被动声传感器网时延概率定位算法

声传感器测量目标发出的声波信号存在纯方位量测、时延较大的特点,通过对多个声传感器组网,可以实现对目标的定位和时延校准处理.提出了一种被动声传感器网时延概率定位的综合处理算法.首先,对多个传感器量测数据进行动态选择,选出测向线交角更接近90°的两个传感器量测数据进行交叉定位,获得目标初始位置;其次,进行时延校准处理,并重新确定测向线交角更接近90°的两个传感器量测数据进行交叉定位.获得新的目标初始位置估计;最后,利用概率定位对新的初始位置进行概率修正,进而获得目标较为准确的位置估计,形成航迹.仿真结果表明,此算法具有计算量小,实时性强,定位精度高的特点.  

Learning Generative Models of Scene Features

We present a method for learning a set of generative models which are suitable for representing selected image-domain features of a scene as a function of changes in the camera viewpoint. Such models are important for robotic tasks, such as probabilistic position estimation (i.e. localization), as well as visualization. Our approach entails the automatic selection of the features, as well as the synthesis of models of their visual behavior. The model we propose is capable of generating maximum-likelihood views, as well as a measure of the likelihood of a particular view from a particular camera position. Training the models involves regularizing observations of the features from known camera locations. The uncertainty of the model is evaluated using cross validation, which allows for a priori evaluation of features and their attributes. The features themselves are initially selected as salient points by a measure of visual attention, and are tracked across multiple views. While the motivation for this work is for robot localization, the results have implications for image interpolation, image-based scene reconstruction and object recognition. This paper presents a formulation of the problem and illustrative experimental results.  

A survey on sensor localization

Localization is one of the fundamental problems in wireless sensor networks (WSNs), since locations of the sensor nodes are critical to both network operations and most application level tasks. Although the GPS based localization schemes can be used to determine node locations within a few meters, the cost of GPS devices and non-availability of GPS signals in confined environments prevent their use in large scale sensor networks. There exists an extensive body of research that aims at obtaining locations as well as spatial relations of nodes in WSNs without requiring specialized hardware and/or employing only a limited number of anchors that are aware of their own locations. In this paper, we present a comprehensive survey on sensor localization in WSNs covering motivations, problem formulations, solution approaches and performance summary. Future research issues will also be discussed.