Binary clutch control during a rolling garage shift

摘要

A vehicle includes an engine, torque converter, and transmission assembly. The transmission assembly includes gear sets each having a plurality of nodes, an input member, a binary clutch connected to a node of one of the gear sets, friction clutches, and a controller. The controller detects a requested rolling garage shift of the transmission into a forward drive mode above a calibrated threshold absolute speed, and controls an amount of slip across a selected assisting clutch via modulation of pressure commands to the selected assisting clutch once the vehicle has slowed below the first calibrated threshold speed. The controller also stages the binary clutch to a calibrated staging pressure while controlling slip across the selected assisting clutch, and commands an engagement of the binary clutch and a release of the selected assisting clutch when a speed of the binary node reaches zero or a calibrated low non-zero speed.

主权项

1. A vehicle comprising:
an engine; a torque converter having a turbine and a pump, wherein the pump is directly connected to the engine; and a transmission assembly having:
a plurality of gear sets each having a plurality of nodes, wherein the nodes are gear elements selected from the group consisting of a ring gear, a sun gear, and a planetary carrier;an input member that is directly connected to the turbine;a binary clutch connected to a node of one of the plurality of gear sets, wherein the node to which the binary clutch is connected is a binary node;a plurality of friction clutches; anda controller in communication with the binary clutch and the plurality of friction clutches, wherein the controller includes a processor and memory on which is recorded instructions for controlling the transmission during a requested rolling garage shift into a forward drive mode or a reverse mode from above a calibrated threshold absolute speed, wherein the controller is programmed to:
detect the requested rolling garage shift;control an amount of slip across a selected assisting clutch via modulation of a pressure command to the selected assisting clutch when the vehicle has slowed below the calibrated threshold absolute speed, wherein the selected assisting clutch is one of the plurality of friction clutches;stage the binary clutch while controlling the amount of slip across the selected assisting clutch, including moving the binary clutch to a calibrated staging position; andcommand an engagement of the binary clutch and a release of the selected assisting clutch when a speed of the binary node reaches zero or a calibrated low non-zero speed.