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Miao, Feng, Diange Yang, Junjie Wen, and Xiaomin Lian. "Moving sound source localization based on triangulation method." Journal of Sound and Vibration 385 (December 2016): 93–103. http://dx.doi.org/10.1016/j.jsv.2016.09.001.
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Kanakaraj, Swetha, and Deepthika Pitchaikani. "Experimental Study of Source Localization in Acoustic Emission using Triangulation Method." IOP Conference Series: Materials Science and Engineering 1197, no. 1 (November 1, 2021): 012061. http://dx.doi.org/10.1088/1757-899x/1197/1/012061.
Повний текст джерелаАнотація:
Abstract Conventional repair and rehabilitation techniques have proven effective only to treat damage and arrest it. Hence, the need to prevent the damage, to know the growing damage before a complete collapse is necessary. Thus, acoustic emission is a proven method for structural health monitoring, to find and rectify the damage at its early stage. The Acoustic emission technique could be directly applied for monitoring large structures made of concrete, aircrafts & bridges. It helps in recognition of structural damage prior, which helps in avoiding catastrophic failure. The proper and efficient detection of damage makes structure safer for the public. This is a low-cost & less intricate technique than conventional methods. Quantitative criteria of acoustic sensing will provide efficient diagnosis and prognosis of structural damage. This paper surmounts the triangulation method of source localization of acoustic emission. The data is gathered by the sensors and then used to know the location of damage/source and respective characteristics of the wave. MATLAB is used for defining the energy of the signals captured by the sensors. Thus, the signal parameter’s study and verification of the source’s location using sensors is justified to be correct in the acoustic emission technique.
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Aziz, M. A., and C. T. Allen. "Experimental Results of a Differential Angle-of-Arrival Based 2D Localization Method Using Signals of Opportunity." International Journal of Navigation and Observation 2018 (March 25, 2018): 1–6. http://dx.doi.org/10.1155/2018/5470895.
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This paper presents a study of differential AoA (Angle-of-Arrival) based 2D localization method utilizing FM radio signals (88 MHz–108 MHz) as Signals of Opportunity (SOP). Given prior knowledge of the transmitters’ position and signal characteristics, the proposed technique utilizes triangulation to localize receiver’s 2D position. Dual antenna interferometry provides the received signals’ AoA required for triangulation. Reliance on precise knowledge of antenna system’s orientation is removed by utilizing differential Angle of Arrivals (dAoAs). The 2D localization accuracy is improved by utilizing colocated transmitters, a concept proposed in this paper as supertowers. Analysis, simulation, and ground-based experiments have been presented; results showed that when the SNR (Signal-to-Noise Ratio) is higher than 45 dB, the proposed method localizes the receiver’s 2D position with an error of less than 15 m.
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Li, Qingqing, Paavo Nevalainen, Jorge Peña Queralta, Jukka Heikkonen, and Tomi Westerlund. "Localization in Unstructured Environments: Towards Autonomous Robots in Forests with Delaunay Triangulation." Remote Sensing 12, no. 11 (June 9, 2020): 1870. http://dx.doi.org/10.3390/rs12111870.
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Autonomous harvesting and transportation is a long-term goal of the forest industry. One of the main challenges is the accurate localization of both vehicles and trees in a forest. Forests are unstructured environments where it is difficult to find a group of significant landmarks for current fast feature-based place recognition algorithms. This paper proposes a novel approach where local point clouds are matched to a global tree map using the Delaunay triangularization as the representation format. Instead of point cloud based matching methods, we utilize a topology-based method. First, tree trunk positions are registered at a prior run done by a forest harvester. Second, the resulting map is Delaunay triangularized. Third, a local submap of the autonomous robot is registered, triangularized and matched using triangular similarity maximization to estimate the position of the robot. We test our method on a dataset accumulated from a forestry site at Lieksa, Finland. A total length of 200 m of harvester path was recorded by an industrial harvester with a 3D laser scanner and a geolocation unit fixed to the frame. Our experiments show a 12 cm s.t.d. in the location accuracy and with real-time data processing for speeds not exceeding 0.5 m/s. The accuracy and speed limit are realistic during forest operations.
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Zhang, Li Chuan, Ming Yong Liu, and Fu Bin Zhang. "Cooperative Localization Method for AUV Using Acoustic Communication Measurement." Advanced Engineering Forum 4 (June 2012): 227–31. http://dx.doi.org/10.4028/www.scientific.net/aef.4.227.
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In this paper, we propose an algorithm based on double acoustic measurement for cooperative navigation of multiple autonomous underwater vehicles. Research on cooperative navigation of AUV is an important topic to solve the navigation problem in long range and deep sea. We investigate the improvement in navigation accuracy. In the Leader-follow structure, the leader AUV is equipped with high precision navigation system, and the follow AUV is equipped with low precision navigation system. They all are equipped with acoustic device to measure relative location. Traditionally geometry triangulation method is used to calculate the position of follow AUV, the method may cause fault error solution. Double acoustic communication measurement method was designed, which fused the proprioceptive and exteroceptive sensors. The research results prove that the navigation accuracy has been improved effectively.
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Brassart, Eric, Claude Pegard, and Mustapha Mouaddib. "Localization using infrared beacons." Robotica 18, no. 2 (March 2000): 153–61. http://dx.doi.org/10.1017/s0263574799001927.
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In this paper, we deal with a localization system allowing one to determine the position and orientation of a mobile robot. This system uses active beacons distributed at the ceiling of the navigation area. These beacons can transmit a coded infrared signal which allows the robots to identify the sender. A CCD camera associated to an infrared receiver allows one to compute the position with a triangulation method which needs reduced processing time. Calibration and correcting distortion stages are performed to improve accuracy in the determination of the position. Dynamic localisation is established for most actual mobile robots used in indoor areas.
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Baddeley, David, Mark B. Cannell, and Christian Soeller. "Visualization of Localization Microscopy Data." Microscopy and Microanalysis 16, no. 1 (January 18, 2010): 64–72. http://dx.doi.org/10.1017/s143192760999122x.
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AbstractLocalization microscopy techniques based on localizing single fluorophore molecules now routinely achieve accuracies better than 30 nm. Unlike conventional optical microscopies, localization microscopy experiments do not generate an image but a list of discrete coordinates of estimated fluorophore positions. Data display and analysis therefore generally require visualization methods that translate the position data into conventional images. Here we investigate the properties of several widely used visualization techniques and show that a commonly used algorithm based on rendering Gaussians may lead to a 1.44-fold loss of resolution. Existing methods typically do not explicitly take sampling considerations into account and thus may produce spurious structures. We present two additional visualization algorithms, an adaptive histogram method based on quad-trees and a Delaunay triangulation based visualization of point data that address some of these deficiencies. The new visualization methods are designed to suppress erroneous detail in poorly sampled image areas but avoid loss of resolution in well-sampled regions. A number of criteria for scoring visualization methods are developed as a guide for choosing among visualization methods and are used to qualitatively compare various algorithms.
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Żak, Bogdan, and Stanisław Hożyń. "Moving Object Detection, Localization and Tracking Using Stereo Vison System." Solid State Phenomena 236 (July 2015): 134–41. http://dx.doi.org/10.4028/www.scientific.net/ssp.236.134.
