Cummins Electronics Company, Inc.

Cummins Engine Company, Inc.

Larry R Webber

Gregory R White

Jon A Steeby

Bryan S Gatewood

Mark L Wilson

Dean S Anderson

Richard E Kleine

Peter J Griffen

Edwin A Johnson

Lloyd E Flory

Peter L Griffen

An electronic engine control controls the selection and confirmation of automatically selectable gears in a manual/automatic transmission. Failure to disengage the engine from the transmission within a predetermined time period, failure to reach a predetermined synchronous engine RPM window within another predetermined time period and failure to confirm gear engagement within yet another predetermined time period are three automatic shift failure modes which may cause an automatic shift attempt to fail or be aborted. A fourth automatic shift failure may occur if the clutch pedal is depressed during an automatic shift attempt. If any of the foregoing automatic shift failure mechanisms is detected, an error recovery algorithm which forms a part of the present invention determines the easiest/safest transmission gear to command to prevent the driver from having to manually attempt to engage the transmission after a failed automatic shift attempt.

Apparatus and method for commanding a gear after an aborted shift

An apparatus and method of electronically controlling a manual/automatic transmission after a power reset is provided. Within a predetermined time period after a power reset, the current commanded transmission gear is held, or alternatively the highest of the electronically selectable gears is commanded, until an accurate determination of the vehicle speed can be made. If the vehicle speed is thereafter determined to be below a minimum vehicle speed value, the transmission is commanded to the neutral position, or alternatively, the lowest of the electronically selectable gears is commanded. If the vehicle speed is above the minimum vehicle speed value, or alternatively, above a maximum vehicle speed value, then the transmission is commanded to the highest of the electronically selectable gears. In either case, further electronic shifts are inhibited for a predetermined time period after recovery from the power reset is accomplished.

Apparatus and method for controlling a manual-automatic transmission

An electronic engine control monitors engine speed, vehicle speed and determines various engine RPM values and RPM ranges used in fueling a motor vehicle engine to achieve desired engine speeds prior to and during an automatic gear shift sequence. The engine is coupled to a manual/automatic transmission that includes manually selectable gear ratio operation modes and automatically selectable gear ratio operation modes. In order to verify engagement of the automatically selectable gear ratio operation modes, a predetermined reverse torque is introduced into the drivetrain by fueling the engine to certain predetermined levels after an automatic gear shift sequence begins and monitoring engine speed to test whether engine speed is within calculated synchronous engine speed ranges corresponding to the gear ratio of the desired automatically selectable gear ratio operation mode.

Apparatus and method for verifying gear engagement in controlling the

A control system for controlling automatic shifting of a manual/automatic transmission is disclosed including a cruise control system and an auto-shift mode for controlling automatic upshift and downshift operations between the top two gears of a heavy duty truck transmission. Certain failures of equipment or incorrect driving habits of operators are corrected for with algorithms which prevent undesirable operating conditions which compromise the acceptability of an electronically controlled heavy duty truck transmission equipped vehicle. The mechanism by which auto-shift operation of the transmission is requested is also compared with parameters such as vehicle speed and engine speed in order to determine whether gears should be engaged or disengaged, the gears being those subject to auto-shift control of the system controller.

Method and device for controlling critical switch failure and neutral

An engine compression brake control device is disclosed. The control device is electronic and prevents activation of the engine compression brakes during operating states wherein undesirable conditions will result if the engine brakes are active. The electronic control device monitors various conditions and activates the engine brakes only if all of the following conditions are simultaneously detected: a valid gear ratio is detected; the driver has requested or enabled engine compression brake operation; the clutch pedal is out; the throttle is at a minimum engine speed position; and the electronic controller is not presently attempting to execute an electronically controlled final drive gear shift.

Method and apparatus for control of engine compression brakes before,

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.

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Fredericksburg, TX, United States of America

Larry R Webber