Experimental Characterization of a Feedforward Control for the Replication of Moving Resistances on a Chassis Dynamometer

Dynamometers are devices that for long have been employed for acquiring power and torque outputting a prime mover, such as an engine. However, with the improvements in controllability, they may as well be applied nowadays to reproduce in laboratory conditions real operational loads, increasing the replicability of the tests and the reproducibility of the results. In this regard, the main goal of the present work is to describe the first outcomes of a project being carried in the Laboratory for Integrated Systems of Unicamp whose main goal is to further develop its chassis dynamometer for emulating real driving resistances, such as inclines and aerodynamic drag, upon the driveline of the vehicle being tested. In a first attempt to improve the control platform of the device, a lookup table was created in order to control an eddy-current brake and to verify its dynamical performance under voltage inputs. Compensation for the difference in inertia between the vehicle and the dynamometer and for the aerodynamic drag was also provided during the execution of an FTP-72 drive cycle. After the inclusion of the control structure, correlation coefficients of around 0.95 have been found when comparing the torque read at the torquemeter with the expected torque with compensation.