Multi‐sensor track‐to‐track fusion via linear minimum variance sense estimators

An integrated approach that consists of sensor‐based filtering algorithms, local processors, and a global processor is employed to describe the distributed fusion problem when several sensors execute surveillance over a certain area. For the sensor tracking systems, each filtering algorithm utilized in the reference Cartesian coordinate system is presented for target tracking, with the radar measuring range, bearing, and elevation angle in the spherical coordinate system (SCS). For the local processors, each track‐to‐track fusion algorithm is used to merge two tracks representing the same target. The number of 2‐combinations of a set with N distinct sensors is considered for central track fusion. For the global processor, the data fusion algorithms, simplified maximum likelihood (SML) estimator and covariance matching method (CMM), based on linear minimum variance (LMV) estimation fusion theory, are developed for use in a centralized track‐to‐track fusion situation. The resulting global fusers can be implemented in a parallel structure to facilitate estimation fusion calculation. Simulation results show that the proposed SML estimator has a more robust capability of improving tracking accuracy than the CMM and the LMV estimators. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Information fusion for automotive applications – An overview

This article focusses on the fusion of information from various automotive sensors like radar, video, and lidar for enhanced safety and traffic efficiency. Fusion is not restricted to data from sensors onboard the same vehicle but vehicular communication systems allow to propagate and fuse information with sensor data from other vehicles or from the road infrastructure as well. This enables vehicles to perceive information from regions that are hardly accessible otherwise and represents the basis for cooperative driving maneuvers. While the Bayesian framework builds the basis for information fusion, automobile environments are characterized by their a priori unknown topology, i.e., the number, type, and structure of the perceived objects is highly variable. Multi-object detection and tracking methods are a first step to cope with this challenge. Obviously, the existence or non-existence of an object is of paramount importance for safe driving. Such decisions are highly influenced by the association step that assigns sensor measurements to object tracks. Methods that involve multiple sequences of binary assignments are compared with soft-assignment strategies. Finally, fusion based on finite set statistics that (theoretically) avoid an explicit association are discussed.     

Autonomous collision detection and avoidance for ARAGON USV: Development and field tests

This study addresses the development of algorithms for multiple target detection and tracking in the framework of sensor fusion and its application to autonomous navigation and collision avoidance systems for the unmanned surface vehicle (USV) Aragon. To provide autonomous navigation capabilities, various perception sensors such as radar, lidar, and cameras have been mounted on the USV platform and automatic ship detection algorithms are applied to the sensor measurements. The relative position information between the USV and nearby objects is obtained to estimate the motion of the target objects in a sensor‐level tracking filter. The estimated motion information from the individual tracking filters is then combined in a central‐level fusion tracker to achieve persistent and reliable target tracking performance. For automatic ship collision avoidance, the combined track data are used as obstacle information, and appropriate collision avoidance maneuvers are designed and executed in accordance with the international regulations for preventing collisions at sea (COLREGs). In this paper, the development processes of the vehicle platform and the autonomous navigation algorithms are described, and the results of field experiments are presented and discussed.     

基于加权证据理论的模糊信息融合目标识别

在异类多传感器信息融合目标识别中,不同传感器对系统提供的证据等级不同。为此,提出一种模糊信息融合目标识别方法。将各证据按证据权进行转化,用Dempster-Shafer(D-S)证据理论进行合成,利用模糊数学模型对传感器测量值和数据库中的数据进行建模,根据证据距离得到各证据的相互支持度,进而获得传感器对系统提供信息量的权重。分析结果表明,该方法具有较高的精度和可靠性。     

On exploiting ‘negative’ sensor evidence for target tracking and sensor data fusion

In various applications of target tracking and sensor data fusion all available information related to the sensor systems used and the underlying scenario should be exploited for improving the tracking/fusion results. Besides the individual sensor measurements themselves, this in particular includes the use of more refined models for describing the sensor performance. By incorporating this type of background information into the processing chain, it is possible to exploit ‘negative’ sensor evidence. The notion of ‘negative’ sensor evidence covers the conclusions to be drawn from expected but actually missing sensor measurements for improving the position or velocity estimates of targets under track. Even a failed attempt to detect a target is a useful sensor output, which can be exploited by appropriate sensor models providing background information. The basic idea is illustrated by selected examples taken from more advanced tracking and sensor data fusion applications such as group target tracking, tracking with agile beam radar, ground moving target tracking, or tracking under jamming conditions.     