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The aim of this study was to design an moving object detection, localization and tracking algorithm able to detect, localize and track especially humans and vehicles. We focused on triangulation techniques to calculate the position of the detected objects in a stereo vision rig coordinates frame. For objects detection and tracking the novel algorithm, based on statistical image processing methods, was proposed. Verification of a proper operation of the elaborated method was made by conducting series of experiments. Our results indicate that the algorithm localizes, detects and tracks objects accurately for the most tested conditions.
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Lin, S. C., G. P. Too, and C. W. Tu. "Development of the Source Reconstruction System by Combining Sound Source Localization and Time Reversal Method." Journal of Mechanics 34, no. 1 (March 9, 2016): 35–40. http://dx.doi.org/10.1017/jmech.2016.13.
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AbstractThis study explored the target sound source location at unknown situation and processed the received signal to determine the location of the target, including the reconstructed signal of source immediately. In this paper, it used triangulation sound sources localization and time reversal method (TRM) to reconstruct the source signals. The purpose is to use a sound source localization method with a simple device to quickly locate the position of the sound source. This method uses the microphone array to measure signal from the target sound source. Then, the sound source location is calculated and is indicated by Cartesian coordinates. The sound source location is then used to evaluate free field impulse response function which can replace the impulse response function used in time-reversal method. This process reduces the computation time greatly which makes possible for a real time source localization and source signal separation.
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Ruan, L., L. Zhang, F. Cheng, and Y. Long. "THE GLOBAL OPTIMAL PLACEMENT OF BLE BEACON FOR LOCALIZATION BASED ON INDOOR MAP." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4 (September 19, 2018): 529–34. http://dx.doi.org/10.5194/isprs-archives-xlii-4-529-2018.
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<p><strong>Abstract.</strong> Anchor Nodes in a localization system obviously play a crucial role in determining the system’s quality. Their placement directly affects the localization accuracy and their number directly impacts the total cost of the system. Nowadays, the deployment of Bluetooth nodes in industry generally relies on the experience knowledge of engineers and the cost of positioning beacon does not considered the global level. In this paper, we put forward a method to extract the number and location of BLE beacon automatically and ensure a high positioning accuracy of the indoor positioning system based the rules of indoor positioning, which use all kinds of space objects and structure characteristics of indoor map. The triangulation method was selected to study the global optimal placement of BLE beacon for localization based on indoor map. The impacts and requirements of BLE beacon placement were systematic analysed from the triangulation positioning method, indoor positioning environment and indoor user distribution characteristics. According to the characteristics of indoor environment structure and user distribution, we built an optimization model of BLE beacon placement method based on genetic algorithm which can generate the number and the location of BLE beacon. At last, the Bluetooth indoor positioning prototype system is developed to compare the experience method deployment scheme and the global optimization deployment scheme in the real indoor positioning environment.</p>
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Dubuc, Brennan, Arvin Ebrahimkhanlou, and Salvatore Salamone. "Localization of multiple acoustic emission events occurring closely in time in thin-walled pipes using sparse reconstruction." Journal of Intelligent Material Systems and Structures 29, no. 11 (May 1, 2018): 2362–73. http://dx.doi.org/10.1177/1045389x18770857.
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A sparse reconstruction approach capable of localizing multiple acoustic emission events is proposed. The approach is specifically designed for localizing events that occur closely in time, where triangulation methods can fail. To perform localization, the approach uses information contained in the entire length of acoustic emission signals and is implemented using the matching pursuit algorithm. Implementation is considered theoretically for large-diameter thin-walled pipes. The approach is validated on experimental data of simulated acoustic emission events in a thin-walled pipe. The experimental data correspond to helical guided ultrasonic waves generated by standard pencil lead breaks (Hsu-Nielsen sources) on its outer surface. The acoustic emission signals are recorded by sparsely distributed low-profile piezoelectric transducers instrumented on the outer surface. Experimental examples are presented for the failure of the triangulation method when multiple sources are present while highlighting the capabilities of the proposed technique. It is demonstrated that the approach possesses the ability of localizing multiple events occurring closely in time. An example is also presented for the localization of a more commonly encountered isolated acoustic emission event.
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Liu, Haitao, Thia Kirubarajan, and Qian Xiao. "Arbitrary Microphone Array Optimization Method Based on TDOA for Specific Localization Scenarios." Sensors 19, no. 19 (October 7, 2019): 4326. http://dx.doi.org/10.3390/s19194326.
Повний текст джерелаАнотація:
Various microphone array geometries (e.g., linear, circular, square, cubic, spherical, etc.) have been used to improve the positioning accuracy of sound source localization. However, whether these array structures are optimal for various specific localization scenarios is still a subject of debate. This paper addresses a microphone array optimization method for sound source localization based on TDOA (time difference of arrival). The geometric structure of the microphone array is established in parametric form. A triangulation method with TDOA was used to build the spatial sound source location model, which consists of a group of nonlinear multivariate equations. Through reasonable transformation, the nonlinear multivariate equations can be converted to a group of linear equations that can be approximately solved by the weighted least square method. Then, an optimization model based on particle swarm optimization (PSO) algorithm was constructed to optimize the geometric parameters of the microphone array under different localization scenarios combined with the spatial sound source localization model. In the optimization model, a reasonable fitness evaluation function is established which can comprehensively consider the positioning accuracy and robustness of the microphone array. In order to verify the array optimization method, two specific localization scenarios and two array optimization strategies for each localization scenario were constructed. The optimal array structure parameters were obtained through numerical iteration simulation. The localization performance of the optimal array structures obtained by the method proposed in this paper was compared with the optimal structures proposed in the literature as well as with random array structures. The simulation results show that the optimized array structure gave better positioning accuracy and robustness under both specific localization scenarios. The optimization model proposed could solve the problem of array geometric structure design based on TDOA and could achieve the customization of microphone array structures under different specific localization scenarios.
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Shao, Chenguang. "Wireless Sensor Network Target Localization Algorithm Based on Two- and Three-Dimensional Delaunay Partitions." Journal of Sensors 2021 (November 17, 2021): 1–20. http://dx.doi.org/10.1155/2021/4047684.
Повний текст джерелаАнотація:
The target localization algorithm is critical in the field of wireless sensor networks (WSNs) and is widely used in many applications. In the conventional localization method, the location distribution of the anchor nodes is fixed and cannot be adjusted dynamically according to the deployment environment. The resulting localization accuracy is not high, and the localization algorithm is not applicable to three-dimensional (3D) conditions. Therefore, a Delaunay-triangulation-based WSN localization method, which can be adapted to two-dimensional (2D) and 3D conditions, was proposed. Based on the location of the target node, we searched for the triangle or tetrahedron surrounding the target node and designed the localization algorithm in stages to accurately calculate the coordinate value of the target. The relationship between the number of target nodes and the number of generated graphs was analysed through numerous experiments, and the proposed 2D localization algorithm was verified by extending it the 3D coordinate system. Experimental results revealed that the proposed algorithm can effectively improve the flexibility of the anchor node layout and target localization accuracy.
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Sisala, Joseph, and Abdi T. Abdalla. "Multipath Exploitation-Based Indoor Target Localization Model Using Single Marginal Antenna." Tanzania Journal of Engineering and Technology 39, no. 1 (June 30, 2020): 13–20. http://dx.doi.org/10.52339/tjet.v39i1.515.
