麥克風陣列排列模式在微銑削刀具磨耗偵測之影響分析

Analysis of Microphone Array Arrangement for Sound Based Micro Tool Wear Monitoring

呂長恩(Chang-En Lu) ； 盧銘詮(Ming-Chyuan Lu) ； 鄭瑞霖(Ruei-Lin Jheng)

《中華民國振動與噪音工程學會論文集》 2014 (2014/06) Pp. 373-380

摘要

在切削加工過程中，應用聲音建構自動化刀具狀態偵測系統容易因背景噪音的干擾而造成系統之誤動作，因此為了提升偵測系統的穩定性，抑制噪音技術扮演著重要的角色。本研究探討環狀排列麥克風陣列在降低干擾噪音之效能，以及對於刀具磨耗偵測系統的影響。實驗過程採用直徑700μm之微細銑刀，工件為SK2高碳鋼，並在切削過程以喇叭提供人工噪音源，並利用麥克風陣列擷取切削時的聲音訊號。擷取之聲音訊號以整合麥克風陣列與偉納濾波器進行濾波處理，結果顯示麥克風陣列整合偉納濾波能有效的改善噪音對微刀具磨耗偵測之影響。另外，分析麥克風陣列排列方式對刀具磨耗辨識之性能影響方面，結果顯示整合環列麥克風陣列較直線排列麥克風陣列系統能更有效的去除雜訊，在適當選擇特徵值之頻寬厚，在高能量之噪音干擾下，可以達到100%的辨識成功率。

關鍵字

刀具狀態偵測 ； 波束成型法 ； 偉納濾波

並列摘要

The effect of the arrangement of microphone array on micro tool wear monitoring in micro milling was studied in this paper with two arrangements for the installation of microphone arrays. In experimental setup, 700um micro end mill was used in cutting SK2 workpiece. To simulate the noise occurring during factory, the speaker was installed inside the cutting chamber to generate the broad band noise during cutting. After sound signals were collected by microphone during cutting with various tool wear conditions, they were processed by system with the combination of the microphone array filter and Wiener filter. The results show that the classification rate can be improved by adopting the microphone array along with Wiener filter compared to the case without filters selected. By the way, circular arrangement of microphone can provide the better classification rate than the case with microphone array installed in linear arrangement. With proper selection of bandwidth for feature selection, 100% classification rate can be obtained by processing the sound signal with the combination of microphone array and the Wiener filter.

並列關鍵字

microphone array ； tool wear monitoring ； micro milling ； audible sound