Abstract: A system and method of dithering speed and/or torque for shifting a transmission of a vehicle having an engine, a reversible, variable displacement hydraulic motor/pump which can be driven by the engine, a hydraulic accumulator supplied by said motor/pump, and at least one reversible hydraulic driving motor for propelling the vehicle supplied with fluid by the hydraulic accumulator and/or by said motor/pump operating as a pump. A transmission unit connects the engine with the variable displacement hydraulic motor/pump during a first mode of operation (city mode) and connects the engine to a vehicle drive wheel during a second mode of operation. The system utilizes stored hydraulic energy to dither the output of the driving motor in order to achieve quick and smooth shifts between city and highway mode, or between various ranges within the city mode.

Abstract: The transmission controller changes the gear position of the subtransmission mechanism and varies the speed ratio of the variator in an opposite direction to a speed ratio variation direction of the subtransmission mechanism when the actual through speed ratio passes a predetermined mode switch line. When the improvement in the shift response of the continuously variable transmission is determined to be required and the actual through speed ratio passes the mode switch line from a Low side to the High side, the transmission controller increases a shift speed of the subtransmission mechanism compared with a normal coordinated shift.

Abstract: A belt continuously-variable transmission control apparatus includes: a belt continuously-variable transmission including; a primary pulley arranged to receive a torque from a driving source; a secondary pulley arranged to output the torque to driving wheels; a belt wound around the primary pulley and the secondary pulley; a hydraulic pressure control section configured to control a hydraulic pressure of one of the primary pulley and the secondary pulley which is a capacity side, and thereby to bring the belt, the primary pulley and the secondary pulley to a slip state; and a torque control section configured to control the torque of the driving source, and thereby to bring the slip state to a predetermined slip state.

Abstract: A hydraulic control system of continuously variable transmission includes: a first sheave pressure regulating valve (17) that regulates a line pressure (Pl), which is used for hydraulic control as a source pressure, to obtain a first sheave pressure (Pin); a fail-safe valve (19) that selects and outputs any one of the first sheave pressure (Pin) or a fail-safe hydraulic pressure (second sheave pressure Pout) that is applied to a drive pulley (21) at the time of a failure due to an excessive first sheave pressure (Pin) to the drive pulley (21); and a first regulator valve (12) and a second regulator valve (13) that regulate the line pressure (Pl). An output pressure (Psf) of the fail-safe valve (19) is supplied to the first and second regulator valves (12 and 13) in a feedback manner as a drive pulley (21) side hydraulic pressure to thereby regulate the line pressure (Pl).

Abstract: The transmission controller performs a non-coordinated shift, in which the gear position of the subtransmission mechanism is modified from the second gear position to the first gear position at a higher speed than when the gear position of the subtransmission mechanism is modified by a coordinated shift while permitting a deviation between the through speed ratio and the target through speed ratio, instead of the coordinated shift when it is determined that the second speed kick down shift is to be performed.

Abstract: Methods and systems for managing acceleration of a motor vehicle having an automatic transmission by controlling transmission turbine acceleration are provided. A desired transmission turbine acceleration is determined based on vehicle speed, turbine speed, and other information obtained from the vehicle transmission. One or more torque limits are determined as a function of the turbine acceleration. The torque limits are applied to manage acceleration of the vehicle.

Abstract: A control device for an automatic transmission is disclosed wherein a shift point depending on a variation in vehicle acceleration is modified on a real time basis in accordance with not only a corrected result on a shift point depending on piece-to-piece variations of automatic transmissions, but also actual acceleration for shortening a time required for learning with high precision with no need to be matched. Shift point real-time modifying means is provided for modifying the altered shift point based on a value of a ratio between a value of actual engine-rotation acceleration at an upshift-determining timing during a power-on running and a value of reference engine-rotation acceleration obtained by substituting a value of actual engine-rotation acceleration to a value for a reference running state having no impact on acceleration of a vehicle, and a target maximum engine rotation speed.

