Measurement and preliminary analysis of powertrain vibrations in vehicle production environment

In a vehicle production environment, obtaining information on the condition of the assembled vehicle, allows for increased quality while minimizing rework minutes at the same time. The cost of this information is associated with additional time in production, increasing the overall cost of the vehicle. The focus of this paper is development of a system for contactless measurement and investigation of vibrations present in the vehicle and the Rolling Road vehicle testing facility as a mean of identifying failures or degradation in the vehicle or testing facility. Measurements are performed using a contactless Laser Vibrometer based system which facilitates capturing the vibrations without interfering with the vehicle and other standard testing procedures. Signal conditioning and analysis methods are applied to measured vibration signals in an attempt to detect irregularities and determine their transient characteristics from the captured signals. Data analysis techniques employed in this initial trial of the system include Short Time Fourier and Wavelet Transforms. Proposed testing method including experimental setup, captured signals and some preliminary analysis results are discussed in this paper.