权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Study on inprocess sensing of tool failure utilizing microphones

利用麦克风进行刀具故障在线检测的研究

基本信息

批准号：
08650155
负责人：
MURATA Ryoji
金额：
$ 1.41万
依托单位：
Science University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

The study deals with the monitoring system for turning process, and investigates under various cutting conditions. Cutting sound is detected by microphones, and is transformed to frequency spectrum by a FFT analyzer. This pays attention to the changes of peak on frequency spectrum of cutting sound as tool wear increases. Experimental results show that when flank wear increases, the peak value increases and the peak frequency reduces slightly.The method utilizing cutting sound is very effective to detect tool wear as it is non-contact measurement, but at the same time it has a problem. There are many sound sources in practical environment. Surrounding sound interrupts the monitoring system and makes accuracy of detection of tool wear worse. Therefore, it is necessary and indispensable for a practical monitoring system utilizing cutting sound to have an ability to specify the sound source locations.The study also makes an attempt to give the acoustic sensor sharp directivity in order to detect the only sound from specified sound source. As the method to make directivity, two methods which use a microphone-array or a parabolic refledctor are adopted. Each method is experimentally investigated whether it can specify location of several sound sources and distinguish from other sound sources. In the experiment with the microphone-array, two cutting processes are examined with two lathes.At that time, sounds generated from the lathes are identified by varying direction of the microphone-array. The experiment shows that the array system can hold down sensitivity for unexpected sound from other source than a pointed sound source by the array, and can distinguish expected sound from several sound sources. Another method by the parabolic reflector is examined as well, and almost the same results are obtained.

研究了车削加工过程的监控系统，并在不同的切削条件下进行了实验研究。切割声由传声器检测，并由FFT分析仪转换成频谱。这是由于考虑了切削声频谱上的峰值随刀具磨损量的增加而变化。实验结果表明，随着后刀面磨损量的增加，切削声的峰值逐渐增大，峰值频率略有降低，利用切削声的非接触测量方法对刀具磨损量的检测非常有效，但同时也存在一定的问题。在实际环境中存在着多种声源。周围的声音干扰了监控系统，使刀具磨损检测的准确性变差。因此，对于一个实际的切割声监测系统来说，确定声源位置的能力是必要的和不可缺少的，本研究还试图使声传感器具有尖锐的指向性，以便从指定的声源中检测出唯一的声音。作为实现方向性的方法，采用了使用麦克风阵列和抛物面反射器的两种方法。实验研究了每种方法是否能够确定多个声源的位置并与其他声源区分开。在麦克风阵列实验中，使用两台车床进行了两次切削过程的实验，同时通过改变麦克风阵列的方向来识别车床发出的声音。实验结果表明，该阵列系统可以抑制对非点声源的敏感性，并能区分多个声源中的期望声。本文还研究了抛物面反射器的另一种方法，得到了几乎相同的结果。