Abstract: A shift controller for an automatic transmission mechanism is configured such that when the engine is in a driven state in which the engine is driven by a travel inertia force or the like and an accumulated pressure amount of the accumulator is equal to or less than a predetermined threshold, the excessive engine brake force, which is generated due to the accumulation of at least a portion of the hydraulic pressure generated from the mechanical hydraulic pump in the accumulator, is inhibited or reduced by conducting upshifting that relatively decreases the gear ratio of the automatic transmission mechanism. Therefore, the generation of the excessive engine brake force can be inhibited or reduced even when the engine is in the driven state and pressure accumulation is performed.

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: Provided is control device and method for a belt type continuously variable transmission which can reduce drive energy consumption by a decrease in belt friction when the estimated accuracy of belt slip condition is high and which can prevent the belt from greatly slipping during belt slip control when the estimated accuracy of belt slip condition is low. The device includes a primary pulley (42), a secondary pulley (43), and a belt (44) and controls gear ratio based on the running radius of the belt (44) on the pulley by controlling the primary oil pressure and the secondary oil pressure.

Abstract: A control device and a control method for a belt type-continuously variable transmission capable of preventing a belt slip from occurring by restricting that an input torque to the belt type-continuously variable transmission is excessive relative to a belt clamp force when returning from a belt slip control to a normal control are provided are provided. The control device includes a primary pulley (42), a secondary pulley (43), and a belt (44) and is configured to control a variable speed ratio determined by a running radius ratio of the belt (44) on the pulleys by controlling a primary hydraulic pressure and a secondary hydraulic pressure.

Abstract: When a through speed ratio, which is an overall speed ratio of a variator and a subtransmission mechanism, varies from a larger speed ratio than a mode switch speed ratio to a smaller speed ratio than the mode switch speed ratio, a gear position of the subtransmission mechanism is changed from a first gear position to a second gear position and the speed ratio of the variator is modified to a large speed ratio side. The mode switch speed ratio is set midway between a low speed mode Highest speed ratio and a high speed mode Lowest speed ratio.

Abstract: An oil pump driven by an engine generates a hydraulic pressure supplied to a frictional engagement element. An accumulator provided at an intermediate position of an oil path supplies the hydraulic pressure generated by the oil pump to the frictional engagement element. A controller stops the engine after a hydraulic pressure reducing condition to reduce the hydraulic pressure supplied to the frictional engagement element holds and the hydraulic pressure supplied to the frictional engagement element is reduced.

Abstract: In a shift control device for an automatic transmission according to this invention, when the engine load increases such that a kickdown is required, and a gear position calculated in accordance with the shift map from an operating condition defined by a look-ahead vehicle speed at a predetermined future time is lower than a current gear position and the look-ahead vehicle speed is higher than a predetermined vehicle speed, control is performed to shift to a higher gear position than the target gear position.

Abstract: The line hydraulic pressure setting portion sets the line hydraulic pressure PL, which is the base pressure for the required shift control pressure Pin and the required belt clamping pressure Pd, based on the higher of the required pressures Pin and Pd. At this time, if the continuously variable transmission is to be shifted up, the required Pin calculating portion calculates the required shift control pressure Pin based on one of the target speed ratio ?* and the actual speed ratio ? with which the required shift pressure Pv is calculated to be higher than with the other. As such, the required shift control pressure Pin is set to the minimum necessary level for shifting up the continuously variable transmission and the line hydraulic pressure PL is appropriately set to a level for obtaining the required shift control pressure Pin.

Abstract: A vehicle drive control device includes a continuously variable transmission mechanism (hereinafter referred to as CVT (6) of a torque control type capable of continuously varying a transmission gear ratio, and a controller (34) which controls operations of the CVT (6) and an engine (2). The controller (34) includes a first control section (43; 43A) which controls a torque of the CVT (6) based on a target transmission input torque (TTRN,T), and a second control section (44) which controls a torque of the engine (2) based on a target engine rotation speed (?e,T).