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Recently, indoor target localization became an area of interest due to its diverse applications. In indoor target localization, surrounding environment creates multipath components, which can be exploited to aid in localization process. A number of studies have been proposed to employ multipath exploitation in localizing indoor targets. However, their localization errors can still be improved. This study proposed a new localization model based on multipath exploitation techniques by using triangulation method. Ultra-wide band signals were resolved and associated using marginal antenna-based scheme. The estimate of the target location was then obtained using measured round-trip time delays. The location was determined by applying the simple trigonometry on the triangle in which real radar, virtual radars, and the target location are the vertices of the triangle in question. Simulation results show that the proposed method has improved the localization error over a wide range of timing errors, target locations and room sizes with the overall maximum localization error of 1.4 m equivalent to 22.2% improvement as compared to 1.8 m localization error obtained using the method developed by the Muqaibel et al. (2017).
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LU, XIANLING, DEYING LI, YI HONG, and WENPING CHEN. "A LOW-COST RANGE-FREE LOCALIZATION SCHEME FOR THREE-DIMENSIONAL UNDERWATER SENSOR NETWORKS." Discrete Mathematics, Algorithms and Applications 05, no. 01 (March 2013): 1350005. http://dx.doi.org/10.1142/s1793830913500055.
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Localization is one of the fundamental tasks for underwater sensors networks (USNs). It is required for data tagging, target detection, route protocols, and so on. In this paper, we propose an efficient low-cost range-free localization scheme for 3D underwater sensor networks (3D-LRLS) without any additional hardware infrastructure. In our scheme, each anchor node has variable transmission power levels. At first, the power levels of each anchor are decided by the Delaunay triangulation for the network space. Then, ordinary sensors listen to the beacons sent from the anchor nodes. Based on the beacon messages, each node calculates its location individually by a low computational complexity method. The extensive simulation results demonstrate that 3D-LRLS is efficient in terms of both localization ratio and localization accuracy.
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Jang, Byeong-Wook, and Chun-Gon Kim. "Impact localization of composite stiffened panel with triangulation method using normalized magnitudes of fiber optic sensor signals." Composite Structures 211 (March 2019): 522–29. http://dx.doi.org/10.1016/j.compstruct.2019.01.028.
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Eu, Kok Seng, Kian Meng Yap, and Tiam Hee Tee. "Single Beacon Indoor Localization System Based on Counter-Synchronized Compass and RSSI." Applied Mechanics and Materials 627 (September 2014): 217–22. http://dx.doi.org/10.4028/www.scientific.net/amm.627.217.
Повний текст джерелаАнотація:
Indoor localization system has been a popular research area in recent decades and many of them are based on multiple beacons localization method. However, there are some special applications to which the multiple beacons method is not an optimal solution due to its overdesign and cost of redundancy. Multiple beacons method uses at least three transducers and each transducer’s location must be known to find the location of a target object by using either Triangulation or Trilateration calculation. When the multiple beacons method is applied in an items lost and found system, the precise Cartesian coordinates of a target item can be found, but it is definitely overdesign and incurring redundant cost. It is due to the fact that the target item requires only two simple information i.e. Clock orientation and distance information; therefore, single beacon is enough for the task. In this paper, we propose a single beacon localization method to optimize the solution in the items lost and found system by utilizing clock orientation and estimated distance information. The proposed single beacon localization algorithm has been demonstrated and proven that it can be one of the optimal solutions for items lost and found system.
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Wang, Mingyang, Xinbo Chen, Pengyuan Lv, Baobao Jin, Wei Wang, and Yong Shen. "UWB Based Relative Planar Localization with Enhanced Precision for Intelligent Vehicles." Actuators 10, no. 7 (June 26, 2021): 144. http://dx.doi.org/10.3390/act10070144.
Повний текст джерелаАнотація:
Along with the rapid development of advanced driving assistance systems for intelligent vehicles, essential functions such as forward collision warning and collaborative cruise control need to detect the relative positions of surrounding vehicles. This paper proposes a relative planar localization system based on the ultra-wideband (UWB) ranging technology. Three UWB modules are installed on the top of each vehicle. Because of the limited space on the vehicle roof compared with the ranging error, the traditional triangulation method leads to significant positioning errors. Therefore, an optimal localization algorithm combining homotopy and the Levenberg–Marquardt method is first proposed to enhance the precision. The triangular side lengths and directed area are introduced as constraints. Secondly, a UWB sensor error self-correction method is presented to further improve the ranging accuracy. Finally, we carry out simulations and experiments to show that the presented algorithm in this paper significantly improves the relative position and orientation precision of both the pure UWB localization system and the fusion system integrated with dead reckoning.
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Mebarki, Abdelkrim. "Adaptive Distance Grid Based Algorithm for Farthest Point Seeding Streamline Placement." Open Computer Science 6, no. 1 (July 11, 2016): 91–99. http://dx.doi.org/10.1515/comp-2016-0007.
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AbstractStreamlines are commonly used in scientific visualization. They are the most used geometric items in primitive-based visualization algorithms. In this paper, a modified version of the farthest point seeding strategy streamline placement is presented. The main advantage compared to the original method is the use of a simple easy to implement underlying data structure. The Delaunay triangulation used in the original algorithm is heavy and susceptible to the calculation robustness errors. The distances between lines and the localization of the biggest void in the domain are approximated using the Delaunay triangulation. This paper presents an adaptive distance grid to model the visualization domain and incorporate anywhere the local distance to all the other streamlines and the boundaries exactly without any approximation. The streamlines are started at the farthest point from all the existing ones and the domain boundaries. The localization of the seed point position is directly accessible via the distance adaptive grid. The grid update is direct too, and is done by a greedy algorithm avoiding any additional cost. The obtained results are sufficient, and the extension to multi-resolution is straight and simple.
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Hammouda, Marwan, Anna Maria Vegni, and Valeria Loscrí. "On the Noise Effect of Fingerprinting-Based Positioning Error in Underwater Visible Light Networks." Sensors 21, no. 16 (August 10, 2021): 5398. http://dx.doi.org/10.3390/s21165398.
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This paper assesses the performance of a localization technique for underwater visible light networks. The proposed approach is based on a fingerprinting technique, collecting the channel impulse responses from different wireless optical signals in the visible range. A local database related to the power level distribution within a maritime environment is built and exploited to estimate user position, e.g., a diver moving in a given space for underwater fish monitoring. In this paper, we investigate on the noise effect on the localization accuracy in underwater scenarios and for different water turbidity coefficient and we demonstrate that the estimation error suffers on variable channel impulse responses. Different configuration parameters and environmental scenarios have been considered, showing that the LED transmitter deployment can be effective in the localization estimation. A comparison of the proposed localization approach to the traditional triangulation method has been finally carried out, showing the effectiveness of the fingerprinting-based solution for a lower number of LED transmitters.
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Wan, Wenhui, Tianyi Yu, Kaichang Di, Jia Wang, Zhaoqin Liu, Lichun Li, Bin Liu, et al. "Visual Localization of the Tianwen-1 Lander Using Orbital, Descent and Rover Images." Remote Sensing 13, no. 17 (August 30, 2021): 3439. http://dx.doi.org/10.3390/rs13173439.
