Patent ID: 7608013
Filing Date: 2009-10-27
Classification: F16H,Y10T

Abstract:
1. A method of controlling a downshift in a transmission having a main box and a compounder coupled to the main box and having at least one gearset and at least one clutch separate from the main box, the method comprising: initiating an upshift in the compounder including application of at least one clutch in the compounder; initiating venting of a clutch being released in the main box; determining occurrence of slip in the compounder and the main box; controlling, after slip has occurred in the main box, a duty cycle of a solenoid associated with the clutch being released in the main box as a function of a desired acceleration of the main box; determining a target input speed for the gear into which the transmission is being shifted; initiating filling of a clutch to be applied in the main box; and controlling a duty cycle of a solenoid of the clutch being applied in the main box when the input speed exceeds the target input speed to control the apply rate of the clutch being applied to bring the input speed to the target input speed.