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Many Location Based Services (LBS) have emerged in the past few years. However, the provision of underlying positioning technologies to support these services in indoor environments is still challenging. The indoor environment with its propagation complexity presents a burden to achieve affordable, high accuracy and real-time positioning. A recent development, the Improved FOCUSS for Arrival Time...
Localization is a major issue and a challenging task for underwater acoustic networks. The characteristics of underwater acoustic networks are fundamentally different from that of terrestrial networks. For example, it is not easy to get GPS into water and underwater acoustic networks often just have few anchors. Thus many of the localization schemes for terrestrial networks cannot be used directly...
Location awareness for wireless sensor networks has attracted significant interests in recent years. In hostile environments, there may be malicious attacks to mislead the location estimation of target nodes. In this paper, we propose a novel secured localization method by applying cooperative semi-definite programming (SDP) algorithm. We also introduce residual normalization to improve the SDP approximation...
As a new information acquisition and processing technology, wireless sensor networks can achieve tasks with complex large-scale monitoring and tracking in wide range of applications, but the localization for node itself is the basis of most applications. APIT is a major localization algorithm of ranged free algorithms, but the algorithm has the problems of big localization errors and low coverage...
Positioning in wireless networks has recently concentrated the interest of the research community. Outdoor positioning has been addressed successfully, but location indoors poses some open issues. Time-based ranging techniques, such as 2-way time-of-arrival (TOA), are promising for indoor positioning but present issues such as scalability and landmark dependency. Handling these problems separately...
It is often useful or even indispensable to know the locations of the nodes in a wireless sensor network (WSN), from both network functionality and applications point of view. A potential yet one of the most challenging method is to utilize received signal strength indicator (RSSI) for distance estimation. Albeit easily adopted, using of RSSI is notorious for imprecise distance estimates which can...
In this paper we demonstrate a design and experimentation of a relative localization solution for a multi robot team involving both ground and aerial robots. The relative localization method proposed in this paper has the ability to localize a dynamic agent with respect to only one leader ground robot in a GPS denied environment. The sensor solution proposed in the study employs a combination of an...
The localization of sensor nodes is one of the key issues for sensor network systems. Therefore, to obtain precise location information, several localization systems have been researched. However, they require an arranged space using a large number of anchor nodes whose locations are well known, or they need advance information such as radio conditions in the space. Otherwise, the systems cannot be...
To quickly deploy a location system at target sites, locator devices, so-called anchor nodes, are preferred to be portable and they are expected to self-localize their positions. Features of ultra-wideband impulse radio (UWB-IR) technology are suitable to design a self-localizable positioning system while maintaining a sub-meter accuracy for target localization. This paper discusses the design of...
This paper presents a novel ‘Energy Efficient Tracking’ (EET) algorithm that tries to meet the localization accuracy requirement, Pa, imposed by a generic location-based application while the energy consumption for ranging and communication is optimized. More specifically, given the set of range measurements performed by a mobile node with respect to its neighboring anchors (i.e., nodes whose exact...
Information on atmospheric pressure may be used in local positioning systems based on wireless sensors networks. This paper discusses the possibility of improving positioning accuracy in multistory buildings. Also pressure sensor data are used to save radio bandwidth and thus to decrease power consumption of radio modules. It is applicable especially in the systems with server-centric control of ranging...
In this paper a detailed analysis of an UltraWideband correlation receiver is presented. The synchronization methods are discussed and analyzed in terms of practical realizability. All algorithms are implemented on FPGA and tested with a real UWB transceiver. The measurement results are then evaluated and compared to the ones found in the literature. Finally an application example for the correlation...
In the recent decades, short-range wireless has become of great importance in the applications of Intelligent Transportation Systems (ITS); especially, that serve traffic management and safety. Various approaches are concerned with optimal positioning of a vehicle and Base-Stations (BSs) placement within a specific area. The optimization problem stands as an exhaustive challenge. This paper discuses...
The development of cooperative vehicle safety (CVS) applications, such as collision warnings, turning assistants, and speed advisories, etc., has received great attention in the past few years. Accurate vehicular localization is essential to enable these applications. In this study, motivated by the proliferation of the Global Positioning System (GPS) devices, and the increasing sophistication of...
In this paper, a tracking scheme based on adaptive weighted technique is proposed to reduce the computational load of traditional data-fusion algorithm for heterogeneous measurements. For the location-estimation technique with the data fusion of radio-based ranging measurement and speed-based sensing measurement, the proposed tracking scheme based on the Bayesian approach is handled by a state space...
In this paper we demonstrate results of a technique for synchronizing clocks and estimating ranges between a pair of RF transceivers. The technique uses a periodic exchange of ranging waveforms between two transceivers along with sophisticated delay estimation and tracking. The technique was implemented on wireless testbed transceivers with independent clocks and tested over-the-air in stationary...
To improve the positioning accuracy of the vision system for apple-picking robot, a method characterized by a marker to recover the spatial location of the apple is proposed. Then the spatial location of the apple obtained with the stem as the matched point is accomplished to get its corresponding depth value of different working distances. Finally, the measured distance with the marker is as a reference...
Due to the decentralized nature of structured P2P systems, there is no a direct way for a single node of getting aggregate statistics about the whole network, such as its current size. In this paper we focus on the problem of estimating the size of one of the most popular structured P2P networks, Chord, using a sampling-based approach. With this approach, a node calculates an estimate of the network...
In order to study influence rules of the obstacle's material, placed distance and deflection angle on the ultrasonic sensor ranging accuracy in the mobile robot, the quadratic orthogonal rotational combination design was carried out. The ranging data was collected by using ultrasonic sensors in the mobile robot, and then the changing curves and regression equations of various factors interaction were...
In this paper we address the problem of minimizing the energy cost of positioning a node in a wireless sensor network, using time of arrival measurements. A sensor needs to receive at least three distance measurements to known anchors in order to position itself. The accuracy of its position estimation depends on the signal to noise ratio of the beacons from the anchor nodes, whose power levels are...
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