Control of a chassis dynamometer

Chassis dynamometers are essential tools in testing vehicles in the laboratory. The main purpose of a chassis dynamometer used in emission testing is to simulate vehicle drive wheel torques encountered on the road. The University of Tennessee, Knoxville has an older Sun Electric, model RAM 937, chassis dynamometer, which was originally designed to utilize an eddy current absorber unit to provide road load power to the vehicle. The dynamometer utilizes outdated analog controls that simulates the inertia of the vehicle only on acceleration in a limited range. This thesis covers the design and implementation of a new control system for a Sun Electric chassis dynamometer. The revamped chassis dynamometer incorporates a robust digital controller, user-friendly operator interface, and data acquisition system. Inertia simulation was added to the control scheme to enable the operator to perform accurate coast down testing of the vehicle. This improved chassis dynamometer is being used at the National Transportation Research Center, NTRC.