Method of cold starting an internal combustion engine in hybrid applications

• Main Authors: BRANDEL TODD D, SCHWENKE R TRAVIS, CHIN POH FONG
• Format: Patent
• Language: English
• Published: 05.05.2015
• Subjects: BLASTING; COMBUSTION ENGINES; CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE ORDIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TOTHE CONTROL OF A PARTICULAR SUB-UNIT; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDEDFOR; STARTING OF COMBUSTION ENGINES; TRANSPORTING; VEHICLES IN GENERAL; WEAPONS

A method to start operation of an internal combustion engine of a hybrid powertrain includes initiating rotation of a crankshaft of the engine with at least one electric machine in accordance with a first ramping profile until a first predetermined speed is achieved in response to an engine start event during a cold start condition. Engine speed is monitored and the engine is fired while controlling the engine speed to maintain the first predetermined speed with the at least one electric machine. The first ramping profile is adjusted at a rate corresponding to an estimated rate at which the engine speed is increasing during the engine firing. When at least one predetermined combustion quality parameter is achieved, the engine speed is controlled in accordance with a second ramping profile until a second predetermined speed is achieved based on controlling combustion parameters of the engine.