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Tianwen-1, China’s first Mars exploration mission, was successfully landed in the southern part of Utopia Planitia on 15 May 2021 (UTC+8). Timely and accurately determining the landing location is critical for the subsequent mission operations. For timely localization, the remote landmarks, selected from the panorama generated by the earliest received Navigation and Terrain Cameras (NaTeCam) images, were matched with the Digital Orthophoto Map (DOM) generated by high resolution imaging camera (HiRIC) images to obtain the initial result based on the triangulation method. Then, the initial localization result was refined by the descent images received later and the NaTeCam DOM. Finally, the lander location was determined to be (25.066°N, 109.925°E). Verified by the new orbital image with the lander and Zhurong rover visible, the localization accuracy was within a pixel of the HiRIC DOM.
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Jekosch, Simon, and Ennes Sarradj. "An Extension of the Virtual Rotating Array Method Using Arbitrary Microphone Configurations for the Localization of Rotating Sound Sources." Acoustics 2, no. 2 (May 15, 2020): 330–42. http://dx.doi.org/10.3390/acoustics2020019.
Повний текст джерелаАнотація:
The characterization of rotating aeroacoustic sources using microphone array methods has been proven to be a useful tool. One technique to identify rotating sources is the virtual rotating array method. The method interpolates the pressure time data signals between the microphones in a stationary array to compensate the motion of the rotating sources. One major drawback of the method is the requirement of ring array geometries that are centred around the rotating axis. This contribution extends the virtual rotating array method to arbitrary microphone configurations. Two different ways to interpolate the time signals between the microphone locations are proposed. The first method constructs a mesh between the microphone positions using Delaunay-triangulation and interpolates over the mesh faces using piecewise linear functions. The second one is a meshless technique which is based on radial basis function interpolation. The methods are tested on synthetic array data from a benchmark test case as well as on experimental data obtained with a spiral array and a five-bladed fan.
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Li, Yushi, George Baciu, Yu Han, and Chenhui Li. "Improved SfM-Based Indoor Localization with Occlusion Removal." International Journal of Software Science and Computational Intelligence 10, no. 3 (July 2018): 24–40. http://dx.doi.org/10.4018/ijssci.2018070102.
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This article describes a novel 3D image-based indoor localization system integrated with an improved SfM (structure from motion) approach and an obstacle removal component. In contrast with existing state-of-the-art localization techniques focusing on static outdoor or indoor environments, the adverse effects, generated by moving obstacles in busy indoor spaces, are considered in this work. In particular, the problem of occlusion removal is converted into a separation problem of moving foreground and static background. A low-rank and sparse matrix decomposition approach is used to solve this problem efficiently. Moreover, a SfM with RT (re-triangulation) is adopted in order to handle the drifting problem of incremental SfM method in indoor scene reconstruction. To evaluate the performance of the system, three data sets and the corresponding query sets are established to simulate different states of the indoor environment. Quantitative experimental results demonstrate that both query registration rate and localization accuracy increase significantly after integrating the authors' improvements.
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Ramírez-Hernández, Luis R., Julio C. Rodríguez-Quiñonez, Moises J. Castro-Toscano, Daniel Hernández-Balbuena, Wendy Flores-Fuentes, Raúl Rascón-Carmona, Lars Lindner, and Oleg Sergiyenko. "Improve three-dimensional point localization accuracy in stereo vision systems using a novel camera calibration method." International Journal of Advanced Robotic Systems 17, no. 1 (January 1, 2020): 172988141989671. http://dx.doi.org/10.1177/1729881419896717.
Повний текст джерелаАнотація:
Computer vision systems have demonstrated to be useful in applications of autonomous navigation, especially with the use of stereo vision systems for the three-dimensional mapping of the environment. This article presents a novel camera calibration method to improve the accuracy of stereo vision systems for three-dimensional point localization. The proposed camera calibration method uses the least square method to model the error caused by the image digitalization and the lens distortion. To obtain particular three-dimensional point coordinates, the stereo vision systems use the information of two images taken by two different cameras. Then, the system locates the two-dimensional pixel coordinates of the three-dimensional point in both images and coverts them into angles. With the obtained angles, the system finds the three-dimensional point coordinates through a triangulation process. The proposed camera calibration method is applied in the stereo vision systems, and a comparative analysis between the real and calibrated three-dimensional data points is performed to validate the improvements. Moreover, the developed method is compared with three classical calibration methods to analyze their advantages in terms of accuracy with respect to tested methods.
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Lin, Zhi Gui, Lin Li, Hui Qi Zhang, Min Li, and Fang Qin Yao. "An APIT Algorithm Based on DV-HOP Multi-Hop." Advanced Materials Research 787 (September 2013): 1038–43. http://dx.doi.org/10.4028/www.scientific.net/amr.787.1038.
Повний текст джерелаАнотація:
Aiming at misjudgment formed by PIT (Point-In-triangulation Test) and position failure formed by edge effect in APIT algorithm, this paper introduces a multi-hop mechanism of DV-HOP algorithm and presents an APIT algorithm of based on DV-HOP multi-hop mechanism (AHMH-APIT). The AHMH-APIT algorithm uses DV-HOP multi-hop to compensate edge effect and anchor circle intersection region to replace triangulation, and uses weighted method to calculate the regional centroid. The paper simulated the AHMH-APIT algorithm by Matlab .The simulation result shows that, in the case of nodes being randomly distributed, compared with the APIT, all nodes can be positioned. Even if the number of anchor nodes and the communication radius is relatively small, unknown nodes can be positioned. And then the AHMH-APIT algorithm reduces average localization error and energy cost of communication.
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Villalpando-Hernandez, Rafaela, David Munoz-Rodriguez, and Cesar Vargas-Rosales. "Relational Positioning Method for 2D and 3D Ad Hoc Sensor Networks in Industry 4.0." Applied Sciences 11, no. 19 (September 24, 2021): 8907. http://dx.doi.org/10.3390/app11198907.
Повний текст джерелаАнотація:
Industry 4.0, or smart factory, refers to the fourth industrial revolution, as a result of which it is expected that massive sensor deployment, high device connectivity, automation, and real-time data acquisition support improve industrial processes. Sensor fault detection and operator tracking allow adequate performance of the sensor network supporting Industry 4.0, and sensor localization has become crucial to enable sensor fault detection. Hence, the development of new localization methods is necessary for environments where GPS localization technology is unfeasible. Furthermore, position location information (PLI) is a crucial requirement for the deployment of multiple services and applications in wireless ad hoc and sensor networks supporting Industry 4.0. Three-dimensional (3D) scenarios are considered to extend the applicability of PLI-based services. However, PLI acquisition presents several challenges within any 3D ad hoc sensor network paradigm. For instance, conventional triangulation algorithms are often no longer applicable due to the lack of direct land-fixed references and the inclusion of a third-dimension coordinate. In this paper, a PL relational searching algorithm suitable for 2D and 3D ad hoc environments was formulated in terms of a discretized searching space and a vertex weight assignment process according to distance relationships from anchor nodes to the node to be located on a feasibility space. The applicability of the proposed algorithm was examined through analytic formulation and simulation processes. Results show small distance errors (less than 1 m) are achievable for some scenarios.
