Patent ID: 7130734
Filing Date: 2006-10-31
Classification: B60K,B60W,F16H,Y02T,Y10T

Abstract:
1. Method for scheduling shifts from a fixed-ratio mode to first and second modes in an electrically variable transmission including an input member and an output member, first and second clutches, said first mode characterized by simultaneous first clutch application and second clutch release, said second mode characterized by simultaneous first clutch release and second clutch application, said fixed-ratio mode characterized by simultaneous first and second clutch applications wherein the transmission input member is mechanically coupled to the transmission output member through a predetermined fixed ratio, comprising: calculating a first signal as the difference between a desired input member speed and an actual input member speed; calculating a second signal as the time rate of change of the first signal; and calculating a third signal as the time rate of change of an output member speed; scheduling shifts in accordance with shift confidence factors determined as functions of the first, second and third signals wherein shifts into the first mode are scheduled in accordance with a first shift confidence factor and shifts into the second mode are scheduled in accordance with a second shift confidence factor; and, wherein the first shift confidence factor generally trends larger when the first and second signals are positive and generally trends smaller when the first and second signals are negative, and the second shift confidence factor generally trends smaller when the first and second signals are positive and generally trends larger when the first and second signals are negative.