Abstract: A control apparatus for a vehicle includes an engagement-pressure control portion that increases the engagement pressure to a predetermined pressure for a friction engagement element to be engaged during a torque phase of an upshift in an automatic transmission. When the inertia phase starts, the control apparatus increases the engagement pressure at a predetermined gradient. The control apparatus also includes a torque-boost control portion that executes a torque-boost control that boosts the torque output from the power source during the torque phase; and a torque-boost permission portion that determines whether the torque-boost control should be restricted. When it is determined that the torque-boost control should not be restricted, the predetermined pressure is set to a greater value, and the predetermined gradient is set to a smaller value than when it is determined that the torque-boost control should be restricted.

Abstract: An engagement-pressure control portion and a first torque decrease control portion are provided. The engagement-pressure control portion controls an engagement pressure for a friction engagement element to be engaged when an automatic transmission upshifts so that the engagement pressure increases to a standby pressure at which an inertia phase does not start on the condition that torque output from a power source is equal to a first predetermined value, and then the engagement pressure is maintained at the standby pressure. The first torque decrease control portion controls the torque output from the power source so that the torque gradually decreases from the first predetermined value after the engagement pressure for the friction engagement element is maintained at the standby pressure, and a predetermined condition is satisfied.

Abstract: Hydraulic pressure supplied to a first brake and a second brake in a transmission is controlled during an upshift such that the second brake releases from an applied state, and the first brake applies from a released state. The hydraulic pressure supplied to the first brake is increased to a standby pressure. When a period of time has passed after the upshift starts, the output torque of a powertrain is increased. The standby pressure is corrected according to a decrease rate of an input shaft rotation speed of the transmission during an inertia phase of the upshift. An ECU executes a program that includes the step of setting the period of time from the start of the upshift until the output torque of the powertrain starts to increase, according to the standby pressure.

Abstract: An improved control for an automatically shiftable transmission upshift, wherein the engine output torque and on-coming clutch pressure are coordinated during the shift based on an inverse dynamic model of the transmission to achieve a desired output torque trajectory. At the initiation of an upshift, the engine torque is commanded to decrease in a ramp-like or sloping fashion to and engine output torque value calculated using the dynamic model. This ramp-like or sloping decrease provides smooth shifting, while reducing the likelihood of tie-up between on-coming and off-going clutches within the automatically shiftable transmission.

Abstract: Strain gauges and a torque value calculating unit detect a torque value acting on a sun gear based on a reaction force. An input equivalent value calculating unit calculates an input torque equivalent value based on the detected torque value, and a hydraulic pressure control unit controls output from a starting clutch by controlling operation of a hydraulic servo, based on the input torque equivalent value calculated by the input equivalent value calculating unit. Therefore, by measuring the input torque equivalent value derived from a value for torque acting on the fixed sun gear in an automatic speed change mechanism and then monitoring the input torque equivalent value as a target input torque, the control unit precisely controls the hydraulic pressure to the starting clutch FB control.

Abstract: In a shift control device and a shift control method of an automatic transmission that establishes a plurality of gear steps of different speed change ratios by selectively engaging a plurality of friction engagement devices, one of a shift start time point and an inertia phase start time point is used as a reference time. In a power-off shift, the shift action is compulsorily ended when the elapsed time from the reference time exceeds a first time. In a power-on shift, the shift action is compulsorily ended when the elapsed time from the reference time exceeds a second time that is set shorter than the first time. If a switch from the power-off shift to the power-on shift occurs halfway through the power-off shift, the shift action is compulsorily ended when the elapsed time from the time point of the switch exceeds a predetermined time.

Abstract: A method for controlling a coast down downshift that is produced in an automatic transmission by disengaging an off-going control element and engaging an oncoming control element, including the steps of determining a first desired pressure magnitude of the off-going control element and a first desired pressure magnitude of the oncoming control element, executing the current downshift using said first desired pressure magnitudes, determining during execution of the current downshift corrections of said first desired pressure magnitudes that occur during the current downshift, determining a second desired pressure magnitude of the off-going control element and a second desired pressure magnitude of the oncoming control element, using said corrections and the second desired pressure magnitude to determine a subsequent desired pressure magnitude of the off-going control element and a subsequent desired pressure magnitude of the oncoming control element, and executing a downshift using said subsequent desired pres

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: In a hydraulic control apparatus for a vehicular automatic transmission, if it is determined that there is a failure that may cause tie-up in an automatic transmission, communication is provided between a first output port and a first drain port in a switching valve. As a result, a hydraulic frictional engagement device, which should be disengaged when there is a failure, is disengaged. Also, a specific shift speed is achieved by controlling the switching valve. Therefore, it is not necessary to select a shift speed that is achieved on the condition that the hydraulic frictional engagement device, which should be disengaged when there is a failure, is engaged. Thus, it is possible to prevent a shift that may impair driveability when there is a failure that may cause tie-up in the automatic transmission.

