Abstract: Methods and systems are described for vehicle coasting optimization. The system may include a vehicle having an engine, a drivetrain, and an accelerator. The system may include selecting a fuel-saving mode based on an anticipated braking requirement in response to detecting the vehicle is non-stationary and the accelerator is disengaged. The system may include generating an instruction corresponding the selected fuel-saving mode, wherein the instruction is configured to control at least the engine and the drivetrain.

Abstract: An electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control when shift control is performed during the performance of lockup control, the electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control. Besides, the electronic control unit places priority on the shift control and starts the lockup initial oil pressure control after the completion of the shift initial oil pressure control, when the lockup control is performed during the performance of the shift control. Therefore, the shift initial oil pressure control and the lockup initial oil pressure control are prevented from occurring at the same time when the shift control and the lockup control are performed at the same time.

Abstract: A method is used to control a hydrostatic drive including a drive machine, a hydraulic pump coupled to the drive machine, and a hydraulic motor coupled to the hydraulic pump via a hydraulic working circuit. In the method, at least one of multiple manipulated variables of the hydrostatic drive is ascertained and set, in the course of a precontrol, from a specified setpoint value for at least one of the controlled variables, including a pressure in the hydraulic working circuit, a speed of the hydraulic pump, and an output variable of the hydrostatic drive. In the method, the remaining controlled variables and/or manipulated variables are automatically updated.

Abstract: A motor vehicle includes a transmission and a transmission fluid pump for transport of transmission oil to and within the transmission. The transmission fluid pump has a moving element which is coupled to a summation shaft of a planetary gear train. The planetary gear train has a ring gear which is operated by a first drive, and a sun gear which is operated by a second drive. A freewheel mechanism is arranged between the sun gear or a shaft connected to the sun gear and a further element so that the second drive can be switched off, when the first drive operates at high speeds while yet maintaining proper operation of the transmission fluid pump.

Abstract: A vehicle driving apparatus includes a rotating electrical machine and an engagement device, which are disposed on a power transmission path linking an input member drive-coupled to an internal combustion engine and an output member drive-coupled to a wheel. The engagement device includes an engagement input coupled to the input member, an engagement output that forms a pair with the engagement input and is coupled to the rotating electrical machine, a friction member disposed between the engagement input and the engagement output, and a pressing member that presses the friction member in a pressing direction. An oil pressure chamber is formed between the pressing member and either the engagement input or the engagement output. A biasing spring biases the pressing member in the pressing direction when no oil pressure is supplied to the oil pressure chamber and is disposed on an exterior of the oil pressure chamber.

Abstract: There is disclosed a continuously variable ratio transmission assembly (“variator”) comprising a roller which transmits drive between a pair of races, the roller being movable in accordance with changes in variator ratio, a hydraulic actuator which applies a biasing force to the roller, at least one valve connected to the actuator through a hydraulic line to control pressure applied to the actuator and so to control the biasing force, and an electronic control which determines the required biasing force and sets the valve accordingly, wherein the valve setting is additionally dependent upon a rate of flow in the hydraulic line.

Abstract: Construction of a continuously variable transmission device for a vehicle is achieved that, when a shift lever is shifted to a selection position for a direction opposite the traveling direction at that time, it is capable of preventing the vehicle from continuing to travel at high speed in a direction opposite the direction intended by the operator. When the shift lever is shifted to a selection position of a direction opposite the traveling direction at that time, and the vehicle speed is faster than a specified speed (V1), the connection of a clutch device that transmits power between a continuously variable transmission mechanism and a differential gear mechanism is disconnected, and the drive force from the drive source is prevented from being further transmitted to the wheels.

Abstract: A system for controlling a transmission fluid circuit includes a lube circuit, a source of control pressure, a first valve for engaging and disengaging a control element whose engagement produces desired forward gears, and a control valve, responsive to control pressure, that alternately connects the lube circuit to a sump and disconnects fluid feed to the first valve, and disconnects the lube circuit from the sump and feeds fluid to the first valve.

