Abstract: An all-wheel-drive vehicle includes a primary axle operably coupled to an engine and a secondary axle having an input operably coupled to the engine a first halfshaft, a second halfshaft, a first clutch selectively connecting the first halfshaft to the input, and a second clutch selectively connecting the second halfshaft to the input. A transmission has an input coupled to the engine and output coupled to the primary drive axle. A driveshaft couples a power-transfer unit and the input, and a third clutch selectively couples the output to the driveshaft. A controller is programmed to, during a power-limiting routine, command a torque to the engine based on closed-loop feedback control such that the torque decreases when a calculated slip of a selected one of the first and second clutches is greater than a target slip of the selected clutch and increases when the calculated slip is less than the target slip.

Abstract: A method of controlling a launch clutch during an engine restart event commands a positive torque capacity before the engine reaches idle speed. Early application of the launch clutch reduces the time delay between brake pedal release and vehicle acceleration. To avoid excessive drag on the engine during the restart event, the torque capacity is adjusted using closed loop control. A controller calculates a maximum rate of change of torque capacity based on measured engine speed and an engine acceleration and does not increase the commanded torque capacity faster than the calculated rate. In some circumstances the maximum rate of change may be negative, resulting in a reduction in commanded torque capacity.

Abstract: A shift mistake detection apparatus detects an operation value of an accelerator pedal in a vehicle and a shift range selected by a shift operation of a driver of the vehicle (e.g. reverse, drive, park). The apparatus detects a shift mistake operation when (i) the shift range selected by the shift operation is in a reverse range and the vehicle begins to travel in reverse according to an operation of the accelerator pedal, and (ii) a steep step operation and a steep return operation of the accelerator pedal is detected. The steep step and return operations of the accelerator pedal have an operation value that is greater than or equal to a normal operation value, where the normal operation value may be a value detected when a driver of a vehicle intentionally travels in reverse (i.e., there is no shift mistake).

Abstract: A method for control of a gearbox, installed in a motor vehicle (1): The method effects a downshift of the gearbox (20) from a first gear (G1), for which the acceleration ? of the vehicle (1) is negative, to a second gear (G2), for which the acceleration ? is positive or substantially equal to nil. The downshift involves at least one intermediate gear step between the first gear (G1) and the second gear (G2), using an engine speed ?G1 in the first gear (G1) as an input parameter when effecting the downshift. Also a system, a motor vehicle, a computer program and a computer program product for performing the method are disclosed.

Abstract: A method for control of a gearbox (20) installed in a motor vehicle (1), which method effects a downshift of the gearbox (20) from a first gear (G1), for which the acceleration a of said vehicle (1) is negative, to a second gear (G2), for which the acceleration a is positive or substantially equal to nil, which downshift involves at least one intermediate gear step between the first gear (G1) and second gear (G2). An engine speed for changing gear at an intermediate gear step is higher than an engine speed for changing gear at a preceding intermediate gear step. Also a system, a motor vehicle, a computer program and a computer program product for performing the method are disclosed.

Abstract: A method and a HAC system controls a hill-state assist control (HAC) operation when restarting an engine of the vehicle having an idle stop and go (ISG) system for an automatic transmission. The method includes starting restarting of the engine by the ISG system and an HAC operation, monitoring the RPM of the engine, and releasing the HAC operation in a case where the RPM of the engine meets an HAC release condition, and maintaining the HAC operation until the HAC release condition is met in a case where the RPM of the engine does not meet the HAC release condition.

Abstract: A system and method for controlling a powertrain of a vehicle having an engine configured to output a variable torque, can include a transmission with a plurality of gear ratios and selectively driven by the variable torque, and a pair of wheels selectively driven by the transmission. The system can include a longitudinal acceleration sensor and a controller. The controller can be in electrical communication with the longitudinal acceleration sensor. The controller can be configured to determine an inertial value of the vehicle based on data from the longitudinal acceleration sensor prior to a shift from one of the plurality of gear ratios to another of the plurality of gear ratios.

Abstract: A system for control of one or more gearshift points, including at least one control unit for controlling a gearbox in a motor vehicle. The engine is connected to, in order to drive, the gearbox, wherein the speed of the engine is controlled by an accelerator pedal which is connected to the engine and gearbox and can assume a plurality of positions. A shift point is controlled by the accelerator pedal and represents an engine speed at which the gearbox effects a downshift or upshift. The system operates in a first mode in which the one or more shift points are controlled on the basis of movements of the accelerator pedal, and also applies a limitation upon the change in the one or more shift points per unit time. Also a method, a motor vehicle, a computer program and a computer program product for the system are disclosed.

