Patent ID: 8527120

Claim:
Method for controlling a powertrain comprising an electro-mechanical transmission, an internal combustion engine and an electric machine, the engine providing an engine input torque to the transmission and the electric machine providing an electric machine input torque to the transmission, the transmission providing an output torque comprising the engine and electric machine input torques, the method comprising: operating the engine substantially at wide open throttle; monitoring an output torque request; controlling the engine input torque employing an engine control module by controlling a valve overlap setting for a cylinder of the engine based upon the output torque request wherein controlling the valve overlap setting for the cylinder modulates a residual burnt gas fraction within the cylinder utilizing at least one of a modified exhaust valve lift curve that decelerates at a first deceleration rate from a peak exhaust opening to a predetermined exhaust valve opening and then decelerates at a second deceleration rate from the predetermined exhaust valve opening in accordance with an extended low slope lift portion of the modified exhaust valve lift curve for a predetermined exhaust valve closing phase angle duration, wherein a magnitude of the second deceleration rate is less than a magnitude of the first deceleration rate, and a modified intake valve lift curve that accelerates at a first acceleration rate from a predetermined intake valve opening in accordance with an extended low slope portion of the modified intake valve lift curve for a predetermined intake valve opening phase angle duration and then accelerates at a second acceleration rate after the predetermined intake valve opening phase angle duration, wherein a magnitude of the first acceleration rate is less than a magnitude of the second acceleration rate; and controlling the electric machine input torque based upon the output torque request and a time-lag difference between the output torque request and the controlled engine input torque.