Abstract: A line pressure valve includes a valve housing having a central cavity and a plurality of inlet and outlet ports, and a spool positioned within the central cavity and axially displaceable therein, the spool having a plurality of radial cutouts that fluidly connect respective inlet and outlet ports based on an axial position of the spool with respect to the valve housing. First and second pumps are fluidly connectable and disconnectable respectively to and from the fluid circuit based on the axial position of the spool via the inlet and outlet ports.

Abstract: A line pressure valve includes a valve housing having a central cavity and a plurality of inlet and outlet ports, and a spool positioned within the central cavity and axially displaceable therein, the spool having a plurality of radial cutouts that fluidly connect respective inlet and outlet ports based on an axial position of the spool with respect to the valve housing. First and second pumps are fluidly connectable and disconnectable respectively to and from the fluid circuit based on the axial position of the spool via the inlet and outlet ports.

Abstract: An autonomous solenoid controller which in its broad aspect includes a microprocessor, a communication bus, and a solenoid driver. The microprocessor includes logic in order to control drivers for at least one solenoid. The communications bus is operably connected to the microprocessor so that the communications bus and the microprocessor communicate with one another. The communication bus communicates with an outside transmission control unit. The solenoid driver is electrically connected between the microprocessor and the solenoid, such that the microprocessor commands the solenoid driver to alter the position of the solenoid.

Abstract: Flare control is provided for downshifts in a computer controlled automatic transmission by providing an adaptive pressure term which is adjusted in response to detected flare conditions. During a downshift, engine acceleration is monitored and flare is detected when negative engine acceleration remains below a predetermined level for a predetermined duration. The level of engine acceleration indicative of flare changes with vehicle speed.

Abstract: A motor vehicle having an automatic transmission coupled to an internal combustion engine includes computer based control of powertrain functions including engine torque management and ratio change controls. Shift pressure is scheduled off of the total torque to be transferred to the on-coming friction element, estimated as a function of transmission input torque and powertrain inertia torque constituents. Engine torque during a shift is reduced in a manner which accounts for the relative contributions of transmission input torque and inertia torque constituents of shift torque in order to arrive at a predetermined target shift torque regardless of the proportion mix of the torque constituents.

Abstract: A torque converter clutch control having a controlled capacity mode of operation wherein clutch slip is controlled to a reference slip during periods of positive engine torque provides for a coast mode of operation wherein the clutch slip is controlled to a reference slip during periods of negative torque conditions. The control allows the drivetrain of the vehicle to couple torque to the engine thereby reducing fueling requirements and posturing the system for more efficient transitions into the controlled capacity mode. Drivetrain disturbances are not transferred to the vehicle by virtue of the controlled slip.

Abstract: A torque converter clutch control provides for a controlled capacity mode of operation wherein clutch slip is controlled to a reference value. A lock mode is also provided wherein clutch slip is eliminated. The transition from the controlled capacity mode to the lock mode is caused to occur when clutch slip is stabilized by increasing clutch engagement force by an amount sufficient to smoothly reduce slip speed to zero and thereafter maintain zero slip. The increase in engagement force is marginally sufficient to maintain slip at zero thereby allowing engine torque excursions to be absorbed by allowing slip during such excursions. Transitions back to the controlled capacity mode are adapted to current torque and slip conditions.

Abstract: A torque converter clutch control system has a plurality of operating modes among them an off mode wherein torque coupling is fluidic, a controlled capacity mode wherein the torque coupling is fluidic and mechanical during period of positive engine torque, an apply mode for smoothly transitioning from the OFF mode to the controlled capacity mode, and a release mode for smoothly transitioning from the controlled capacity mode to the off mode. Additionally, a lock mode is provided wherein torque coupling is mechanical via the torque converter clutch and a coast mode wherein torque coupling is mechanical and fluidic during periods of negative torque.

Abstract: A transmission has a manual selector valve which is reciprocally and rotatably mounted in a valve body and operable in a conventional "H" shift pattern to permit selection of first through fifth forward drive conditions, a neutral condition and a reverse drive condition in a planetary transmission. The selector valve has a line pressure chamber formed thereon that remains in fluid communication with a line feed passage in the valve body throughout the "H" pattern. This line pressure chamber is selectively alignable with respective clutch and brake apply passages formed in the valve body to control the flow of pressurized oil for the engagement of respective clutches and brakes. A plurality of exhaust chambers formed therein are also selectively connectible with the clutch and brake apply passages to control disengagement of the respective clutches and brakes not required for the selected drive condition.

