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Time of arrival (TOA) based techniques are widely used in many ranging and localization problems. But because their performance highly depends on the accuracy of the TOA estimation of direct-paths, it's challenging to achieve accurate position estimations under dense multipath or Non-Line-of-Sight (NLOS) condition. In this paper, an algorithm which combines Time difference of arrival (TDOA) technique...
Distance measurement between nodes in wireless sensor networks is a prerequisite for a variety of applications and algorithms. However, special hardware allowing such measurements is expensive, especially if dealing with hundreds or thousands of nodes. Fekete et al. presented an approach on distance estimation based on only the neighborhood information available to all nodes in the network. We improve...
In many applications of Wireless Sensor Networks (WSN), it is crucial to know the location of sensor nodes. Although several methods have been proposed, most of them have poor performance in irregularly shaped networks. MDS-MAP is one of the localization methods based on multidimensional scaling (MDS) technique. It uses the connectivity information to derive the location of the nodes in the network...
The presence of undetected direct path conditions in the TOA (Time of Arrival)-based indoor geolocation introduces major errors into distance measurements. In the proposed location estimation, an improved procedure is introduced in Ultra-wideband (UWB) systems in Line of Sight (LOS) and Non-Line of Sight (NLOS) multipath environments by incorporating the skewness as new statistic information of multipath...
This paper compares methods of localization in order to try and reduce the processing overhead of optimal multi-lateration whilst still achieving close to its accuracy. Three methods of localization are examined, firstly optimal multi-lateration (OML), which provides the benchmark in terms of accuracy achievable. Secondly sub-optimal blind trilateration (SBT) which randomly selects the minimum feasible...
Nowadays, positioning favored to have the best accuracy to estimate position standing on the basis of time among all of estimation techniques. ToA estimation and TDoA estimation are typical techniques based on time. ToA is known that it is more accurate than TDoA but calculating time of ToA burden. Moreover, the calculating time increases with the increase of reference nodes. In this paper, we propose...
Distributed localization algorithm continues to be an important and challenging topic in today's wireless sensor networks (WSNs). The accurate estimations of distances among nodes are premises for the accurate estimations of node positions. In this paper, we propose some schemes towards the DV-Hop algorithm to improve the distance estimations. These improvements are based on accurate analysis of hop...
Simultaneous localization and mapping (SLAM) is an important topic in the autonomous mobile robot research. An improved Rao-Blackwellised particle filter (IRBPF) algorithm is proposed for the mobile robot to SLAM, which can simultaneously localize the robot and build up the map in the structured indoor environment. Firstly, IRBPF respectively uses particle filters (PF) to estimate the posterior probability...
This paper presents experiments on a method of estimating the size and perimeter length of a target object by using networked binary sensors whose locations are not known. Although these sensors only report whether the target object is detected or not, our proposed estimation method yields the size and the perimeter length of the target object by using sensors that have different sensing area sizes...
The subject of array calibration has received significant attention in recent years as it is increasingly recognized that undesired electromagnetic interactions, and more specifically mutual coupling between the array elements, can affect the array performance. However, it is currently unclear how the calibration should be performed to obtain the most accurate results and ensure the best performance...
In this paper we use the MAP criterion to locate a region containing a source. Sensors placed in a field of interest divide the latter into smaller regions and take measurements that are transmitted over noisy wireless channels. We propose implementations of our algorithm that consider complete and limited communication among sensors and seek to choose the most likely hypothesis. Each hypothesis corresponds...
In this paper, a novel distributed algorithm to deal with the problem of estimating the network centroid in a multi-agent system is proposed. In this scenario, agents are assumed to be lacking any global reference frame or absolute position information. The proposed algorithm can be thought as a general tool to retrieve information about the centroid of a network of agents. Indeed, this allows to...
Blind source extraction is one of the most important problems for multi-sensor networks. We propose a blind source extraction and deconvolution method in the presence of noise. We use MA-model for the signal generation model, and the convolutive observation model. The parameter of MA-model and the observations are obtained from an alternating least square (ALS) algorithm. The reconstruction is done...
In this paper, a particle swarm optimization (PSO) based multilateration algorithm is presented for a UWB communications based sensor network. The particle swarm uses simple operators and is a bottom-up approach for identifying the location in a 2D space. Hence the PSO uses less energy. For comparison we present two alternative approaches traditionally used for this problem. The first one is (a) traditional...
Aiming at the problem that cruise missiles may crash each other during their cooperative combat, the Time-Space intelligence Judge model of multi-path intersection was put forward. Owing to its complexity to judge based on analytic method, pixel-simulation method was adopted; Considering the deviation in the process of flight, base value of intersection judge was got by using the range estimation...
In this paper, we propose name resolution middleware that involves positional awareness to identify target hosts in wireless visible area communication (WVAC). WVAC is a wireless communication network that enables users to exchange information with nearby hosts, especially within the users' visible area, wherein the underlying network can be locally and temporarily constructed without the aid of any...
In this work, a new method to adaptively determine the weights of experts in group decision based on TOPSIS group ideal solution is developed, given the weights of attributes and subjective weights of experts. By adjusting the weights of experts according to the similarity between individual decision and group decision that is based on TOPSIS group ideal solution, the relatively stable weights of...
Several proposals have been presented to supplement the traditional measure of routing efficiency in P2P networks, i.e. the (average) number of hops for lookup operations, with measures of the latency incurred in the underlying network. So far, no solution has been presented to this ldquolatencyrdquo problem without incurring in extra and heavy management costs. We propose Relaxed-2-Chord, a new design...
Outlier detection is one of the common tasks in engineering applications. Its aim is to identify uncommon records from large amounts of data. Many efforts have been done to reach this goal. But different approach should be introduced according to different application area. In some engineering cases, much frequency uncommon records may appear in a short time. In this paper, a new method is put forward...
An accurate real-time application which locates mobile users in an indoor environment is highly demanded in hospitals, warehouses, etc., provided that minor changes in their infrastructure are required. Most present-day location techniques require a great calibration effort, or special devices which are not cost-effective. Avoiding these needs, this paper implements an autonomous positioning technique...
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