Acoustic Positioning System for 3D Localization of Sound Sources Based on the Time of Arrival of a Signal for a Low-Cost System

The localization of sound sources has received increasing interest over the last few decades, given its wide range of applications. The triangulation method using the Time of Arrival (ToA) of a signal has shown to be useful and easy-to-use and, at the same time, provides accurate results. In this work, the acoustic trilateration method is applied in experimental measures to study and demonstrate its precision in air. Firstly, the method is tested in an anechoic chamber (low reverberating environment) demonstrating its functionality and accuracy. The next step has been the application of the method by using a low-cost system to demonstrate how a non-anechoic environment affects the accuracy of the localization. The detection of the received signal is implemented using a cross-correlation method in the time domain for both cases. Furthermore, the influence of the number and positions of the receiver that are used for this process in the accuracy of the results is also studied.

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Indoor Localization System Using Wi-Fi Technology

Iraqi Journal of Computer Communication Control and System Engineering ◽

10.33103/uot.ijccce.19.2.8 ◽

2019 ◽

pp. 69-77

Keyword(s):

Global Positioning System ◽

Indoor Localization ◽

Tracking System ◽

Low Cost ◽

Positioning System ◽

Test Results ◽

Localization System ◽

Transmission Technique ◽

Wide Range ◽

Global Positioning

Recently, indoor localization has witnessed an increase in interest, due to the potential wide range of using in different applications, such as Internet of Things (IoT). It is also providing a solution for the absence of Global Positioning System (GPS) signals inside buildings. Different techniques have been used for performing the indoor localization, such as sensors and wireless technologies. In this paper, an indoor localization and object tracking system is proposed based on WiFi transmission technique. It is done by distributing different WiFi sources around the building to read the data of the tracked objects. This is to measure the distance between the WiFi receiver and the object to allocate and track it efficiently. The test results show that the proposed system is working in an efficient way with low cost.

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Validation of a Low-Cost Electromyography (EMG) System via a Commercial and Accurate EMG Device: Pilot Study

Sensors ◽

10.3390/s19235214 ◽

2019 ◽

Vol 19 (23) ◽

pp. 5214 ◽

Cited By ~ 2

Author(s):

Sergio Fuentes del Toro ◽

Yuyang Wei ◽

Ester Olmeda ◽

Lei Ren ◽

Wei Guowu ◽

...

Keyword(s):

Pilot Study ◽

Linear Correlation ◽

Low Cost ◽

Rectus Femoris ◽

Research Areas ◽

Cost System ◽

Wide Range ◽

Spearman’S Correlation ◽

Rectus Femoris Muscle ◽

Femoris Muscle

Electromyography (EMG) devices are well-suited for measuring the behaviour of muscles during an exercise or a task, and are widely used in many different research areas. Their disadvantage is that commercial systems are expensive. We designed a low-cost EMG system with enough accuracy and reliability to be used in a wide range of possible ways. The present article focuses on the validation of the low-cost system we designed, which is compared with a commercially available, accurate device. The evaluation was done by means of a set of experiments, in which volunteers performed isometric and dynamic exercises while EMG signals from the rectus femoris muscle were registered by both the proposed low-cost system and a commercial system simultaneously. Analysis and assessment of three indicators to estimate the similarity between both signals were developed. These indicated a very good result, with spearman’s correlation averaging above 0.60, the energy ratio close to the 80% and the linear correlation coefficient approximating 100%. The agreement between both systems (custom and commercial) is excellent, although there are also some limitations, such as the delay of the signal (<1 s) and noise due to the hardware and assembly in the proposed system.

