1,273 research outputs found

    Development of wireless bruxism monitoring device based on pressure-sensitive polymer composite

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    A wireless pressure sensing bite guard has been developed for monitoring the progress of bruxism (teeth grinding during sleep); as well as protecting the teeth from damages. For sensing the pressure effectively in the restricted space and hostile environment, a pressure sensitive polymer composite has been fabricated and encapsulated into a conventional bite guard which is safe for in-situ applications. The device is anticipated to give real-time data through wireless data transmission and to have a long working life (weeks). A microcontroller-based electronic circuit has been built in-house for data collection and transmission. A low power approach is configured to increase the working life of the device. This device is a useful tool for understanding and treating bruxism

    Design and Implementation of a Composite Array Resistivity Data Logger for High-Resolution 2D Inversion Modeling

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    The use of resistivity meters to model subsurface conditions is widespread. However, commercial instruments are mostly limited to conventional configurations, such as Wenner, Schlumberger, and dipole-dipole. Moreover, we cannot modify the program on the instrument. In this study, we designed and implemented a DC resistivity meter that can potentially be developed in the future and can be used in composite array configurations. This instrument uses a half-bridge SMPS as a power supply, which is capable of generating a large power, an Arduino Uno, and several sensor modules as part of a flexible and easy-to-program control unit. We conducted laboratory and field tests, comparing two types of configurations, namely Wenner and composite arrays (dipole-dipole and gradient). We then processed the data using ResIPy software, which enables displaying complex data sets in the form of 2D cross-sections and assessing the quality of post-processing data. We obtained good data with low RMS misfit that matched the synthetic media created in laboratory testing and compared well with previous research

    Development of Digital Resistivity Meter

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    A digital resistivity meter was designed and constructed using microcontroller (PIC16F877A) and other carefully selected components. The meter was developed, using the state of the art technology, to measure the earth’s electrical resistivity through application of direct current electrical resistivity method. It was designed as a system with various subunits implemented as modules, to help greatly in trouble shooting the system in case of system failure. This meter injected currents of 0.1mA, 1mA and 10mA and two, 6V batteries connected in series powered it. Its capability of accepting analog input and displaying digital output gives it advantage of minimizing errors associated with output display. Microcontroller operated using a configuration of hardware components and functional software written and burnt into the microcontroller’s memory. The meter was tested with a specially designed test unit and the generated results were compared with the calculated values, the two agreed. Keywords: Electrical resistivity, microcontroller, analog, digita

    Rancang bangun data logger berbasis Arduino sebagai penyimpan data

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    Sistem perekaman data dapat dibuat dengan membangun data logger berbasis Arduino. Data logger multi chanel berbasis Arduino uno telah dibuat. Pembuatan data logger ini bertujuan untuk memenuhi kebutuhan perekaman data pada setiap alat ukur yang membutuhkan perekaman data. Data logger dibuat dengan menggunakan modul multiplekser 74HC4051 yang memiliki 8 input sebagai media pengembangan jalur masukan pada arduino. Setiap sinyal yang masuk pada modul multiplekser akan dikirim ke Arduino uno untuk proses perhitungan dan pemilahan chanel. Setiap data hasil perhitungan disimpan pada modul penyimpanan yang berupa microSD. Pengujian sistem dilakukan dengan menggunakan variasi tegangan pada setiap chanel. Berdasarkan hasil pengujian, multiplekser dapat menyalurkan setiap sinyal yang diterima pada setiap chanel dengan baik tanpa terjadi kesalahan jalur. Modul penyimpanan juga dapat menyimpan setiap data yang diterima oleh arduino uno dengan interval penyimpanan setiap detik. Multiplekser mempunyai tingkat akurasi 100% terhadap pemilahan jalur. Modul penyimpanan sebagai data logger juga mempunyai akurasi sebesar 100%.A Data recording system using an Arduino-based multi-channel data logger has been designed. This data logger can be installed in any measuring instrument that requires data recording. The data logger comprises a 74HC4051 multiplexer module that has eight inputs for developing input lines on the Arduino. Every signal that enters the multiplexer module will be sent to Arduino Uno for calculations and channel sorting. Each calculation data is stored on a storage module in the form of a microSD. The system is tested by using voltage variations on each channel. Based on the test results, the multiplexer can properly channel every signal they receive without path errors. The storage module can also store every data received by the Arduino Uno with a storage interval of every second. The multiplexer has a 100% accuracy rate for line sorting. The storage module as a data logger also has an accuracy of 100%

