng,Xinhan Huang, Li He

The unscented Kalman filter (UKF) has become a popular alternative to the extended Kalman filter (EKF) during the last decade. UKF propagates the so called sigma points by function evaluations using the unscented transformation (UT), and this is at first glance very different from the standard EKF algorithm which is based on a linearized model. The claimed advantages with UKF are that it propagates the first two moments of the posterior distribution and that it does not require gradients of the system model. We point out several less known links between EKF and UKF in terms of two conceptually different implementations of the Kalman filter: the standard one based on the discrete Riccati equation, and one based on a formula on conditional expectations that does not involve an explicit Riccati equation. First, it is shown that the sigma point function evaluations can be used in the classical EKF rather than an explicitly linearized model. Second, a less cited version of the EKF based on a second-order Taylor expansion is shown to be quite closely related to UKF. The different algorithms and results are illustrated with examples inspired by core observation models in target tracking and sensor network applications.

Underwater target tracking system can be kept covert using the bearing-only or the bearing-Doppler measurements (passive measurements), which will reduce the risk of been detected. According to the characteristics of underwater target tracking, the square root unscented Kalman filter (SRUKF) algorithm, which is based on the Bayesian theory, was applied to the underwater bearing-only and bearing-Doppler non-maneuverable target tracking problem. Aiming at the shortcomings of the unscented Kalman filter (UKF), the SRUKF uses the QR decomposition and the Cholesky factor updating, in order to avoid that the process noise covariance matrix loses its positive definiteness during the target tracking period. The SRUKF uses sigma sampling to avoid the linearization of the nonlinear bearing-only and the bearing-Doppler measurements. To ensure the target state observability in underwater target tracking, the paper uses single maneuvering observer to track the single non-maneuverable target. The simulation results show that the SRUKF has better tracking performance than the extended Kalman filter (EKF) and the UKF in tracking accuracy and stability, and the computational complexity of the SRUKF algorithm is low.

Radar systems are used for estimating the position and velocity of aircraft and ships from range and bearing measurements. In this article, we consider two motion models for a civilian aircraft: a constant velocity model and a coordinated turn model. Both kinematics models are written in state-space terms, where the velocity perturbations are modeled by a white noise acceleration model. In order to estimate the aircraft states given noisy measurements obtained from sensor outputs, we follow a Bayesian statistical approach that calculates the estimators of the unknown states. In our simulation, we recreate an air traffic control scenario and implement two nonlinear filtering algorithms in order to perform target tracking of the aircraft. The nonlinear Bayesian-based filters for this target tracking problem are the unscented Kalman filter and the Gauss-Hermite Kalman filter. Finally, the performance of both nonlinear filters is evaluated with a performance metric, root mean squared error, in Monte-Carlo runs.KeywordsTarget trackingUnscented Kalman filterGauss-Hermite Kalman filter

A target tracking method based on data fusion of infrared and radar is proposed to improve tracking precision. Unscented Kalman filter (UKF) is applied to process data on distributed fusion architectures. The method combines the advantages of UKF and track-to-track algorithms. The cross-covariances of the two sensors are used to estimate overall covariance and states. The overall estimation is obtained by the track-to-track fusion algorithm for the optimal combination of two correlated estimates. The proposed method is applied to simulating target tracking of infrared and radar. The simulation results show the proposed method has advantages in higher precision, and probability of detection is increased.

<div class="section abstract"><div class="htmlview paragraph">As a new form of electric vehicle, Four-wheel-independent electric vehicle with X-By-Wire (XBW) inherits all the advantages of in-wheel motor drive electric vehicles. The vehicle steering system is liberated from traditional mechanical steering mechanism and forms an advanced vehicle with all- wheel independent driving, braking and steering. Compared with conventional vehicles, it has more controllable degrees of freedom. The design of the integrated vehicle dynamics control systems helps to achieve the steering, driving and braking coordinated control and improves the vehicle's handling stability. In order to solve the problem of lacking of vehicle state information in the integrated control, some methods are used to estimate the vehicle state of four-wheel-independent electric vehicles with XBW. In order to improve the estimation accuracy, unscented Kalman filter (UKF) is used to estimate the vehicle state variables in this paper. At the same time, simulations in several typical working conditions have been carried out based on the simulation models of four-wheel- independent electric vehicle with XBW, which are established by CarSim and Simulink together. The simulation results show that: Unscented Kalman Filter can achieve a high-precision in the estimation of vehicle state.</div></div>

In this paper, according to the characteristics of underwater target tracking, extended Kalman filter (EKF) algorithm was applied to address underwater bearing-only non-maneuverable target tracking problem. To ensure the observability in bearing-only passive target tracking, we use two sensor arrays in uniform rectilinear motion to track the single target. EKF is recursive Bayesian filter algorithm based on the linearization of the nonlinearities in the state and the measurement system. And the simulation experiment shows that, to the constant velocity single target, the bearings-only EKF algorithm with dual-array has good results, also the EKF has lower computation complexity than unscented Kalman filter and particle filter. It confirms the effectiveness of the EKF algorithm in solving the underwater bearing-only target tracking problem.

Robust stable iterated unscented Kalman filter based on maximum correntropy criterion

RADAR plays a crucial role in target tracking. A faulty tracking is vulnerable to fatal errors. Since RADAR signals contain noise in them, filters are used to remove the noise. This paper implements Extended Kalman Filter (EKF), Unscented Kalman Filter (UKF) and Cubature Kalman Filter (CKF) for radar target tracking. Each filter is exposed to the same environment and the results are observed. A radar target tracking model is proposed with an input chirp signal of 77 GHz. The turn rate is varied between 0.2 and 150. The simulations are carried out in MATLAB. Since every simulation generates random motions of the target, the filter can be gauged only on the basis of how well the estimated trajectory follows the true trajectory. The findings have shown that EKF works best for large turn rate and high noise, in comparison to UKF and CKF, thus making it an appropriate choice for such applications.