Abstract: A transmission includes a gear ratio change mechanism, a driving circuit and an electronic control unit (ECU). The gear ratio change mechanism has a motor for continuously varying the gear ratio. The driving circuit applies a pulse voltage to the motor. The ECU outputs a control signal to the driving circuit. The duty ratio and/or the pulse height of the pulse voltage is changed according to the control signal. The ECU performs a low-pass filtering process on the control signal to output the low-pass filtered control signal to the driving circuit. Gear ratio change shocks are thereby suppressed.

Abstract: A straddle-type vehicle in which drivability is ensured when starting the vehicle. The vehicle includes a control device that controls a continuously variable transmission. A plurality of driving modes “A” and “B” are set in the control device. The control device performs a first control that switches the driving mode to driving mode “A” before start of the engine; a second control that switches between driving modes A” and “B” in response to operation of a mode switching operation member; and a third control that limits the second control and inhibits switching from the driving mode “A” to driving mode “B”, when the control device detects that the engine has not been started.

Abstract: An apparatus and method for controlling a CVT (continuously variable transmission), and a program for executing the control method that reduces a transmission shock during a braking operation. When a foot brake switch is turned on and a vehicle speed is less than or equal to a threshold speed, the ECU increases a clamping pressure applied to a transmission belt to a pressure level higher than a normal pressure. When the vehicle speed falls to or below the threshold speed when the foot brake switch is turned on, the ECU prohibits an increase in the clamping pressure applied to the transmission belt.

Abstract: A hydraulic control system for a vehicular drive system including a hydraulically operated belt-and-pulley type continuously variable transmission and a hydraulically operated frictional coupling device engaged for running of a vehicle, the hydraulic control system including: a first solenoid valve for regulating a belt-tensioning hydraulic pressure for tensioning a belt of the transmission, a second solenoid valve for regulating a transient coupling hydraulic pressure to be applied to the frictional coupling device in the process of an engaging action, a line-pressure regulating valve for regulating a line pressure used for hydraulically operated devices of the mechanism, and a hydraulic-circuit switching device operable to apply a control pressure of the second solenoid-operated valve to the line-pressure regulating valve after the frictional coupling device has been placed in a fully engaged state, and to apply a first control pressure of the first solenoid-operated valve to the line-pressure regulating va

Abstract: A method of controlling an automated step-down transmission, arranged in a drivetrain between an engine and a drive axle, which includes a multi-stage main transmission and a range group. The main transmission has an intermediate transmission style with a countershaft having a transmission brake and an input shaft connected, via a clutch, to the engine. The main transmission shifts, without being synchronized, and the range group shifts, after synchronization, such that the engaged gear ratio of the main transmission remains engaged during a range shift operation. The range shift is accomplished by firstly reducing drive engine torque; secondly, disengaging the existing gear ratio of the range group; thirdly, remotely synchronizing the target gear ratio in the range group; fourthly, engaging the target gear ratio in the range group; and fifthly, increasing the drive engine torque.

Abstract: Systems and methods for efficiently and effectively controlling the rate of change of ratio, not simply the ratio, in a CVT. By controlling the rate of change of ratio, the acceleration or deceleration of a vehicle can be controlled in an efficient manner. Furthermore, the rate of change of ratio can be controlled by controlling the clamping pressure of the pulleys and/or differential pressure between the pulleys with minimal slip by using a servo control mechanism adapted for control by a system controller based on equilibrium mapping and other control parameters.

Abstract: A control system for controlling a belt-type continuously variable transmission having a pulley capable of varying its groove width to which a belt is applied, in which the pulley is provided with an oil chamber to which the oil pressure is fed so that the pulley clamps the belt, in which the capacity of the oil chamber is varied in accordance with a change in the groove width, and in which the oil pressure in the oil chamber is controlled in accordance with a deviation between a target oil pressure and an actual oil pressure, comprising: a pressure-receiving capacity change detecting device for detecting a change in the capacity of the oil chamber; and an oil pressure control contents altering device for altering a degree to reflect the deviation on the oil pressure control of the oil chamber on the basis of a change in the capacity.

