Abstract: A method for controlling a vehicle drive unit, which comprises at least two individual drives, at least one of which is able to provide a negative torque. A vehicle control unit is provided, within which a continuous torque comparison is performed within a monitoring level. A permissible torque is ascertained therein. Using a torque range checker it is established whether ascertained setpoint torques lie within torque ranges of the at least two individual drives.

Abstract: The present application is directed to methods and systems for improving the operation of transmissions for automotive vehicles, and in particular, the “factory installed” automotive transmission installed by an original automobile manufacturer. The methods and systems modify both the structural components and hydraulic circuitry of an original automotive transmission to adjust applied pressure and shifting patterns to improve the efficient operation of the automotive transmission.

Abstract: A manual valve of a hydraulic pressure control system for an automatic transmission of a vehicle according to the present invention comprises a valve body provided with a line pressure receiving port, a P/N range port for supplying hydraulic pressure in more than one range of parking range P and neutral range N, a plurality of hydraulic pressure supplying ports and a plurality of exhaust ports; and a valve spool slidably inserted into the valve body and having a plurality of valve lands, a first valve land of said plurality of valve lands having a exhaust groove depressed toward a neighboring land, wherein: each width of the line pressure receiving port and the P/N range port is smaller than each diameter of said plurality of valve lands, whereby a tight seal is maintained when each of the line pressure receiving port and the P/N range port is blocked by said plurality of valve lands; and each width of the plurality of hydraulic pressure supplying ports is greater than each diameter of said plurality of valv

Abstract: The present invention is directed to methods and systems for improving the operation of a transmission for an automotive vehicle, and in particular the transmission as installed by the original automobile manufacturer. The methods and systems of the present invention modify the original hydraulic fluid circuits of the automotive transmission provided by the automobile manufacturer to enable the transmission to select first gear at any time, and to enable the transmission to produce quick applies during upshifts and fast releases during downshifts for high performance operation with only minimum ratio sharing or overlap during gear changes. The modification of the original automotive transmission to achieve these goals includes modification of the hydraulic fluid circuits of the factory. installed transmission; by enlarging the size of pre-existing.

Abstract: A system for overriding hold mode operation of an automated transmission coupled to an internal combustion engine is provided, wherein the transmission is operable in the hold mode of operation to maintain engagement of a currently engaged transmission gear. A control computer is operable to monitor at least one vehicle operating parameter and determine whether hold mode operation is inappropriate based thereon. If hold mode operation is inappropriate, the control computer is operable to either initiate an automatic upshift to a numerically higher transmission gear or limit engine or vehicle speed to a predefined speed value. In this manner, the system of the present invention is operable to allow hold mode operation only when a legitimate need therefore exists.

Abstract: A shift by wire vehicle transmission includes control methods for engaging gears after the vehicle has been at rest or coasting. When the vehicle is started from a stop or rest, a default starting gear is automatically selected. The driver can override the default gear and choose to start driving the vehicle in one gear above or below the default starting gear by manipulating a shift lever. Similarly, the driver can override the default starting gear to begin driving the vehicle in reverse. When the vehicle has been coasting, the transmission control unit chooses the next gear based upon a signal that is provided when the driver manipulates the shift lever. Depending on the indicated desire of the driver, the system controller automatically selects a gear depending upon vehicle speed and torque conditions.

Abstract: The present invention is directed to methods and systems for improving the operation of a transmission for an automotive vehicle, and in particular the transmission as installed by the original automobile manufacturer. The methods and systems of the present invention modify the original hydraulic fluid circuits of the automotive transmission provided by the automobile manufacturer to enable the transmission to select first gear at any time, and to enable the transmission to produce quick applies during upshifts and fast releases during downshifts for high performance operation with only minimum ratio sharing or overlap during gear changes.

Abstract: Method and systems are provided for improving the operation of a transmission for an automotive vehicle, and in particular the transmission as installed by the original automobile manufacturer. The methods and systems of the present invention modify the original hydraulic fluid circuits of the automotive transmission provided by the automobile manufacturer to enable the transmission to manually select any available ratio at any time, to select first gear at any time, and to enable the transmission to produce quick applies during upshifts and fast releases during downshifts for improved performance and heavy duty use with only minimum ratio sharing or overlap during gear changes.

Abstract: In an automatic transmission in which a shifting command can be output by a manual operation of a manual shift lever, in addition to an automatic shifting based on a usual shifting map, the shifting command is possibly executed while preventing an over-revolution and stalling of an engine due to an inappropriate shifting command. If the vehicle speed is in a shifting prohibiting range with a possibility that an over-revolution or stalling of the engine may be caused, when a shifting command is output, the shifting is prohibited, and a timer is set. When the present vehicle speed is translated from the shifting prohibiting range to a shifting permitting range as a result of change in vehicle speed, during counting by the timer, the shifting which has been prohibited is executed.

Abstract: An automatic transmission for outputting shifting commands by manual operation of a manual shift lever in addition to an automatic shifting. When a first-stage shifting command is output, a clutch timer is set. When a second-stage shifting command is output during counting by the clutch timer, the second-stage shifting is prohibited. A shifting command storage timer is set simultaneously with the prohibition of the second-stage shifting. If the time is counted up by the clutch timer during counting by the shifting command storage timer, the second-stage shifting is permitted at this time point. If the time is counted up by the shifting command storage timer earlier than by the clutch timer, the second-stage shifting command is canceled. Thus, the first- and second-stage shifting operations are prevented from being continuously conducted, thereby suppressing the time lag required for the engagement of the hydraulic engagement element to the minimum.

Abstract: A control system and method for automated mechanical transmission systems (10) of the type interpreting a first predetermined combination of parameters as a request or requirement for a direct shift to a predetermined default start ratio (GR.sub.DS) is provided. The control provides a predetermined series of actions by which the vehicle operator may manually select a new default start ratio such as, for example, by manipulation of shift selection device (1) displaceable in a first direction to select upshifts and in a second direction to select downshifts.

Abstract: A hydraulic control for an automatic transmission is composed of a gear shift mechanism having first and second frictional engagement elements, a hydraulic control unit for the engagement elements, and an electronic control unit for the hydraulic control unit. The first element is engaged to achieve a first speed stage and the second element is engaged to achieve a second speed stage faster than and closest to the first speed stage. The hydraulic control unit has a first directional control valve for switching the feeding and discharge of hydraulic pressure between the first and second engagement elements, responsive to a first solenoid signal from the electronic control unit. A second directional control valve is adapted to be switched by a second solenoid signal from the electronic control unit to achieve a third speed stage yet faster than the second speed stage. The first engagement element has a discharge line connected to a drain line via the second directional control valve.

Abstract: A hydraulic control for a power transmission has an electronically operated mode during normal operation. In the event of loss of electrical power, a power interrupt valve is operable in conjunction with a manual valve to direct fluid pressure to the proper devices as selected by the operator, thereby permitting operation to continue in a manual override mode.

Abstract: A shift valve of a hydraulic control system for an automatic transmission system, which ensures safety by maintaining a standard shifting operation when an electronic control system is out of order.