Joint time-frequency analysis of tracking laser doppler vibrometry data on a rolling tire

The vibration analysis of a rolling tire is a very interesting but difficult task. To obtain realistic results on the dynamic characteristics of the tire, laboratory tests should be performed under simulated operative conditions, that is, when the tire is rolling. This task is not easy to achieve with traditional measurement techniques. In this paper Tracking Laser Doppler Vibrometer (TLDV) has been applied for the measurement of time histories of the vibration velocity of a tire. A Lagrangian approach was adopted: data were acquired with the target in continuously changing conditions. In fact, the measurement point rotates with the tire and therefore it enters and exits from the contact area. In order to analyse vibration data, that are in an unsteady condition, a joint time-frequency analysis has been performed. Different algorithms have been compared and some preliminary results are shown in this work.