Abstract: In a speed ratio control device for a belt continuously variable transmission according to this invention, when a speed ratio is subjected to feedback control on the basis of a difference between an actual speed ratio and a target speed ratio, pressure supplied to a primary pulley is corrected through feedforward (S17, S18) in order to suppress variation in the groove width of the primary pulley caused by a rapid variation in an input torque into the primary pulley (S17) while traveling in a fixed speed ratio mode (S14) in which the target speed ratio is held at a fixed value.

Abstract: In the case where a belt return of a continuously variable transmission is not determined when the vehicle speed has become equal to or lower than a threshold value, control that causes a hydraulic actuator to have an intermediate pressure by setting a duty of a duty solenoid based on an input torque and an oil temperature and closing control are repeatedly performed, in accordance with the running and the stopping of the vehicle. As a result, it is possible to inhibit the continuously variable transmission from being shifted up due to a gradual increase in the hydraulic pressure in the hydraulic actuator caused by a line pressure seeping to the hydraulic actuator side through a small clearance in a spool of a flow rate control valve in a hydraulic circuit, and it is also possible to allow the continuously variable transmission to be shifted down.

Abstract: A variator torque control system and method utilize a hydraulic actuator to control the variator output via a torque control map, wherein the values of the torque control map are evaluated and modified during use of the map to improve map accuracy. In an example, errors in the map are evaluated to determine whether a system fault has occurred.

Abstract: A method of operating a clutch during vehicle launch including increasing a first hydraulic pressure in an inner chamber from a first to a second level; decreasing a second hydraulic pressure in an outer chamber from a third to a fourth level in response to engine speed and throttle position for the vehicle; and slipping the clutch in response to increasing and decreasing the first and second pressures, respectively. The first hydraulic pressure urges a clutch disposed between the engine and an impeller for a vehicle torque converter to an engaged position. The second hydraulic pressure opposes the first hydraulic pressure. In some aspects, the method includes determining a temperature for oil in a transmission in the vehicle. Then, decreasing the second hydraulic pressure includes decreasing the second pressure in response to the determined temperature. In some aspects, the clutch and the chambers are located in the torque converter.

Abstract: An ECU executes a program that includes the steps of i) calculating a sporty running counting SC based on a state of a vehicle according to an operation of a driver; ii) changing a condition for executing sporty running in which an upshift is inhibited when an accelerator is suddenly released and in which a downshift is promoted during sudden braking such that the condition is easier to satisfy and changing a condition for returning from sporty running so that it is more difficult to satisfy when the sporty running count SC is equal to or greater than a threshold value; and iii) changing the condition for executing sporty running so that it is more difficult to satisfy and changing the condition for returning from sporty running so that it is easier to satisfy when the sporty running count SC is not equal to or greater than the threshold value.

Abstract: A speed ratio change control device for a belt type continuously variable transmission calculates a maximum thrust that can be generated by the primary pulley on the basis of an upper limit value of the line pressure, calculates an upper limit value of a shift speed on the basis of the maximum thrust, and sets the target speed ratio on the basis of the upper limit value of the shift speed.

Abstract: A speed change control device carries out speed change control of a stepless speed change mechanism in accordance with the vehicle speed. The speed change control device includes: first vehicle speed selection means for comparing a first vehicle speed obtained from the rotation speed of an output member 26 of the stepless speed change mechanism and a second vehicle speed obtained from the rotation speed of the wheels and for selecting the lower of the first and second vehicle speeds as the substitute vehicle speed; and second vehicle speed selection means for comparing the third vehicle speed obtained from the output side rotation speed of a clutch mechanism and the substitute vehicle speed, and for selecting the higher of the third vehicle speed and the substitute vehicle speed as the control vehicle speed. The control vehicle speed is used as the vehicle speed V for carrying out speed change control.