Abstract: A control system operable to engage a torque transmitting mechanism, the control system having at least one variable bleed solenoid valve operable to selectively provide pressurized fluid to selectively engage at least one torque transmitting mechanism. An electronic control unit is also provided to provide control to the at least one variable bleed solenoid valve. The electronic control unit commands the variable bleed solenoid valve to provide the pressurized fluid to the at least one torque transmitting mechanism for a first predetermined time and to subsequently substantially disallow the pressurized fluid to the at least one torque transmitting mechanism for a second predetermined time subsequent to the first predetermined time. The electronic control unit subsequently commands an intermediate pressure level to trim the torque transmitting mechanism into engagement. A method for providing engagement to the torque transmitting mechanism is also provided.

Abstract: A shift control method of an automatic transmission for controlling a shift from an nth speed, achieved by engagement of first and second frictional elements to an (n?3)th speed, achieved by engagement of third and fourth frictional elements. The method includes (a) beginning release control of the first element; (b) beginning release control of the second element after step (a) and after the shift is completed; (e) beginning engagement control of the third element; and (d) beginning engagement control of the fourth element after step (c). An alternative method includes (a) beginning release control of the first element; (b) beginning engagement control of the third element after step (a); (c) beginning actual engagement of the third element; (d) beginning actual release of the first element after step (c); (e) beginning engagement control of the fourth element after step (d); (f) beginning release control of the second element after step (e).

Abstract: A hydraulic control apparatus and method of controlling it for an automatic dual clutch transmission, which includes a first clutch with a first partial transmission and a second clutch with a second partial transmission, as well as a shifting system for engaging/releasing gears of the two partial transmissions. A first switching valve in a first position AI connects a first pressure regulator to the first clutch and disconnects it from the shifting system and in a second position BI connects the first pressure regulator to the shifting system and disconnects it from the first clutch, and that a second switching valve in a first position AII connects a second pressure regulator to the second clutch and disconnects it from the shifting system and in a second position BII connects the second pressure regulator to the shifting system and disconnects it from the second clutch.

Abstract: An engine torque control device is configured to lessen shift shock while shortening the shift time during downshifting with an automatic transmission. When a downshift requirement is generated, a disengagement control of a higher gear clutch (current gear ratio) is commenced, and at the same time, a first synchronizing control is commenced. The first synchronizing control has a torque-up control with a first synchronizing speed DNe1 set as the target speed TNe, during a first control period. When the first control period has concluded and there is a transition to a second control period. In the second control period, an engagement control of a lower gear clutch (the post-shift gear ratio) is commenced, and at the same time, there is a switch to a second synchronizing control. In the second synchronizing control, the target speed TNe is set to a second synchronizing speed DNe2 at the post-shift gear ratio.

Abstract: A calibration system for calibrating a transmission adjusts a clutch fill pulse width and hold level current for an oncoming clutch via calibration shifts during operation of the associated machine, thus establishing the desired shift timing and duration. The pulse width is calibrated based on torque transfer characteristics of the clutch during a test shift, and the hold level current is calibrated based on the shift duration of a further test shift.

Abstract: A method and an apparatus are provided to control operation of an electro-mechanical transmission device selectively operative in one of a plurality of fixed gear modes and two continuously variable modes. The method comprises controlling the flow control devices of the electro-hydraulic control circuit, and monitoring a plurality of pressure monitoring devices in the electro-hydraulic control circuit. A fault is identified in the electro-hydraulic control circuit when a signal output of one of the pressure monitoring devices does not correspond to an expected signal output for the pressure monitoring device after an elapsed time period.

Abstract: A hydraulic control system of an automatic transmission that precisely control is operating hydraulic pressure supplied to a frictional element during shifting and can eliminate oil leak under a maximum operating hydraulic pressure. The hydraulic control system controls a hydraulic pressure generated by a hydraulic pump to from an operating hydraulic pressure for a frictional element selectively operating at each shift ratio. A hydraulic line is configured such that the operating hydraulic pressure of the frictional element is controlled by a pressure control valve and a switching valve that are controlled by a solenoid valve. An exhaust hydraulic line of the pressure control valve is connected to an exhaust hydraulic line of the switching valve such that the exhaust hydraulic line of the pressure control valve can be controlled by a switching of the switching valve.