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Munguía, Rodrigo, Carlos López-Franco, Emmanuel Nuño, and Adriana López-Franco. "Method for SLAM Based on Omnidirectional Vision: A Delayed-EKF Approach." Journal of Sensors 2017 (2017): 1–14. http://dx.doi.org/10.1155/2017/7342931.
Повний текст джерелаАнотація:
This work presents a method for implementing a visual-based simultaneous localization and mapping (SLAM) system using omnidirectional vision data, with application to autonomous mobile robots. In SLAM, a mobile robot operates in an unknown environment using only on-board sensors to simultaneously build a map of its surroundings, which it uses to track its position. The SLAM is perhaps one of the most fundamental problems to solve in robotics to build mobile robots truly autonomous. The visual sensor used in this work is an omnidirectional vision sensor; this sensor provides a wide field of view which is advantageous in a mobile robot in an autonomous navigation task. Since the visual sensor used in this work is monocular, a method to recover the depth of the features is required. To estimate the unknown depth we propose a novel stochastic triangulation technique. The system proposed in this work can be applied to indoor or cluttered environments for performing visual-based navigation when GPS signal is not available. Experiments with synthetic and real data are presented in order to validate the proposal.
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Ding, Jing, Zhigang Yan, and Xuchen We. "High-Accuracy Recognition and Localization of Moving Targets in an Indoor Environment Using Binocular Stereo Vision." ISPRS International Journal of Geo-Information 10, no. 4 (April 6, 2021): 234. http://dx.doi.org/10.3390/ijgi10040234.
Повний текст джерелаАнотація:
To obtain effective indoor moving target localization, a reliable and stable moving target localization method based on binocular stereo vision is proposed in this paper. A moving target recognition extraction algorithm, which integrates displacement pyramid Horn–Schunck (HS) optical flow, Delaunay triangulation and Otsu threshold segmentation, is presented to separate a moving target from a complex background, called the Otsu Delaunay HS (O-DHS) method. Additionally, a stereo matching algorithm based on deep matching and stereo vision is presented to obtain dense stereo matching points pairs, called stereo deep matching (S-DM). The stereo matching point pairs of the moving target were extracted with the moving target area and stereo deep matching point pairs, then the three dimensional coordinates of the points in the moving target area were reconstructed according to the principle of binocular vision’s parallel structure. Finally, the moving target was located by the centroid method. The experimental results showed that this method can better resist image noise and repeated texture, can effectively detect and separate moving targets, and can match stereo image points in repeated textured areas more accurately and stability. This method can effectively improve the effectiveness, accuracy and robustness of three-dimensional moving target coordinates.
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Wei, Lijun, Cindy Cappelle, Yassine Ruichek, and Frédérick Zann. "GPS and Stereovision-Based Visual Odometry: Application to Urban Scene Mapping and Intelligent Vehicle Localization." International Journal of Vehicular Technology 2011 (May 17, 2011): 1–17. http://dx.doi.org/10.1155/2011/439074.
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We propose an approach for vehicle localization in dense urban environments using a stereoscopic system and a GPS sensor. Stereoscopic system is used to capture the stereo video flow, to recover the environments, and to estimate the vehicle motion based on feature detection, matching, and triangulation from every image pair. A relative depth constraint is applied to eliminate the tracking couples which are inconsistent with the vehicle ego-motion. Then the optimal rotation and translation between the current and the reference frames are computed using an RANSAC based minimization method. Meanwhile, GPS positions are obtained by an on-board GPS receiver and periodically used to adjust the vehicle orientations and positions estimated by stereovision. The proposed method is tested with two real sequences obtained by a GEM vehicle equipped with a stereoscopic system and a RTK-GPS receiver. The results show that the vision/GPS integrated trajectory can fit the ground truth better than the vision-only method, especially for the vehicle orientation. And vice-versa, the stereovision-based motion estimation method can correct the GPS signal failures (e.g., GPS jumps) due to multipath problem or other noises.
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Hao, Zhanjun, Beibei Li, and Xiaochao Dang. "A Method for Improving UWB Indoor Positioning." Mathematical Problems in Engineering 2018 (December 12, 2018): 1–17. http://dx.doi.org/10.1155/2018/8740872.
Повний текст джерелаАнотація:
The existing positioning methods that use received signal strength indication (RSSI) and channel state information (CSI) may suffer from multipath and shadowing in a complex wireless environment, which can result in more positioning errors. This paper proposes a method for accurate multilabel positioning in the non-line-of-sight (NLOS) environment. First, the position is roughly estimated using the orthogonal variable spreading factor (OVSF-TH) algorithm, which can automatically match the signal interference. The ultra-wideband (UWB) spectral density and pulse amplitude in the time domain are used to determine the direction of the label and enhance estimation of the mobile label direction. Then, the location of the tag is obtained by triangulation, and a coordinate-based coordinate estimation method is proposed to calculate the relative displacement of multiple tags to determine the label position. Finally, by setting up a real experimental environment, the influence of the number of base stations on the accuracy and the performance of the localization method under different circumstances are analyzed. The theoretical analysis and experimental results show that the method is simple to deploy, inexpensive, and very accurate in terms of positioning, having a clearly effective indoor positioning accuracy. Compared with other existing positioning methods, this method can achieve more accurate positioning. Moreover, it has important theoretical and practical applicability because of the reliability and accuracy of indoor positioning in an NLOS environment.
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Marino-Merlo, Eugenio, Andrea Bulletti, Pietro Giannelli, Marco Calzolai, and Lorenzo Capineri. "Analysis of Errors in the Estimation of Impact Positions in Plate-Like Structure through the Triangulation Formula by Piezoelectric Sensors Monitoring." Sensors 18, no. 10 (October 12, 2018): 3426. http://dx.doi.org/10.3390/s18103426.
Повний текст джерелаАнотація:
The structural health monitoring (SHM) of critical structures is a complex task that involves the use of different sensors that are also aimed at the identification of the location of the impact point using ultrasonic sensors. For the evaluation of the impact position, reference is often made to the well-known triangulation method. This method requires the estimation of the differential time of arrival (DToA) and the group velocity of the Lamb waves propagating into a plate-like structure: the uncertainty of these two parameters is taken into consideration as main cause of localization error. The work proposes a simple laboratory procedure based on a set-up with a pair of sensors that are symmetrically placed with respect to the impact point, to estimate the uncertainty of the DToA and the propagation velocity estimates. According to a theoretical analysis of the error for the impact position, the experimental uncertainties of DToA and the propagation velocity are used to estimate the overall limit of the SHM system for the impact positioning. Because the error for the DToA estimate depends also on the adopted signal processing, three common methods are selected and compared: the threshold, the correlation method, and a likelihood algorithm. Finally, the analysis of the positioning error using multisensory configuration is reported as useful for the design of the SHM system.
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Dyshkant, N. F. "About Some Localization Problems in Delaunay Triangulations." Modeling and Analysis of Information Systems 19, no. 6 (March 12, 2015): 112–26. http://dx.doi.org/10.18255/1818-1015-2012-6-112-126.
