Gm Global Technolgoy Operations, Inc.

Other

James L Abington

Dongxu Li

Matthew D Whitton

Christopher Jay Weingartz

Craig J Hawkins

Colin Hultengren

Timothy R Stockdale

Matthew Kempeinen

Jacob V Renquist

Paul R Peterson

Chet Daavettila

A vehicle propulsion system that includes a prime mover having an output shaft, a torque converter including a compressor coupled to the output shaft of the prime mover, a turbine fluidly coupled to the compressor, and a torque converter clutch for selectively mechanically coupling the compressor to the turbine, a continuously variable transmission (CVT) coupled to the turbine of the torque converter, and a controller that is programmed to receive signals indicating operating conditions of the vehicle propulsion system, determine whether the received signals indicate a reduction in ratio in the CVT is impending, determine whether to open the torque converter clutch based upon a determination that a reduction in ratio is impending, and open the torque converter clutch in response to a determination to open the torque converter clutch.

Method and system for controlling a vehicle propulsion system

A continuously variable transmission, a control system, and a method is provided for synchronizing a clutch application state change and a continuous upshift in a motor vehicle propulsion system having a continuously variable transmission (CVT). The control system and method are configured to determine whether a continuous upshift of the CVT is impending. The continuous upshift is defined as a pulley ratio change exceeding a predetermined threshold for a predetermined pulley ratio change period. If a continuous upshift is impending, the control system and method are configured to alter a clutch engagement state after a predetermined delay period to synchronize the change in clutch engagement state with an engine speed change.

Synchronizing clutch apply state with continuous ratio shift in a continuously variable transmission

A continuously variable transmission, a control system, and a method are provided. The control system and method are configured to learn a desired running pressure to be applied to a clutch that is lower than a pulley clamping pressure and higher than a pressure at which the clutch would slip (a clutch critical pressure), so that the clutch can act as a fuse to avoid pulley slip. A plurality of clutch slip tests are performed, each of which include decreasing pressure supplied to the clutch until a clutch slip occurs. Clutch slip data points are collected at the point of slip and used to determine a gain and an offset, where the gain is a clutch pressure versus clutch torque capacity gain, and the offset is a clutch pressure offset, which is used to determine the clutch critical pressure.

Adaptive clutch slip learning for critical capacity clutch fusing in a continuously variable transmission

A method of controlling a clutch-to-clutch power-on upshift of a transmission includes defining a possible engine torque as a latched possible engine torque value. An on-coming clutch torque phase target value is defined as a latched on-coming clutch torque value, and held constant until a final ramp. A commanded engine torque is reduced and maintained to a maximum torque reduction value until a shift completion ratio is achieved. The commanded engine torque is increased until the commanded engine torque is equal to a restore ramp target value. Both the on-coming clutch torque and the commanded engine torque are simultaneously increased at a final ramp rate, such that the increase in the on-coming clutch torque parallels the increase in the commanded engine torque, until an actual engine torque is substantially equal to the possible engine torque, to complete the shift.

Method of controlling a vehicle during a clutch-to-clutch power upshift of a transmission

Growing community of inventors

White Lake, MI, United States of America

James L Abington