Method of Detecting Engine Combustion Degradation in a HEV
Publication Date: 2005-Feb-18
The IP.com Prior Art Database
Throughout the life of a vehicle, the engine's combustion process can degrade. In a conventional vehicle, methods have been developed to detect large changes to the combustion process such as misfire. A method to determine the actual torque produced by the engine could be used to determine the health of the engine. Hybrid electric vehicles utilize a combination of an internal combustion engine with an electric motor to provide the power needed to propel a vehicle for improved fuel economy over a conventional vehicle. In certain HEV configurations an electric machine is connected directly to the engine. Algorithms exist that can accurately calculate the torque produced in the electric machine. Under operating conditions where the engine/motor are not coupled to the driveline, for example, in park or neutral, the electric machine can be used as an engine dynamometer. A method is described to determine the status of the engine combustion process using the electric machine as a dynamometer.