Study on identifying detailed vibration characteristics of car body
The flexure vibration of car body in running vehicle often occurs intermittently
and with relatively short duration. This means that when analyzing vibration
by using conventional FFT (Fast Fourier Transform) method, it is difficult
to obtain frequency characteristics, such as acceleration PSD (Power Spectrum
Density), with sufficient reliability.
To handle this problem, the RTRI developed a method based on the linear prediction model to analyze acceleration spectrum and/or natural mode properties. This method has features that it can identify clearly defined spectrum from short time data, and it is easily applied to analyze multi input multi output (MIMO) problem such as running test data.
Figure 1. Acceleration PSD from short time
Figure 2. Example of identified model snaps and natural frequencies
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