Engine power management for a selectable one-way clutch or mechanical diode in automatic transmissions

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 between an output member and a torque converter, said method comprising:

• operating said selectable one-way clutch through an engine braking event;
• monitoring a speed of an engine to torque converter shaft;
• monitoring a speed of a torque converter to transmission shaft;
• monitoring a relative rotational speed of said torque converter based upon said speed of said engine to torque converter shaft and said speed of said torque converter to transmission shaft;
• monitoring a command to end said engine braking event;
• when said monitoring detects said command to end said engine braking event, diagnosing if a locked selectable one-way clutch condition is present based upon said relative rotational speed;
• commanding said engine to increase speed to a speed resolving said locked selectable one-way clutch condition;
• and
• commanding disengagement of said selectable one-way clutch.

Apparatus 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 between an output member and a torque converter, said apparatus comprising:

• a sensor monitoring a rotational speed of a torque converter pump;
• a sensor monitoring a rotational speed of a torque converter turbine;
• a control system configured to:
• monitor said rotational speed of said torque converter pump;
• monitor said rotational speed of said torque converter turbine;
• monitor a transmission status including a command to upshift from an engaged selectable one-way clutch gear state;
• determine if a locked selectable one-way clutch condition is present based upon said rotational speed of said torque converter pump and said rotational speed of said torque converter turbine;
• command a speed of said engine sufficient to overcome said locked selectable one-way clutch condition;
• and
• command said selectable one-way clutch to disengage.