Gm Global Technolgoy Operations, Inc.

Harinath Atmaram

Matthew D Whitton

William Robert Mayhew

Brian H Fiore

Yue-Yun Wang

Zhen J Zhang

Mark A Schang

Ronald W Van Diepen

Jose C Zavala Jurado

Robert L Williams

Mateusz M Nowak

Gionata Cimini

David Szpara

Bryan P Jagielo

A control system to control slip of a torque converter clutch includes a clutch plant model configured to predict a value of a parameter that relates to torque converter clutch slip as a function of clutch plant model inputs comprising commanded clutch pressure and of torque from the torque generative device. The control system also includes a model predictive controller configured to receive signals that allow determination of a desired value of the parameter that relates to torque converter clutch slip and a predicted value of the parameter that relates to torque converter clutch slip, receive a signal representing reported torque of the torque generative device, identify an optimal commanded clutch pressure value that will result in an optimal value of an objective function based on the clutch plant model, and provide a command signal to an actuator effective to control commanded clutch pressure to the torque converter clutch.

Model predictive control of torque converter clutch slip

A vehicle includes an engine, dual-clutch transmission (DCT), and controller. The controller executes a method to control a requested change-of-mind shift of the DCT to a second desired gear state. The requested shift is initiated after a prior-requested but not yet fully-executed shift of the DCT to a first desired gear state. The controller detects the requested shift, identifies the second desired gear state, and aborts the prior-requested shift immediately upon identifying the second desired gear state. The controller also shifts the DCT to the second desired gear state using a calibrated shift profile corresponding to the detected shift. The calibrated shift profile describes required oncoming and offgoing clutch torques needed for achieving the second desired gear state. Engine speed control may be used to synchronize engine and input shaft speeds.

Change-of-mind shift control of a dual-clutch transmission

A method of controlling a transmission includes determining if the transmission is currently executing a first torque controlled shift from a first gear ratio to a second gear ratio. A torque controlled shift is defined as a shift control operation in which the speed of the engine is controlled to perform a shift operation. When a second torque controlled shift is detected while the transmission is currently executing the first torque controlled shift, a dual torque controlled shift strategy is executed, which merges a first shift control strategy for executing the first torque controlled shift with a second shift control strategy for executing the second torque controlled shift. The dual torque controlled shift strategy seamlessly executes the first torque controlled shift and the second torque controlled shift without a time delay and engine torque disruption therebetween.

Method of controlling a transmission

A method of controlling shifts in a multi-speed transmission includes beginning an initial shift, which changes the transmission from a starting gear to an initial target gear, and executing an adjusted shift, which changes the transmission to an adjusted target gear having higher speed ratio than the initial target gear, when transition conditions are satisfied. The transition conditions include a threshold increase in torque request, which is sufficient to require the transmission to be placed into the adjusted target gear. The transition conditions also include a common controlling clutch, which is partially engaged during the initial shift and the adjusted shift and is an off-going clutch to place the transmission in the adjusted target gear. Executing the adjusted shift does not include placing the transmission in a neutral mode. Furthermore, executing the adjusted shift does not include completing the initial shift.

Change of mind shift control

A method of controlling shifts in a multi-speed transmission includes beginning an initial shift, which changes the transmission from a starting gear to an initial target gear, and executing an adjusted shift, which changes the transmission to an adjusted target gear having higher speed ratio than the initial target gear, when transition conditions are satisfied. The transition conditions include a threshold increase in torque request, which is sufficient to require the transmission to be placed into the adjusted target gear. The transition conditions also include a common controlling clutch, which is an off-going clutch to place the transmission in the adjusted target gear. Executing the adjusted shift does not include placing the transmission in a neutral mode. Furthermore, executing the adjusted shift does not include completing the initial shift.

A control system for a transmission coupled to an engine includes first, second, and third modules. The first module detects a closed throttle downshift of the transmission. The second module detects a request for a power-on downshift of the transmission. The third module controls a clutch of the transmission when the request for the power-on downshift is detected during the closed throttle downshift, wherein the third module one of (i) decreases a pressure applied to the clutch to a first predetermined pressure before an end of the closed throttle downshift and (ii) controls a pressure applied to the clutch to a second predetermined pressure at the end of the closed throttle downshift.

System and method for improved closed throttle downshifts

A control system includes a shift stage determination module and a clutch control module. The shift stage determination module determines a duration of a first power-on downshift when a second power-on downshift is requested, where a power-on downshift is a downshift of a transmission that occurs when an accelerator pedal is depressed. The clutch control module completes the first power-on downshift and selectively starts controlling the second power-on downshift before the first power-on downshift ends.

Growing community of inventors

Novi, MI, United States of America

Harinath Atmaram