Achieving a Vehicle Level Sound Quality Target by a Cascade to System Level Noise and Vibration Targets 2005-01-2394
This paper describes a process to achieve a pre-defined vehicle level interior sound quality target, by a sound engineering cascade to targeted noise and vibration development at the system level.
Air-borne and structure-borne contributors to interior sound are identified at the system level using a comprehensive Transfer Path Analysis (TPA) in both the frequency and time domains. For significant contributors, the relative importance of the source system (powertrain) and path system (vehicle) are determined.
System level changes are simulated, and their effect on interior sound evaluated using TPA. A set of feasible changes is identified that, when combined, achieves the vehicle level interior sound quality target. This set of changes defines system level targets for noise and vibration development, cascaded from the vehicle level target.
Development of the significant systems towards these targets in a demonstrator vehicle has confirmed that the vehicle level sound quality target can be achieved by this process.
This paper will focus upon the following:
The target setting and cascading process
Methodology observations from a comprehensive TPA
TPA tools and processes
System engineering to achieve the vehicle level target