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A Particle Filter Approach to Approximate Posterior Cramer-Rao Lower Bound: The Case of Hidden States

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2013年第4期49卷 2478-2495页

作者： Tulsyan, Aditya Huang, Biao Gopaluni, R. Bhushan Forbes, J. Fraser Univ Alberta Edmonton AB T6G 2V4 Canada Univ Alberta Dept Chem & Mat Engn Edmonton AB T6G 2V4 Canada Univ British Columbia Dept Chem & Biol Engn Vancouver BC V5Z 1M9 Canada

The posterior Cramer-Rao lower bound (PCRLB) derived in [1] provides a bound on the mean square error (MSE) obtained with any nonlinear state filter. Computing the PCRLB involves solving complex, multi-dimensional expectations, which do not lend themselves to an easy analytical solution. Furthermore, any attempt to approximate it using numerical or simulation-based approaches require a priori access to the true states, which may not be available, except in simulations or in carefully designed experiments. To allow recursive approximation of the PCRLB when the states are hidden or unmeasured, a new approach based on sequential Monte-Carlo (SMC) or particle filters (PFs) is proposed. The approach uses SMC methods to estimate the hidden states using a sequence of the available sensor measurements. The developed method is general and can be used to approximate the PCRLB in nonlinear systems with non-Gaussian state and sensor noise. The efficacy of the developed method is illustrated on two simulation examples, including a practical problem of ballistic target tracking at reentry phase.

关键词： SIGNAL-to-noise ratio tracking algorithms ANALYTICAL solutions (Mathematical analysis) MONTE Carlo method RADAR targets NONLINEAR systems

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A Discrete-Time Chattering Free Sliding Mode Control with Multirate Sampling Method for Flight Simulator

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MATHEMATICAL PROBLEMS IN ENGINEERING 2013年第1期2013卷 1-8页

作者： Wu, Yunjie Liu, Youmin Zhang, Wulong Beihang Univ Sch Automat Sci & Elect Engn Beijing 100191 Peoples R China Beijing Simulat Ctr Natl Def Sci & Technol Key Lab Missile Control Sy Beijing 100854 Peoples R China

In order to improve the tracking accuracy of flight simulator and expend its frequency response, a multirate-sampling-method-based discrete-time chattering free sliding mode control is developed and imported into the systems. By constructing the multirate sampling sliding mode controller, the flight simulator can perfectly track a given reference signal with an arbitrarily small dynamic tracking error, and the problems caused by a contradiction of reference signal period and control period in traditional design method can be eliminated. It is proved by theoretical analysis that the extremely high dynamic tracking precision can be obtained. Meanwhile, the robustness is guaranteed by sliding mode control even though there are modeling mismatch, external disturbances and measure noise. The validity of the proposed method is confirmed by experiments on flight simulator.

关键词： DISCRETE-time systems SLIDING mode control SAMPLING (Statistics) ROBUST control MEASURE theory tracking algorithms

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Hidden Markov models for radio localization in mixed LOS/NLOS conditions

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2007年第4期55卷 1525-1542页

作者： Morelli, Carlo Nicoli, Monica Rampa, Vittorio Spagnolini, Umberto Politecn Milan Dipartimento Elettr & Informat I-20133 Milan Italy CNR IEIIT CNR I-20133 Milan Italy

This paper deals with the problem of radio localization of moving terminals (MTs) for indoor applications with mixed line-of-sight/non-line-of-sight (LOS/NLOS) conditions. To reduce false localizations, a grid-based Bayesian approach is proposed to jointly track the sequence of the positions and the sight conditions of the MT. This method is based on the assumption that both the MT position and the sight condition are Markov chains whose state is hidden in the received signals [hidden Markov model (HMM)]. The observations used for the HMM localization are obtained from the power-delay profile of the received signals. In ultrawideband (UWB) systems, the use of the whole power-delay profile, rather than the total power only, allows to reach higher localization accuracy, as the power-profile is a joint measurement of time of arrival and power. Numerical results show that the proposed HMM method improves the accuracy of localization with respect to conventional ranging methods, especially in mixed LOS/NLOS indoor environments.

