Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
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 outdoor environments, the sound speed depends on the air characteristics, the most important being temperature and humidity. The accuracy of sound speed estimation has direct influence on performance of ultrasonic sensing applications, like those based on the distance measuring and the sound wavelength. In this paper, fuzzy estimation of sound speed is studied, using expert rules generated from...
In this paper, we study the problem of optimal trajectory generation for a team of mobile robots tracking a moving target using distance and bearing measurements. Contrary to previous approaches, we explicitly consider limits on the robots' speed and impose constraints on the minimum distance at which the robots are allowed to approach the target. We first address the case of a single sensor and show...
We present an approach to navigating a biped robot safely and efficiently through a complicated environment of previously unknown obstacles and terrain using only on-board sensing and odometry. Sensing of the environment is performed by a pivoting laser scanner, which continues to update the terrain representation as the robot walks. Safe stepping motions are planned from this data to follow the user's...
Vector acoustic field of the ocean provides associated information about pressure and particle velocity for acoustic signal processing, of which vector phase, like acoustic intensity and phase difference etc, includes a great deal of information related to source target, for instance, target depth and range etc. And it makes source localization feasible using a single vector sensor. Due to the influences...
In order to equip mobile robots for the measurement of distances in unstructured environments, we employed wide-band ultrasound transducers, based on ferroelectric polymer technology, to simulate the function of bio-sonar, according to strategies observed in the flight of bats. A complete electronic system was appropriately designed, which proved to be more efficient than the first prototype, having...
A novel time-of-flight (ToF) 3D-image sensor based on photogate (PG) active pixel structures fabricated in a standard 0.35 mum CMOS process is presented. Distance measurements are performed using a pulsed near-infrared (lambda = 905 nm) laser with pulse widths of 30 ns to 60 ns for distance measurements up to 9 m. The developed ToF pixel consists of a photogate (APG = 30 x 30 mum2) and four floating...
Transitioning nanoscale devices from the realm of one-of-a-kind feats into robust and reproducible nanosystems - that is, useable technology - is a monumental challenge that transcends the capabilities of any one laboratory. Some solid progress is now being achieved toward this end, and these efforts are critical for realizing the promise of ldquoactiverdquo nanotechnology. At least two essential...
In this paper, a novel compressive sensing for manifold learning protocol (CSML) is proposed for localization in wireless sensor networks (WSNs). Intersensor communication costs are reduced significantly by applying the theory of compressive sensing, which indicates that sparse signals can be recovered from far fewer samples than that needed by the Nyquist sampling theorem. We represent the pair-wise...
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...
Real-time positioning is an important part of the modern train control system. An efficient method to improve the positioning accuracy and reliability is the multi-sensor integrated positioning system, and GNSS is introduced to the existing train positioning based on odometer (ODO) in this paper, where the accuracy and error source of train positioning based on ODO are analyzed, and an effective slide...
In this paper we show how to accurately track position and orientation of a mobile robot using positioning only RF ultrasound transceiver system and dead-reckoning. The solution is based on geometrical displacement of the positioning device from the axis of rotation of the robot which brings dependency in position of the device and robot's orientation and enables the correction of the absolute orientation...
Single vehicle road departure (SVRD) is a main cause of enormous loss of life and property on highways. In total, SVRD accidents amount to around 20 percent of traffic accidents and 40 percent of fatalities in total. Recent developments of advanced driver assistant system (ADAS) such as lane departure warning (LDW) system which perceives road boundaries through optical sensors that trigger a warning...
In this note we consider centralized and decentralized control policies for the detection and containment of a moving source in 2D diffusion-advection PDE, often describing environmental processes. Such a task is enabled by the employment of a network of sensing devices judiciously located within the 2D spatial domain. These devices are assumed to have actuating capabilities aimed at containing the...
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...
In this paper, we study the localization problem in large-scale Underwater Wireless Sensor Networks (UWSNs). Unlike in the terrestrial positioning, the global positioning system (GPS) can not work efficiently underwater. The limited bandwidth, the severely impaired channel and the cost of underwater equipment all makes the localization problem very challenging. Most current localization schemes are...
We consider the recognition of dangerous situations in vehicle traffic. Unscented Kalman filters are used to predict vehicle trajectories within a short prediction horizon [t0, t0+ Deltat]. Based on this prediction, for each vehicle pair the mutual distance is computed for [t0, t0+ Deltat], whereby the distance accounts for the geometric distance, for the prediction uncertainties as well as for the...
Many anticipated deployment scenarios, in particular military, healthcare, and disaster-recovery applications, of Wireless Sensor Networks (WSNs) require reliable source to sink communication. Since transmission range of sensors is quite limited, to achieve higher end-to-end transmission reliability, WSNs generally employ intermediate backbone links (wired or wireless) that can deliver packets at...
In this paper, path loss measurements performed with low cost MicaZ modules used for on-body wireless sensor networks have been shown. By combining the experimental activities with simulation results based on simple canonical geometries, it has been possible to extract some simple path loss models. Time domain properties of the field attenuation are also under investigation. The path loss data will...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.