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We study some problems of nodes localization in a Delaunay triangulation and problem-solving procedures. For the problem of the set of nodes the computationally efficient approach that uses Euclidean minimum spanning tree of Delaunay triangulation is proposed. Efficient estimations for computational comlexity of the proposed methods in the average and in the worst cases are proved.computational geometry, geometric search, Delaunay triangulation, merging of overlapping triangulations, unregular discrete mesh, computational complexity
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Fadlila, Nurul, Hanifatur Rosyidah, and Is Susiloningtyas. "Supporting Factors of Sex Workers Behavior on HIV/AIDS Prevention: A Qualitative Study." JURNAL KEBIDANAN 10, no. 1 (April 30, 2020): 14–18. http://dx.doi.org/10.31983/jkb.v10i1.5545.
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As of November 2018, the number of HIV cases in Semarang reached up to 546. Sex workers have the highest risk to contract HIV/AIDS due to many sexual couples exposure. In 2018, the number of HIV in Argorejo location has increased three times compared to 2017. The purpose of the study was to describe the source of female sex workers information media to act in an effort to prevent HIV / AIDS in the Argorejo Localization in Semarang City. This study used descriptive qualitative method. Data collection techniques was in-depth interviews. Population in this research is female sex workers in the Argorejo Localization, Semarang City. A descriptive phenomenological study was used describe the experience of female sex workers during in prostitution. Eleven female sex workers, a foster mother also two health workers as data resource triangulation to collect the data. This analysis also uses content analysis. Most of the sex workers have heard of HIV/AIDS from magazine, social media, sign or poster in dorm and from friends. HIV/AIDS cases that have occurred to the sex workers’ colleagues were one of the guides to behave or in other words considering the experience that has happened before is a strong predictor for behavior in the future.
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Weiland, J., B. Kunze, H. Dittmar, B. Marx, A. Schiebahn, P. Jäschke, L. Overmeyer, and U. Reisgen. "Individualized and controlled laser beam pretreatment process for adhesive bonding of fiber-reinforced plastics—Part I: Optical detection of impurities on the component surface." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 234, no. 5 (May 28, 2020): 426–35. http://dx.doi.org/10.1177/0954408920927548.
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This paper deals with the detection and localization of impurities such as release agent residues and fingerprints on fiber-reinforced plastic surfaces in an inline process step. This information can be used to carry out a locally individual and controlled surface pretreatment using laser radiation in order to improve the adhesion conditions. In this paper, surfaces from polyamide 6 reinforced with glass fiber are considered. To detect the impurities, inline images of the joining surfaces are taken using a laser line triangulation system. These image data are then examined with a specially developed algorithm of digital image processing. The real-time algorithm is based on the method of material-specific threshold values. In addition to real impurities, the algorithm was validated with artificial impurities. The central result of this work is the detection and local impurities of release agent residues and fingerprints down to a detail size of 0.3 mm.
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Kalhori, Hamed, Shabnam Tashakori, and Benjamin Halkon. "Experimental Study on Impact Force Identification on a Multi-Storey Tower Structure Using Different Transducers." Vibration 4, no. 1 (January 29, 2021): 101–16. http://dx.doi.org/10.3390/vibration4010009.
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This paper presents the identification of both location and magnitude of impact forces applied on different positions of a multi-storey tower structure using different types of transducers, i.e., an accelerometer, a laser Doppler vibrometer, and a triangulation displacement sensor. Herein, a model-based inverse method is exploited to reconstruct unknown impact forces based on various recorded dynamic signals. Furthermore, the superposition approach is employed to identify the impact location. Therein, it is assumed that several impact forces are applied simultaneously on potential locations of the multi-storey tower structure, while only one impact has non-zero magnitude. The purpose is then to detect the location of that non-zero impact. The influence of using different hammer tip materials for establishing the transfer function is investigated, where it is concluded that the hammer with a harder tip leads to a more accurate transfer function. An accuracy error function is proposed to evaluate the reconstruction precision. Moreover, the effect of sensor type and location on the accuracy of the reconstruction is studied, where it is shown that the proximity between the impact and sensor locations is a dominant factor in impact force reconstruction. In addition, the efficacy of using different transducers is studied for the impact localization, where it is demonstrated that reducing the degree of under-determinacy by using a combination of system responses of the same type can improve the localization accuracy.
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Sedunov, Alexander, Hady Salloum, Nikolay Sedunov, Christopher Francis, Sergey Tsyuryupa, Aleksandr Merzhevskiy, Daniel Kadyrov, and Alexander Sutin. "Stevens Passive Acoustic Detection System (SPADES -2) and its prospective application for windfarm underwater noise assessment." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A239. http://dx.doi.org/10.1121/10.0011185.
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Stevens Institute of Technology has been conducting development and field tests of various underwater passive acoustic systems for several years. Several such systems provided localization of boats and divers triangulation. The new version of SPADES has a tethered low-cost bottom-mounted circular 2.2-m underwater acoustic array with eight custom-built hydrophones. The cost of the array was significantly reduced by manufacturing the hydrophones in-house and utilizing a lightweight and low-cost tether. The tether can provide power and communication up to 1 km away and power to the data acquisition. The software has been developed for real-time direction-finding using Steered Power Response Phase Transform (SRP-PHAT) method, combined with region-zeroing (RZ) approach to multi-source separation and custom noise background estimation subtraction. The array was tested for seven months in the shallow and busy waters of the Hudson River tracking small boat activity. The system’s reliability and long tether make it attractive for long-term observation of underwater noise such as monitoring wind farm noise marine mammals and shipping traffic. Direction-finding can help identify noise unrelated to wind farms.
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Font, Josep Maria, and Joaquim A. Batlle. "MOBILE ROBOT LOCALIZATION. REVISITING THE TRIANGULATION METHODS." IFAC Proceedings Volumes 39, no. 15 (2006): 340–45. http://dx.doi.org/10.3182/20060906-3-it-2910.00058.
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Hoseini, Seyyed, and Peyman Kabiri. "A Novel Feature-Based Approach for Indoor Monocular SLAM." Electronics 7, no. 11 (November 7, 2018): 305. http://dx.doi.org/10.3390/electronics7110305.
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Camera tracking and the construction of a robust and accurate map in unknown environments are still challenging tasks in computer vision and robotic applications. Visual Simultaneous Localization and Mapping (SLAM) along with Augmented Reality (AR) are two important applications, and their performance is entirely dependent on the accuracy of the camera tracking routine. This paper presents a novel feature-based approach for the monocular SLAM problem using a hand-held camera in room-sized workspaces with a maximum scene depth of 4–5 m. In the core of the proposed method, there is a Particle Filter (PF) responsible for the estimation of extrinsic parameters of the camera. In addition, contrary to key-frame based methods, the proposed system tracks the camera frame by frame and constructs a robust and accurate map incrementally. Moreover, the proposed algorithm initially constructs a metric sparse map. To this end, a chessboard pattern with a known cell size has been placed in front of the camera for a few frames. This enables the algorithm to accurately compute the pose of the camera and therefore, the depth of the primary detected natural feature points are easily calculated. Afterwards, camera pose estimation for each new incoming frame is carried out in a framework that is merely working with a set of visible natural landmarks. Moreover, to recover the depth of the newly detected landmarks, a delayed approach based on linear triangulation is used. The proposed method is applied to a realworld VGA quality video (640 × 480 pixels) where the translation error of the camera pose is less than 2 cm on average and the orientation error is less than 3 degrees, which indicates the effectiveness and accuracy of the developed algorithm.
