Abstract: A method for controlling an input clutch of a vehicle transmission during a tip-in includes using a current gear and rate of change of transmission input speed to determine a first torque modifier, if a peak or trough occurred in input speed, using the current gear and a difference between measured input speed and expected input speed to determine a second torque modifier, and changing a torque capacity of said clutch using said modifiers.

Abstract: A method for controlling a driveline having a transmission clutch includes locking the clutch before a driveline lash crossing occurs; maintaining a locked clutch during the lash crossing; after the lash crossing occurs, increasing a clutch capacity at a slower rate than a driveline twist torque rate; and after the lash crossing occurs, producing clutch slip by controlling engine torque and clutch capacity such that engine torque exceeds clutch capacity.

Abstract: A method for controlling a power-off downshift in a powershift transmission includes disengaging the current gear, synchronizing engine speed and a speed of the target gear layshaft by increasing a torque capacity of the target gear clutch, disengaging the clutch, engaging the target gear, and reengaging the clutch.

Abstract: A method for controlling a torque direction transition in a dual clutch transmission includes decreasing a torque capacity of a transmission input clutch when clutch slip reaches a target slip during a power-off condition, producing a subsequent power-on condition, and increasing torque capacity of said clutch when clutch slip reaches a second target slip.

Abstract: A method for controlling a vehicle torque converter lockup clutch during a deceleration coasting event includes producing slip across the clutch by reducing the clutch's torque capacity, decreasing said slip by increasing said torque capacity, and maintaining slip across the clutch.

Abstract: A method for controlling a driveline having a transmission clutch includes locking the clutch before a driveline lash crossing occurs; maintaining a locked clutch during the lash crossing; after the lash crossing occurs, increasing a clutch capacity at a slower rate than a driveline twist torque rate; and after the lash crossing occurs, producing clutch slip by controlling engine torque and clutch capacity such that engine torque exceeds clutch capacity.

Abstract: A method for controlling a power-off downshift in a powershift transmission includes disengaging the current gear, synchronizing engine speed and a speed of the target gear layshaft by increasing a torque capacity of the target gear clutch, disengaging the clutch, engaging the target gear, and reengaging the clutch.

Abstract: A method for controlling a torque direction transition in a dual clutch transmission includes decreasing a torque capacity of a transmission input clutch when clutch slip reaches a target slip during a power-off condition, producing a subsequent power-on condition, and increasing torque capacity of said clutch when clutch slip reaches a second target slip.

Abstract: In a motor vehicle powertrain that includes a diesel engine, a particulate filter and a torque converter, a method for correcting an indicated engine output torque includes estimating a magnitude of torque being transmitted from the engine to the torque converter while regenerating the particulate filter, determining a reference magnitude of current engine torque being produced while regenerating the particulate filter, determining a torque error from a difference between the estimated magnitude and the reference magnitude, recording the torque error, determining a current torque error from the recorded torque error using a current engine speed and a current reference engine torque as indices to the recorded engine toque error, producing a corrected engine torque from the sum of the current torque error and the current reference engine torque, and using the corrected engine torque to control operation of the transmission.

Abstract: A method for controlling a vehicle powertrain includes holding the vehicle stopped on a grade by automatically producing wheel brake torque while driver demand torque is less than wheel brake torque, automatically releasing wheel brake torque when driver demand torque equals or exceeds wheel brake torque, and launching the vehicle using engine torque.

Abstract: A method for controlling a vehicle torque converter lockup clutch during a deceleration coasting event includes producing slip across the clutch by reducing the clutch's torque capacity, decreasing said slip by increasing said torque capacity, and maintaining slip across the clutch.

Abstract: A method for controlling speed of an input shaft to a hydraulically actuated clutch that includes a hydraulic balance dam volume includes determining a limit speed of the input shaft that varies as a function of time during a predetermined period after the clutch starts rotation and that causes a servo piston for actuating the clutch to move toward an engaged position, rotating the input shaft during the period, limiting a speed of the input shaft during said period to a determined limit speed corresponding to a current time after beginning the period, and allowing the speed of the input shaft to increase to a speed greater than the determined limit speed after expiration of the period.

Abstract: In a motor vehicle powertrain that includes a diesel engine, a particulate filter and a torque converter, a method for correcting an indicated engine output torque includes estimating a magnitude of torque being transmitted from the engine to the torque converter while regenerating the particulate filter, determining a reference magnitude of current engine torque being produced while regenerating the particulate filter, determining a torque error from a difference between the estimated magnitude and the reference magnitude, recording the torque error, determining a current torque error from the recorded torque error using a current engine speed and a current reference engine torque as indices to the recorded engine toque error, producing a corrected engine torque from the sum of the current torque error and the current reference engine torque, and using the corrected engine torque to control operation of the transmission.

Abstract: A method for controlling speed of an input shaft to a hydraulically actuated clutch that includes a hydraulic balance dam volume includes determining a limit speed of the input shaft that varies as a function of time during a predetermined period after the clutch starts rotation and that causes a servo piston for actuating the clutch to move toward an engaged position, rotating the input shaft during the period, limiting a speed of the input shaft during said period to a determined limit speed corresponding to a current time after beginning the period, and allowing the speed of the input shaft to increase to a speed greater than the determined limit speed after expiration of the period.

Abstract: A method and apparatus for controlling a two-stage valve using a closed-loop control system, the system including a variable gain element, the method involving continually performing the steps of estimating the flow gain of the pilot stage of the valve; comparing the estimated flow gain with a reference flow gain; and in response to said comparison step, adjusting the gain of the variable gain element to maintain a substantially constant closed-loop gain.