Method and Apparatus for Starting an Engine of a Modular Hybrid Transmission Based Upon Demanded Torque

Abstract

A control system including a method and apparatus for operating a hybrid vehicle. A disconnect clutch selectively separates an electric machine from a combustion engine. If a wide open throttle or high torque command is requested and the combustion engine is shut down, a 12 volt starter may be used to start the combustion engine while disconnected from the electric machine and all of the electric machine torque available may be used for traction.

What is claimed is: 
     
         1 . A system for starting an engine of a vehicle that has a motor that is selectively coupled to the engine by a clutch, the system comprising:
 an engine control module;   a pedal position sensor that provides a pedal position signal to the engine control module;   a starter motor actuated by the engine control module based upon the pedal position signal; and   the engine control module sending a clutch apply signal to the clutch to apply the clutch when an engine speed is within a predetermined range of a motor speed.   
     
     
         2 . The system of  claim 1  wherein the pedal position sensor provides the pedal position signal to the engine control module when the pedal position exceeds a threshold minimum value. 
     
     
         3 . The system of  claim 1  wherein the clutch is applied when motor speed and the engine speed are within a calibrated threshold difference. 
     
     
         4 . The system of  claim 3  wherein a pressure applied by the clutch is increased to lock-up the clutch after the clutch is applied. 
     
     
         5 . The system of  claim 1  wherein the engine control module sends a maximum torque application signal to the motor when the starter motor is actuated.