Deflection characterisation of rotary systems using ground-based radar
01 Oct 2019-The Journal of Engineering (The Institution of Engineering and Technology)-Vol. 2019, Iss: 20, pp 7215-7219
TL;DR: This study presents a modelling environment to simulate radar returns to analyse rotary systems, and demonstrates the characterisation of dynamic deflection parameters using a fast, portable ground-based interferometric radar (GBR).
Abstract: In the last two decades, an increase in large rotary machines/systems has been witnessed. To ensure safe operation of these systems especially due to extreme stress caused by centrifugal forces as well as the wind or water loadings, regular structural health monitoring (SHM) of the unbalanced parameters, particularly at the blade tips is necessary. For this, the use of non-contact sensors provides the most appropriate approach; however, millimetric out-of-plane deflection monitoring using non-contact sensors at distances >1 m has not been comprehensively addressed for rotary systems, like wind turbines. This study presents a modelling environment to simulate radar returns to analyse rotary systems. Employing Sammon mapping as a dimensionality reduction procedure in conjunction with 2D visualisation, the study demonstrates the characterisation of dynamic deflection parameters using a fast, portable ground-based interferometric radar (GBR). Comparisons between the GBR results with those of a Leica AR20 GPS indicate a divergence ±12.79 mm. The study utilises SHM framework to acquire, normalise, extract, and validate GBR signals within an SHM framework for structures under test or for deflection validation of the new system. Further, it contributes to the non-contact structural fatigue damage detection during design, testing, and operating stages of rotary structures blade tips.
Citations
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Journal Article•
TL;DR: The Micro-Doppler Effect in Radar by V. C. Chen as discussed by the authors is a book review of "The Micro Doppler effect in radar" by Chen et al. 2011. 290pp + diskette.
Abstract: This is a book review of 'The Micro-Doppler Effect in Radar' by V. C. Chen. Artech House, 16 Sussex Street, London, SW1V 4RW, UK. 2011. 290pp + diskette. Illustrated. £90. ISBN 978-1-60807-057-2.
439 citations
TL;DR: A novel iterative convolutional neural network strategy with an autocorrelation pre-processing instead of the traditional micro-Doppler image pre- processing to classify activities or subjects accurately is presented.
Abstract: The accurate classification of activity patterns based on radar signatures is still an open problem and is a key to detect anomalous behavior for security and health applications. This paper presents a novel iterative convolutional neural network strategy with an autocorrelation pre-processing instead of the traditional micro-Doppler image pre-processing to classify activities or subjects accurately. The proposed strategy uses an iterative deep learning framework for the automatic definition and extraction of features. This is followed by a traditional supervised learning classifier to label different activities. Using three human subjects and their real motion captured data, 12 000 radar signatures were simulated by varying additive white Gaussian noise. In addition, 6720 experimental radar signatures were captured with a frequency-modulated continuous radar at 5.8 GHz with 400 MHz of instantaneous bandwidth from seven activities using one subject and 4800 signatures from five subjects while walking. The simulated and experimental data were both used to validate our proposed method, with signal–noise ratio varying from −20 to 20 dB and with 88.74% average accuracy at −10 dB and 100% peak accuracy at 15 dB. The proposed iterative convolutional neural networks followed with random forests not only outperform the feature-based methods using micro-Doppler images but also outperform the classification methods using other types of supervised classifiers after our proposed iterative convolutional neural network.
55 citations
15 Apr 2021
TL;DR: Wiley as discussed by the authors made no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose.
Abstract: A complete list of the titles in this series appears at the end of this volume. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at (800) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com.
26 citations
31 Jul 2015
TL;DR: In this paper, the Savonius rotor blades were made using glass reinforced fiber and compared with the existing blades in terms of their performance and production cost with the new blades made by the same manufacturer.
