66 research outputs found

    Measurement model of brass plated tyre steel cord based on wave feature extraction

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    In the production of Truck and Bus Radial (TBR) vehicle tyres, one of the essential components is the wire that supports the tyre. There are several types of tyre wire, one of which is Brass Plated Tyre Steel Cord (BPTSC), produced by Bekaert Indonesia Company. BPTSC object has a micro-size with a diameter of 0.230 mm and has a wave shape. In checking the quality of steel straps, brass-coated tyres are usually measured manually by experienced experts by measuring instruments to measure the diameter using a micrometre, wave amount, and wavelength using a profile projector. The manual measurement process results in inaccuracy due to fatigue in employees' eyes and low lighting and must be repeated, thus, consuming more time. Technological developments that use computer vision are increasingly widespread. Moreover, from the results of studies in various literature, it is proposed to combine the models obtained to find new models to solve this problem. The objectives of this study were to implement and evaluate an automatic segmentation method for obtaining regions of interest, to propose a BPTSC diameter, wave amount, and wavelength measurement model based on its edge, and to evaluate the proposed model by comparing the results with standard and industrial measurement results. The technique to prepare the brass plated tyre steel cord was done in two ways: image acquisition techniques with enhanced image quality, noise removal, and edge detection. Secondly, ground truth techniques were utilised to find the truth about the stages of the image acquisition process. Finally, sensitivity testing was conducted to find the similarity between the acquired images and the ground truth data using Jaccard, Dice, and Cosine similarity method. From 148 wire samples, the average similarity value was 93% by Jaccard, 96% by Dice, and 91% by the Cosine method. Thus, it can be concluded that the acquisition stage of the brass-coated steel tyre cable with image processing techniques can be carried out. For the subsequent process, the pixel distance and the sliding windows model applied can correctly detect the diameter of the BPTSC properly. The wave amount and wavelength of BPTSC objects in the form of waves were measured using several local minima and maxima approaches. This included maxima of local minima maxima distance, the average of local minima maxima distance, and perpendicular shape to centre distance for measuring wave amounts. While for wavelength measurements, the midpoint of local maxima minima distance and the intersection of local maxima minima with a central line were used. Measurement results were evaluated to determine the accuracy and efficiency of the measurement process compared to standard production values using the accuracy, precision, recall, and Root Mean Square Error (RMSE) test. From the evaluation results of the two methods, the accuracy rate of diameter measurement is 97%, wave rate measurement is 95%, and wavelength measurement is 90%. A new model was formed from the evaluation results that could solve these problems and provide scientific and beneficial contributions to society in general and the companies related to this industry

    Reasoning about Scene and Image Structure for Computer Vision

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    The wide availability of cheap consumer cameras has democratized photography for novices and experts alike, with more than a trillion photographs taken each year. While many of these cameras---especially those on mobile phones---have inexpensive optics and make imperfect measurements, the use of modern computational techniques can allow the recovery of high-quality photographs as well as of scene attributes. In this dissertation, we explore algorithms to infer a wide variety of physical and visual properties of the world, including color, geometry, reflectance etc., from images taken by casual photographers in unconstrained settings. We specifically focus on neural network-based methods, while incorporating domain knowledge about scene structure and the physics of image formation. We describe novel techniques to produce high-quality images in poor lighting environments, train scene map estimators in the absence of ground-truth data and learn to output our understanding and uncertainty on the scene given observed images. The key to inferring scene properties from casual photography is to exploit the internal structure of natural scenes and the expressive capacity of neural networks. We demonstrate that neural networks can be used to identify the internal structure of scenes maps, and that our prior understanding on natural scenes can shape the design, training and the output representation of neural networks

    Computational imaging and automated identification for aqueous environments

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    Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2011Sampling the vast volumes of the ocean requires tools capable of observing from a distance while retaining detail necessary for biology and ecology, ideal for optical methods. Algorithms that work with existing SeaBED AUV imagery are developed, including habitat classi fication with bag-of-words models and multi-stage boosting for rock sh detection. Methods for extracting images of sh from videos of longline operations are demonstrated. A prototype digital holographic imaging device is designed and tested for quantitative in situ microscale imaging. Theory to support the device is developed, including particle noise and the effects of motion. A Wigner-domain model provides optimal settings and optical limits for spherical and planar holographic references. Algorithms to extract the information from real-world digital holograms are created. Focus metrics are discussed, including a novel focus detector using local Zernike moments. Two methods for estimating lateral positions of objects in holograms without reconstruction are presented by extending a summation kernel to spherical references and using a local frequency signature from a Riesz transform. A new metric for quickly estimating object depths without reconstruction is proposed and tested. An example application, quantifying oil droplet size distributions in an underwater plume, demonstrates the efficacy of the prototype and algorithms.Funding was provided by NOAA Grant #5710002014, NOAA NMFS Grant #NA17RJ1223, NSF Grant #OCE-0925284, and NOAA Grant #NA10OAR417008

    Condition Monitoring and Optical Strain Measurement for Power Industry Components

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    Condition monitoring and life extension of components is vital to reducing risk of failure and operational costs in the power industry. Optical strain measurement techniques have been studied and developed for use in condition monitoring of power plant steam pipes and wind turbine components. In addition, these techniques have been used to assist evaluation of damage mechanisms in these components. Power plant steam pipes operate at high temperature (approximately 600°C) and pressure, and as a result undergo large creep deformations. Monitoring creep strain is a key factor in assessing remaining life of important components. An optical strain measurement system developed by EON, Automatic Reference Creep Measurement And Control (ARCMAC) has been researched as to its combined effectiveness with Digital Image Correlation (DIC) in obtaining accurate and reliable strain measurement for high temperature components. DIC has also been used to monitor and evaluate damage in composite wind turbine blade components. The use of this optical strain technique has allowed comparison of experimentally-derived full-field strain maps to be compared with finite element analysis (FEA) results. Additionally, the use of acoustic emission (AE) as a condition monitoring technique for wind turbine blades has been investigated. Use of these techniques has given greater understanding of failure mechanisms in wind turbine components; in particular, transverse tensile damage and delamination have been investigated. The influence of the Brazier effect upon wind turbine blade failure has also been researched. Results of this research have evaluated accuracy of using optical strain measurement techniques as well as their ability to effectively measure strain in particular regions of interest. The application of such techniques is an important requirement for both power plant and wind turbine components. Finally, studies into the use of optical strain measurement techniques as lab-based tools to study failure mechanisms have been performed
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