An interacting multiple model based on unscented Kalman filter (IMM-UKF) is widely applied to positioning and tracking targets in various tracking scenarios. At the same time, visible light positioning (VLP) is developing rapidly due to the low cost and accuracy. Therefore, indoor positioning and tracking based on VLP combined with the IMM-UKF has attracted considerable interest. However, existing algorithms work on the assumption that the light-emitting diodes used for tracking are all point light sources, which ignores the geometry of these transmitters and results in low tracking accuracy. To overcome this problem, this paper proposes an innovative tracking algorithm based on VLP. This algorithm considers the shapes of the lights in combination with existing tracking algorithms, such as IMM-UKF. Simulation results show that in a standard Gaussian noise environment, the larger the transmitter is, the more meaningful the proposed algorithm is. INDEX TERMS Target positioning and tracking, visible light positioning (VLP), interacting multiple model (IMM), unscented Kalman filter (UKF), shapes of transmitters.

For localizing and tracking of an underwater maneuvering target by sonobuoys, a novel algorithm is proposed based on the scalar weight interactive multiple model (SIMM) and the unscented Kalman filter (UKF). Firstly, the SIMMUKF algorithm is directly obtained by combining the SIMM with the UKF. However, the filter estimation errors corresponding to each model are assumed to be uncorrelated in the SIMMUKF algorithm. In order to solve this problem, the multi-sensor optimal information fusion under the criterion of linear minimum variance is utilized to correct the estimated probability in the SIMMUKF algorithm. Then, a target motion model probability correction algorithm referred to as Modified-SIMMUKF (M-SIMMUKF) is obtained. The tracking accuracy of the M-SIMMUKF algorithm is higher. Numerical results validated the proposed scheme.

This paper describes an integrated system for automatic vehicle location and status reporting (AVM), and two-way mobile digital communications (MDC) operating in the 900 MHz band. In the AVM system developed by Hazeltine Corporation, vehicle location is derived from multilateration measurements in fixed site receivers (FSR's) deployed throughout the coverage area. These measurements are made on pulse transmissions from simple equipments in the vehicle and are relayed from FSR's to a central computer, where vehicle location is computed and presented on a CRT display. The basic AVM system also includes a two-way digital communications capability wherein vehicle status is appended to the location signal and transmitted to the dispatcher without use of the voice radio. The basic AVM system can be modularly expanded, using its digital communication capability to provide two-way transmission of extended length text messages between the dispatcher and vehicle operator. This is accomplished by (1) installing a mobile data terminal (MDT) in the vehicle, which communicates through the AVM transponder, and (2) by augmenting the central data processing sub-system to perform communications functions. The already-deployed FSR network needs no modification or expansion and land mobile radio channels are not required. In addition to dispatcher/vehicle data communications, the vehicle operator can directly access remote computer data bases via the MDT. Besides describing the basic AVM system, this paper summarizes the results of AVM test programs in Dallas and Philadelphia, and describes the Mobile Data Communication (MDC) capability of the integrated AVM/MDC system.

Target tracking, nonlinear control, and fault detection are typically evaluated with only a Root Mean Square (RMS). RMS is an absolute measurement of the system performance and does not provide a statistic as to the tracker, controller, or fault detection algorithmic performance. For this paper, we investigate the non-credibility index (NCI) and average normalized estimation error square (ANEES) for nonlinear estimation for the Kalman Filter (KF), the Central Difference Filter (DD1), the unscented Kalman filter (UKF), and the particle filter (PF). Fault detection and target track performance is dependent on target maneuvers, sensor errors, model parameters, and state estimation which need to be understood relative to the filter performance versus the absolute performance (i.e. root mean square) of the system. Utilizing the developments of the Nonlinear Estimation Framework (NEF) toolbox, we develop methods of nonlinear relative comparison performance between nonlinear filters in a unified scenario.

Heterogeneous multi-sensor’s fusion tracking can detect precise distance and angle to the target. For heterogeneous multi-sensor issues, radar, infrared sensor and laser sensor’s data fusion, and target tracking are studied, weighted fusion algorithm based on Lagrange and unscented kalman filter are adopted, which make date fusion and tracking filtering for target. Simulation results show that the radar / infrared / laser sensors can realize data fusion and tracking to the target, and the accuracy is significantly higher than radar and infrared/laser, and then tracking effect is better.

This paper compares state estimation techniques for nonlinear stochastic dynamic systems, which are important for target tracking. Recently, several methods for nonlinear state estimation have appeared utilizing various random-point-based approximations for global filters (e.g., particle filter and ensemble Kalman filter) and local filters (e.g., Monte-Carlo Kalman filter and stochastic integration filters). A special emphasis is placed on derivations, algorithms, and commonalities of these filters. All filters described are put into a common framework, and it is proved that within a single iteration, they provide asymptotically equivalent results. Additionally, some deterministic-point-based filters (e.g., unscented Kalman filter, cubature Kalman filter, and quadrature Kalman filter) are shown to be special cases of a random-point-based filter. The paper demonstrates and compares the filters in three examples, a random variable transformation, re-entry vehicle tracking, and bearings-only tracking. The results show that the stochastic integration filter provides better accuracy than the Monte-Carlo Kalman filter and the ensemble Kalman filter with lower computational costs.