Abstract: A continuously variable transmission apparatus includes a toroidal-type continuously variable transmission, a planetary gear type transmission and a clutch apparatus that connects the toroidal-type continuously variable transmission and the planetary gear type transmission. The clutch apparatus includes: a low speed clutch engaged for realizing a low speed mode and disengaged for realizing a high speed, a high speed clutch engaged for realizing the high speed mode and disengaged for realizing the low speed mode and a controller. The controller controls the transmission ratio of the toroidal-type continuously variable transmission so that rotational speeds of members connected via the clutch apparatus equals with each other, and then disengages the one of the low speed clutch and the high speed clutch after engaging the other.

Abstract: A transmission system in a vehicle using a motor to transmit power can assist acceleration by generating auxiliary engine power during acceleration in addition to gear changing by the motor. In this system, however, the acceleration assistance is interrupted in gear changing since the motor power is used to drive a vehicle when a gear-shifting is made. In a conventional geared transmission mechanism, the torque decreases after a gear change for up-shifting is made. If acceleration assistance is added, the torque reduction in shifting becomes greater and gives uncomfortable shocks and feelings to the driver. Torque transition is conducted along a torque transmission route of dog clutch, second intermediate shaft, motor, first intermediate shaft, and gear position of first intermediate shaft before shifting.

Abstract: A vehicle transmission transmits torque from an engine to a drive axle and includes a power shift transmission and a reverser module. A control system and method automatically partially disengages the reverser module during a shift of the power shift transmission with nearly no effect upon the operating condition of the engine, so that a portion of the torque generated by the engine continues to be transmitted at all times to the drive axle.

Abstract: A control apparatus of an automatic transmission includes first, second and third frictional elements, first and second shift control sections issuing a hydraulic pressure command to the first, second and third frictional elements for engagement and release thereof at primary and secondary shifts, a judging section judging a shift from a first speed stage to a third speed stage, and a third shift control section initiating the primary shift when the shift is judged, and initiating the secondary shift before an end of the primary shift while executing the primary shift when a gear ratio reaches a first predetermined gear ratio. the third shift control section compares two pressure command values of the first frictional element, respectively issued by the first and second shift control sections for the primary and secondary shifts, and selects a greater pressure command value, and outputs it to the first frictional element.

Abstract: In automatic shift control apparatus and method for a manual transmission, at least one clutch is interposed between an engine and the manual transmission and a controller performs a feedback control for an engagement force of the clutch after a gear shift for the manual transmission is ended in such a manner that an input revolution speed of the clutch is directed toward another revolution speed thereof after the gear shift occurs at a predetermined time variation rate, the controller setting mutually different feedback control gains in a variation region of the input revolution speed of the clutch in which the input revolution speed of the clutch is directed toward the other revolution speed after the gear shift occurs and in a convergence region of the input revolution speed in which the input revolution speed of the clutch has reached to the other revolution speed after the gear shift occurs.

Abstract: A power train for a motor vehicle is configured with a control unit operable to increase or decrease the flow of operating fluid as a function of the instantaneous demand for the supply of the operating fluid to at least one of multiple clutch arrangements in such a way that the control unit decreases or interrupts the flow of operating fluid when the supply demand is low and increases the flow of operating fluid unit when the supply demand is high.

Abstract: A system for controlling pressure in a transmission comprises a transmission control unit, a valve controller that receives a desired pressure as input from the transmission control unit, a valve driver, a valve that regulates an amount of fluid in a transmission clutch, and a pressure transducer that reads a pressure in the transmission clutch and outputs a pressure reading to the valve controller, wherein the valve controller comprises logic for outputting to the valve driver an instruction for controlling the valve, the instruction being formulated using the desired pressure and the pressure reading.

Abstract: When an engine is restarted after a predetermined period of being stopped oil is supplied to a clutch pack for a 2–3 and/or 3–4 shift while a transmission is engaged in the first speed for the first time since starting. The amount of oil drained during the predetermined period of being stopped is complemented in advance such that shift quality of a first 2–3 and/or 3–4 shift is enhanced.

