메뉴 건너뛰기
.. 내서재 .. 알림
소속 기관/학교 인증
인증하면 논문, 학술자료 등을  무료로 열람할 수 있어요.
한국대학교, 누리자동차, 시립도서관 등 나의 기관을 확인해보세요
(국내 대학 90% 이상 구독 중)
로그인 회원가입 고객센터 ENG
주제분류

추천
검색

논문 기본 정보

자료유형
학위논문
저자정보

김종수 (한양대학교, 한양대학교 대학원)

지도교수
유홍희
발행연도
2014
저작권
한양대학교 논문은 저작권에 의해 보호받습니다.

이용수0

표지
AI에게 요청하기
추천
검색

이 논문의 연구 히스토리 (2)

초록· 키워드

오류제보하기
For the fault diagnosis of a mechanical system, pattern recognition methods have been widely used in recent research. A pattern recognition method determines the soundness of a mechanical system by detecting the variation of the system vibration characteristics. The Hidden Markov Model (HMM) and Artificial Neural Network (ANN) are recently used as the pattern recognition method in various fields. Most of the previous related researches use only one pattern recognition tool to classify the signals. In this research, a hybrid method that combines the HMM and ANN for the fault diagnosis of a mechanical system is introduced in order to improve the diagnostic accuracy. As a target model of fault diagnosis, a rotating wind turbine blade having a crack is selected. By extracting the acceleration from rotating blade having a crack, conduct the diagnosis about identifying the presence of a crack and finding the location and depth of a crack. Because vibration characteristics of a rotating blade according to location and depth of a crack have differences, it is possible to identify the crack location and depth using pattern recognition. In this research, the Fast Fourier Transform (FFT) is employed to extract feature vector. Moreover, to improve the diagnostic accuracy of the method in spite of noise existence, a moment having a few specific frequencies is applied to the blade.

목차

Contents
List of Figures …………………………………………… ⅲ
List of Tables ……………………………………………… ⅴ
국문요지 …………………………………………………… ⅵ
Chapter 1. Introduction …………………………………… 1
Chapter 2. Introduction to the HMM and ANN ………… 5
2.1 Hidden Markov Model (HMM) ………………………… 5
2.2 Artificial Neural Network (ANN) ………………… 8
Chapter 3. Feature Vector Extraction ………………… 11
3.1 Target Model of Fault Diagnosis ………………… 11
3.2 Feature Vector Extraction Using FFT …………… 13
Chapter 4. A Fault Diagnosis Algorithm ……………… 20
4.1 Hybrid Model Using the Hidden Markov Model
and Artificial Neural Network …………………… 20
4.2 Fault Diagnosis Algorithm Using Hybrid Model … 22
Chapter 5. Diagnostic Results ………………………… 24
5.1 Comparing the HMM and Hybrid Model in
Crack Diagnostic Results ………………………… 24
5.2 Diagnostic Results Concerning the
Presence of Cracks …………………………………… 25
5.3 Diagnostic Results Concerning the
Location and Depth of a Crack …………………… 27
Chapter 6. Conclusions …………………………………… 32
References …………………………………………………… 34
ABSTRACT ……………………………………………………… 37

최근 본 자료

전체보기

댓글(0)

0