    Design of a low-cost electrical resistivity meter for near surface surveys

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    A programmable automated electrical resistivity meter was designed and constructed. The device was created to perform near surface studies, particularly for archaeogeophysical target characterization. Real field and laboratory model studies can be performed changing the current input of the device. The equipment consists of two independent devices, each one with its own microcontroller platform. They are interconnected through serial data transfer protocol. The first device, works as a resistivity meter where the ABMN electrode positions are programmed and permits the interaction with the user. The second one, connects the current and voltage channels to the programmed electrode positions. A physical model and field measurements were performed with different electrode configurations such as Dipole-Dipole, Werner-Schlumberger and Wenner γ112 in order to verify the performance of the automated electrical resistivity meter. The measurements give mean relative standard deviation values between 0.6% and 5.5% and data inversion convergence between 1.3% and 7.2%. Even though this open source and low cost electrical resistivity meter was design primarily for archaeogeophysical studies, it could be adapted to other geophysical issues such as contamination plumes detection and characterization, tunnel detection, etc.Fil: de la Vega, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Grupo de Geofísica Aplicada; ArgentinaFil: Bongiovanni, Maria Victoria Flavia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ingeniería. Laboratorio de Investigación Desarrollo y Transferencia - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Laboratorio de Investigación Desarrollo y Transferencia; ArgentinaFil: Grünhut Duenyas, Vivian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ingeniería. Laboratorio de Investigación Desarrollo y Transferencia - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Laboratorio de Investigación Desarrollo y Transferencia; Argentin

    Miniature Resistance Measurement Device for Structural Health Monitoring of Reinforced Concrete Infrastructure

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    A vast amount of civil infrastructure is constructed using reinforced concrete, which can be susceptible to corrosion, posing significant risks. Corrosion of reinforced concrete has various causes, with chloride ingress known to be a major contributor. Monitoring this chloride ingress would allow for preventative maintenance to be less intrusive at a lower cost. Currently, chloride sensing methods are bulky and expensive, leaving the majority of concrete infrastructures unmonitored. This paper presents the design and fabrication of a miniature, low-cost device that can be embedded into concrete at various locations and depths. The device measures localized concrete resistance, correlating to the chloride ingress in the concrete using equations listed in this paper, and calculated results from two experiments are presented. The device benefits from a four-probe architecture, injecting a fixed frequency AC waveform across its outer electrodes within the cement block. Voltage across the internal electrodes is measured with a microcontroller and converted to a resistance value, communicated serially to an external computer. A final test showcases the ability of the device for three-dimensional mass deployment

    Determination of Sugar Level and the Existence of Magic Sugar in Various Beverages using a Glucose Meter with Four-Point Probe and Electrochemical Impedance

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    Nowadays, people are being inconsiderate about the healthy lifestyle that might lead us to be unhealthy and be prone to developing tumors in the kidney due to some kind of sugar being used. In order to minimize these problems, the team will raise people awareness. Raising people awareness is not the same as telling them what to do. It is about giving them the knowledge to let them decide for themselves. This is why the team developed a device that can measure the sugar level and determine the existence of magic sugar in various beverages. The device is composed of two major parts: first is the circuit that will measure the impedance of a liquid sample and second, is a four-point probe, which includes a microcontroller that will display and interpret the results. The Four-point probe applies the concept of Wenner method and Electrochemical Impedance. After constructing the device, the team performed its calibration that requires different liquid samples. Based on its gathered data, different graphical representations were formulated and translated into mathematical equations in order to integrate it onto the microcontroller. Whenever the microcontroller encounters an unknown solution, it can determine the sugar level and classify the type of sugar being used

    Design and Development of Data Acquisition for Leakage Current at Electrical Tracking Test

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    Abstract—In electrical power systems, the insulator is the material that determines whether the electrical energy can be supplied or delivered to a place of excellent quality and does not harm the human and the environment around such high voltage electrical conductor devices. In testing leakage current in the laboratory, current and voltage changes in input and current changes and output voltages change very quickly, making it difficult to detect with the usual measuring device. For that required software to simulate the test. One method used to test the insulation resistance of the insulator material is the Inclined Plane Tracking (IPT) method. That is a method used to represent the leakage current on the surface of an insulation. The insulation and leakage resistance simulation in this test is performed by Multisim 14 software by simulating the insulation resistance with a potentiometer that changes resistance when a leak current occurs in the test. The resistance is increased step by step to know the parameters of current and voltage at the time of testing. In this simulation testing is done in stages, so it can be known Source Voltage, Input Voltage, Input Current, Leakage Current and Output Voltage. Simulation using Multisim 14 software can represent insulation resistance, leakage current and output voltage that can be used to obtain replacement resistance (Rp), leakage current (Iout), output voltage (Vout), alternating current (Iloss) and replacement voltage (Vloss). Simulation Software Proteus can simulate data received in the form of analog into digital data. Further processed according to the data required. Keywords— Inclined Plane Tracking (IPT), Leakage Current, Data Acquisitio

    Motor control of a hub motor for electric skateboard propulsion : a thesis presented in partial fulfilment of the requirements for the degree of Masters in Engineering at Massey University, Palmerston North, New Zealand