Abstract: There is provided a control system for a powertrain system including an electro-mechanical transmission that is selectively operative in a plurality of fixed gear modes and continuously variable modes. The control system is adapted to execute the following steps, comprising determining a range of permissible engine input speeds and a range of permissible engine input torques, and determining motor input torques for the first and second electrical machines based upon the range of permissible engine input speeds and the range of permissible engine input torques. A cost is determined for each of the motor input torques. A preferred engine input speed and a preferred engine input torque are identified based upon the costs for the motor input torques.

Abstract: A speed change control device for a belt type continuously variable transmission has a speed change control unit (32) which controls an oil pressure for determining a speed ratio of the continuously variable transmission (10) by operating a step motor (40), and detects a rotation speed of a primary pulley or a secondary pulley. A driving speed of the step motor (40) is limited using two or more of a temperature of a working oil of the speed change control unit (32), the speed ratio of the continuously variable transmission (10), and the detected rotation speed as parameters.

Abstract: During Low return control, in which a speed ratio determined by a contact radius of a V-belt (4) with a non-rotating primary pulley (2) and a non-rotating secondary pulley (3) is shifted toward lowest speed ratio while the vehicle is stationary, an estimated speed ratio (ic) is calculated on the basis of a secondary pulley pressure (Psec). When a start request is issued to the vehicle while Low return control is underway, a primary pulley pressure (Ppri) and the secondary pulley pressure (Psec) are controlled on the basis of the estimated speed ratio (ic).

Abstract: A control apparatus for an automatic transmission includes a control section having a normal control section configured to actuate the step motor at a first speed by using a feedback control including an integral control in accordance with the target pulley ratio and the actual pulley ratio, a high speed control section configured to actuate the step motor at a second speed higher than the first speed by an open loop control based on the target pulley ratio, a judgment section configured to judge whether there is a high speed operation request, and a switch section configured to select the normal control performed by the normal control section at a normal condition, and to switch to the high speed control when a switch start condition is satisfied, the switch start condition including a first condition that the judgment section judges there is the high speed operation request.

Abstract: This invention is a speed ratio change control device for a belt type continuously variable transmission that a minimum generated pressure of the primary pressure is estimated on the basis of a displacement speed of the movable sheave of the primary pulley and an opening area of a drain side passage of the speed ratio change control valve (S4), an upper limit value of a shift speed is calculated on the basis of the minimum generated pressure (S6), and the target speed ratio is set on the basis of the upper limit value of the shift speed (S10).

Abstract: A continuously variable power-branched transmission for a motor vehicle, including an input shaft, a variable speed drive unit having pairs of conical disks and a continuously variable transmission ratio, a gear system, and an output shaft. Two control clutches connect the variable speed drive unit and the gear system so that when going through the entire transmission ratio range of the power-branched transmission the adjustment range of the variable speed drive unit is passed through a plurality of times. The transmission also includes rotational speed sensors and a controller that determines whether a change in rotational speed is triggered by a change in the transmission ratio, and when it is not triggered by a change in the transmission ratio, the controller adjusts the variable speed drive unit so that the change in rotational speed not triggered by a change in the transmission ratio is compensated.

Abstract: A motor vehicle automatic gearbox, with infinitely-variable ratio, may be operated in a constant speed mode, or in an acceleration mode in which the motor revolution speed is increased or reduced in steps.

Abstract: A method for operating a continuously variable conical pulley transmission having two conical pulley sets that are operatively coupled by a endless torque-transmitting means, so that the transmission ratio between the conical pulley sets is continuously variable. A hydraulic medium is supplied to the continuously variable conical pulley transmission in a stop phase of a start/stop operation by means of a pump unit that includes a pump that is driven by an electric motor. The electric motor is controlled as a function of the temperature of the hydraulic medium.