Abstract: A method for controlling a transmission gear change to a desired gear includes disengaging an offgoing transmission control element, changing engine speed to a synchronous speed of the desired gear, decreasing engine output torque, and engaging an oncoming transmission control element.

Abstract: A control apparatus of an automatic transmission including a start intended operation detecting unit detecting a vehicle starting operation; and a clutch control unit engaging the clutch from the clutch disengaged state and the automatic speed change mechanism is placed in a neutral state, when the vehicle starting operation is detected. The clutch control unit includes an initial engagement control unit performing initial engagement control that starts frictional contact of the clutch by supplying hydraulic pressure to a hydraulic servo of the clutch, and a slip start control unit establishing a speed ratio of the automatic speed change mechanism at the start by slip-controlling the clutch after the initial engagement control is terminated, thereby increasing output shaft rotational speed of the automatic speed change mechanism without reducing the input shaft rotational speed of the automatic speed change mechanism to less than the input shaft rotational speed at the end of initial engagement control.

Abstract: A system for controlling power downshifts of a transmission includes a flare generation module, a flare control module, and a shift control module. The flare generation module generates turbine speed flare by decreasing pressure applied to an off-going clutch of the transmission. The flare control module decreases the turbine speed flare by increasing the pressure applied to the off-going clutch of the transmission. The shift control module increases a pressure applied to an on-coming clutch of the transmission when the turbine speed flare is less than a predetermined amount from a desired turbine speed flare.

Abstract: A method of operating a vehicle drive train having a drive machine, a transmission apparatus having a plurality of shift elements and an output drive. The plurality of shift elements are engaged or disengaged in a power flow for achieving different transmission ratios within the transmission apparatus. The output drive is coupled to a transmission output shaft and the drive machine is coupled to a transmission input shaft of the transmission apparatus. Upon a request to interrupt power flow within the transmission apparatus, between the transmission input shaft and the transmission output shaft, a maximum number of shift elements are transferred to and/or held in an engaged operating state, and the remaining portion of the shift elements are transferred to and/or held in a disengaged operating state with the transmission output shaft being rotatable.

Abstract: A transmission system is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members a plurality of torque transmitting devices, a launch clutch, and a hydraulic circuit. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices may include clutches and brakes.

Abstract: A method and system provides a Brake Transmission Shift Interlock Override mode in a vehicle including a shift-by-wire transmission. With power applied and ignition on, a driver will press and hold an override switch for a calibrated time. While the override switch is pressed, the driver presses a non-Park button for another calibrated time. The result will be that the vehicle is placed in the selected range wherein the transmission will not automatically shift to Park upon detecting a triggering event. The driver is able to shift the vehicle from Park, even if an electrical failure prevents the transmission from shifting out of Park. As such the vehicle can be driven until the failure is serviced.

Abstract: A method for operating a motor vehicle hybrid powertrain having an engine, a motor-generator and a multi-speed automatically-shiftable transmission, wherein the engine and the motor-generator operate to supply torque to the transmission for driving a vehicle. The method includes modulating the torque supply from the motor-generator to the transmission during a gear shift to minimize a transmission output torque disturbance.

Abstract: A clutch control device includes: a plurality of hydraulic clutches built into a transmission; a clutch switching pattern storage device in which a plurality of clutch switching patterns, each defining engage/release changeover timing with which the plurality of hydraulic clutches are engaged/released are stored in correspondence to individual speed change patterns adopted by the transmission; a clutch switching pattern selection device that selects a clutch switching pattern stored in the clutch switching pattern storage device in correspondence to a speed change pattern for the transmission at a time of speed change; and a hydraulic control device that executes hydraulic control for the plurality of hydraulic clutches in correspondence to the clutch switching pattern selected by the clutch switching pattern selection device.