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Travnikova, A. S., S. A. Misirov, S. V. Berdnikov, and L. M. Mestetskiy. "ESTIMATES OF CHANGES IN THE RELIEF OF THE COASTAL ZONE DURING ABRASION USING REMOTE SENSING DATA: METHODOLOGICAL APPROACHES AND PRELIMINARY RESULTS." ECOLOGY ECONOMY INFORMATICS. GEOINFORMATION TECHNOLOGIES AND SPACE MONITORING 2, no. 5 (2020): 124–30. http://dx.doi.org/10.23885/2500-123x-2020-2-5-124-130.
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The article offers a method for assessing changes in the relief of the Azov sea coastline and the localization of areas of erosion using discrete surface models obtained from remote sensing of the Earth using unmanned aerial vehicles (UAVs). This problem arises because of the need to monitor the dynamics of the coastline: due to the activation of various natural and man-made processes, there is an intensive destruction of the shores of the seas of Russia. Existing modern methods of land topographic survey do not allow you to quickly get information about changes in the state of the coastline or are expensive, and the large extent of the zone subject to erosion makes the traditional instrumental approach of measuring at reference points very labor-intensive. Also, the data obtained by the instrumental method reflects the problem point-by-point, rather than along the entire coastline. In this paper, we developed an algorithm and software for building a three-dimensional terrain model (using Delaunay triangulation) based on the so-called “dense point cloud” obtained when shooting terrain from an unmanned aerial vehicle (UAV). we proposed and programmatically implemented an algorithm for comparing (subtracting) two 3D models based on surveys performed by the same camera, but at different times of the day, in different seasons, and at different heights with an interval of 2 years, to identify significant changes in terrain in the area of the coastal slope, caused by abrasive and collapse processes. Experimental studies of the developed approach were conducted at the test site (500 by 300 m in size) on the southern shore of the Taganrog Bay. As a result of the considered experimental studies of comparing two 3D terrain models based on dense point clouds, additional working hypotheses (steps) that need to be solved were formulated to identify significant differences due to the destruction of the coast
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Zhu, Na, and Tamim Reza. "A modified cross-correlation algorithm to achieve the time difference of arrival in sound source localization." Measurement and Control 52, no. 3-4 (February 28, 2019): 212–21. http://dx.doi.org/10.1177/0020294019827977.
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The accuracy in ranging and direction in locating a target source is crucial in sound source localization and different methods have been proposed due to important applications of sound source localization. One of the methods in sound source localization is triangulation with the time difference of arrival information. In this literature, a modified cross-correlation algorithm is introduced to increase the accuracy in time difference of arrival, thus further improving the sound source localization results. A numerical model is generated by assuming multiple sound sources broadcasting in room environment and the location of the target sound source is identified with the triangulation algorithm. Real-time data are produced through experimental setup using an array of four microphones with a target source and background noise. The signals are processed by modified cross-correlation and conventional cross-correlation for comparison. The impacts of the signal-to-noise ratio and time difference of arrival on sound source localization results are demonstrated and discussed. Experimental validation conducted in a non-ideal environment has shown that the modified cross-correlation algorithm can minimize the error in time difference of arrival to be used in sound source localization, thus improving the accuracy in both sound source ranging and direction.
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Thoen, Bart, Stijn Wielandt, and Lieven De Strycker. "Improving AoA Localization Accuracy in Wireless Acoustic Sensor Networks with Angular Probability Density Functions." Sensors 19, no. 4 (February 21, 2019): 900. http://dx.doi.org/10.3390/s19040900.
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Advances in energy efficient electronic components create new opportunities for wireless acoustic sensor networks. Such sensors can be deployed to localize unwanted and unexpected sound events in surveillance applications, home assisted living, etc. This research focused on a wireless acoustic sensor network with low-profile low-power linear MEMS microphone arrays, enabling the retrieval of angular information of sound events. The angular information was wirelessly transmitted to a central server, which estimated the location of the sound event. Common angle-of-arrival localization approaches use triangulation, however this article presents a way of using angular probability density functions combined with a matching algorithm to localize sound events. First, two computationally efficient delay-based angle-of-arrival calculation methods were investigated. The matching algorithm is described and compared to a common triangulation approach. The two localization algorithms were experimentally evaluated in a 4.25 m by 9.20 m room, localizing white noise and vocal sounds. The results demonstrate the superior accuracy of the proposed matching algorithm over a common triangulation approach. When localizing a white noise source, an accuracy improvement of up to 114% was achieved.
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Nowacki, Jakub, Mariusz Dąbkowski, Piotr Niklas, and Grzegorz Redlarski. "Localization of Mobile Robot Using Radio Waves." Solid State Phenomena 147-149 (January 2009): 95–100. http://dx.doi.org/10.4028/www.scientific.net/ssp.147-149.95.
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In this paper the authors present the localization system which uses triangulation and trilateration to position mobile robot in the two-dimensional space. Distance was measured with the strength of radio signal emitted by devices of existing communication network, which were constructed by the authors. To get the actual distance in the function of radio signal strength the calibration curve, which was set empirically, made from the spline of linear functions was used. Research in this paper can be divided into two parts: the quality tests of communication and the localization using radio waves. Quantity measure of the correctly transmitted frames showed that the communication network works with the credibility of 80%, which is good result for the radio waves. Outcome of the localization quality showed that the position error did not surpass 1.7 m, which is a good result compared to the error of a typical GPS receiver is 15 m. Summing up, the localization system proposed by the authors is working well. Furthermore the test showed that triangulation and trilateration are universal methods of positioning and they can be used in other systems. Additionally the test indicated that the accuracy can by increased by using devices with a better signal strength measure.
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Meschino, Simone, Lara Pajewski, and Giuseppe Schettini. "A SAP-DoA Method for the Localization of Two Buried Objects." International Journal of Antennas and Propagation 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/702176.
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A localization technique for buried metallic and dielectric objects is proposed and tested. An array of isotropic antennas investigates a scenario with cylindrical targets buried in a dielectric soil. The targets are in the near field of the array, and a Sub-Array Processing (SAP) approach is adopted: the array is partitioned into subarrays, and Direction of Arrival (DoA) algorithms are used to process the electromagnetic field received by each subarray and estimate the dominant arrival direction of the signal. By triangulating all the estimated DoAs, a crossing pattern is obtained. It is filtered by a Poisson-based procedure and subsequently elaborated by the -means clustering method in order to distinguish between targets and background, estimate the number of targets, and find their position. Several simulations have been performed to compare different DoA algorithms and to test the localization method in the presence of two buried cylinders. Different values of the permittivity of the involved dielectric materials have been considered; the target positions and size have also been varied. The proposed procedure can be useful for ground-penetrating radar applications, near-surface probing, and for the detection and localization of defects in a hosting medium.
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Shang, Jianga, Xuke Hu, Fuqiang Gu, Di Wang, and Shengsheng Yu. "Improvement Schemes for Indoor Mobile Location Estimation: A Survey." Mathematical Problems in Engineering 2015 (2015): 1–32. http://dx.doi.org/10.1155/2015/397298.
