New Concept of Chassis Dyno Procedure for Squeal Noises Evaluation 2007-01-2265
Nowadays, the sever customer targets in term of squeal require an increasing number of different tests. This paper addresses how to develop a new test bench procedure which helps to fulfill this new target with more efficiency.
With a single standard test procedure, we want to:
find out a maximum number of frequencies in a minimum number of stops,
improve road correlation with adapted braking conditions including detection of the low pressure risks,
improve the stability of the results to get more valuable test comparison.
A statistical analysis performed over three years of chassis dyno matrix test shows that noise risks in low pressures conditions are usually not well estimated in standard procedures. Indeed, pressure, speed and temperature steps are arbitrarily constant in most standard procedures and do not take into account the non-linear influence of these parameters on the noise generation.
The objective of this new chassis dyno procedure is to improve the distribution of braking pressure conditions in a single procedure without lengthening the test duration.
The large scale statistical study performed on three years of tests permits to determine an optimal pressure distribution of tested conditions. Some of the results are presented in this paper.