Abstract: A method for controlling a shift during a shift of an automatic transmission controls to complete an N to N?2 shift and an N?2 to N?3 shift simultaneously such that the shift during a shift is smoothly performed when the N?2 to N?3 shift where one frictional element is released is required to be performed during the N to N?2 shift where another frictional element is released and the other frictional element is engaged.

Abstract: When a charge control is applied to a clutch during a shifting operation of an automatic transmission, a charge counter of this clutch is set to a predetermined value. When a drain control is applied to the clutch, the charge counter is counted down. In response to renewal of requested gear position during the shifting operation, a judgment is made as to whether the state of charge is clear with respect to hydraulic fluid supplied to the clutch (i.e. to-be-newly-charged clutch) before the charge control is applied to this clutch for establishing a renewed requested gear position. When the charge counter of this clutch is currently counted down, it is decided that the charged condition of hydraulic fluid supplied to the clutch is unclear. Thus, a multi-stage gear shifting control (i.e. replacement or renewal of target gear position) is prohibited, thereby suppressing generation of shift shock.

Abstract: The present invention provides a mechanism and method of launching a vehicle using a conventional automatic shifting power transmission. By slipping a first gear reaction clutch during a launch, an efficient hydrodynamic fluid drive with a low stall speed may be used with negligible impact on launch performance. The reduced stall speed characteristic of the hydrodynamic drive may provide improved efficiency in other vehicle operating regions.

Abstract: A method of controlling a downshift in a transmission having a main box and a compounder that has at least one gearset and at least one friction element separate from the main box includes initiating an upshift in the compounder including application of at least one friction element (e.g. a clutch) in the compounder, and releasing a friction element (e.g. a clutch) in the main box providing a swap shift. The speed phase in the compounder may trigger the speed phase in the main box, and vice versa. Target fluid volumes in one or both of a clutch being released in the main box and a clutch being applied in the compounder may be controlled and adjusted, if necessary, as a function of specific event timing in prior shifts.

Abstract: A gear ratio shift control and control method controls gear ratio upshifts in a multiple-ratio transmission for an automotive vehicle. Pressure actuated friction elements establish torque flow paths in transmission gearing as they are selectively engaged and released. A net torque reduction at a transmission torque output shaft during an upshift event is reduced by increasing transmission input torque prior to the start of the inertia phase of the upshift event.

Abstract: An automatic transmission for a vehicle includes a multi-plate clutch having an applied state and a released state and an overrunning clutch having an engaged state and an overrunning state. In addition, the transmission includes a controller that effectuates a gear shift of the transmission by applying a volume of fluid to the multi-plate clutch to toggle the multi-plate clutch from the released state to the applied state at approximately the same time the overrunning clutch is toggled into the overrunning state. The applied volume of fluid at which the multi-plate clutch is applied is substantially given by the following equation: VF=VL?(k*T) where VF is the volume, VL is the instantaneous volume at any time, k is a constant, and T is the input torque to the transmission.

Abstract: A control apparatus of an automatic transmission having first and second frictional engagement elements that achieve lower and higher speed gear stages respectively, includes a target value determination section setting a rotation speed difference between input and output sides of the frictional engagement element, a total torque capacity calculation section calculating a total torque capacity, a distribution ratio determination section setting a distribution ratio of the total torque capacity to the first and second frictional engagement elements, an individual torque capacity calculation section calculating individual torque capacities respectively required of the first and second frictional engagement elements, and an engagement control section controlling engagement conditions of the first and second frictional engagement elements in accordance with the individual torque capacity.

Abstract: An automatic transmission has an electronic control unit and a hydraulic control unit. The electronic control unit outputs an engagement command pressure to a solenoid disposed in a hydraulic control unit to generate a shelf pressure to upshift the automatic transmission. The engagement command pressure is corrected downwardly when the maximum rate of the gear ratio change is larger than the rate of change of a thrust-up determination gear ratio, and upwardly when the maximum rate of the gear ratio change is smaller than the rate change of a prolongation determination gear ratio. By correcting the engagement command pressure using the maximum rate of the gear ratio change, a proper output shaft torque wave form can be obtained so that a fluctuation of an output shaft torque during a torque phase while upshifting has no strong influence on the acceleration of a vehicle to achieve a comfortable shift feeling.

