scholarly journals Positioning Combination Method of USBL Using Four-Element Stereo Array

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7722
Author(s):  
Wei Wang ◽  
Min Zhu ◽  
Bo Yang
Keyword(s):  
Incident Angle ◽  
Combination Method ◽  
Short Baseline ◽  
Localization Method ◽  
Triangular Pyramid ◽  
The Poor ◽  
Planar Array ◽  
Virtual Array ◽  
Simulation Results ◽  
Localization Approach

In the present article, an ultra-short baseline (USBL) combined location method based on three four-element stereo arrays is proposed. In order to solve the problem of the poor positioning effect of acoustic positioning under a high incident angle of signal, two kinds of four-element stereo arrays are designed, and the localization approach of the new array is given. At the same time, for the regular triangular pyramid array, a virtual array element is proposed to construct a planar cross array to improve the poor positioning effect of the regular triangular pyramid array at a low incident angle. This paper analyzes the positioning performance of three arrays. Combined with the traditional cross-planar array localization method, a set of positioning strategies to switch the two localization methods under different incident angles were designed. The switching thresholds of the two methods were analyzed by simulation. Simulation results show that the new arrays can locate stably at different incident angles and improve the overall positioning performance of the array.

scholarly journals An Improved Localization Method for the Transition between Autonomous Underwater Vehicle Homing and Docking

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2468
Author(s):  
Ri Lin ◽  
Feng Zhang ◽  
Dejun Li ◽  
Mingwei Lin ◽  
Gengli Zhou ◽  
...  
Keyword(s):  
Data Exchange ◽  
Autonomous Underwater Vehicle ◽  
Autonomous Underwater Vehicles ◽  
Optimization Method ◽  
Short Baseline ◽  
Localization Accuracy ◽  
Localization Method ◽  
Mapping Algorithm ◽  
Localization And Mapping ◽  
Update Rate

Docking technology for autonomous underwater vehicles (AUVs) involves energy supply, data exchange and navigation, and plays an important role to extend the endurance of the AUVs. The navigation method used in the transition between AUV homing and docking influences subsequent tasks. How to improve the accuracy of the navigation in this stage is important. However, when using ultra-short baseline (USBL), outliers and slow localization updating rates could possibly cause localization errors. Optical navigation methods using underwater lights and cameras are easily affected by the ambient light. All these may reduce the rate of successful docking. In this paper, research on an improved localization method based on multi-sensor information fusion is carried out. To improve the localization performance of AUVs under motion mutation and light variation conditions, an improved underwater simultaneous localization and mapping algorithm based on ORB features (IU-ORBSALM) is proposed. A nonlinear optimization method is proposed to optimize the scale of monocular visual odometry in IU-ORBSLAM and the AUV pose. Localization tests and five docking missions are executed in a swimming pool. The localization results indicate that the localization accuracy and update rate are both improved. The 100% successful docking rate achieved verifies the feasibility of the proposed localization method.

Monte Carlo calculation of A 3 B (111) ordering transition and surface X-ray intensities

1990 ◽  
Vol 46 (2) ◽  
pp. 86-94 ◽  
Author(s):  
X.-M. Zhu ◽  
H. Zabel
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Calculation ◽  
Incident Angle ◽  
Surface Region ◽  
Conducting Surface ◽  
X Ray ◽  
Main Emphasis ◽  
Simulation Results ◽  
Ordering Transition ◽  
Surface Diffraction

A Monte Carlo simulation of an ordering phase transition in the surface region of a f.c.c.-type A 3 B binary alloy is reported. The main emphasis of this simulation is the evaluation of short and long-range-order correlations near the surface which are used for calculating X-ray intensities under grazing-incident-angle conditions. These calculations suggest effective ways of conducting surface diffraction experiments on order-disorder phase transitions. The simulation results are also compared with available experimental data.

scholarly journals Increasing Utilization of Redundant Virtual Array for DOA Estimation Based on Coprime Array

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Chenghong Zhan ◽  
Guoping Hu ◽  
Zixin Zhang ◽  
Ziang Feng
Keyword(s):  
Parameter Estimation ◽  
High Precision ◽  
Degrees Of Freedom ◽  
Doa Estimation ◽  
Far Field ◽  
Virtual Array ◽  
Previous Algorithm ◽  
Array Structure ◽  
Simulation Results ◽  
Coprime Array

In this paper, we initiated a method to estimate the direction of arrival (DOA) of far-field, narrowband, and incoherent targets using coprime array. First, we proposed a coprime array structure and analysed the distribution of difference coarray (DCA). The degrees of freedom (DOF) of the proposed coprime array became clearer by referring to the DCA conception. However, previous algorithm only uses the continuous virtual array, which causes the virtual array elements in the repeated position being abandoned. Therefore, the paper analyses the distribution of virtual array based on DCA conception and averages the receiving signal on these redundant virtual array elements to increase the utilization of receiving data. As a result, the algorithm has high precision in parameter estimation. Simulation results have shown the superiority of the proposed algorithm.