Abstract: A method of controlling a transmission (e.g., CVT) comprises dividing the entire range of an input torque to a transmission from an engine into a plurality of partial torque ranges; setting the maximum torque of the respective partial torque ranges as a representative torque of the respective partial torque ranges; and setting a target hydraulic pressure, which is to be provided to the transmission, according to the representative torque and a predetermined target speed ratio. The method allows a target hydraulic pressure for controlling a transmission to be maintained constant even though an input torque from an engine is changed, and allows the transmission to maintain a speed ratio constant, thereby ensure a stable and smooth ride.

Abstract: The following steps are performed in the control method: determining a mode of operation from amongst a permanent mode and a transient mode, as a function of a set of variables comprising said estimated values; correcting the value of the speed of rotation of the outlet shaft in such a manner that: if the mode has been determined as being the permanent mode, then the moving average (L?) of the gear ratio (L) over a period (T) of a plurality of unit time intervals lies between a first threshold value (S1) that is negative and a second threshold value (S2) that is positive; and if the mode has been determined as being the transient mode, then said moving average (L?) of the gear ratio (L) lies outside the range of values defined by the first and second threshold value (S1, S2).

Abstract: A speed-ratio control apparatus for controlling a speed ratio of a continuously variable transmission of a vehicle, such that an actual input speed of the transmission coincides with a target input speed, the apparatus including an acceleration-requirement determining portion operable to determine whether non-rapid acceleration or rapid acceleration of the vehicle is required by a vehicle operator, and a target-input-speed setting portion operable, upon determination of the operator's requirement for the non-rapid acceleration, to implement an instantaneous stepping increase of the target input speed to a first transient target value, (ii) hold the target input speed at the first transient target value in a first portion of a rapid shifting period, (iii) instantaneously reduce, at the end of the first portion of the rapid shifting period, the target input speed to an initial value of a second transient target value which initial value is close to the actual input speed and lower than the first transient targe

Abstract: A continuously variable transmission is mounted on a vehicle capable of selecting plural drive modes and changes a target engine speed between drive modes. A pulley ratio is controlled by a motor. An ECU for transmission control includes a calculation section which outputs a target engine speed as a function of throttle opening and vehicle speed, and a motor control value determination section which outputs a control value for controlling the motor based on the target engine speed and an actual engine speed. In a case where, when a drive mode is selected, the current target engine speed changes by an amount exceeding a predetermined judgment value according to vehicle speed, the motor control value determination section updates the current target engine speed in a stepwise manner. The resulting configuration reduces a shift shock caused by a drive mode change.

Abstract: A hydraulic control apparatus of a belt-drive CVT, controlling a transmission ratio by changing respective effective rotation radii of driving and driven pulleys, includes vehicle information sensors; hydraulic actuators changing the respective rotation radii; and a control unit determining each fluid pressure command value provided for the pulleys, and controlling the hydraulic actuators based on the fluid pressure command values. The control unit acquires an actual displacement amount of one of the pulleys. When changing a transmission to the highest or lowest speed transmission, the control unit sets a target displacement amount of one of the pulleys; estimates a rapidly changing amount of the working fluid pressure, occurring at close to an end of the speed change; and corrects the fluid pressure command value by the rapidly changing amount at a time when a rate of the actual displacement amount with respect to the target displacement amount has reached a predetermined rate ?0.

Abstract: A control apparatus for a continuously variable transmission of a vehicle is provided for switching the transmission from a continuously variable transmission mode to a stepped transmission mode without giving any discomfort to the driver, and for appropriately responding to a request for acceleration from the operator during the stepped transmission mode. The control apparatus comprises an ECU for setting a target transmission ratio in accordance with the detected operating condition of the vehicle, controlling the transmission ratio of the continuously variable transmission to reach the set target transmission ratio, and switching the transmission mode between a CVT mode and an AT mode. When the transmission mode is switched from the CVT mode to the AT mode, the ECU sets the target transmission ratio to a transmission ratio in the CVT mode immediately before the switching.