Abstract: An automatic transmission controller has an electronic control circuit, an electromagnetic valve, and a pressure control valve. The electronic control circuit generates a control current. The electromagnetic valve regulates a command pressure in accordance with the control current. The pressure control valve has a spool and is formed with a spool hole. The spool reciprocates in the spool hole in accordance with the command pressure to regulate a pressure supplied to a friction element of an automatic transmission. In a standby state, when the friction element is in a disengaged state, the electronic control circuit generates an oscillating current as the control current so that the electromagnetic valve generates a standby command pressure that makes the spool reciprocate in a range in which no pressure is supplied to the friction element.

Abstract: In shift control apparatus and method for an automatic transmission in which an engine speed is inputted, and a shift change in a shift stage of the automatic transmission is performed to make a gear shift, a shift revolution synchronization control in synchronization with the engine speed is performed and, in a case where the gear shift is made under a driving state in which there is a possibility of an occurrence of a shift shock, an engagement section which performs a power transmission under a presently selected shift stage is gradually released and another engagement section which enables a power transmission through the next selection scheduled shift stage is gradually engaged without an execution of the shift revolution synchronization control.

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: A shift control system of an automatic transmission and a method thereof include controlling the off-going and on-coming clutches according to hydraulic pressures of the off-going and on-coming clutches calculated based on a flare amount when a flare occurs, controlling the on-coming clutch according to hydraulic pressure of the on-coming clutch calculated based on a shifting time interval when the flare does not occur and the shifting time interval is smaller than or equal to a predetermined time interval, and controlling the off-going and on-coming clutches according to hydraulic pressures of the off-going and on-coming clutches calculated based on an excess rate of change of a turbine speed when the shifting time interval is larger than a predetermined time interval.

Abstract: A high acceleration time shift control apparatus and method for a vehicle is provided. The high acceleration time shift control apparatus includes a transmission which achieves plural shift speeds whose gear ratios are different from each other; and a high acceleration time upshifting control device which changes a shift speed of the transmission to a higher speed based on a predetermined determination rotational speed such that an input rotational speed of the transmission substantially reaches a target maximum rotational speed when a request for high acceleration is made by a driver.

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: A continuously variable transmission has: an input shaft, an output shaft, a toroidal type continuously variable transmission, and a planetary gear mechanism including a sun gear, a ring gear and a planetary gear. The power transmitted to first and second power transmission systems is made to converge to two gears of the planetary gear mechanism, and a remaining gear is coupled with the output shaft. A mode changeover device effects a changeover between, during forward movement, a first mode for a low speed side, which utilizes the first power transmission system and a second mode for a high speed side, which utilizes the first and second power transmission systems. Such changeover is effected by the operation of connecting and disconnecting a first mode clutch and a second mode clutch. The operation of effecting the changeover between the first mode and the second mode is effected in 0.2 to 1 second.

Abstract: A method for a shift control of a power shift transmission includes closing an incoming, engaging clutch unit assigned to a new gear and opening the outgoing, disengaging clutch unit assigned to an old gear such that the closing and the opening overlap in time. The incoming clutch unit is closed after performing a filling operation for providing a filling pressure for the incoming clutch unit. The filling operation is concluded by a filling end. In case of a manually triggered power shift, the filling operation for the incoming clutch unit is performed with an increased filling pressure corresponding to an order of magnitude of the clutch capacity of the outgoing clutch unit. After the filling end is identified, the outgoing clutch unit is opened and, overlapping in time, a clutch capacity of the incoming clutch unit is adapted.

Abstract: A transmission system includes a first clutch, a second clutch, and a controller. The controller communicates with the first and second clutches and commands a gear shift. The controller calculates a torque phase time for the gear shift and determines a desired torque trajectory within said torque phase time. The controller determines on-coming torque values for the second clutch and off-going torque values for the first clutch to achieve the desired torque trajectory within the torque phase time. The controller calculates an on-coming clutch pressure based on the on-coming torque value, and an off-going clutch pressure based on the off-going torque value. The controller delays actuation of the first and second clutches to compensate for hydraulic delays.

Abstract: A shift control method for a gearset with greater than or equal to 5 speeds, allowing to perform a sequential shift and a multi-skip shift in relation to the multi-shift stages, contributing to an improved response during shifting. The shift control method comprises steps of performing a preceding shift control when disengagement components of a preceding shift stage and a final target shift stage are identical during skip shifting, then executing a one-stage skip control toward the final target shift stage if a certain set of required conditions are satisfied; and standing by for a predetermined time period without performing the preceding shift control when the disengagement components of the preceding shift stage and the final target shift stage are different during skip shifting, then performing a one-stage skip control toward the final target shift stage only if pertinent conditions are met.

