Method of NVH Quality Rating of Diesel Combustion Noise Using Typical Driving Modes

The development of a new method to evaluate the NVH quality of diesel combustion noise bases upon following questions by regarding typical driving modes:

• Driving behavior with diesel vehicles
• Which driving situation causes an annoying diesel combustion noise
• Judgment of diesel combustion noise as good or bad

A suitable test course was determined to regard typical driving situations as well as the European driving behavior. Vehicles of different segments were tested on that course. The recorded driving style and the simultaneously given comments on the diesel combustion noise results to a typical driving mode linked to acoustics sensation of diesel combustion noise.

The next step was to simulate this driving mode on the chassis dynamometer for acoustical measurements. The recordings of several vehicles were evaluated in listening test to identify a metric. The base of metric was objective analyses evaluating diesel combustion noise in relevant driving situations.

A special technical chart represents the results of different driving situations with regard to relevance, frequency of occurrence, significance and level.