Abstract: A vehicular powertrain includes an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine. A method for operating the powertrain includes monitoring operator inputs, monitoring a transmission output, and terminating an engine operating mode when a time-rate change in the transmission output exceeds a threshold absent a change in the monitored operator inputs.

Abstract: A control apparatus of a transmission for a vehicle, which includes an electric generator provided between an engine and the transmission and regenerating electricity when torque is transmitted from a drive shaft of the vehicle via the transmission in a braking condition, includes a releasing speed measuring unit, an up-shifting operation allowing unit and an up-shifting operation restraining unit. The releasing speed measuring unit measures a releasing speed of an accelerator pedal. The up-shifting operation allowing unit is applied to allow an up-shifting operation under the accelerator pedal being released when a releasing speed of the accelerator pedal is lower than a first threshold value. The up-shifting operation restraining unit is applied to restrain the up-shifting operation under the accelerator pedal being released when the releasing speed of the accelerator pedal is equal to or lower than the first threshold value.

Abstract: A method for operating the powertrain includes monitoring operator inputs, monitoring a transmission output, and terminating an engine operating mode when a time-rate change in the transmission output exceeds a threshold absent a change in the monitored operator inputs.

Abstract: A vehicle control system for regulating operation of a vehicle having a transmission includes a first module that processes an output shaft signal which is based on rotation of an output shaft of the transmission through a third order Kalman filter to determine an acceleration of the output shaft A second module calculates the acceleration of the vehicle based on the acceleration of said output shaft. A third module regulates operation of the vehicle based on the acceleration of the vehicle.

Abstract: Methods and apparatus for control of a transmission are described, including provision of a shift initiation signal to the transmission when the engine speed attains an initiation point engine speed, the initiation point engine speed being adjustable as a function of a rate of change of engine speed so as to reduce engine speed variability at shift endpoints.

Abstract: A creep control device for a vehicle having an automatic transmission including a torque converter with a lock-up clutch. The creep control device includes a throttle angle sensor for detecting a throttle angle, a vehicle speed sensor for detecting a running speed of the vehicle, a slope sensor for detecting a road surface slope, and a lock-up clutch engagement control unit for controlling the degree of engagement of the lock-up clutch. When the throttle angle is detected to be nearly zero by the throttle angle sensor and the running speed is detected to be vary small or zero by the vehicle speed sensor in the condition where the shift position is in a running range, the degree of engagement of the lock-up clutch is controlled to decrease with an increase in the road surface slope by the lock-up clutch control unit.

Abstract: A method is disclosed for optimizing the gear-shifting sequence in a step-variable transmission fitted in a motor vehicle, in particular in an automated shift transmission, which has a plurality of gears, which can be engaged and disengaged by means of respective clutches, the method comprising the following steps: registering at least one of a tolerance-dependent and a wear-dependent parameter of a clutch of the step-variable transmission; and adjustment of a set-point displacement value of a gear-shifting member of the clutch, which corresponds to the parameter and which is approached in the course of a gear shift, as a function of the value of the parameter registered.

Abstract: A motor vehicle driveline that can transmit power in a 4×4 mode includes two front wheels, a rear drive shaft, a differential mechanism for transmitting power to two rear axle shafts connected driveably through the differential to the rear driveshaft, and a clutch for engaging and disengaging a drive connection in the differential mechanism. A method for controlling operation of the clutch includes the steps of operating the driveline in 4×4 mode, determining a current accelerator pedal position, determining whether a current accelerator pedal position is less than a reference position for a predetermined period, determining a current speed of each front wheel of the vehicle, determining whether a current speed difference between the front wheels of the vehicle is less than a reference wheel slip for a first predetermined period, determining during a second predetermined period whether a current time rate of speed change of the rear drive shaft is less than a reference rear wheel slip.

Abstract: An automatic transmission control device of a vehicle performs a gear change operation based on a deceleration of the vehicle. The automatic transmission control device detects the deceleration of the vehicle and an engine rotational speed. The device also stores a peak value of the engine rotation speed during a period in which a vehicle travels with one predetermined gear step, and includes a relationship map showing the relationship between the deceleration and a shift-down rotational speed. The device performs an automatic shift-down when the engine rotational speed is lowered from the peak value by a predetermined rotational speed which is obtained from the map based on the deceleration.