Abstract: An exemplary control device includes an input torque detection unit that detects an input torque input to the input shaft; and a controller that: determines torque distribution of two of the friction engagement elements that form the shift speeds; and calculates a transmission torque of the two friction engagement elements based on the input torque and the torque distribution and sets the engagement pressure to obtain a torque capacity that can transmit the transmission torque, wherein the controller sets the engagement pressure such that slippage does not occur in the two friction engagement elements in a state where engagement of the two friction engagement elements forms the shift speeds and such that, even if an additional friction engagement element engages based on the line pressure while the two friction engagement elements are engaged, one of the three friction engagement elements is caused to slip.

Abstract: A hydraulic control system for a automatic transmission includes a plurality of solenoids and valves in fluid communication with a plurality of shift actuators. The shift actuators are operable to actuate a plurality of torque transmitting devices. Selective activation of combinations of the solenoids allows for a pressurized fluid to activate at least one of the shift actuators. The solenoids are configured to provide a forward gear ratio and a reverse gear ratio when the solenoids are deengerized.

Abstract: During control of a shift of a first friction engagement element from an engaged state into a disengaged state and a shift of a second friction engagement element from a disengaged state into an engaged state for a gear shift to a first target gear from a second target gear, a desired torque capacity of the first friction engagement element is set based on an actual transmission gear ratio by interpolation from values of the desired torque capacity corresponding to at least first and second reference transmission gear ratios, wherein the first reference transmission gear ratio is a transmission gear ratio at start of an inertia phase of the shift control. When the first reference transmission gear ratio is between the actual transmission gear ratio and the second reference transmission gear ratio, the desired torque capacity is set to the value corresponding to the first reference transmission gear ratio.

Abstract: A method of controlling an automatic transmission of a motor vehicle having clutches controlled by an electronic control unit. A transmission rotational speed in an initial transmission stage is determined. If a first transmission shifting rotational speed is reached, the transmission is shifted from the initial transmission stage to a target transmission stage. A target transmission rotational speed of the target transmission stage is then ascertained. A difference is next ascertained between the target transmission rotational speed and a second shifting transmission rotational speed. An initial counter value, of a counter, is determined, which depends on the transmission rotational speed difference. The counter is next caused to carry out counting, from the initial counter value, as time progresses. If and when the counter value reaches zero, the transmission is shifted from the target transmission stage toward the initial transmission stage.

Abstract: A control device controlling a vehicle's automatic transmission. The automatic transmission engages first and second friction engagement elements by fluid pressure from a pump operating using motive power from the vehicle's motor when a shift position is at a reverse traveling position, places the first friction engagement element on standby at a predetermined pressure that is higher than a stroke starting pressure by which a piston stroke is started and lower than a complete engagement pressure or engages the first friction engagement at the complete engagement pressure when the shift position is at a non-traveling position, and engages a third friction engagement element as a starting shift speed when the shift position is at a forward traveling position.

Abstract: A method for operating a motor vehicle drivetrain comprising at least an automatic transmission and a drive assembly. The automatic transmission includes at least five shifting elements to transmit torque and/or power. In each forward and reverse gear, three shifting elements are engaged and the remaining two shifting elements are disengaged. Two consecutive gearshifts are carried out through selection of the five shifting elements. During a first gearshift, implemented as a multiple gearshift, a subsequent second gearshift, implemented as either a single or multiple gearshift, is prepared. During the first gearshift, a first shifting element is disengaged, a second shifting element is engaged, a third shifting element is prepared for disengagement in a subsequent second gearshift and a fourth shifting element is prepared for engagement. Further, during the first gearshift and the subsequent second gearshift, a fifth shifting element is retained in at least a substantially engaged state.

