Experimental Apparatus for Assessing the Nonlinear Dynamics of Engine Restart and Shutdown

An experimental apparatus has been designed and fabricated to assess the nonlinear dynamics of internal combustion engine (ICE) restart and shutdown. The final objective for the apparatus is to validate the application of two-scale command shaping (TSCS) for reduction of unwanted vibrations during ICE restart. The apparatus allows user-specified torque profiles to be applied to a three-cylinder ICE from an electric machine (EM). In turn, the apparatus can measure oscillations in the driveline and chassis, which will ultimately determine the efficacy of TSCS as applied to engine restart. Preliminary results from the apparatus document its ability to measure the unwanted oscillations in the response of the powertrain during ICE restart and shutdown. The apparatus is also expected to provide data, combined with parameter estimation techniques, to determine otherwise uncertain parameters associated with the ICE and EM.