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: An improved adaptive transmission pressure control in which cumulative adaptive corrections are stored in a multi-cell memory array, the cells being associated with specified contiguous ranges of a vehicle operating parameter, such as engine throttle position. Periodically determined adaptive correction amounts are applied to a selected cell which includes the engine throttle setting measured at the initiation of the shift and to two or more cells associated with contiguous engine throttle ranges. In this way, a relatively large number of cells may be employed to minimize approximation errors, while maintaining a cell-to-cell continuum of pressure correction values. In operation, an electro-hydraulic pressure regulator is controlled as a combined function of a predefined pressure command obtained from a normal table look-up and a cumulative correction amount obtained from the memory array.

Abstract: An improved control, which dynamically adjusts the shift control parameters in response to an indication of the driving style of the vehicle operator. The driving style indication is used to form a dynamic shift factor DSF, which is used to ratiometrically schedule the shift pattern, line pressure and desired shift time between predefined Normal and Performance values to provide a shift control parameter uniquely suited to the driving style of the operator of the vehicle.

Abstract: An improved detent shift control in which upshift initiation is adjusted in relation to the engine acceleration and the expected shift delay time so that the engine speed limit is not exceeded. Data recorded in the course of the shift is analyzed upon completion of the shift, and the control adaptively adjusts the expected delay time if a significant timing error is detected. Whenever the engine throttle position exceeds a detent threshold, a shift trigger speed for the next higher gear is determined by subtracting a delay-based speed from the desired engine shift speed. The delay-based speed is determined according to the product of the engine acceleration and the stored delay time. The shift is initiated when the engine speed reaches the trigger speed so that the engine speed is prevented from exceeding the desired shift speed.

Abstract: A transmission range selection apparatus including electrically activated range selection valving elements for selectively defining fluid supply states for each primary operating mode of the transmission. Two electrically operated valving elements selectively define fluid supply states for each of four operating modes: Park/Neutral, Reverse, Drive and Drive/Braking. These four operating modes, in conjunction with electronic positioning of the transmission shift valves enables automatic selection of any operating mode of the transmission by a state-of-the-art electronic control unit.

Abstract: An improved control, which dynamically adjusts the shift control parameters in response to the driving habits of the operator, as judged by an indication of the average peak acceleration during specified operation of the vehicle. To determine the indication of average peak acceleration, the longitudinal acceleration of the vehicle is continuously determined in the course of vehicle operation. The peak acceleration values occurring in successive ratio-dependent time intervals are identified and accumulated to form cumulative and average peak acceleration terms. The average peak acceleration term is used to form a dynamic shift factor which is used to ratiometrically schedule the shift pattern, line pressure and desired shift time between predefined Normal and Performance values to provide a continum of shift control parameters uniquely suited to the driving style of the operator of the vehicle.

Abstract: An electronically mechanized control method for regulating the engagement rate or stroke time of a fluid operated torque transmitting device, wherein the flow rate is controlled with a flow control device having a low flow state and a high flow state. The shift is initiated with the flow control device in the high flow state. After a variable delay time, the flow control valve is activated to the low flow state to complete the shift. The delay time is scheduled as an open-loop function of various system parameters to achieve the optimum amount of overlap between the on-coming and off-going torque transmitting devices. An adaptive learning control superimposed on the open-loop control trims the open-loop schedule to compensate for changes in system parameters or tolerance variations which affect the stroke time.

Abstract: An electronically mechanized control method for regulating the engagement rate or stroke time of a fluid operated torque transmitting device, wherein the flow rate is controlled through a coordinated control of the supply pressure and an on-off fluid restriction device. At the initiation of a shift involving engagement of the rate controlled torque transmitting device, an appropriate stroke time is determined in terms of a suitable combination of line pressure and fluid restriction to be commanded for the duration of the shift. The on-off fluid restriction device comprises a first orifice which always remains in the servo supply circuit and second orifice which is selectively connected in parallel with the first orifice via a solenoid operated shuttle valve.

Abstract: An improved control method for properly coordinating a double transition upshift. The state changes of the various clutches of the transmission are sequenced in relation to a dynamic measure of the transmission speed ratio so as to provide consistent high quality shifting. Closed-loop pressure controls are employed in conjunction with the sequencing to ensure timely shift completion.

Abstract: A friction device, such as a clutch or brake, has a fluid-operated piston that is pressurized to cause engagement of the friction device. An accumulator and flow restriction are disposed to assist in controlling engagement time of the friction device. The accumulator and flow restriction are disconnected from each other and from the friction device during disengagement. A shift valve is positioned to provide the desired fluid connections during engagement and disengagement.

Abstract: An improved control method for properly coordinating a double transition downshift. The state changes of the various clutches of the transmission are sequenced in relation to a dynamic measure of the transmission speed ratio so as to provide consistent high quality shifting. Adaptive pressure controls are employed in conjunction with the sequencing to compensate for variability.