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    Redacted for copyright reasons: Appendix A - Journal Article Published in IEEE International Instrumentation and Measurement Technology Conference (I2MTC 2012). Rowe, A. & Sen Gupta, G. (2012). Instrumentation and control of a high power BLDC motor for small vehicle applications.An electric powered skateboard was designed and built for testing and development of an innovative hub motor propulsion system and motor controller. The electric skateboard prototype is able to reach speeds of over 50km/h and achieve a range of over 35km on a single battery charge. The prototype weighs 8.6kg and can easily be carried by the user. This mode of transport has potential uses in recreational use, motor sports (racing), short commutes, and most notably, in ‘the last mile’ of public transport – getting to and from a train station, bus stop, etc. to the user’s final destination. Typical electric powered skateboards use external motors(s) requiring a power transmission assembly to drive the wheels. The hub motor design places the motor(s) inside the skateboard wheels and drives the wheels directly. This removes the need for power transmission assemblies therefore reductions in size, weight, cost, audible noise, and maintenance are realised. The hub motor built for this prototype has proven to be a highly feasible option over typical drive systems and further improvements to the design are discussed in this report. Advances in the processor capability of low cost microcontrollers has allowed for advanced motor control techniques to be implemented on low cost consumer level motor controllers which, until recent times, have been using the basic ‘Six-Step Control’ technique to drive Permanent Magnet Synchronous Motors. The custom built motor controllers allow for firmware to be flashed to the microcontroller. Firmware was written for the basic motor control technique, Six-Step Control and for the advanced motor control technique, ‘Field Oriented Control’ (FOC). This allowed for the two control techniques to be tested and compared using identical hardware for each. Six-Step Control drives a three phase motor by controlling the inverter output to six discrete states. The states are stepped through sequentially. This results in a square wave AC waveform. Theory shows that this is not optimal as the magnetic flux produced in the stator is not always perpendicular to the magnet poles but rather aligned to the nearest 60°. FOC addresses this by controlling the magnetic flux to always be perpendicular to the magnet poles in order to maximise torque. The inverter is essentially controlled to produce a continuously variable voltage vector output in terms of both magnitude and direction (vector control). Bench testing of the control techniques was performed using two motors coupled together with one motor driving and the other motor running as a generator. The generator motor was shown to provide a highly consistent and repeatable load on the driving motor under test and therefore comparisons could be made between the performance of the motor while controlled under Six-Step Control and FOC. This test indicated that FOC was able to drive the motor more efficiently than Six-Step Control, however the FOC implementation requires further development to achieve greater efficiency under high load demands. Furthermore, on-road testing was performed using the motor controllers in the electric skateboard prototype to compare the performance of the two control techniques in a real world application. The results from this test were inconclusive due to large variation in the results between repeated tests

    Content-based indexing of low resolution documents

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    In any multimedia presentation, the trend for attendees taking pictures of slides that interest them during the presentation using capturing devices is gaining popularity. To enhance the image usefulness, the images captured could be linked to image or video database. The database can be used for the purpose of file archiving, teaching and learning, research and knowledge management, which concern image search. However, the above-mentioned devices include cameras or mobiles phones have low resolution resulted from poor lighting and noise. Content-Based Image Retrieval (CBIR) is considered among the most interesting and promising fields as far as image search is concerned. Image search is related with finding images that are similar for the known query image found in a given image database. This thesis concerns with the methods used for the purpose of identifying documents that are captured using image capturing devices. In addition, the thesis also concerns with a technique that can be used to retrieve images from an indexed image database. Both concerns above apply digital image processing technique. To build an indexed structure for fast and high quality content-based retrieval of an image, some existing representative signatures and the key indexes used have been revised. The retrieval performance is very much relying on how the indexing is done. The retrieval approaches that are currently in existence including making use of shape, colour and texture features. Putting into consideration these features relative to individual databases, the majority of retrievals approaches have poor results on low resolution documents, consuming a lot of time and in the some cases, for the given query image, irrelevant images are obtained. The proposed identification and indexing method in the thesis uses a Visual Signature (VS). VS consists of the captures slides textual layout’s graphical information, shape’s moment and spatial distribution of colour. This approach, which is signature-based are considered for fast and efficient matching to fulfil the needs of real-time applications. The approach also has the capability to overcome the problem low resolution document such as noisy image, the environment’s varying lighting conditions and complex backgrounds. We present hierarchy indexing techniques, whose foundation are tree and clustering. K-means clustering are used for visual features like colour since their spatial distribution give a good image’s global information. Tree indexing for extracted layout and shape features are structured hierarchically and Euclidean distance is used to get similarity image for CBIR. The assessment of the proposed indexing scheme is conducted based on recall and precision, a standard CBIR retrieval performance evaluation. We develop CBIR system and conduct various retrieval experiments with the fundamental aim of comparing the accuracy during image retrieval. A new algorithm that can be used with integrated visual signatures, especially in late fusion query was introduced. The algorithm has the capability of reducing any shortcoming associated with normalisation in initial fusion technique. Slides from conferences, lectures and meetings presentation are used for comparing the proposed technique’s performances with that of the existing approaches with the help of real data. This finding of the thesis presents exciting possibilities as the CBIR systems is able to produce high quality result even for a query, which uses low resolution documents. In the future, the utilization of multimodal signatures, relevance feedback and artificial intelligence technique are recommended to be used in CBIR system to further enhance the performance
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