Gm Global Technolgoy Operations, Inc.

Other

Jeremy V Horgan

Christopher E Whitney

Dara Monajemi

Brian H Fiore

Scott A Hearld

Chunhao J Lee

Farzad Samie

Dongxu Li

Chi-Kuan Kao

Kumaraswamy V Hebbale

Jeffrey M Kaiser

Todd R Shupe

Joel H Gunderson

Xu Chen

Krishnendu Kar

Darrell Lee Robinette

Matthew Pruski

Mark A Schang

Ryan Z Goode

John S Mitchell

Daniel N Wehrwein

Christine E Cabrera

Lars Mikael Buur

A method and system are provided for shifting a vehicle transmission having several members. Each member is a first, second, or third node of a planetary gear set (of multiple planetary gear sets), or an input, output, or stationary member. A first torque transmitting mechanism is applied to transfer torque between first and second members in a low gear state. In some versions, a second torque transmitting mechanism is applied in the low gear state without substantially transferring torque between third and fourth members, and then the second torque transmitting mechanism is disengaged. A third torque transmitting mechanism is then applied without substantially transferring torque between the third and fourth members in the low gear state. The transmission is upshifted by disengaging the first torque transmitting mechanism, keeping the third torque transmitting mechanism applied, and applying the second torque transmitting mechanism to transfer torque between the third and fourth members.

Upshift shudder mitigation through clutch manipulation

A system includes a torque converter having a turbine, a transmission having friction clutches and an input member connected to the turbine, and a controller. The controller is programmed to control a change-of-mind shift maneuver of the transmission. By executing a method, the controller detects the change-of-mind shift maneuver, predicts an acceleration profile of the turbine for a next-requested shift of the detected shift maneuver as a function of a calibrated desired shift time and an output speed of the transmission, calculates a shift control value for a next-requested shift of the shift maneuver using the predicted acceleration profile, and executes the next-requested shift via the clutches using the calculated shift control value. The shift maneuver may be a skip-at-sync quick shift-to-quick shift or power downshift-to-power downshift. The shift value may be a clutch pressure for an offgoing holding clutch or a torque management level from an engine.

Predictive control of a change-of-mind-shift maneuver

A method of controlling a transmission includes determining if an internal combustion engine of the vehicle is currently operating with active fuel management, or if the internal combustion engine is currently operating without active fuel management. The vehicle controller further determines if a possible engine torque is equal to, greater than, or less than a required engine torque. The transmission is upshifted when the internal combustion engine is currently operating with active fuel management, and when the possible engine torque is equal to or greater than the required engine torque. When the possible engine torque is less than the required engine torque, active fuel management is exited so that the internal combustion engine is currently operating without active fuel management. When the internal combustion engine is currently operating without active fuel management, the vehicle controller upshifts the transmission from the current gear ratio to the higher gear ratio.

Method of controlling an upshift of a transmission

A system includes a desired turbine power module and an engine actuator module. The desired turbine power module determines a desired amount of power at a turbine of a torque converter based on an accelerator pedal position and a vehicle speed. The torque converter transfers torque from an engine to a driveline and includes an impeller and the turbine. The impeller is connected to a crankshaft of the engine. The turbine is connected to a transmission in the driveline and is at least one of hydraulically coupled and mechanically coupled to the impeller. The engine actuator module controls an actuator of the engine based on the desired turbine power.

System and method for controlling an engine based on a desired turbine power to account for losses in a torque converter

A method of controlling clutches in a multi-speed transmission includes beginning a current shift from a starting gear to an initial target gear, and determining whether the current shift is a downshift. The method determines jump-stage eligibility of a first clutch. Determining jump-stage eligibility includes determining whether the first clutch is a holding clutch for the current shift, and determining whether the first clutch is an off-going clutch for a legal shift from the initial starting gear to an adjusted target gear having a higher speed ratio than the initial starting gear. If the first clutch is not jump-stage eligible, the method maintains pressure of the first clutch at a current pressure. If the first clutch is jump-stage eligible, the method reduces the pressure of the first clutch from the current pressure to a staging pressure, which is greater than a slipping pressure.

Power downshift clutch control

A powertrain system includes an internal combustion engine rotatably coupled to a non-combustion torque machine and a torque converter which is rotatably coupled to an input member of a transmission. A method for operating the powertrain system includes operating the torque converter in a controlled slip operating state and controlling a torque converter clutch capacity in response to a driver requested braking torque. Target torque outputs from the engine and from the torque machine are determined in response to the driver requested braking torque subjected to a time delay. A torque modifier for the torque machine is determined in response to a torque converter clutch slip error. Torque output from the engine is controlled in response to the target torque output from the engine, and torque output from the torque machine is controlled in response to the target torque output and the torque modifier from the torque machine.

Method and apparatus for controlling a torque converter clutch in a multi-mode powertrain system

A vehicle powertrain includes an engine, transmission, torque converter assembly, and controller. The controller includes recorded lumped inertia models of the powertrain and instructions for executing a clutch-to-clutch shift using these models. The models collectively reduce powertrain dynamics to two or three degrees of freedom. The controller executes a method to estimate clutch torques using the models. The models may include a first primary inertia block describing engine inertia and inertia of a torque converter pump, and a second primary inertia model describing the inertia of the turbine and transmission as reflected to the input member. The second primary inertia model includes bulk inertia models for each fixed gear state and each possible shift maneuver. The controller derives a required output torque value as a closed-loop target value using the lumped inertia models and a requested input torque, and uses the estimated clutch torque to achieve the target value.

Transmission clutch control using lumped inertia modeling

A powertrain system includes an engine control module that generates a negative torque transition signal based on a pending negative torque event of an engine. A transmission control module receives the negative torque transition signal from the engine control module. The transmission control module increases a slip speed of a torque converter clutch in preparation for the pending negative torque event by adjusting pressure in the torque converter clutch prior to the pending negative torque event. The transmission control module decreases the slip speed in the torque converter clutch based on completion of a transition at least one of to the pending negative torque event and from the pending negative torque event.

Driveline stiffness relaxation systems and methods for DFCO operation

A powertrain includes a torque generative device and a torque converter having an impeller, a turbine and a torque converter clutch. A method to control torque converter slip includes monitoring a reference slip and a turbine speed of the torque converter, determining a turbine torque based upon the reference slip and the turbine speed, determining a feed forward torque converter clutch pressure command based upon the turbine torque, a torque generative device torque, and a TCC gain, and controlling the torque converter clutch based upon the feed forward torque converter clutch pressure command.

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Northville, MI, United States of America

Jeremy V Horgan