红外/雷达双模导引头融合器硬件及软件实现

基于单传感器(雷达或红外)的系统存在着局限性。介绍了基于多传感器(雷达和红外)信号融合的目标识别和跟踪系统,它能利用不同传感器的数据互补和冗余。主要讨论了利用DSP处理芯片为核心的控制器的硬件设计与软件的实现。该控制器利用雷达系统与红外系统的信号对导弹进行控制。在较远距离时,该控制器利用雷达系统的信号对导引头进行控制,同时利用该信号对红外伺服系统进行控制,在较近距离时,当红外系统在控制下稳定跟踪目标后,该设备将原先的雷达系统控制信号转换为更精确的红外系统控制信号。     

A new multiple decisions fusion rule for targets detection in multiple sensors distributed detection systems with data fusion

Currently, multiple sensors distributed detection systems with data fusion are used extensively in both civilian and military applications. The optimality of most detection fusion rules implemented in these systems relies on the knowledge of probability distributions for all distributed sensors. The overall detection performance of the central processor is often worse than expected due to instabilities of the sensors probability density functions. This paper proposes a new multiple decisions fusion rule for targets detection in distributed multiple sensor systems with data fusion. Unlike the published studies, in which the overall decision is based on single binary decision from each individual sensor and requires the knowledge of the sensors probability distributions, the proposed fusion method derives the overall decision based on multiple decisions from each individual sensor assuming that the probability distributions are not known. Therefore, the proposed fusion rule is insensitive to instabilities of the sensors probability distributions. The proposed multiple decisions fusion rule is derived and its overall performance is evaluated. Comparisons with the performance of single sensor, optimum hard detection, optimum centralized detection, and a multiple thresholds decision fusion, are also provided. The results show that the proposed multiple decisions fusion rule has higher performance than the optimum hard detection and the multiple thresholds detection systems. Thus it reduces the loss in performance between the optimum centralized detection and the optimum hard detection systems. Extension of the proposed method to the case of target detection when some probability density functions are known and applications to binary communication systems are also addressed.     

Geo-referenced flight path estimation based on spatio-temporal information extracted from aircraft take-off noise

The closer proximity between airports and residential areas has created a growing attention regarding noise pollution. The noise abatement procedures established by the aeronautical authorities and the models for computing noise contours around airports are proof of that. There are also models for identifying aircraft taking off which have focused on the correlation between the aircraft position and the noise signal. However, this correlation has been made so far without spatial information. The present study proposes a method to estimate the geo-referenced flight path followed by an aircraft taking off, using the spatio-temporal information extracted from the noise signal and improved with a smoothing algorithm. A microphone array with twelve sensors is used in order to evaluate different sensor spacings and the spatial aliasing effect when working with take-off noise signals. The flight path estimation method assumes that the aircraft is following a ground track collinear to the runway and was compared against radar information and Automatic Dependent Surveillance-Broadcast (ADS-B) data. The average method accuracy was between 3 and 6 meters. The estimated flight path has a ground length of about two kilometers, including locations at least one kilometer apart from the measurement point.     

An integrated highly synchronous,high resolution,real time eye tracking system for dynamic flight movement

Electronic surveillance systems are being used rapidly today, ranging from a simple video camera to a complex biometric surveillance system for facial patterns and intelligent computer vision based surveillance systems, which are applied in many fields such as home monitoring, security surveillance of important places and mission critical tasks like air traffic control surveillance. Such systems normally involve a computer system and a human surveillance operator, who looks at the dynamic display to perform his surveillance tasks. Exploitation of shared information between these physical heterogeneous data capture systems with human operated functions is one emerging aspect in electronic surveillance that has yet to be addressed deeply. Hence, an innovative interaction interface for such knowledge extraction and representation is required. Such an interface should establish a data activity register frame which captures information depicting various surveillance activities at a specified spatial and time reference.This paper presents a real time eye tracking system, which integrates two sets of activity data in a highly dynamic changing and synchronous manner in real-time with respect to both spatial and time frames, through the “Dynamic Data Alignment and Timestamp Synchronisation Model”. This model matches the timestamps of the two data streams, aligns them to the same spatial reference frame before fusing them together into a data activity register frame. The Air Traffic Control (ATC) domain is used to illustrate this model, where experiments are conducted under simulated radar traffic situations with participants and their radar input data. Test results revealed that this model is able to synchronise the timestamp of the eye and dynamic display data, align both of these data spatially, while taking into account dynamic changes in space and time on a simulated radar display. This system can also distinguish and show variations in the monitoring behaviour of participants. As such, new knowledge can be extracted and represented through this innovative interface, which can then be applied to other applications in the field of electronic surveillance to unearth monitoring behaviour of the human surveillance operator.     