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Location estimation is significant in mobile and ubiquitous computing systems. The complexity and smaller scale of the indoor environment impose a great impact on location estimation. The key of location estimation lies in the representation and fusion of uncertain information from multiple sources. The improvement of location estimation is a complicated and comprehensive issue. A lot of research has been done to address this issue. However, existing research typically focuses on certain aspects of the problem and specific methods. This paper reviews mainstream schemes on improving indoor location estimation from multiple levels and perspectives by combining existing works and our own working experiences. Initially, we analyze the error sources of common indoor localization techniques and provide a multilayered conceptual framework of improvement schemes for location estimation. This is followed by a discussion of probabilistic methods for location estimation, including Bayes filters, Kalman filters, extended Kalman filters, sigma-point Kalman filters, particle filters, and hidden Markov models. Then, we investigate the hybrid localization methods, including multimodal fingerprinting, triangulation fusing multiple measurements, combination of wireless positioning with pedestrian dead reckoning (PDR), and cooperative localization. Next, we focus on the location determination approaches that fuse spatial contexts, namely, map matching, landmark fusion, and spatial model-aided methods. Finally, we present the directions for future research.
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Jia, Songmin, Ke Wang, and Xiuzhi Li. "Mobile Robot Simultaneous Localization and Mapping Based on a Monocular Camera." Journal of Robotics 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/7630340.
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This paper proposes a novel monocular vision-based SLAM (Simultaneous Localization and Mapping) algorithm for mobile robot. In this proposed method, the tracking and mapping procedures are split into two separate tasks and performed in parallel threads. In the tracking thread, a ground feature-based pose estimation method is employed to initialize the algorithm for the constraint moving of the mobile robot. And an initial map is built by triangulating the matched features for further tracking procedure. In the mapping thread, an epipolar searching procedure is utilized for finding the matching features. A homography-based outlier rejection method is adopted for rejecting the mismatched features. The indoor experimental results demonstrate that the proposed algorithm has a great performance on map building and verify the feasibility and effectiveness of the proposed algorithm.
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Twaakyondo, Hashim M., and Juma H. Lungo. "Open Source Software in Health Information Systems: Opportunities and Challenges." Tanzania Journal of Engineering and Technology 31, no. 1 (June 30, 2008): 36–45. http://dx.doi.org/10.52339/tjet.v31i1.546.
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The paper presents results of a study seeking to identify constraining and motivating factors associated with the adoption and use of Free Open Source Software to computerise health Information Systems in a developing country. The study approach is interpretive research to case study with a triangulation of several qualitative data collection methods such as interviews, group discussions and document analysis. The findings indicate that using open source software has advantages and disadvantages. The advantages are low entry cost to adopting software, possibilities of software localization, avoiding being hostage of proprietary software and foster knowledge acquisition among software developers. The disadvantages are the need for constant internet access, high switching costs, and lack of human resources especially IT professionals to maintain the software since users get more rights in using and maintaining the system. The study concludes that because of the dynamics in health information systems, open source is appropriate.
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Bhatti, Ghulam. "Machine Learning Based Localization in Large-Scale Wireless Sensor Networks." Sensors 18, no. 12 (November 28, 2018): 4179. http://dx.doi.org/10.3390/s18124179.
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The rapid proliferation of wireless sensor networks over the past few years has posed some serious technical challenges to researchers. The primary function of a multi-hop wireless sensor network (WSN) is to collect and forward sensor data towards the destination node. However, for many applications, the knowledge of the location of sensor nodes is crucial for meaningful interpretation of the sensor data. Localization refers to the process of estimating the location of sensor nodes in a WSN. Self-localization is required in large wireless sensor networks where these nodes cannot be manually positioned. Traditional methods iteratively localize these nodes by using triangulation. However, the inherent instability in wireless signals introduces an error, however minute it might be, in the estimated position of the target node. This results in the embedded error propagating and magnifying rapidly. Machine learning based localizing algorithms for large wireless sensor networks do not function in an iterative manner. In this paper, we investigate the suitability of some of these algorithms while exploring different trade-offs. Specifically, we first formulate a novel way of defining multiple feature vectors for mapping the localizing problem onto different machine learning models. As opposed to treating the localization as a classification problem, as done in the most of the reported work, we treat it as a regression problem. We have studied the impact of varying network parameters, such as network size, anchor population, transmitted signal power, and wireless channel quality, on the localizing accuracy of these models. We have also studied the impact of deploying the anchor nodes in a grid rather than placing these nodes randomly in the deployment area. Our results have revealed interesting insights while using the multivariate regression model and support vector machine (SVM) regression model with radial basis function (RBF) kernel.
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Lenticchia, Erica, Amedeo Manuello Bertetto, and Rosario Ceravolo. "AE propagation velocity calculation for stiffness estimation in Pier Luigi Nervi’s concrete structures." Curved and Layered Structures 8, no. 1 (January 1, 2021): 109–18. http://dx.doi.org/10.1515/cls-2021-0010.
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Abstract In the present paper, the acoustic emission (AE) device is used with an innovative approach, based on the calculation of P-wave propagation velocity (vp ), to detect the stiffness characteristics and the diffused damage of in-service old concrete structures. The paper presents the result of a recent testing campaign carried out on the slant pillars composing the vertical bearing structures designed by Pier Luigi Nervi in one of his most iconic buildings: the Hall B of Torino Esposizioni. In order to investigate the properties of these inclined pillars, localizations of artificial sources (hammer impacts), by the triangulation procedure, were performed on three different inclined elements characterized by stiffness discrepancies due to different causes: the casting procedures, executed in different stages, and the enlargement of the hall happened a few years later the beginning of the construction. In the present work, the relationship between the velocity of AE signals and the elastic characteristics (principally elastic modulus, E) is evaluated in order to discriminate the stiffness level of the slanted pillars. The procedure presented made it possible to develop an innovative investigation method able to estimate, by means of AE, the state of conservation and the elastic properties and the damage level of the monitored concrete and reinforced concrete structures.
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Röhrig, Christof, and Frank Künemund. "MOBILE ROBOT LOCALIZATION USING WLAN SIGNAL STRENGTHS." International Journal of Computing, August 1, 2014, 73–83. http://dx.doi.org/10.47839/ijc.7.2.513.
Повний текст джерелаАнотація:
Many buildings are already equipped with a WLAN infrastructure, as an inexpensive communication technology. In this paper two methods that estimate the position and the heading (pose) of a mobile robot using WLAN technology are described. The proposed techniques for localizing a mobile robot are based on the use of received signal strength values of WLAN access points in range. Both use a radio map based method. For interpolation of the radio map weigthed Euclidean distance and Euclidean distance in combination with Delaunay triangulation is proposed. Measured signal strength values of an omnidirectional antenna and a beam antenna are compared with the values of a radio map, in order to estimate the pose of a mobile robot, whereby the directionality of the beam antenna is used to estimate the heading of the robot. The paper presents the experimental results of measurements in an office building.
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Jang, Byeong-Wook, and Chun-Gon Kim. "Acoustic emission source localization in composite stiffened plate using triangulation method with signal magnitudes and arrival times." Advanced Composite Materials, July 2, 2020, 1–15. http://dx.doi.org/10.1080/09243046.2020.1786903.
Повний текст джерела