Abstract: An automatic transmission of a motor vehicle, comprising a plurality of planetary gear units; a plurality of frictional elements, the frictional elements assuming engaged/disengaged condition upon receiving a ratio change instruction thereby to establish a desired speed of the transmission with the aid of the planetary gear units; a deceleration detecting means that detects a deceleration of the motor vehicle; a gear ratio detecting means that detects an actual gear ratio that is actually established in the transmission; and an interlock judgment means that judges whether or not the transmission is subjected to an interlock, the interlock being a condition wherein upon receiving the ratio change instruction, at least one of the frictional elements is brought into unintended engagement.

Abstract: A method for controlling trapped air in a clutch of an automatic clutch-to-clutch transmission includes, calculating a pulse on time based on a clutch volume and adaptive convergence. A pulse off time is calculated based on a temperature of transmission fluid. A pulse number is calculated based on the temperature of transmission fluid. A maximum pressure is commanded to the clutch based on the pulse on time and a minimum pressure is then commanded to the clutch based on the pulse off time. A pulse counter is incremented when the pulse off time expires. The steps of commanding maximum pressure, then commanding minimum pressure, and incrementing the pulse counter are repeated until the pulse counter equals a desired pulse number.

Abstract: A method for operating a motor vehicle drivetrain with at least an automatic transmission and a drive motor. The automatic transmission includes at least five shift elements to transmit torque and/or power. In each of the forward and reverse gears, at least three shift elements are engaged and the remaining shift elements are disengaged. Two consecutive gearshifts are carried out through selection of the five shift elements. During a first gearshift, implemented as a multiple gearshift, a subsequent second gearshift, implemented as either a single or multiple gearshift, is prepared. During the first gearshift, a first shift element is disengaged, a second shift element is engaged, a third shift element is prepared for disengagement in a subsequent second gearshift and a fourth shift element is prepared for engagement. Further, during the first gearshift and the subsequent second gearshift, a fifth shift element is retained in at least a substantially engaged state.

Abstract: A cost for manufacturing an automatic transmission can be reduced since a separate solenoid valve for controlling a damper clutch is not required when a hydraulic control system of an automatic transmission for a vehicle includes: a regulator valve that forms a line pressure by regulating a hydraulic pressure generated by a hydraulic pump; a torque converter control valve that receives a hydraulic pressure from the regulator valve and supplies a torque converter operating pressure to a torque converter; and a damper clutch control valve that receives the hydraulic pressure of the torque converter control valve and selectively supplies the torque converter operating pressure and a damper clutch operating pressure, wherein the damper clutch control valve is controlled by a control pressure supplied from a switch valve that is controlled an operating pressure of an overdrive clutch that operates at third and fourth forward speeds.

Abstract: An automatic transmission control device with a hydraulic control system controlled by an electric transmission control device. The system including several pressure control valves, actuated electrically by the transmission control device, and several switching valves and pressure regulation valves, actuated by hydraulic pilot pressure, which is adjustable with the pressure control valves. Each shift element is associated with one of the pressure control valve. An engagement prevention valve is actuated by one of a control pressure of the first shift element and a pressure signal equivalent to the control pressure of the first shift element to engage the reverse drive gear. A pressure supply line of the second shift element for obtaining the reversing gear is blocked when the engagement prevention valve is in its first switch position and open when the engagement prevention valve is in its second switch position.

Abstract: An automatic transmission includes a planetary gear arrangement, and a plurality of engaging elements each arranged to vary an engagement state among the rotating elements of the planetary gear arrangement in such a manner to establish a normal gear ratio set and an emergency gear ratio set excluded from the normal gear ratio set. A control section performs the following: selecting a gear from the normal gear ratio set in accordance with a running state of a vehicle under normal operating conditions; controlling the engagement state of each of the engaging elements in such a manner to shift into the selected gear; establishing, when an interlock state is detected, an escape gear by releasing one of the engaging elements needed to be applied to establish the selected gear; and identifying an incorrectly-applied engaging element in accordance with the running state of the vehicle resulting from establishing the escape gear.