关键词： Bayesian estimation hidden Markov models (HMM) mobile positioning source localization tracking algorithms ultra-wideband (UWB) communications wireless networks

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A comparative study of predictive transmit power control schemes for S-UMTS

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WIRELESS NETWORKS 2005年第3期11卷 215-222页

作者： Gombachika, HSH Tafazolli, R Evans, BG Univ Malawi Blantyre 3 Malawi Univ Surrey CCSR Surrey GU2 7XH England

Transmit power control is indispensable in Direct Sequence Code Division Multiple Access (DS/CDMA) based systems such as the Satellite Universal Mobile Telecommunication System (S-UMTS). Since S-UMTS aims at achieving close integration with the terrestrial component (T-UMTS) in its complementary role, it is going to implement closed-loop transmit power control (TPC) at a slow rate of once every frame. In addition, predictive schemes can be used to mitigate the effects of delay. In this regard, recursive-least-squares (RLS) and least-mean-square (LMS) algorithms are normally employed. The RLS algorithm has a higher convergence rate than the LMS algorithm: an attractive attribute when the fading process abruptly changes. The LMS algorithm, on the other hand, has better tracking property than the RLS algorithm: an attractive attribute when the changes in the fading process are persistently slow. However, the mobile satellite system channel exhibits both attributes: abrupt changes and slow drifts. In this paper, therefore, we compare the performance of predictive TPC based on the RLS and the LMS algorithms for S-UMTS with the conventional TPC as a reference. We demonstrate that the predictive TPC schemes perform better than the conventional TPC scheme. However, the performance gain achieved depends on the predictive algorithm used, the environment in which the user equipment is operating, and loop delays. We show that, in general, the LMS based predictive TPC offers better performance than the RLS based predictive TPC scheme in S-UMTS environment.

关键词： S-UMTS power control tracking algorithms predictive TPC

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The Fast Track Trigger at the H1 experiment design concepts and algorithms

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NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 2006年第1期566卷 130-132页

作者： Schoening, Andre ETH Honggerberg Inst Particle Phys CH-8093 Zurich Switzerland

The HI Collaboration has built a new Fast Track Trigger which performs a full reconstruction of charged particles in a high multiplicity environment. At the first trigger level (2.3 mu s) coarse tracks are reconstructed in two dimensions whereas at the second level (23 mu s) all tracks are reconstructed with high precision in all three dimensions. This allows to identify particle resonances at the third trigger level (<= 100 mu s). The conceptual design and the implementation of the fast track finding algorithms are discussed. First results from the 2005 running period are presented. (c) 2006 Elsevier B.V. All rights reserved.

关键词： H1 experiment track trigger tracking algorithms

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Vertical characteristics of cyclonic tracks over the eastern Mediterranean during the cold period of the year

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THEORETICAL AND APPLIED CLIMATOLOGY 2013年第3-4期112卷 375-388页

作者： Flocas, H. A. Kountouris, P. Kouroutzoglou, J. Hatzaki, M. Keay, K. Simmonds, I. Univ Athens Dept Environm Phys Meteorol Fac Phys Athens 15784 Greece Univ Melbourne Sch Earth Sci Melbourne Vic 3010 Australia Bur Meteorol Melbourne Vic Australia

The vertical structure of surface cyclonic tracks affecting the eastern Mediterranean region is studied on a climatological basis for the cold period of the year. The dataset used is the 1A degrees x 1A degrees ERA-40 Reanalysis for a 40-year period (1962-2001). The vertical tracking of surface cyclonic tracks was performed with the aid of the Melbourne University Vertical tracking Algorithm. It was found that about 83 % of the cyclones were extended up to the 500-hPa level and almost 65 % up to 200-hPa level, implying that the cyclones are in general well organized. The surface tracks that originate within the examined area exhibit the smallest vertical extension, intensity, radius, and depth compared to the cyclones originating in the other sectors. Moreover, the 500-hPa counterparts for the said cyclones are mainly located to the north-west or south-west of the surface cyclone position, consistent with the baroclinic character of the Mediterranean cyclones. The zonal (eastward) component of motion predominates both at the surface and at 500 hPa.