Abstract: In a motor vehicle including a power source, an accelerator pedal, a powershift transmission for producing a selected gear, first and second input shafts, a first input clutch for connecting the selected gear and the first input shaft to the power source, a second input clutch for connecting an alternate gear and the second input shaft to the power source, a method for controlling the transmission while the vehicle is coasting. Displacement of the accelerator pedal is monitored to identify a tip-out and a tip-in, and clutch slip is monitored. The first clutch is maintained in a stroked state following a tip-out and while clutch slip is less than a reference magnitude of clutch slip. When clutch slip exceeds the reference magnitude, the torque capacity of the first clutch is controlled in response to a driver demand torque. Engine torque is used to control clutch slip to the desired clutch slip and to produce a desired engine speed corresponding to the desired clutch slip.

Abstract: A power-on 2-3 upshift control method for an automatic transmission comprises: determining whether a power-on 2-3 upshift condition exists; extracting an initial hydraulic pressure control duty and hydraulic pressure control duty depending on an input torque from a map table for an on-coming friction element and an off-going friction element, if it is determined that the power-on 2-3 upshift condition exists, and performing a shift control for the upshift; and completely releasing a hydraulic pressure of the off-going friction element at a point at which a hydraulic pressure for the on-coming friction element is capable of tolerating a turbine torque.

Abstract: An electric machine coupled to an internal combustion engine in a motor vehicle, a control unit being provided for specifying an optimal efficiency operating state or for specifying a dynamically optimal operating state for the electric machine. Switchover means are used for switching over the usually specified optimal efficiency operating state to the dynamically optimal operating state before operating procedures in the motor vehicle which require a rapid torque setting.

Abstract: A method for controlling an engine coupled to a transmission is described. The method is especially suited for a transmission having at least one gear in which an over-running clutch is present. The invention describes a method for adjusting an engine operating parameter to maintain transmission input speed at or below a synchronous transmission input speed when the transmission is in the gear with the over-running clutch. The synchronous transmission input speed is based on transmission state and transmission output speed. Alternatively, vehicle speed can be used in place of transmission output speed.

Abstract: A control apparatus and method for a vehicle including a stepped automatic transmission and a shift control device which controls an operation of the automatic transmission based on a vehicle state such as a value corresponding to a driving force required for the vehicle, according to a pre-stored shift pattern having a shift line for determining whether shifting is performed from one shift speed to an adjacent shift speed.

Abstract: The invention relates to a method for carrying out gear shifting in a twin-clutch gearbox comprising at least two gearbox input shafts which are respectively coupled to the engine by means of a clutch. According to the invention, after recognizing a desire to change gear, the clutch associated with the active torque transmitting gearbox input shaft is opened until the slip limit is reached and the engine torque is controlled according to the type of shifting in order to achieve the vehicle acceleration desired by the driver.

Abstract: A method for controlling an engine coupled to a transmission is described. The method is especially suited for a transmission having at least one gear in which an over-running clutch is present. The invention describes a method for adjusting an engine operating parameter to maintain transmission input speed at or below a synchronous transmission input speed when the transmission is in the gear with the over-running clutch. The synchronous transmission input speed is based on transmission state and transmission output speed. Alternatively, vehicle speed can be used in place of transmission output speed.

Abstract: A shift control apparatus of a transmission for a vehicle having an input shaft driven by an engine and an output shaft connecting with a drive wheel for automatically changing a speed ratio between the input shaft and the output shaft, comprises accelerator pedal operating amount detecting means for detecting an operating amount of an accelerator pedal, road gradient detecting means for detecting a gradient of a road on which the vehicle travels, vehicle speed detecting means for detecting a vehicle speed, kick-down mode establishing means for establishing a kick-down mode when the operating amount of the accelerator pedal exceeds a threshold value and control means for changing the threshold value based on the road gradient and the vehicle speed.

Abstract: A transmission control apparatus includes transmission lines disposed between a pair of transmission shafts and a hydraulic multiple disc transmission clutch disposed on one side of the transmission lines. Power from an engine is transmitted via one of the transmission lines to a traveling unit. Each of the transmission lines has a friction clutch. A first gear mechanism operated by a first actuator is disposed between one of the transmission shafts and the first transmission line. A second gear mechanism operated by a second actuator is disposed between one of the transmission shafts and the second transmission line. When the first transmission line is powered, a first system operates the second gear mechanism into a speed position; the first clutch to a non-transmitting state and the second clutch to a transmitting state, thereby providing a progressive shifting of the transmission clutch from a transmitting state to a semi-transmitting state.