基于相似性测度的异类传感器的数据融合算法

雷达具有较好的测距性能,红外传感器具有高精度的测角性能。雷达和红外传感器是异类传感器系统的一个典型组合,但是异类传感器信息融合因没有现成的数学工具和方法而面临诸多困难。提出一种基于相似性测度的数据融合方法,能够有效提高数据正确关联概率和多目标跟踪的精度。     

基于ADS-B和WEB的雷达精度分析系统

为便捷的解决雷达精度标定问题,本文介绍了一种基于广播式自动相关监视系统（ADS-B）的雷达精度准实时分析系统。针对民航航迹用于雷达动态精度分析的可行性,从ADS-B数据率、位置精度、最大可接收距离等多个方面进行了探讨,并搭建原理样机在高精度雷达上进行了验证、标定。最后基于WEB架构设计了雷达精度实时分析系统,系统在某中远程雷达上进行多个批次测试,结果表明该方法有效且可行。     

低空目标的雷达/可见光协同监视跟踪方法研究

近年来,随着通用航空和旋翼无人机的飞速发展,对相关空域的安全性监视与管理提出了迫切要求。由于雷达在低空空域存在探测盲区,极易受到杂波干扰,无法准确获取目标信息,而ADS-B系统大规模布设存在局限性,低空空域的有效监视与管理成为研究的热点。研究了一种低空目标的雷达/可见光协同监视跟踪方法,该方法基于跟踪-学习-检测（TLD）架构,将雷达作为主跟踪器,可见光传感器作为检测器,通过交互多模型算法和学习器实现量测模型切换和数据在线更新,从而获取更准确的目标状态信息,实现低空空域更精确的监视和目标跟踪,数据仿真说明了该方法的有效性。     

ADS-B与TCAS II数据融合算法研究

面对空中交通密度越来越大,TCAS II在实际应用中暴露出的虚警和不必要告警等问题愈加明显。为了提供可靠连续的监视信息,提高防撞系统的性能,给出了一种ADS-B与TCAS II组合监视数据融合算法。该算法首先建立了飞机状态空间模型,并分析了ADS-B和TCAS II数据内容和特点,然后研究了数据融合前需要解决的关键问题,利用Kalman滤波器对数据进行处理,采用了在线性最小方差意义下的按标量加权最优信息融合准则和算法对数据进行融合。对该算法进行仿真,结果表明融合后的数据估计误差比任何一个传感器单独估计的误差都要小,说明该算法能够得到较高精度的数据,有效增强了防撞系统的性能。     

Coordinated dispatching of proximity sensors for the surveillance of manoeuvring targets

The surveillance of a manoeuvring target with multiple sensors in a coordinated manner requires a method for selecting and positioning groups of sensors in real time. Herein, the principles of dispatching, as used for the effective operation of service vehicles, are considered. The object trajectory is first discretized into a number of demand instants (data acquisition times), to which groups of sensors are assigned, respectively. Heuristic rules are used to determine the composition of each sensor group by evaluating the potential contribution of each sensor. In the case of dynamic sensors, the position of each sensor with respect to the target is also specified. Our proposed approach aims to improve the quality of the surveillance data in three ways: (1) The assigned sensors are manoeuvred into “optimal” sensing positions, (2) the uncertainty of the measured data is mitigated through sensor fusion, and (3) the poses of the unassigned sensors are adjusted to ensure that the surveillance system can react to future object manoeuvres. If a priori target trajectory information is available, the system performance may be further improved by optimizing the initial pose of each sensor off-line. The advantages of dispatching dynamic sensors over similar static-sensor systems are demonstrated through comprehensive simulations.     