关键词： CYCLONES MEDITERRANEAN climate CLIMATE research tracking algorithms

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Visual Vehicle tracking Based on Deep Representation and Semisupervised Learning

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JOURNAL OF SENSORS 2017年第3-9期2017卷 6471250-6471250页

作者： Cai, Yingfeng Wang, Hai Sun, Xiao-qiang Chen, Long Jiangsu Univ Automot Engn Res Inst Zhenjiang 212013 Jiangsu Peoples R China Jiangsu Univ Sch Automot & Traff Engn Zhenjiang 212013 Jiangsu Peoples R China

Discriminative tracking methods use binary classification to discriminate between the foreground and background and have achieved some useful results. However, the use of labeled training samples is insufficient for them to achieve accurate tracking. Hence, discriminative classifiers must use their own classification results to update themselves, which may lead to feedback-induced tracking drift. To overcome these problems, we propose a semisupervised tracking algorithm that uses deep representation and transfer learning. Firstly, a 2D multilayer deep belief network is trained with a large amount of unlabeled samples. The nonlinear mapping point at the top of this network is subtracted as the feature dictionary. Then, this feature dictionary is utilized to transfer train and update a deep tracker. The positive samples for training are the tracked vehicles, and the negative samples are the background images. Finally, a particle filter is used to estimate vehicle position. We demonstrate experimentally that our proposed vehicle tracking algorithm can effectively restrain drift while also maintaining the adaption of vehicle appearance. Compared with similar algorithms, our method achieves a better tracking success rate and fewer average central-pixel errors.

关键词： tracking algorithms Supervised learning (Machine learning) Error analysis (Mathematics) Feedback control systems Image analysis

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A Minimax Unbiased Estimation Fusion in Distributed Multisensor Localization and tracking

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2012年第unknown期000卷 1-8页

作者： Qu, Xiaomei Zhou, Jie Sichuan Univ Coll Math Chengdu 610064 Sichuan Peoples R China SW Univ Nationalities Coll Comp Sci & Technol Chengdu 610041 Sichuan Peoples R China

A minimax estimation fusion in distributed multisensor systems is proposed, which aims to minimize the worst-case squared estimation error when the cross-covariances between local sensors are unknown and the normalized estimation errors of local sensors are norm bounded. The proposed estimation fusion is called as the Chebyshev fusion estimation (CFE) because its geometrical interpretation is in coincidence with the Chebyshev center, which is a nonlinear combination of local estimates. Theoretically, the CFE is better than any local estimator in the sense of the worst-case squared estimation error and is robust to the choice of the supporting bound. The simulation results illustrate that the proposed CFE is a robust fusion in localization and tracking and more accurate than the previous covariance intersection (CI) method.

关键词： MULTISENSOR data fusion tracking algorithms SAMPLING error (Statistics) NONLINEAR systems ROBUST control CHEBYSHEV systems

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Detection and tracking of Road Barrier Based on Radar and Vision Sensor Fusion

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JOURNAL OF SENSORS 2016年第9-26期2016卷 1963450-1963450页

作者： Kim, Taeryun Song, Bongsob Ajou Univ Dept Mech Engn Suwon 16499 South Korea

The detection and tracking algorithms of road barrier including tunnel and guardrail are proposed to enhance performance and reliability for driver assistance systems. Although the road barrier is one of the key features to determine a safe drivable area, it may be recognized incorrectly due to performance degradation of commercial sensors such as radar and monocular camera. Two frequent cases among many challenging problems are considered with the commercial sensors. The first case is that few tracks of radar to road barrier are detected due to material type of road barrier. The second one is inaccuracy of relative lateral position by radar, thus resulting in large variance of distance between a vehicle and road barrier. To overcome the problems, the detection and estimation algorithms of tracks corresponding to road barrier are proposed. Then, the tracking algorithm based on a probabilistic data association filter (PDAF) is used to reduce variation of lateral distance between vehicle and road barrier. Finally, the proposed algorithms are validated via field test data and their performance is compared with that of road barrier measured by lidar.

关键词： Guardrails on roads Image sensors Driver assistance systems Reliability (Engineering) tracking algorithms

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Multiphase bubbly flow visualization using particle image velocimetry

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VISUALIZATION AND IMAGING IN TRANSPORT PHENOMENA 2002年第1期972卷 223-228页

作者： Hassan, YA Texas A&M Univ Dept Nucl Engn College Stn TX 77843 USA

This article describes advances made in using particle image velocimetry (PIV) techniques in the study of multiphase bubbly flow. One of the fundamental issues in bubbly flow is the prediction of the velocity field. A methodology that allows for velocity field measurements of both components of a two-phase bubbly flow is presented. The bubble shape is also constructed via a shadow imaging technique combined with PIV.

关键词： bubbly flow particle image velocimetry tracking algorithms turbulence

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