Abstract: In a method for controlling a drive unit, a driver command value is formed while considering the current transmission ratio and the drive unit is controlled in dependence upon the driver command value. In addition, a predicted driver command value is determined in dependence upon transmission ratios other than the current transmission ratio. In addition, the minimum and maximum possible values are considered in the formation of the driver command value. A correction of the driver command value is undertaken in dependence upon the difference between minimum possible torque and minimum requested torque or between maximum possible torque and maximum requested torque.

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: A control device for an automatic transmission has a torque transmission provided between an input shaft and an output shaft of a gear-type transmission The torque transmission in at least one change gear stage is a friction clutch. When performing a change gear from one change gear stage to another change gear stage, the friction clutch is controlled. A transfer torque capacity detector detects or computes transfer torque of the friction clutch when performing a change gear to a predetermined change gear stage, and a clutch release timing determining apparatus determines a timing when releasing the claw-type clutch into a neutral state based on the value detected or computed by the torque capacity detector.

Abstract: A drive-force distribution controller for a four-wheel-drive vehicle in which drive force produced by an engine is transmitted directly to front or rear wheels and is transmitted to the remaining wheels via a torque distribution clutch, and the engagement force of the torque distribution clutch is controlled in accordance with traveling conditions of the vehicle. The controller includes a calculation unit for calculating variation per unit time in rotational speed difference between the front wheels and the rear wheels; and a control unit for controlling the engagement force such that the engagement force increases as the variation per unit time in the rotational speed difference increases.

Abstract: A controller (80) calculates a target speed ratio of a continuously variable transmission (2) incorporated into an infinitely variable transmission for a vehicle and a target vehicle acceleration based on a vehicle running state. When a predetermined creep torque control condition holds (S90-S93, S101), the controller (80) corrects the target speed ratio such that the deviation of the target acceleration from the real vehicle acceleration to decrease. By controlling the speed ratio of the continuously variable transmission to the corrected target speed ratio, the infinitely variable transmission generates a creep torque consistent with the driver's intention.

Abstract: An automatic shift-down apparatus for an automatic transmission which comprises vehicle speed detection device for detecting the speed of a vehicle; vehicle-speed variation rate calculation device for calculating the variation rate of the detected vehicle speed; shift-start vehicle speed calculation device for calculating, on the basis of the calculated vehicle-speed variation rate and a time required to complete a shift operation, a shift-start vehicle speed which enables the shift operation to finish before the vehicle speed attains a shift-completion speed; and a shift device which starts a shift operation when the detected vehicle speed attains the calculated shift-start vehicle speed.

Abstract: A method is proposed for the control and regulation of a drive system of a motor vehicle having one electronic transmission control for an automatic transmission and connected therewith an electronic engine control for a prime mover. In a coasting operation of the drive system, during a change over of a transmission element from an open to a closed or a slipping state during a coupling procedure of the transmission or a regulation procedure of the transmission element, rotatory masses of the engine are regulated and accelerated under control so that a vehicle deceleration is less than a presettable tolerance value.

Abstract: The invention concerns a process for evaluating a driving dynamic request of a driver for the driving strategy of one of an automatic or automated transmission of a motor vehicle. It is proposed to calculate an accelerator pedal stroke, from the accelerator pedal actuation, which is supplied to the driving strategy as an input parameter to the driving strategy equivalent to the driving dynamic request. To this end, a rough value of the accelerator pedal stroke is calculated, especially by subtraction of the accelerator pedal position at beginning of the accelerator pedal movement from the accelerator pedal position, from accelerator pedal values which are in fixed event-dependent ratio to each other. The accelerator pedal stroke results from an event-dependent filtering of the rough value of the accelerator pedal stroke during which a filtering function starts at the end of the accelerator pedal movement, especially when the accelerator pedal position is constant over a presettable time.

Abstract: A method for influencing the driving dynamics of a motor vehicle wherein the vehicle speed and the transverse acceleration are feed as input signals to a regulating and control unit in which an actuation signal is produced when a limiting value of a variable which determines the driving condition is exceeded. When a limiting value of the vehicle speed and/or the transverse acceleration is exceeded, throttle-valve actuating signals for limiting the throttle-valve position are provided and when a determined change in the transverse acceleration over time exceeds a limiting value, a clutch actuating signal is produced for opening the clutch.

