【正文】 故障信號的數(shù)據(jù)采集 ...................................................................................................... 8 第 3 章 小波分析及信號處理 ................................................................................................ 9 小波分析在信號處理中的應(yīng)用現(xiàn)狀 .............................................................................. 9 小波分析理論 ................................................................................................................ 10 小波分析的基本概念及特點 .................................................................................. 10 多分辨率分析 ..........................................................................................................11 3． 3 小波包分析 ................................................................................................................. 12 小波包的定義 ......................................................................................................... 12 小波包的子空間分解 ............................................................................................. 12 小波包的分解與重構(gòu)算法 ..................................................................................... 12 小波基函數(shù)的選擇 ........................................................................................................ 13 信號的小波包降噪 ........................................................................................................ 15 小波包降噪的方法和步驟 ..................................................................................... 15 降噪效果的評價標準 ............................................................................................. 16 v 故障信號的小波包降噪 ......................................................................................... 17 故障信號的特征提取 .................................................................................................... 18 第 4 章 BP 神經(jīng)網(wǎng)絡(luò)及在故障診斷中的應(yīng)用 .................................................................... 21 人工神經(jīng)網(wǎng)絡(luò)在故障診斷中的應(yīng)用現(xiàn)狀 .................................................................... 21 BP 神經(jīng)網(wǎng)絡(luò) ................................................................................................................... 21 BP 神經(jīng)網(wǎng)絡(luò)的結(jié)構(gòu) ................................................................................................ 21 BP 算法描述 ............................................................................................................ 22 BP 神經(jīng)網(wǎng)絡(luò)的優(yōu)缺點 ............................................................................................ 24 BP 神經(jīng)網(wǎng)絡(luò)的設(shè)計 ....................................................................................................... 24 學習樣本的確定 ..................................................................................................... 24 網(wǎng)絡(luò)層數(shù)的考慮 ..................................................................................................... 25 輸入、輸出和隱含層的設(shè)計 .................................................................................. 25 激勵函數(shù)的選擇 ..................................................................................................... 26 網(wǎng)絡(luò)初始值的選取 .................................................................................................. 26 學習算法的選擇 ...................................................................................................... 26 學習速率 ................................................................................................................. 26 訓練停止條件 ......................................................................................................... 27 BP 神經(jīng)網(wǎng)絡(luò)在故障 診斷中的應(yīng)用 ............................................................................... 27 BP 神經(jīng)網(wǎng)絡(luò)故障診斷結(jié)果分析 ................................................................................... 30 第 5 章 GA+BP 神經(jīng)網(wǎng)絡(luò)及其在故障診斷中的應(yīng)用 ........................................................ 31 遺傳算法簡介 ................................................................................................................ 31 標準遺傳算法 ................................................................................................................ 31 遺傳算法的特點 ............................................................................................................ 32 GA+BP 算法 設(shè)計 ........................................................................................................... 33 遺傳 編碼與解碼 ..................................................................................................... 33 適應(yīng)度函數(shù)的設(shè)計 ................................................................................................. 36 遺傳算子的設(shè)計 ..................................................................................................... 36 控制參數(shù)的選擇 ..................................................................................................... 39 vi GA+BP 算法的步驟 ................................................................................................ 41 GA+BP 神經(jīng)網(wǎng)絡(luò)在故障診斷中的應(yīng)用 ....................................................................... 42 網(wǎng)絡(luò)的設(shè)計 .............................................................................................................. 42 故障診斷仿真實驗 ................................................................................................. 43 故障診斷結(jié)果分析 ................................................................................................. 45 BP 神經(jīng)網(wǎng)絡(luò)與 GA+BP 神經(jīng)網(wǎng)絡(luò)故障診斷結(jié)果對比分析 ........................................ 45 結(jié)論 ........................................................................................................................................ 47 參考文獻 ................................................................................................................................ 49 攻讀學位期間取得的成果 ...................................................................... 錯誤 !未定義書簽。 致 謝 ............................................................................................................