1997-05-20

Time Dependent Correlation Analysis of Truck Pass-by-Noise Signals 971986

The data measured during an ISO 362 pass-by-noise test are strongly non-stationary due to the fast acceleration of the vehicle and its moving position with respect to the ISO microphone position. Nevertheless, one would like to obtain an understanding of the relative contribution of the various noise generating components during the test.
Since the classical signal analysis procedures based on the FFT calculation and auto/crosspower averaging for coherence/correlation analysis are no longer applicable, as they implicitly assume signal (and process) stationarity, an approach based on Autoregressive Vector (ARV) modelling of a set of measurement signals was developed and applied.
An ARV model is calculated directly from a set of time data of limited duration. The auto- and crosspower functions are directly calculated from the ARV model, avoiding the classical averaging procedure and allowing a repetitive calculation over multiple data segments, even for a short duration phenomenon as the pass-by test.
From these spectra, a time varying principal component and ordinary as well as virtual coherence calculation can be performed, attempting at describing a causal relationship between reference measurements on the truck (tyre, engine, exhaust, ⃛) and the pass-by microphones. One of the main features of the ARV-approach is that this description takes the form of a time/frequency plot, allowing to assess which component contributes the most at which moment.
The method has been validated extensively by a series of truck pass-by-noise tests, which are discussed in detail.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

A Study on Brake Noise of Midium Class Trucks and Buses

891278

View Details

TECHNICAL PAPER

Avoiding Structural Failure Via Fault Tolerant Control - An Application on a Truck Frame

2002-01-3040

View Details

TECHNICAL PAPER

An Approach to Reduce Cargo Damage

2009-01-0769

View Details

X