要地防护反无人机系统设计与实现

提出了一种要地防护反无人机系统设计与实现方法,重点解决了雷达、光电红外、无线电侦测等异类传感器的数据融合以及协同探测等问题.针对小型无人机目标特性,提出了基于多源异类传感器的航迹融合规则;针对雷达与光电红外协同精度不匹配的问题,提出一种光电扇扫搜索的方法,实现了对小型无人机的多传感器接力探测与连续稳定跟踪及有效反制.该系统已在某国家公祭日安保、某核电站低空保障等实践中得到应用实践,有效提高了对小型无人机的探测、跟踪、识别、处置能力.     

A low-complexity sensor fusion algorithm based on a fiber-optic gyroscope aided camera pose estimation system

Visual tracking, as a popular computer vision technique, has a wide range of applications, such as camera pose estimation. Conventional methods for it are mostly based on vision only, which are complex for image processing due to the use of only one sensor. This paper proposes a novel sensor fusion algorithm fusing the data from the camera and the fiber-optic gyroscope. In this system, the camera acquires images and detects the object directly at the beginning of each tracking stage; while the relative motion between the camera and the object measured by the fiber-optic gyroscope can track the object coordinate so that it can improve the effectiveness of visual tracking. Therefore, the sensor fusion algorithm presented based on the tracking system can overcome the drawbacks of the two sensors and take advantage of the sensor fusion to track the object accurately. In addition, the computational complexity of our proposed algorithm is obviously lower compared with the existing approaches(86% reducing for a 0.5 min visual tracking). Experiment results show that this visual tracking system reduces the tracking error by 6.15% comparing with the conventional vision-only tracking scheme(edge detection), and our proposed sensor fusion algorithm can achieve a long-term tracking with the help of bias drift suppression calibration.     

飞机强度试验中结构健康监测采集控制系统

针对结构健康监测在全机疲劳试验中需要采用多种监测系统的特点,结合飞机强度疲劳试验对数据采集的要求,设计了一种将光栅光纤传感器、压电传感器和声发射传感器等集成为一体的飞机结构健康监测系统.设计了多类型传感器采集控制系统,其中采用了分布式、多任务的结构设计,解决了多台设备采集数据的同步性、有效性和一致性.针对多类传感器的数据源多、数据类型多的特点,设计了通用数据结构解决了多类传感器的数据合并处理问题.通过在某全机疲劳试验中的运用,验证了本系统是一种稳定、高效、易扩展的多传感器健康监测集成系统,能够获取更加可靠、全面的健康监测数据,为健康监测在全机疲劳试验中损伤的准确识别,提供了强有力的支撑.     

星基ADS-B监视性能评估软件设计与实现

星基ADS-B是实现广域范围内航空器监视的重要技术手段.为解决星基ADS-B系统监视性能指标评测问题,设计实现了星基ADS-B监视性能评估软件.阐述监视性能评估技术指标及评估方法,介绍了星基ADS-B监视性能评估软件的总体架构,详细叙述了数据接入与处理模块、航迹显示模块及监视性能评估模块的设计思路.利用天拓实验卫星数据...     

Radar sensor network resource allocation for fused target tracking: A brief review

Traditional networked radar fusion technology adopts an open-loop signal processing manner, in which multiple nodes independently detect or track target first, and then send their raw data or processed measurements to the fusion center for target state estimation. In such a working manner, each radar sensor operates within predetermined rules, adopts fixed transmit and receiving mode for changeable target tracking environment, and thus will definitely cause an insufficient use of its limited resource. Resource allocation (RA) has emerged as a promising technology to exploit the limited radar resource in a more efficient way by allocating the available resource parameters w.r.t. multiple nodes collaboratively in view of the fused target tracking performance. The goal of this paper is to provide a brief overview of the RA methods for fused target tracking in radar sensor network. We mainly investigate the existing RA works and divide them into two types, namely tracking quality constrained RA type and performance driven RA type. Solution techniques for both types appeared in the literatures are also summarized. Finally, some potential future research directions in this field are discussed.     

基于模糊推理的多传感器数据融合方法

针对多传感器目标跟踪系统可能出现的传感器漏检现象,提出了一种基于模糊推理的消除漏检现象影响的方法。该算法根据各传感器的量测变化,及时调整参与融合的各传感器量测的数目及其加权系数,保证量测融合值的有效性。通过对两个传感器进行数据融合和目标跟踪的仿真表明,该算法是一种简单有效,有工程应用前景的数据处理算法。该方法同样适用于多于两个传感器的多传感器融合系统。