A Collaborative Multilateral Localization Algorithm for Wireless Sensor Networks

2013 ◽  
Vol 303-306 ◽  
pp. 201-205
Author(s):  
Shao Ping Zhang
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Optimization Method ◽  
Wireless Sensor ◽  
Localization Algorithm ◽  
Localization Accuracy ◽  
Localization Method ◽  
Anchor Nodes ◽  
Simulation Results ◽  
Unknown Node

Localization technology is one of the key supporting technologies in wireless sensor networks. In this paper, a collaborative multilateral localization algorithm is proposed to localization issues for wireless sensor networks. The algorithm applies anchor nodes within two hops to localize unknown nodes, and uses Nelder-Mead simplex optimization method to compute coordinates of the unknown nodes. If an unknown node can not be localized through two-hop anchor nodes, it is localized by anchor nodes and localized nodes within two hops through auxiliary iterative localization method. Simulation results show that the localization accuracy of this algorithm is very good, even in larger range errors.

Corn-Seed Modeling and Simulation Analysis Based on Shape Features

2014 ◽  
Vol 602-605 ◽  
pp. 779-782 ◽  
Author(s):  
Hui Yan ◽  
Duo Long
Keyword(s):  
Modeling And Simulation ◽  
Simulation Analysis ◽  
Modeling Method ◽  
Combination Method ◽  
Shape Features ◽  
Analysis Model ◽  
Corn Seed ◽  
Simulation Results ◽  
Analysis Models

Based on the shape features of corn seed, this paper proposes the modeling method of manual combination of eight spheres, which constructs the analysis models for corn seed Ji Feng 218 and Chang Dan 228 with the purpose of better simulation of corn seeds. Furthermore, another analysis model for Chang Dan 228 is also built with reference to the four-sphere combination method. The comparison between the simulation results from these two models demonstrates the feasibility and superiority of the model of combination of eight spheres.

A Localization Method for WSN Based on Variable Transmission Power

2013 ◽  
Vol 694-697 ◽  
pp. 1055-1059
Author(s):  
Guang Xiong Huang ◽  
Zhi Long Shan
Keyword(s):  
Wireless Sensor Network ◽  
Wireless Sensor ◽  
Location Information ◽  
Transmission Power ◽  
Localization Algorithm ◽  
Localization Method ◽  
Position Accuracy ◽  
Variable Transmission ◽  
Simulation Results ◽  
Range Free

Localization is an essential technology in the application of wireless sensor network. As a range-free localization algorithm, DV-Hop works well in dense and isotropic networks, but not much in irregular and sparse topologies, especially in the big curvature of shortest path case. In this paper, location information beyond the communication range was obtained by means of variable transmission power of enhanced nodes. Besides, three schemes was proposed to meet the need of different scenarios. Moreover, the simulation results validate that our method can improve position accuracy about 20% and ameliorate the performance of DV-Hop in irregular scenario.

Multiple Leakage Detection and Localization Method Based on Bayesian Theory and Genetic Algorithm

2014 ◽  
Vol 635-637 ◽  
pp. 924-927
Author(s):  
Tao Jin ◽  
Ze Yuan Zhou
Keyword(s):  
Genetic Algorithm ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Bayesian Theory ◽  
Leakage Detection ◽  
Localization Method ◽  
Simulation Results ◽  
Detection And Localization ◽  
Leakage Location

To detect and locate the leakage of the pipe correctly, genetic algorithm is combined with Bayesian theory to determine the leaked pipes. Leakage detection and leakage location are carried out separately. Leakage detection is conducted based on the assumption that there is only one leaked pipe, and the simulation result demonstrates its feasibility. When the leakage detection demonstrates there is leaked pipe in the water distribution system, leakage location starts. Based on the information gathered by the manometers, leakage probability in different combinations of the virtual nodal demand can be fixed according to calculating the pressure of the monitored node, then GA is applied to search the maximum Bayesian value, the pipes with maximum Bayesian leakage possibility are believed to be leaked pipes. Optimization programme was made with combination of Matlab and Epanet, numerical simulation results demonstrate the feasibility and effectiveness of the proposed method.

