Cummins Engine Company, Inc.

Cummins Electronics Company, Inc.

Lloyd E Flory

Jon A Steeby

Steven M Bellinger

Thomas Dollmeyer

Gregory R White

Larry R Webber

Matthew W Workman

Dean S Anderson

The present invention allows the vehicle to be operated at higher than normally desired speeds during periods when there is a legitimate need for increased performance, such as downshifting in order to aid in climbing an uphill grade or accelerating with the goal of upshifting. Like the prior art systems, the present invention also imposes a maximum vehicle speed for all non-top gears, but only during steady state conditions (defined as a light engine load existing for a predetermined period of time). During transient conditions (discerned by recognizing gear changes and by high engine load conditions), the control system of the present invention provides lenience from the normal maximum vehicle speed limits for non-top gears. Such lenience provides for increased vehicle performance during periods when it is legitimately needed by the driver. During steady state conditions, the present invention prevents the use of non-top gear during high vehicle speed driving by limiting the vehicle road speed if the transmission is not in top gear.

Method and apparatus for gear down operation prevention

An engine-transmission control system is disclosed which provides for variable shift points of a manual/automatic transmission during cruise control and non-cruise control operation of the vehicle. Vehicle speed, engine speed, and engine loading are variables used individually or in combination in order to determine when shifting of the automatically controllable gear ratio operation states of the manual/automatic transmission will occur. In addition, the system includes modes of operation which include algorithms for determining varying gear shift points so that gear shifting of the top two gears occurs at various vehicle speeds dependent upon input parameters to the cruise control system and additionally in response to which cruise control mode of operation is currently selected by the driver. In addition, control of the automatic shifting of the manual/automatic transmission when the cruise control system is inactive or disabled is determined according to algorithms designed to optimize fuel economy as well as improve driveability of the vehicle and reduce driver fatigue.

Variable electronically controlled shift points for a cruise control

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Edinburgh, IN, United States of America

Lloyd E Flory