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A thorough examination of the use of inertia simulation to provide dynamometers capable of accurately representing vehicle performance is presented. A description of a dynamometer system for brake testing using inertia simulation is provided. The models used to properly represent inertia losses, and both the programs and the results from experimental verification are described. The limitations due to motor power and existing fixed inertia in the system are described. Vehicle and dynamometer characteristics discussed include linear inertia, tire rolling resistance, bearing losses, windage, inclines, and motor field effects. Inertia simulation is shown to accurately model both steady state and transient vehicle performance.

The character and level of noise in a vehicle has changed significantly from the 1970s to today. In the 1970s the challenge was to permit communication from the front seat to the rear at highway speeds. In the last decade, the challenge has grown to provide a vehicle that provides the right "type" of sound while isolating the occupants from disturbing exterior noise. This may involve adding engine noise simulation and sculpting the interior sound to meet customer expectations. More recently, the challenge has been to modify noise controls for extreme light weighting exercises and electric vehicles. In addition, electric vehicles present a different sound environment and the challenge of determining what an EV should sound like. This paper will attempt to discuss these challenges and talk about the future of vehicle interior noise.