Patent ID: 8306709

Claim:
Method for controlling a powertrain in a vehicle comprising an electro-mechanical transmission including a frictionless engagement selectable one-way clutch mechanically-operatively coupled to an internal combustion engine adapted to selectively transmit mechanical power to an output member, said method comprising: monitoring a transmission output speed; monitoring an engine output speed; monitoring an engine braking request; when said selectable one-way clutch is disengaged, allowing transmission of power between the engine and the output member in a first direction and disallowing transmission of power between the engine and the output member in a second direction prohibiting engine braking; when said selectable one-way clutch is engaged, allowing transmission of power between the engine and the output member in the first and second directions, the allowed transmission of power in the second direction consistent with engine braking; when said engine braking request is present, engaging said selectable one-way clutch to provide an engine braking torque, said engaging comprising: within a control system comprising an engine control module and a transmission control module: determining a target engine output speed based upon said transmission output speed; commanding a speed of said engine to said target engine output speed; determining a selectable one-way clutch slip speed based upon said transmission output speed and said engine output speed; and utilizing said selectable one-way clutch slip speed to further command said speed of said engine to create a zero selectable one-way clutch slip speed; and when said selectable one-way clutch slip speed equals zero, engaging said selectable one-way clutch; wherein said selectable one-way clutch is configurable to transmit said power differently based upon a direction of torque.