Abstract: A hydraulic control apparatus of an automatic transmission estimates the possibility of there being a demand for a shift into a gear lower than the current gear during a power-off downshift operation. If there is a possibility that there will be a demand for a shift into the next gear during the shift, the hydraulic control apparatus starts an operation for supplying an apply preparation hydraulic pressure in preparation for the shift into that next gear.

Abstract: A method for operation of a drivetrain including a drive motor and an automatic transmission having at least five shift elements, of which, at least three shift elements are engaged in each forward and reverse gear and the other shift elements are disengaged. Two successive shifts are accomplished by two overlapped single gear shifts such that a) during the first shift, a first shift element is engaged or disengaged while a second shift element is disengaged or engaged; b) during the first shift, second and third shift elements are prepared for either engagement or disengagement, and c) during the first and the second shifts at least one fourth shift element is kept engaged or nearly engaged.

Abstract: An activation control device for clutch packs of a hydraulic double clutch is described and illustrated, and in some embodiments comprises a first pressure line having a filling valve and leading from an oil pressure source to the first clutch pack; a second pressure line having a filling valve and leading from the oil pressure source to the second clutch pack; and first and second draining valves coupled to the first and second pressure lines, respectively, the first draining valve located between the filling valve of the first pressure line and the first clutch pack, and the second draining valve located between the filling valve of the second pressure line and the second clutch pack.

Abstract: An electro-hydraulic control system is provided with a diagnostic system that uses extensive multiplexing of pressure switches to reduce the number of required components. The control system includes a controller with a pressure switch diagnostic system having first, second, third and fourth pressure switches each having a high and a low logic state, first and second logic valves each movable between a respective first position and second position, and first, second, third and fourth trim valves each movable between a respective first position and second position. The pressure switches are multiplexed to report one of the high and low logic state to the controller in accordance with a relatively high and low fluid pressure, respectively, at different ones of the trim valves and logic valves, thereby enabling a determination of a change in or failure to change position of the respective the trim valves or logic valves.

Abstract: An ECU executes a program including the steps of: starting disengagement of a C2 clutch and a B1 brake when downshifting a transmission implementing gears in accordance with combinations of engaged clutches and brakes from sixth gear to third gear, or disengagement of the C2 clutch and a B3 brake when downshifting from fifth gear to second gear; when at least one of the C2 clutch and the B1 brake, or at least one of the C2 clutch and the B3 brake, is completely disengaged, starting engagement of a C1 clutch and the B3 brake when downshifting from sixth gear to third gear, or engagement of the C1 clutch and the B1 brake when downshifting from fifth gear to second gear.

Abstract: An automatic transmission for a vehicle includes a main box controlled using a series of clutches, and an underdrive assembly controlled using a series of clutches and at least one overrunning clutch. In achieving a double-swap downshift from a first transmission “gear” employing a first main box clutch and a first underdrive assembly clutch, to a second transmission “gear” employing a second main box clutch and a second underdrive assembly clutch, a controller delays release of the first main box clutch until after the second underdrive assembly clutch has been prefilled, and fully applies the second underdrive assembly clutch only after slip has been detected in both the main box and the underdrive assembly. Additionally, the controller fully applies the second main box clutch only after the second underdrive assembly clutch has itself been fully applied.

Abstract: An automatic transmission is capable of shifting between multiple speeds by engaging and disengaging multiple frictional engagement devices including at least one clutch and one brake, and is capable of switching between a driving range and a non-driving range with operation of a shift lever, wherein a first brake is engaged to fix an intermediate rotary member to a transmission case in a non-driving range such as neutral range. Thus, rotation of a clutch from drag torque can be stopped and shock due to engagement of a brake can be prevented by engagement of the first brake in the non-driving range.