Abstract: A control apparatus and a control method for an automatic transmission, minimizes torque fluctuations which, if left unchecked, give vehicle passengers a disagreeable feeling upon a gear shift. The control apparatus and method suppresses, such torque fluctuations during a shift of the transmission to improve robustness and provide good shift characteristics. An inertia phase is recognized in which the engine speed starts to drop during the shift. At the beginning of the inertia phase, hydraulic pressures supplied to frictional engaging devices in the transmission are kept constant to suppress the torque fluctuations.

Abstract: In a process for control of an automatic transmission (3) in a vehicle, it is proposed to set an electronic transmission control (4) for a driving state low friction value when slip is detected on the input gears of the vehicle or an ACS deceleration is detected. In an ACS deceleration a meter is determined, via an ACS evaluation function, from the actual acceleration of the vehicle or a parameter (e.g., gear speed increase) corresponding to the actual acceleration. When slip occurs, a meter is determined, via a slip evaluation function, from the theoretical/actual comparison of the vehicle acceleration or a parameter (e.g., torque reserve) corresponding to said comparison. In both an ACS deceleration or when a slip occurs, a winter operation mode is then activated when the meter count exceeds a limit value.

Abstract: A control system/method to minimize unwanted multiple upshifts in an automated mechanical transmission system (12). After a full-throttle upshift (54A), the engine speeds at which upshifts are commanded are increased from a default value (54) to a modified value (72) until the occurrence of a reset event.

Abstract: A down-shift is carried out when a) the sum of a dry force of a vehicle and a predetermined value, is smaller than a running resistance, and b) when an accelerator opening is larger than a threshold value which is based on vehicle speed, road inclination, and speed change step (gear position).

Abstract: An engine-transmission drivetrain includes a torque converter situated between the engine output shaft and the transmission. The torque converter includes a lock-up clutch. A speed sensor, which measures the rotational speed of an output shaft of the transmission, generates a pulse signal. A transmission controller includes a deceleration dependent lock-up release command generator and a torque converter speed dependent lock-up release command generator. The pulse signal from the speed sensor is used as inputs to both of the lock-up release generators. In the deceleration dependent lock-up release command generator, the pulse signal is processed to derive information as to the magnitude of deceleration which the transmission output shaft is subject to. In the torque converter speed dependent lock-up release generator, the pulse signal is processed to derive information as to rotational speed of an output element of the torque converter.

Abstract: Apparatus for estimating a drive mode of a motor vehicle desired by an operator of the motor vehicle, including a variable calculating device and a drive mode estimating device, wherein the variable calculating device calculates at least one of drive mode indicating variables such as a drive force of the vehicle desired by the operator upon starting of the vehicle, a maximum rate of increase of the drive force, a maximum deceleration of the vehicle upon operation of a manually operated member for brake application to the vehicle, a coasting run time of the vehicle and a steady run time of the vehicle, and wherein the drive mode estimating device includes a neural network which receives the drive mode indicating variable or variables calculated by the variable calculating device, so that the drive mode estimating device estimates the drive mode of the motor vehicle desired by the operator on the basis of an output of the neural network.

Abstract: A method of controlling the idle speed of an internal combustion engine of a vehicle from a first idle speed to a second idle speed that is higher than the first idle speed in response to a driver originating indication that is independent of the acceleration control of the vehicle. The higher second idle speed is set to achieve a desired level of vehicle creep. When the driver originating indication indicates that vehicle motion is no longer desired, the engine idle speed is returned to the first lower idle speed. The change between the first lower idle speed and the second higher idle speed can be accomplished in a stepping or ramping fashion. In addition, the first and second idle speeds are adjusted in response to changes in engine operating parameters such as engine coolant temperature, changes in engine load, and vehicle speed.

Abstract: Engine speed control during garage shift maneuvers of a transmission coupled, via a transmission input shaft, to a driven turbine of a hydrodynamic converter, the driven turbine fluidically coupled to a driving pump of the converter, the pump coupled to an engine output shaft, wherein engine output torque is controlled in response to a deviation in turbine acceleration away from a target turbine acceleration, to minimize rate of change in turbine acceleration (jerk) during the garage shift maneuver, so as to reject engine torque load changes that may result in undesirable engine speed variation.

