Patent ID: 8534399
Filing Date: 2013-09-17
Classification: B60K,B60W,Y02T

Abstract:
1. A method of adjusting torque output of a hybrid propulsion system, the hybrid propulsion system including an internal combustion engine to produce torque to a torque converter coupled to a multiple fixed-ratio transmission for transmitting torque to a wheel, and a first electric motor positioned upstream of the torque converter and powered at least by a battery to supply torque to the wheel, the method comprising: shifting the multiple fixed-ratio transmission from a first gear ratio to a second gear ratio upon a first condition and adjusting a lockup state of the torque converter in response to a first state of battery charge interpreted as an indication of increased electrical propulsion path tractive effort capability, the indication of increased electrical propulsion path tractive effort capability reflected as a decrease in tractive effort from a mechanical propulsion path; shifting the multiple fixed-ratio transmission from the first gear ratio to the second gear ratio upon a second condition that is different from the first condition and adjusting said lockup state of the torque converter in response to a second state of battery charge interpreted as an indication of decreased electrical propulsion path effort capability reflected as an increase in tractive effort from said mechanical propulsion path; and adjusting torque output of said first electric motor to reduce a torque differential across the torque converter and to assist locking a torque converter lockup clutch in response to said first and second states of battery charge.