Abstract: An automatic transmission controller for a vehicle has an insufficient gear shifting time determining device that determines whether a gear shifting time for shifting performed by disengagement of two engaging elements and engagement of two engaging elements is insufficient; and a double engage/disengage prohibiting device that prohibits the gear shift after the disengagement of two engaging elements and engagement of two engaging elements when the insufficient shifting time determining device determines that the gear shifting time for shifting after the disengagement of two engaging elements and engagement of two engaging elements is insufficient.

Abstract: A shift control device and a shift control method for a vehicle for reducing shift shock by taking into account the difference in vehicle speeds before and after shifting. In one of the main inventions, the clutch pressure of another clutch (forward clutch) is controlled to match a target vehicle speed to a calculated actual vehicle speed by the time of start of the connecting operation of a selected speed stage clutch. Since such control is performed so that the vehicle speed is caused to match the target vehicle speed, an actual vehicle speed change rate is held within a predetermined range in at least the instant that the connecting operation of the selected speed stage clutch is started. Also, in another one of the main inventions, as shown in FIG.

Abstract: A shift control apparatus that disconnects and connects respective pairs of friction engagement elements during downshift to a speed spaced apart by two or more steps through an intermediate shift speed. A shift controller controls a hydraulic pressure of a second shift release element by feedback control, and in accordance with the increase in the torque capacity of the second shift release element, also controls the torque capacity of a first shift engagement element so as to be sufficiently higher than the amount of change in the torque capacity of the second shift release element. The occurrence of adverse consequences in which a shift shock is generated is effectively suppressed because a sufficient reaction force cannot be ensured during engagement switching due to insufficient torque capacity of the first shift engagement element, and since the second shift release element cannot be appropriately feedback-controlled, difficulty in control of rotation change results.

Abstract: A control system and control method for a swap-shift transmission having auxiliary and main gearsets wherein precise synchronization control of ratio changes of each gearset at the start and at the end of a swap-upshift progression is achieved using an adaptive control to adjust friction element pressure values and slip times for friction elements of each gearset, whereby shift synchronization is achieved throughout the operating life of the transmission.

Abstract: An electro-hydraulic control system for a transmission is provided having first, second, and third selectively engageable torque transmitting mechanisms. The control system includes a main source of fluid pressure and first, second, and third trim valves operable to effect the engagement of respective first, second, and third torque transmitting mechanisms. A latch valve is in fluid communication with the first torque transmitting mechanism and an interlock valve is in selective fluid communication with the latch valve. The first trim valve, latch valve, and interlock valve are in fluid communication with the main source of fluid pressure. The first trim valve operates selectively communicate fluid pressure to the latch valve to effect engagement of the first torque transmitting mechanism, while the interlock valve is operable to selectively communicate fluid pressure to one of the second and third trim valve to effect engagement of the respective second and third torque transmitting mechanisms.

Abstract: An ECT_ECU of the present invention executes a program including the step of setting a determination time T for determining the completion of an upshift in an accelerator off mode to a short determination time T (X) when a slip value NS (NS=NE?NT) between an engine revolution NE and a turbine revolution NT is smaller than a predetermined slip value NS (0) (when the difference between NT and NE is large, and the step of setting the determination time T to a long determination time T (Y) when the slip value NS (NS=NE?NT) is larger than the predetermined slip value NS (0) (when the difference between NT and NE is small).

Abstract: A pressure assisted park servo assembly for an automatic transmission includes a servo or spool valve which receives pressurized hydraulic fluid from various sources including two solenoid valves and transmission ports. The servo valve controls two flows of pressurized hydraulic fluid to a servo assembly to place the transmission in or release it from park. The improved park servo assembly exhibits enhanced operating speed.