Abstract: A driving-torque control system for a four-wheel-drive vehicle includes a transfer clutch employed in a transfer of the four-wheel-drive vehicle for varying a distribution ratio of driving torque between front and rear road wheels depending on a front-and-rear wheel revolution-speed difference. A calculation unit derives a command value of the engaging force of the transfer clutch from the front-and-rear wheel revolution-speed difference. A load-condition detection unit detects an input load condition of the transfer clutch, on the basis of the front-and-rear wheel revolution-speed difference and the command value of the engaging force. A comparing unit compares the input load condition detected by the load-condition detection unit with a predetermined threshold. A compensation unit compensates the engaging force of the transfer clutch so that the transfer clutch is held in a completely engaged state for a predetermined holding time duration, when the input load condition exceeds the predetermined threshold.

Abstract: A shift control apparatus for controlling a speed ratio of an automatic transmission of a motor vehicle having an engine during running of the vehicle on a downhill road, on the basis of an actual acceleration value of the vehicle as compared with a reference acceleration value of the vehicle, the apparatus including a device for determining reduction of an actual output of the engine with respect to a desired output of the engine as represented by an operating amount of an accelerator pedal, and a device for reducing the reference acceleration value by a compensating amount which decreases with an increase in the running speed of the vehicle, upon determination of the reduction of the actual output of the engine.

Abstract: A method and apparatus for controlling a continuously variable transmission having an input and output shaft for use with an automotive vehicle. The transmission is operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft. A target value for the speed of rotation of the input shaft of the transmission is calculated based on the sensed vehicle operating conditions including vehicle acceleration (deceleration). A correction factor per predetermined unit time is calculated based on the vehicle acceleration (deceleration) when the vehicle acceleration (deceleration) exceeds a threshold value with the accelerator pedal being released. The correction factor is used to correct the target input shaft speed value at intervals of the predetermined unit time. The speed ratio is controlled to bring the input shaft speed into coincidence with the corrected target value.

Abstract: In a motor vehicle having an electronically controlled automatic transmission, a method of inhibiting upshifts determines torque and acceleration parameters of the output shaft of the transmission prior to and after a shift. An estimate of the output shaft moment of inertia is determined from the pre and post shift quantities and used in the inhibition of upshifts having inadequate torque capacity.

Abstract: In order to prevent an increase in engine noise during a kick-down, a timer is set concurrently with a downshifting. When the throttle opening degree becomes equal to or larger than a threshold value YTHNST by a rapid depression of an accelerator pedal before lapse of a predetermined time, a lock-up clutch of a torque converter is brought into an engaged state, thereby preventing a revolution speed of an engine from rising rapidly in order to alleviate the engine noise. After the throttle opening degree TH becomes smaller than the threshold value YTHNST and the engagement of the lock-up clutch is released, the lock-up clutch is not brought into the engaged state even if the throttle opening degree TH again becomes equal to or larger than the threshold value YTHNST. Also, when the throttle opening degree TH becomes equal to or larger than the threshold value YTHNST after lapse of the predetermined time, the lock-up clutch is not brought into the engaged state.

Abstract: The toroidal continuous variable transmission limits the amount of change of the target transmission ratio while at the same time taking advantage of the excellent speed change responsiveness to perform acceleration and deceleration of a vehicle in a way the driver expects. The toroidal continuous variable transmission checks if the difference .DELTA.e between the present target transmission ratio and the previous target transmission ratio, which were calculated based on car speed information, is larger than the predetermined maximum value .DELTA.e.sub.max. When the absolute value of .DELTA.e is greater than the maximum value, a target transmission ratio e.sub.cn limited by the maximum value is determined. For this corrected target transmission ratio, a control signal Ve is calculated according to the map stored beforehand in the controller. According to the control signal Ve, the tilt angles of the power rollers in the toroidal speed change unit are changed.

Abstract: A method and apparatus for controlling a continuously variable transmission having an input and output shaft for use with an automotive vehicle. The transmission is operable at a variable speed ratio for transmitting a drive from the input shaft to the output shaft. A target value for the speed of rotation of the input shaft of the transmission is calculated based on the sensed vehicle operating conditions including vehicle acceleration (deceleration). A correction factor per predetermined unit time is calculated based on the vehicle acceleration (deceleration) when the vehicle acceleration (deceleration) exceeds a threshold value with the accelerator pedal being released. The correction factor is used to correct the target input shaft speed value at intervals of the predetermined unit time. The speed ratio is controlled to bring the input shaft speed into coincidence with the corrected target value.