Prediction of Dynamometer Power Absorption to Simulate Light-Duty Vehicle Road Load

When vehicle exhaust emission tests or vehicle fuel consumption measurements are performed on a chassis dynamometer, the dynamometer is usually adjusted to simulate the road experience of the vehicle. In this study, road load versus speed data were obtained from 64 light-duty vehicles.

Dynamometer power absorption settings to simulate the measured road loads are computed. These dynamometer settings are regressed against vehicle frontal area and vehicle inertia weight. It is concluded that the dynamometer load settings are most accurately predicted on the basis of the vehicle frontal area.

The frontal area based prediction system is then improved by separating vehicles into different classes and by including estimations of the effects of the vehicle protuberances.