Patent ID: 6364807
Filing Date: 2002-04-02
Classification: B60K,B60W,Y02T,Y10S,Y10T

Abstract:
A control strategy and method for controlling a pressure-operated engine clutch in a throttle-controlled, hybrid powertrain for an automotive vehicle, the clutch being located at the torque input side of a multiple-ratio power transmission mechanism, the powertrain including a throttle-controlled internal combustion engine and a mechanical spring damper located in a torque flow path between the engine and the clutch, the torque output side of the transmission being connected drivably to traction wheels for the vehicle, and an electric motor in the torque flow path between the damper and the torque input side of the transmission, the strategy and method comprising the steps of:launching the vehicle from a standing start by disengaging the clutch and energizing the electric motor while the clutch is disengaged; controlling the motor using a motor torque control wherein electric power supplied to the motor is a function of throttle position, the throttle position being an indication of commanded torque; commanding a transition from a motor power mode to an engine power mode during a transition time interval; partially energizing the clutch at the beginning of the transition time interval; modulating the pressure applied to the clutch to effect slipping of the clutch during the transition time interval, the clutch pressure being a function of the difference between clutch speed and engine starting speed whereby the motor is in a speed control mode; applying full clutch pressure to the clutch when engine starting speed is approximately equal to motor speed; and activating engine fueling.