Abstract: In a shift control apparatus for an automatic transmission, there is provided a target speed change permitting means which; at the time of a dual changeover shift which is a shift from an Nth speed achieved by bringing a first friction element and a second friction element to an engagement state, to an (N-?)th speed achieved by engaging a third friction element and a fourth friction element, and which has at least one intermediate speed, between the Nth speed and the (N-?)th speed, achieved by engaging the second friction element and the third friction element; checks a driver's shift intention again at the time of attainment of the gear ratio corresponding to the intermediate speed, and permits the target speed to be changed to the speed according to the driver's intention when the target speed is different from the (N-?)th speed.

Abstract: A control apparatus and method for an automatic transmission, by which a shift is executed by simultaneously controlling release and application of different friction engaging elements, are provided which i) control a clamping force of a friction engaging element to be released and a clamping force of a friction engaging element to be applied, ii) adjust an output torque of a prime mover for driving a vehicle, iii) detect a predetermined timing that is after the start of a torque phase during a shift of the automatic transmission and before the clamping force of the friction engaging element to be applied increases to the point at which torque input to the automatic transmission can be transmitted by only the friction engaging element to be applied, and iv) output a command to gradually reduce the clamping force of the friction engaging element to be released and a command to gradually increase the clamping force of the friction engaging element to be applied, in the torque phase.

Abstract: A shift control apparatus has first, second, third and fourth engagement elements, and a shift control processing unit engaging the first and the second engagement elements in order to realize a first shift speed, engaging the third and the fourth engagement in order to realize a second shift speed, and inhibiting an increase in torque capacity of one of the first and second engagement elements before starting of release of the second engagement element when shifting from the first to the second shift speed. During shifting from the first to the second shift speed, an increase in torque capacity of one of the first and second engagement elements is inhibited before starting of release of the second engagement element. This prevents a step-like shift shock from being caused by the slowed progression of shifting when release of the second engagement element is started.

Abstract: In a system for controlling an automatic transmission, an ECU is constructed to carry out changeover control in accordance with shift determination from second speed to first speed to achieve release of a second engaging element and engagement of a first engaging element, detect a magnitude of a torque signal before a predetermined time of shift determination when the changeover control is carried out, and control release of the second engaging element in accordance with the magnitude of the torque signal.

Abstract: A method for a shift control of a power shift transmission includes closing an incoming, engaging clutch unit assigned to a new gear and opening the outgoing, disengaging clutch unit assigned to an old gear such that the closing and the opening overlap in time. The incoming clutch unit is closed after performing a filling operation for providing a filling pressure for the incoming clutch unit. The filling operation is concluded by a filling end. In case of a manually triggered power shift, the filling operation for the incoming clutch unit is performed with an increased filling pressure corresponding to an order of magnitude of the clutch capacity of the outgoing clutch unit. After the filling end is identified, the outgoing clutch unit is opened and, overlapping in time, a clutch capacity of the incoming clutch unit is adapted.

Abstract: A transmission, in particular an automated shift transmission, includes a plurality of selectable and deselectable gear stages for implementing gear changes. The selection and deselection of the gear stages is achieved with the aid of coupling units, in particular with the aid of engageable and disengageable sliding collars. The coupling units are activatable via respective shift rails and respective actuators. The shifting times are reduced and a compact construction of the transmission is achieved by virtue of the fact that a plurality of gear stages is assigned to at least two different shift rails in such a way that respective successive gear stages are assigned to respective different shift rails. As a result, the respective shift rails can be activated at least partially simultaneously in the case of a sequential gear change. A method for controlling a transmission is also provided.

Abstract: A transmission system includes a first clutch, a second clutch, and a controller. The controller communicates with the first and second clutches and commands a gear shift. The controller calculates a torque phase time for the gear shift and determines a desired torque trajectory within said torque phase time. The controller determines on-coming torque values for the second clutch and off-going torque values for the first clutch to achieve the desired torque trajectory within the torque phase time. The controller calculates an on-coming clutch pressure based on the on-coming torque value, and an off-going clutch pressure based on the off-going torque value. The controller delays actuation of the first and second clutches to compensate for hydraulic delays.