Cooperative Positioning Based on Hybrid Information

2013 ◽  
Vol 694-697 ◽  
pp. 940-946 ◽  
Author(s):  
Xiang Hui Zeng ◽  
Hong Tao Hou ◽  
Qiang Chang ◽  
Qun Li ◽  
Wei Ping Wang
Keyword(s):  
Wireless Network ◽  
Series Expansion ◽  
Taylor Series ◽  
Taylor Series Expansion ◽  
Least Square ◽  
Positioning Accuracy ◽  
Localization Method ◽  
Cooperative Positioning ◽  
Simulation Results

A new localization method has been proposed to overcome the limitations of systems relying on GPS or other terrestrial infrastructure. This method fuses both pseudorange measurements from GNSS satellites and RSSI-based ranging measurements between peers of a wireless network, and uses improved collaborative subtree algorithm to partition the network. In each collaborative subtree, the nodes’ positions can be computed by using the least square algorithm based on Taylor series expansion-based. Simulation results showed that this method improves both availability and positioning accuracy.

Development of a Planar Array Infrared Reflection Spectrograph for Reflection—Absorption Spectroscopy of Thin Films at Metal and Water Surfaces

2007 ◽  
Vol 61 (9) ◽  
pp. 916-920 ◽  
Author(s):  
Young Shin Kim ◽  
Christopher M. Snively ◽  
John F. Rabolt ◽  
D. Bruce Chase
Keyword(s):  
Langmuir Films ◽  
Time Resolved ◽  
Single Beam ◽  
The Poor ◽  
Water Trough ◽  
Infrared Reflection ◽  
Air Water Interface ◽  
Planar Array ◽  
Ft Ir ◽  
High Quality Spectrum

Planar array infrared (PA-IR) spectroscopy offers several advantages over Fourier transform infrared (FT-IR) methods, including ultrafast speed (< 100 μs temporal resolution) and excellent sensitivity. However, obtaining spectra in the range of 1800 to 1000 cm−1 of films at the air–water interface remains difficult due to the poor IR reflectivity of water, the extremely low concentration of the thin film on the water subphase, and the interference of water bands. In this study, we report a new planar array infrared reflection spectrograph (PA-IRRS), which has several advantages over conventional approaches. This instrument can record sample and reference spectra simultaneously with an instrumental setup that is the same as that of a single-beam instrument by splitting the incident infrared beam into two sections on a plane mirror (H) or a water trough. With this design, the instrument can accommodate large infrared accessories, such as a water trough, without a loss of infrared beam intensity. Water bands can be subtracted to obtain a high-quality spectrum for poly(L-lactic acid) Langmuir film on the water subphase with a resolution of about 6 cm−1 in 10.8 s. Hence, this PA-IRRS system has great potential for investigating the time-resolved dynamics of a broad range of Langmuir films, such as cellular membranes or biopolymers, on the water subphase.

scholarly journals DOA estimation based on sum–difference coarray with virtual array interpolation concept

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Yarong Ding ◽  
Shiwei Ren ◽  
Weijiang Wang ◽  
Chengbo Xue
Keyword(s):  
Numerical Simulation ◽  
Degrees Of Freedom ◽  
Doa Estimation ◽  
Superior Performance ◽  
Norm Minimization ◽  
Atomic Norm ◽  
Virtual Array ◽  
Simulation Results ◽  
The Difference ◽  
Coprime Array

AbstractThe sum–difference coarray is the union of difference coarray and the sum coarray, which is capable to obtain a higher number of degrees of freedom (DOF) than the difference coarray. However, this method fails to use all information provided by the coprime array because of the existence of holes. In this paper, we introduce the virtual array interpolation into the sum–difference coarray domain. After interpolating the virtual array, we estimate the DOA by reconstructing the covariance matrix to resolve an atomic norm minimization problem in a gridless way. The proposed method is gridless and can effectively utilize the DOF of a larger virtual array. Numerical simulation results verify the effectiveness and the superior performance of the proposed algorithm.

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