Acceleration profile-based control of an offgoing clutch operation

摘要

A vehicle includes a torque generating device, a transmission, and a controller. The transmission has one or more clutches. The controller executes a method, which includes measuring an amount of slip across an identified offgoing clutches and determining whether the offgoing clutches have slipped prior to a modeled clutch torque capacity reaching zero. A status is assigned indicating that the offgoing clutches are released if the offgoing clutch has slipped prior to the modeled clutch capacity reaching zero. The controller induces slip across the identified offgoing clutches to a calibrated low, non-zero level after recording the value, including by enforcing the low, non-zero slip value using one or more acceleration profiles.

主权项

1. A vehicle comprising:
a torque generating device; a transmission having an input member, a planetary gear set, and a clutch set, wherein the input member is connected to and receives input torque from the torque generating device, and also transfers the input torque through the planetary gear set in response to a commanded shift; and a controller in communication with the transmission, wherein the controller includes a tangible, non-transitory memory device on which is recorded a modeled clutch torque capacity of each clutch used in the clutch set and instructions for executing a commanded shift involving an offgoing clutch of the clutch set to a subsequent transmission state; wherein the controller is configured to execute the instructions in response to the commanded shift using at least one calibrated acceleration profile of the offgoing clutch, including:
identifying the offgoing clutch for the commanded shift; andinducing slip across the identified offgoing clutch in an open loop using the at least one calibrated acceleration profile at a point of the torque phase of the commanded shift at which the modeled clutch torque capacity of the offgoing clutch is zero.