Abstract: A shift control method for a gearset with greater than or equal to 5 speeds, allowing to perform a sequential shift and a multi-skip shift in relation to the multi-shift stages, contributing to an improved response during shifting. The shift control method comprises steps of performing a preceding shift control when disengagement components of a preceding shift stage and a final target shift stage are identical during skip shifting, then executing a one-stage skip control toward the final target shift stage if a certain set of required conditions are satisfied; and standing by for a predetermined time period without performing the preceding shift control when the disengagement components of the preceding shift stage and the final target shift stage are different during skip shifting, then performing a one-stage skip control toward the final target shift stage only if pertinent conditions are met.

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: In the method, the transmission ratio of the speed transmission (i_act) is set automatically using stored adjustment characteristic curves, as a function of a variable (FP, tv) which characterizes the engine output, and a variable (v) which characterizes the vehicle speed. The transmission ratio is varied as required by means of a manual intervention by the driver. The transmission ratio of the speed transmission is set as a stepped deviation from a setpoint engine speed (n_eng).

Abstract: An automatic transmission achieves a desired shift through an initial stage shift in which a first engagement element is released and a third engagement element is engaged, and a final stage shift in which a second engagement element is released and a fourth engagement element is engaged. A control apparatus sets an estimated rotation acceleration for a transmission input shaft in accordance with an input torque and an input torque rotation acceleration speed, and controls the release of the second engagement element for moving to the final stage shift according to the estimated rotation acceleration. As a result, it is possible to prevent a shifting delay and/or degradation that occurs between the initial stage and the latter stage by continuous transmission of the input rotation (engine rotation) change when moving from the initial stage to the later stage.

Abstract: Described is a method for the control of a transmission of a motor vehicle, especially an automatic transmission, with hydraulically activated shifting elements. The shifting elements are shifted to engage or disengage by means of specified pressure pattern (pkab, pkzu) which have been input into an electronic control unit. In the said method, an applied pressure (pkab) on a disengaged shifting element, by the release of a force flow generated by a holding pressure (pkab-h) is reduced to a shift pressure (pkab-sd) and a transmission input speed of rotation (nt) experiences a change dependent upon the applied pressure (pkab) on a disengaged shifting element.

Abstract: A method for controlling a gear shift in an automatic transmission of a motor vehicle that is carried out as a deceleration shift of at least one engaging shifting element, without use of a mechanical free-wheeling condition. To increase the ride comfort, it is proposed that during the shifting sequence of the deceleration shift, a free-wheeling condition is simulated by a slip operation or by an opening of a second shift element of the automatic transmission, that is located in the power flow path, preferably using a start-up shift element of the automatic transmission.

Abstract: An automatic transmission is driven by an engine through a torque converter. The transmission includes a plurality of friction elements which are selectively engaged to provide a selected gear thereby to transmit the power of engine to an output shaft of the transmission while changing the rotation speed. A speed change completion degree estimating system is provided, which comprises a first section that derives a difference (Nt−Ne) between an input rotation speed (Nt) of the transmission and an engine rotation speed (Ne); a second section that derives a difference (g×No−Ne) between the input rotation speed (g×No) of the transmission provided after completion of the speed change operation and the engine rotation speed (Ne); and a third section that calculates a speed change completion degree (Shift) of the transmission by using a ratio between the (Nt−Ne) and the (g×No−Ne).

Abstract: A shift control apparatus has first, second, third and fourth engagement elements, and a shift control processing unit engaging the first and the second engagement elements in order to realize a first shift speed, engaging the third and the fourth engagement in order to realize a second shift speed, and inhibiting an increase in torque capacity of one of the first and second engagement elements before starting of release of the second engagement element when shifting from the first to the second shift speed. During shifting from the first to the second shift speed, an increase in torque capacity of one of the first and second engagement elements is inhibited before starting of release of the second engagement element. This prevents a step-like shift shock from being caused by the slowed progression of shifting when release of the second engagement element is started.

Abstract: A shift control apparatus is arranged to effect a shift in an automatic transmission by changeover of friction elements to be engaged with disengagement of a disengagement-side friction element and engagement of an engagement-side friction element. A shift controller is configured to detect an end of a loss stroke in the engagement-side friction element, and performs an operation to decrease the disengagement-side working oil pressure at a set gradient and to increase the engagement-side working oil pressure at a predetermined gradient upon detection of the end of the loss stroke in the engagement-side friction element. The predetermined gradient of the engagement-side working oil pressure for the engagement-side friction element is made lower for a low engine load than for a high engine load.