Gm Global Technolgoy Operations, Inc.

Brandon M Fell

Mateusz M Nowak

Henry R Wright

Steven Patrick Moorman

Shushan Bai

Ning Jin

Craig J Hawkins

Nathan M Picot

Martin Gentile

Julian Heinz

Rainer Kloesel

Falko Hendrischke

Marcel Wachtel

Gregory M Wilson

A fuel management system includes a memory and a control module. The memory stores fuel rate maps for multiple firing fractions, where: each of the firing fractions corresponds to a respective firing pattern of an engine; at least some of the firing patterns include deactivating one or more cylinders. The control module: for each of the firing fractions, determines a fuel efficiency value for each of multiple transmission gear ratios, where fuel efficiency values are provided for transmission ratio and firing fraction pairs; applies drive ability constraints to provide resultant transmission ratio and firing fraction pairs; subsequent to applying the drive ability constraints and based on the fuel efficiency values, selects one of the resultant transmission ratio and firing fraction pairs; and concurrently operates a transmission and the engine according to the selected one of the transmission ratio and firing fraction pairs.

Fuel efficiency based integrated engine firing fraction and transmission ratio selection

A method of adjusting deceleration dependent shift points to maintain a target minimum turbine speed includes calculating a vehicle speed offset based on vehicle acceleration rate a predicted downshift delay for the target minimum turbine speed and converting the target minimum turbine speed to a target vehicle speed based on the deceleration condition. Thereafter, the method continues with determining a target gear based on the vehicle speed offset and the target vehicle speed, and downshifting to the target gear having vehicle speed less than or equal to a vehicle speed corresponding to the current turbine speed. The method ends with maintaining the target gear until a shift delay period is greater than a predetermined delay threshold.

Method of adjusting deceleration dependent shift points

A method for transmission upshift sequencing includes detecting a lift foot gear hold condition is met and that a current engine speed is greater than a pattern gear engine speed for the current gear. If these conditions exists then the current gear is held until a first sequence timer expires and then an upshift event occurs to a first gear having an engine speed less than the current engine speed. The first gear is then held until a at least one other sequence timer expires and, thereafter, at least one other gear is selected and held until the engine speed is less than or equal to a pattern gear engine speed.

Method for controlling upshift sequencing

A vehicle or other system includes hydraulic fluid, an actuatable device such as a clutch that includes a linear actuator, e.g., a clutch piston. The linear actuator is moveable via a pressure from the fluid to actuate the actuatable device. A position sensor measures and outputs a position of the linear actuator as a position signal. A controller is programmed to generate increasing and decreasing position-to-pressure (PTP) curves via measurement of the position, at a predetermined time, in response to a series of respectively increasing and decreasing pressure step commands. The controller adjusts the PTP curves using a calibrated set of offsets, locates a PTP point in a hysteresis range between the adjusted PTP curves, and controls the device using the PTP point. The offsets may include a temperature of the fluid, velocity of the linear actuator, and/or an engine speed.

Adaptive control of a linear actuator

A method of controlling a downhill rolling shift sequence (DRSS) of a vehicle having an engine and a dual-clutch transmission (DCT) includes initiating a DRSS upon detecting a rolling downhill condition of the vehicle in an initial gear state, identifying an exit gear state corresponding to the initial gear state, shifting the DCT to a rolling neutral state when a speed of an initial gear input shaft is equal to an idle speed of the engine, initiating synchronization of the engine speed with the speed of an exit gear input shaft when the shaft speed is equal to the engine idle speed, and shifting the DCT from the rolling neutral state to the exit gear state when the synchronized speed of the engine and the exit gear input shaft is equal to a calibrated exit speed defined by the exit gear state. A system for controlling the DRSS is provided.

Rolling downhill shift control of a transmission

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Milford, MI, United States of America

Brandon M Fell