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A Low-Cost System for Measuring Horizontal Winds from Single-Engine Aircraft

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-13-00143.1 ◽

2014 ◽

Vol 31 (6) ◽

pp. 1312-1320 ◽

Cited By ~ 25

Author(s):

Stephen A. Conley ◽

Ian C. Faloona ◽

Donald H. Lenschow ◽

Anna Karion ◽

Colm Sweeney

Keyword(s):

Global Positioning System ◽

Measurement System ◽

Low Cost ◽

Horizontal Wind ◽

Positioning System ◽

Cost System ◽

Upper Limit ◽

Global Positioning ◽

True Airspeed ◽

Wind Measurements

Abstract The implementation and accuracy of a low-rate (~1 Hz) horizontal wind measurement system is described for a fixed-wing aircraft without modification to the airframe. The system is based on a global positioning system (GPS) compass that provides aircraft heading and a ground-referenced velocity, which, when subtracted from the standard true airspeed, provides estimates of the horizontal wind velocity. A series of tests was performed flying “L”-shaped patterns above the boundary layer, where the winds were assumed to be horizontally homogeneous over the area bounded by the flight (approximately 25 km2). Four headings were flown at each altitude at a constant airspeed. Scaling corrections for both heading and airspeed were found by minimizing the variance in the 1-s wind measurements; an upper limit to the error was then computed by calculating the variance of the corrected wind measurements on each of the four headings. A typical uncertainty found in this manner tends to be less than 0.2 m s−1. The measurement system described herein is inexpensive and relatively easy to implement on single-engine aircraft.

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Vision-based positioning system for auto-docking of unmanned surface vehicles (USVs)

International Journal of Intelligent Robotics and Applications ◽

10.1007/s41315-021-00193-0 ◽

2021 ◽

Author(s):

Øystein Volden ◽

Annette Stahl ◽

Thor I. Fossen

Keyword(s):

Stereo Vision ◽

Field Experiments ◽

Low Cost ◽

Reference Points ◽

Outdoor Environment ◽

Data Driven ◽

Positioning System ◽

Localization Task ◽

Detection Model ◽

Cost System

AbstractThis paper presents an independent stereo-vision based positioning system for docking operations. The low-cost system consists of an object detector and different 3D reconstruction techniques. To address the challenge of robust detections in an unstructured and complex outdoor environment, a learning-based object detection model is proposed. The system employs a complementary modular approach that uses data-driven methods, utilizing data wherever required and traditional computer vision methods when the scope and complexity of the environment are reduced. Both, monocular and stereo-vision based methods are investigated for comparison. Furthermore, easily identifiable markers are utilized to obtain reference points, thus simplifying the localization task. A small unmanned surface vehicle (USV) with a LiDAR-based positioning system was exploited to verify that the proposed vision-based positioning system produces accurate measurements under various docking scenarios. Field experiments have proven that the developed system performs well and can supplement the traditional navigation system for safety-critical docking operations.

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A high-accuracy indoor positioning system based on UWB

MATEC Web of Conferences ◽

10.1051/matecconf/201817301021 ◽

2018 ◽

Vol 173 ◽

pp. 01021

Author(s):

Hanyu Liu ◽

Yanhan Zeng ◽

Ruguo Li ◽

Huajie Huang

Keyword(s):

Indoor Positioning ◽

Mobile Node ◽

High Accuracy ◽

Base Stations ◽

Ultra Wideband ◽

Time Of Arrival ◽

Positioning System ◽

Wide Range ◽

Fixed Base ◽

Indoor Positioning System

In this paper, a high-accuracy indoor positioning system based on the ultra-wideband (UWB) technique is proposed. The proposed system uses a simple ranging process to obtain the distance between the mobile node and the fixed base stations. Besides, an improved time of arrival (ToA) algorithm with Kalman filtering is proposed to improve the positioning accuracy. Measurements have been performed in the real indoor 13m*7.6m environment with many obstacles and the root-mean-square error (RMSE) is less than 0.3m. The proposed system offers a wide range of application in robotics, industrial automation, post-sorting system and so on.

