scholarly journals Optimal Sensor Formation for 3D Cooperative Localization of AUVs Using Time Difference of Arrival (TDOA) Method

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4442 ◽  
Author(s):  
Xu Bo ◽  
Asghar Razzaqi ◽  
Xiaoyu Wang

The cooperative localization of submerged autonomous underwater vehicles (AUVs) using the Time Difference of Arrival (TDOA) measurements of surface AUV sensors is an effective method for many applications of AUVs. Proper positioning of the sensors to maximize the observability of the AUVs is very critical for cooperative localization. In this paper, a novel method for obtaining the optimal formation of sensor AUVs has been presented for the three-dimensional (3D) cooperative localization of targets using the TDOA technique. An evaluation function for estimating the optimal formation has been derived based on Fisher Information Matrix (FIM) theory for a single target as well as multiple-target cooperative localization systems. An iterative stepping algorithm has been followed to solve the evaluation function and obtain the optimal positions of the sensors. The algorithm ensured that the computation complexity should remain limited, even when the number of sensor AUVs is increased. Various simulation examples are then presented to calculate the optimal formation for different systems/situations. The effect of the position of the reference sensor and operating depth of the target AUVs on the optimal formation of the sensors has also been studied, and conclusions are drawn. For implementation of the proposed method for more practical scenarios, a simulation example is also presented for cases when the target’s position is only known with uncertainty.

2019 ◽  
Vol 9 (7) ◽  
pp. 1428 ◽  
Author(s):  
Ran Wang ◽  
Xin Wang ◽  
MingMing Zhu ◽  
YinFu Lin

Autonomous underwater vehicles (AUVs) are widely used, but it is a tough challenge to guarantee the underwater location accuracy of AUVs. In this paper, a novel method is proposed to improve the accuracy of vision-based localization systems in feature-poor underwater environments. The traditional stereo visual simultaneous localization and mapping (SLAM) algorithm, which relies on the detection of tracking features, is used to estimate the position of the camera and establish a map of the environment. However, it is hard to find enough reliable point features in underwater environments and thus the performance of the algorithm is reduced. A stereo point and line SLAM (PL-SLAM) algorithm for localization, which utilizes point and line information simultaneously, was investigated in this study to resolve the problem. Experiments with an AR-marker (Augmented Reality-marker) were carried out to validate the accuracy and effect of the investigated algorithm.


Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5776
Author(s):  
Karol Klincewicz ◽  
Piotr Samczyński

This paper presents a novel method of calculating desynchronization between transmitters working in a single frequency digital video broadcasting-terrestrial (DVB-T) network. The described method can be a useful tool for enhancing passive radar operations and improving passive coherent location (PCL) sensors to correct their measurements of target localization. The paper presents the problem of localizing DVB-T transmitters utilized by passive radars, and proposes a novel method based on Time Difference of Arrival (TDoA) techniques to solve the problem. The proposed technique has been validated using real signals collected by a PCL sensor receiver. The details of the experiment and extensive result analysis are also contained in this article.


Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2892 ◽  
Author(s):  
Javier Díez-González ◽  
Rubén Álvarez ◽  
Lidia Sánchez-González ◽  
Laura Fernández-Robles ◽  
Hilde Pérez ◽  
...  

Time difference of arrival (TDOA) positioning methods have experienced growing importance over the last few years due to their multiple applications in local positioning systems (LPSs). While five sensors are needed to determine an unequivocal three-dimensional position, systems with four nodes present two different solutions that cannot be discarded according to mathematical standards. In this paper, a new methodology to solve the 3D TDOA problems in a sensor network with four beacons is proposed. A confidence interval, which is defined in this paper as a sphere, is defined to use positioning algorithms with four different nodes. It is proven that the separation between solutions in the four-beacon TDOA problem allows the transformation of the problem into an analogous one in which more receivers are implied due to the geometric properties of the intersection of hyperboloids. The achievement of the distance between solutions needs the application of genetic algorithms in order to find an optimized sensor distribution. Results show that positioning algorithms can be used 96.7% of the time with total security in cases where vehicles travel at less than 25 m/s.


2019 ◽  
Vol 11 (7) ◽  
pp. 593-601 ◽  
Author(s):  
Vitomir Djaja-Josko ◽  
Jerzy Kolakowski ◽  
Jozef Modelski

AbstractNowadays, as indoor localization is getting more popular, there is a growing need for reliable and accurate techniques of position determination. Recently, ultrawideband (UWB)-based systems are gaining popularity, since they make achieving positioning errors in the range of dozens of centimeters or even single centimeters, possible. The Time Difference of Arrival (TDOA)-based systems are especially attractive because they allow to simplify tags, in which functionality can be limited to transmission of packets. However, one of TDOA-based solution drawbacks is a need for strict synchronization between anchor nodes, which may be hard to provide in indoor environment. In the paper, a novel method for simplifying synchronization in TDOA-based UWB localization system is described. The paper presents two system architectures based on pairs of synchronized nodes. Results of simulations and experiments included in the article allow for evaluation of both solutions.


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