Abstract: Studies indicate that vertical axis wind turbines provide a more reliable energy conversion technology, as compared to horizontal axis wind turbines, especially in areas of lowly rated and/or uncertain wind speeds. The challenge however is the development of an efficient Savonius rotor blade which is affordable to low income earners in Kenya. The author researched on different technical design solutions and their advantages in terms of noise, shadows and impacts on birds and wildlife. The objectives of this research were thus to design and develop a Savonius rotor blade locally with locally availlable materials and compare its performance and production cost with the existing blades. The blades were made using glass reinforced fibre because of the light weight of the material which enables it to rotate at very low wind speed, it is also long lasting and does not rot hence can survive in all weather conditions. A prototype was made and after testing and understanding it, a more efficient rotor blade was made. Laboratory and field tests were then done. From the developed blade, a laboratory test was conducted using an industrial fan which could go at a maximum speed of 960 revolutions per minute (RPM) which was calibrated to generate an equivalent wind speed of 15 m/s (meters per second). A torque of 367.57 NM (Newton-metre) at a wind speed of 13.7 m/s was obtained. When the blade was connected to a three phase generator, the line voltages obtained were: 7.5, 8.5, and 8.1 V for line L1, L2 and L3 respectively. The Vac from the generator was then rectified by a bridge rectifier and a maximum voltage obtained was 10.5 Vdc which was then used to charge a 12 V dc lead battery. The battery was fully charged after 11 hours, 36 minutes and used to light a 12Vdc bulb for 7 hours. A field test was also done at Ngong hills at a height above the sea level of 2460m (8070 ft) and a maximum wind speed of 6.44 m/s was reached at the time of testing. The angular velocity obtained was 13.58rads/sec, voltage of 5.63V, 6.2V and 5.93V was recorded for each line. The above laboratory test led to a conclusion that it was possible to locally develop a wind conversion technology that is affordable, efficient and adaptable for Kenya’s average wind speed of 4m/s.
1 citations
References
More filters
Journal Article•
TL;DR: The Micro-Doppler Effect in Radar by V. C. Chen as discussed by the authors is a book review of "The Micro Doppler effect in radar" by Chen et al. 2011. 290pp + diskette.
Abstract: This is a book review of 'The Micro-Doppler Effect in Radar' by V. C. Chen. Artech House, 16 Sussex Street, London, SW1V 4RW, UK. 2011. 290pp + diskette. Illustrated. £90. ISBN 978-1-60807-057-2.
439 citations
"Deflection characterisation of rota..." refers methods in this paper
...For the simulative framework, a time-frequency analysis method generating a twodimensional time-frequency spectrum [15] and a range-Doppler analysis method generating three-dimensional information including time-frequency-range declined into two approaches: Chen's approach [15] and our proposed method....
[...]
Book•
04 May 2021
TL;DR: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose.
328 citations
"Deflection characterisation of rota..." refers background in this paper
...The actual movement along the LoS (DefLoS) [24, 25] is thus provided by (7)....
[...]
TL;DR: In this article, the authors reviewed the structure of wind turbines and analyzed the different components in order to detect the faults that may happen and mainly reviewed fault diagnosis methods in wind turbines in the last three years.
Abstract: Wind turbines have been developed fast in the recent years and at the same time have brought some problems. It is important to maintain the healthy condition of the running turbine because the consequences after faults are miserable for both the company and owner. There is a constant need to reduce the costs of operating and maintaining the turbines. Therefore, it is very important to detect the faults/failures early so as to minimize downtime and maximize productivity. This paper reviewed the structure of wind turbines and analyzed the different components of wind turbines in order to detect the faults that may happen. Meanwhile, this paper mainly reviewed fault diagnosis methods of wind turbines in the last three years. The main purpose of this paper is to supply some information on structure healthy condition monitoring (SHCM) and fault diagnosis in wind turbines for related researchers.
226 citations
TL;DR: A review of structural health monitoring methods, including residual cure strain monitoring, for wind turbine blade industry is presented in this article, with potential savings to manufacturing time and reductions in cost through quality control measures, including furthering the scientific understanding of cure strain.
164 citations
TL;DR: A number of commercial and research health monitoring systems have been implemented for wind turbines as discussed by the authors, providing an analysis of the current state of turbine health monitoring and the challenges associated with monitoring each of the major turbine components.
Abstract: Wind energy has played an increasingly vital role in renewable power generation, driving the need for more cost-effective wind energy solutions. Health monitoring of turbines could provide a variety of economic and other benefits to aid in wind growth. A number of commercial and research health monitoring systems have been implemented for wind turbines. This paper surveys these systems, providing an analysis of the current state of turbine health monitoring and the challenges associated with monitoring each of the major turbine components. This paper also contextualizes the survey with the various potential benefits of health monitoring for turbines.
150 citations