Estimating tire condition with wavelet analysis
Masaki Suido, Tetsuya Tabaru, Seiichi Shin · 2006 SICE-ICASE International Joint Conference · 2006
Tire is one of the most important components of automobiles ,since tire is the only interface with roads. However, little is known about the interface. For example, although we can detect the slipping of wheels with the wheel angle sensors, we never know the grip margin for slipping. At this point, we have to design automobiles' electro-controllers with much safety margin. This is undesirable in the meaning of automobile controllability as well as safety. Thus, it is important to get information of tire's surface. In order to get information of tire surface, we made use of tire sound. We recorded the sound from rotating tires with a digital recorder, and got a general time-frequency trend by analyzing them with CWT (Continuous Wavelet Transform). Incidentally, CWT involving the trade off between frequency and time resolution, it is very important to manage the rate of time/frequency resolution to some desirable level. CWT has a parameter which decides the rate. We tuned this parameter to an optimal value for visualizing the tire sound component by rag groove (the groove which is orthogonal to the direction tire's going) in the time-frequency plane. Adopting this way to various tires, we finally found that the sound component varies as the tire wears away.