Gm Global Technolgoy Operations, Inc.

Dennis T Richey

Goro Tamai

Robert Charles Downs

Tony T Hoang

A method of controlling engine crankshaft motion in a hybrid electric drive system having an internal combustion engine and a motor-generator operatively connected to a crankshaft of the engine is disclosed. The steps include monitoring the crankshaft position, forecasting a crankshaft stall position; comparing the forecast stall position with a target range; and if the forecast crankshaft stall position is outside the target range, operating the motor-generator to modify the forecast stall position to be within the target range. These steps properly position the crankshaft for re-initiating engine start-up. The method further includes the steps of calculating an effective lube interval time once the crankshaft speed is zero; comparing the effective lube interval time to a critical time; and if the effective lube interval time is greater than the critical time, pulsing the motor-generator to rock the crankshaft for a pulse time to redistribute a lubricant film.

Crankshaft rotation control in a hybrid electric vehicle

A fuel management control method for a hybrid electric vehicle drive having an internal combustion engine and an electric motor arranged in parallel such that both can propel the vehicle; the system including an electric motor driven fuel pump and a programmable microprocessor; and wherein the method further includes monitoring vehicle speed and sensing braking pressure and directing signals of both vehicle speed and braking to the microprocessor and processing such inputs in accordance with an aggressive fuel management program including shut-off of fuel flow to the gas engine in response to vehicle braking at vehicle speeds above a predetermined maximum hysteresis speed and maintaining the fuel shut off during vehicle coasting above a predetermined speed while controlling the electric motor to provide regenerative braking or vehicle start during such fuel shut off modes of operation.

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Sterling Heights, MI, United States of America

Dennis T Richey