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Extended Joint Sparsity Reconstruction for Spatial and Temporal ERT Imaging

Sensors ◽

10.3390/s18114014 ◽

2018 ◽

Vol 18 (11) ◽

pp. 4014 ◽

Cited By ~ 2

Author(s):

Bo Chen ◽

Juan Abascal ◽

Manuchehr Soleimani

Keyword(s):

Temporal Resolution ◽

High Speed ◽

Low Cost ◽

Control Process ◽

Industrial Applications ◽

High Temporal Resolution ◽

Conductivity Distribution ◽

Dynamic Movement ◽

Wide Range ◽

The Time Domain

Electrical resistance tomography (ERT) is an imaging technique to recover the conductivity distribution with boundary measurements via attached electrodes. There are a wide range of applications using ERT for image reconstruction or parameter calculation due to high speed data collection, low cost, and the advantages of being non-invasive and portable. Although ERT is considered a high temporal resolution method, a temporally regularized method can greatly enhance such a temporal resolution compared to frame-by-frame reconstruction. In some of the cases, especially in the industrial applications, dynamic movement of an object is critical. In practice, it is desirable for monitoring and controlling the dynamic process. ERT can determine the spatial conductivity distribution based on previous work, and ERT potentially shows good performance in exploiting temporal information as well. Many ERT algorithms reconstruct images frame by frame, which is not optimal and would assume that the target is static during collection of each data frame, which is inconsistent with the real case. Although spatiotemporal-based algorithms can account for the temporal effect of dynamic movement and can generate better results, there is not that much work aimed at analyzing the performance in the time domain. In this paper, we discuss the performance of a novel spatiotemporal total variation (STTV) algorithm in both the spatial and temporal domain, and Temporal One-Step Tikhonov-based algorithms were also employed for comparison. The experimental results show that the STTV has a faster response time for temporal variation of the moving object. This robust time response can contribute to a much better control process which is the main aim of the new generation of process tomography systems.

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An underground, wireless, open-source, low-cost system for monitoring oxygen, temperature, and soil moisture

10.5194/soil-2021-72 ◽

2021 ◽

Author(s):

Elad Levintal ◽

Yonatan Ganot ◽

Gail Taylor ◽

Peter Freer-Smith ◽

Kosana Suvocarev ◽

...

Keyword(s):

Wireless Sensor Networks ◽

Soil Moisture ◽

Sensor Networks ◽

Open Source ◽

Low Cost ◽

Wireless Sensor ◽

Soil Parameters ◽

Engineering Knowledge ◽

Cost System ◽

Wide Range

Abstract. The use of wireless sensor networks in the measurement of soil parameters represents one of the least invasive methods available to date. Wireless sensors pose the least disturbance to soil structure and having fewer aboveground cables reduce the risk of undesired equipment damage and potential data loss. However, implementing wireless sensor networks in field studies usually requires advanced and costly engineering knowledge. This study presents a new underground, wireless, open-source, low-cost system for monitoring soil oxygen, temperature, and soil moisture. The process of system design, assembly, programming, deployment, and power management is presented. The system can be left underground for several years without the need for changing the battery. Emphasis was given on modularity so that it can be easily duplicated or changed if needed, and deployed without previous engineering knowledge. Data from this type of system have a wide range of applications, including precision agriculture and high-resolution modelling.

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Application of cross correlation to HREM images of surfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128080 ◽

1987 ◽

Vol 45 ◽

pp. 754-755

Author(s):

D. E. Luzzi ◽

L. D. Marks ◽

M. I. Buckett

Keyword(s):

Cross Correlation ◽

A Priori ◽

Matrix Material ◽

Correlation Method ◽

Accurate Knowledge ◽

Complex Image ◽

Fourier Filtering ◽

The Matrix ◽

Low Pass ◽

Data Reduction Technique

As the HREM becomes increasingly used for the study of dynamic localized phenomena, the development of techniques to recover the desired information from a real image is important. Often, the important features are not strongly scattering in comparison to the matrix material in addition to being masked by statistical and amorphous noise. The desired information will usually involve the accurate knowledge of the position and intensity of the contrast. In order to decipher the desired information from a complex image, cross-correlation (xcf) techniques can be utilized. Unlike other image processing methods which rely on data massaging (e.g. high/low pass filtering or Fourier filtering), the cross-correlation method is a rigorous data reduction technique with no a priori assumptions.We have examined basic cross-correlation procedures using images of discrete gaussian peaks and have developed an iterative procedure to greatly enhance the capabilities of these techniques when the contrast from the peaks overlap.

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