Controlling a clutch between an engine and an electric machine in a hybrid vehicle

Abstract

A parallel hybrid vehicle includes an engine and a motor separated along a driveshaft by a clutch. The motor can operate (either alone or in combination with the engine) to provide positive drive torque to the wheels. The motor can also act as a generator and provide negative torque when converting mechanical energy from the driveshaft into mechanical energy to be stored in a battery. The clutch selectively couples the motor to the engine. Torque and its effects on the clutch can vary dramatically when the motor changes from providing positive and negative torque, and vice versa, while the engine is running. At least one controller in the vehicle is programmed to, while the engine is running, initiate an increase in pressure at the clutch in response to an anticipated change in torque provided by the motor from positive to negative or from negative to positive.

Dependencies are inferred from the claim text.