Calibration of Chassis Dynamometers for Emission-and Fuel Economy Testing Using Wheel Torque Meters

A general calibration method for chassis dynamometers is an important prerequisite for obtaining comparable emissions - and fuel economy test results with reasonable confidence.

At the test facilities of Volvo, Daimler-Benz and Volkswagen the torque calibration principle was studied using rear wheel and front wheel driven cars of the above manufacturers. The driving resistances on the road or on a dynamometer can be directly extracted from the torque data measured in the driven wheels at constant car speeds. The dynamic behaviour of the test car is described by the mean torque over a certain driving cycle, thereby including also acceleration/deceleration effects. Wheel torque measuring systems can easily be adapted to vehicle types of different manufacturers.

The torque principle can also be applied to other fields than the calibration of dynamometers. Examples are vehicle performance measurements and the determination of tire losses.