Abstract: At the time of a failure in the second group of engagement devices, the manner of input of oil pressures to a fail-safe valve group is changed via a priority degree switching valve on the basis of the state of engagement of engagement devices of the first group in such a manner that the predetermined degrees of priority for the supply of one of oil pressures PC4, PB1 output from linear solenoid valves SL4, SL5 to a corresponding one of a clutch C4 and a brake B1 via the fail-safe valve group are changed so as to avoid an event that the fail-safe gear stage established in order to prevent the occurrence of interlock of the automatic transmission involves a downshift of two or more stages from the speed change stage maintained immediately prior to the occurrence of the failure. Therefore, it is possible to prevent the occurrence of an uncomfortable behavior of the vehicle caused by the shift to the fail-safe gear stage.

Abstract: A hydraulic circuit for the control of a double clutch transmission which has two transmission groups, each with an isolating clutch and with a plurality of shift clutches for the engagement and disengagement of gear steps, the hydraulic circuit having for each transmission group a specific hydraulic branch connected to a pump in each case via a safety valve, and each hydraulic branch having in each case a clutch control valve for controlling the assigned isolating clutch and at least one shift control valve for controlling the assigned shift clutches. Here, the safety valves are designed in each case as proportional pressure regulating valves.

Abstract: A powertrain has an electrically variable hybrid transmission having an electro-hydraulic control system, plurality of electrical power units, and a plurality of torque transmitting mechanisms selectively engageable by the electro-hydraulic control system to provide four forward speed ranges, a neutral condition, an electric low speed mode, an electrically variable low and high speed mode, and two electrical power off drive home modes. The electro-hydraulic control system of the present invention has a multiplexed trim system for an electrically variable hybrid transmission. The multiplexed trim system allows engagement control of four torque transmitting mechanism and individual control of fluid flow to effect cooling of two motor/generators by multiplexing three trim valves with two logic valves.

Abstract: An oil hydraulic circuit includes a B2 apply control valve establishing communication between a second feedback oil channel connected to a feedback pressure chamber and a drain port, and between a D 1st speed oil channel and a drain port when SL pressure is supplied, and a B2 control valve cutting off an R-range pressure oil channel from a B2 oil channel, and establishing communication between the B2 oil channel and the D 1st speed oil channel when SLU pressure is supplied. An ECU turns on a solenoid (SL) to supply SL pressure to the B2 apply control valve, and turns on a linear solenoid (SLU) to supply SLU pressure to the B2 control valve, when the shift lever is set at the R position during forward running.

Abstract: According to an aspect of the present invention, an automatic transmission includes plural friction engaging elements configures plural shift ranges based on combinations of each friction engaging element being in engaging or disengaging condition, a controlling unit for controlling the friction engaging elements to be in engaging or disengaging condition by controlling a hydraulic pressure applied.

Abstract: An adaptive shift control method for a geared multiple ratio transmission having friction elements for clutches and brakes to establish and disestablish gear ratio changes wherein at least one ratio change involves engagement of one friction element in synchronism with disengagement of another friction element. Operating parameters are adapted throughout the life of the transmission to reduce synchronous errors by developing and learning pressure and time adjustments for the friction elements.

Abstract: A shift control method for an automatic transmission having a primary shift portion and a secondary shift portion is provided that comprises: starting, if a shift signal is output, a shift in the secondary shift portion, and then starting a shift in the primary shift portion; performing feedback control of duty ratios of friction element solenoids for the primary shift portion with a goal of approaching a change rate of a difference between an input speed and an output speed of the primary shift portion to a first target speed change rate, and simultaneously performing feedback control of duty ratios of friction element solenoids for the secondary shift portion with a goal of approaching a change rate of a turbine speed to a second target speed change rate; and completing the shift in the primary shift portion, and then completing the shift in the secondary shift portion.

Abstract: Each control portion for controlling each friction element includes a switch valve and pressure control valve such that hydraulic pressure supplied to the friction element is fully controlled, and a control portion for controlling a friction element that is operated both at low and high speeds includes a switch valve that senses an operation of a friction member cooperatively with the friction element at the high speed such that the friction member receives different hydraulic pressure at low and high speeds. A plurality of fail-safe valves is included for enhancement of a fail-safe function of an automatic transmission.