Abstract: A transmission TM comprises a metal V-belt mechanism 20, which is provided between an engine ENG and driving wheels DRW and transmits a rotational driving force from the engine ENG toward the driving wheels DRW with a speed change, and a forward/reverse switching mechanism 30, which includes a planetary gear train and switches the rotational direction between for a forward drive and for a reverse drive and transmits the rotational driving force received from the engine ENG to the metal V-belt mechanism 20. An engine control unit 60 for the transmission TM, while the rotational direction is set for a reverse drive, changes the ratio of the metal V-belt mechanism 20 in the direction where the vehicle speed increases by a predetermined ratio and controls the torque input from the engine ENG such that the torque being transmitted to the driving wheels DRW achieves approximately the same magnitude as that achieved while the rotational direction is set for a forward drive.

Abstract: In an area where a required primary pressure is higher than a required secondary pressure after a line pressure is controlled to an oil pressure obtained by adding a margin to a higher oil pressure of the required primary pressure and the required secondary pressure, the line pressure is gradually reduced such that the line pressure does not fall below the required primary pressure by adding a negative correction amount to the line pressure when a predetermined condition is established. Further, the line pressure is controlled back to the oil pressure obtained by adding the margin when the condition ceases to be established. When the condition ceases to be established (S8), a line pressure correction amount at this time is stored as a learned value (S9), and when the condition is reestablished (S5), the line pressure correction amount is substituted with the learned value (S6).

Abstract: A hydraulic pressure control apparatus of a belt-drive continuously variable transmission (CVT) for an automotive vehicle, includes a vehicular information detector that detects engine-and-vehicle operating conditions and a hydraulic actuator that regulates primary and secondary pulley pressures. A CVT control unit calculates a primary-pulley slip-limit pulley thrust and a secondary-pulley slip-limit pulley thrust based on information about the engine-and-vehicle operating conditions. The CVT control unit sets a primary-pulley-thrust command value to the primary-pulley slip-limit pulley thrust and calculates a desired secondary pulley thrust based on a desired transmission ratio, when a pulley ratio is greater than or equal to 1. The CVT control unit sets a secondary-pulley-thrust command value to the secondary-pulley slip-limit pulley thrust and calculates a desired primary pulley thrust suited to the desired transmission ratio, when the pulley ratio is less than 1.

Abstract: A hydraulic system for controlling a belt-driven conical-pulley transmission of a motor vehicle, wherein the transmission has a variably adjustable transmission ratio. The hydraulic system includes a first valve arrangement to ensure a contact pressure in the belt-driven conical-pulley transmission, a second valve arrangement to control the transmission ratio of the belt-driven conical-pulley transmission, and a hydraulic energy source to supply the hydraulic system with hydraulic energy. In order to provide an improved hydraulic system, the system a third valve arrangement for controlling a forward clutch and a reverse clutch.

Abstract: A vehicle with a transmission having a crankshaft and an output shaft. A clutch located between the output shaft and a drive wheel is engaged and disengaged according to a rotational speed of the output shaft. An idle speed control device performs idle speed control to adjust an idle rotational speed of an engine. An electronic control unit (ECU) suppresses or stops the idle speed control when the clutch is engaged, or when an abnormality in the transmission is detected.

Abstract: A shift control apparatus of a belt type continuously variable transmission is comprised of a controller which is arranged to set a first hydraulic pressure controlled variable based on a first target transmission ratio determined based on a vehicle traveling condition, to set a second hydraulic controlled variable based on a second target transmission ratio determined based on a predetermined transfer characteristic, to steplessly control the transmission ratio by controlling hydraulic pressures of primary and secondary pulleys hydraulic based on the first and second hydraulic pressure controlled variables, to detect at least one of the hydraulic pressures of the primary and secondary pulleys, and to correct the second target transmission ratio based on the detected hydraulic pressure.