Abstract: A shift control method and system for an automatic transmission. The control method includes calculating a clutch engaging pressure for each shift speed corresponding to an engine load and calculating an optimal engaging pressure for an operating clutch in each shift ratio. The system includes a control unit and sensors for executing the method.

Abstract: In a control apparatus for an automatic transmission, a return control is executed to engage a clutch that has had its engagement pressure lowered and to disengage a brake so as to resume the state of the automatic transmission from the neutral state under a neutral control to the one where the forward speed is established. As the time for the neutral control becomes longer, the decrease in the torque of an output shaft of the automatic transmission becomes gentler. Accordingly an initial value of a control command value for the clutch pressure is decreased with the increase in the neutral control time such that the engagement of the clutch becomes gentler.

Abstract: An automatic transmission including plural friction engaging elements configures plural shift ranges based on combinations of each friction engaging element being in engaging or disengaging condition and a controlling unit for controlling the friction engaging elements to be in engaging or disengaging condition by controlling a hydraulic pressure applied.

Abstract: An automated vehicle transmission having a wet clutch and an auxiliary motor that is operatively connected to the transmission to overcome residual torque forces in the wet clutch. Residual torque forces in the wet clutch may prevent disengagement of a gear train and also prevent the transmission from shifting into neutral. A control system determines whether residual torque is resisting the disengagement of the gear train for more than a predetermined time period. According to the method, if a shift is delayed for more than the predetermined time period, the auxiliary motor is actuated to apply an oppositely oriented torque to the transmission gear train to overcome the residual torque and allow the transmission to shift into neutral.

Abstract: A change-speed system for a utility vehicle includes a gear change-speed device operated for change speed in response to an operation of an actuator, a hydraulic clutch for selectively engaging/disengaging power transmission to the gear change-speed device, a current-controlled valve mechanism for feeding pressure oil to the hydraulic clutch and a hydraulic clutch controlling portion for controlling oil pressure in the hydraulic clutch by controlling a value of electric current to the valve mechanism. The hydraulic clutch controlling portion is operable to initiate a disengaging process of the hydraulic clutch based on initiation of the operation of the actuator and operable also to initiate an engaging process of the hydraulic clutch based on completion of the operation of the actuator.

Abstract: A power train for a motor vehicle includes a drive unit, a gearbox having first and second input shafts, and a clutch having first and second multi-disk clutch arrangements assigned to respective input shafts for transferring torque between the drive unit and the gearbox. An operating fluid, especially a cooling oil, is supplied to the clutch arrangements for operation under action of the fluid. An actuator arrangement is assigned to the gearbox for engaging and disengaging gears assigned to the first and second input shafts, and a control unit controls the actuator arrangement so that at least one gear is automatically engaged when the clutch is released.

Abstract: A device is provided that issues a vehicle speed signal representative of a vehicle speed. A control unit is configured to carry out when, upon the transmission assuming the second speed, the vehicle speed represented by the vehicle speed signal becomes equal to or lower than a first predetermined speed, starting operation for fully releasing the engaged condition of the first clutch; when thereafter the vehicle speed becomes equal to or lower than a second predetermined speed that is lower than the first predetermined speed, starting operation for releasing the engaged condition of the second clutch; and when thereafter the vehicle speed becomes equal to or lower than a third predetermined speed that is lower than the second predetermined speed, starting operation for fully releasing the engaged condition of the second clutch and starting operation for engaging the first clutch from the fully released condition of the same.

Abstract: There is provided a control system for a vehicle, which is capable of increasing the service life of a transmission belt while preventing slippage thereof, and at the same time improving fuel economy and drivability. The control system for a vehicle sets a transmission transfer torque to be transmitted from a drive pulley of a continuously variable transmission to a driven pulley of the same, and a clutch transfer torque to be transferred by a clutch. When it is determined that the vehicle is traveling on a bad road, the clutch transfer torque is reduced, and the transmission transfer torque is set to a larger value as the clutch transfer torque is larger.

Abstract: A vehicle transmission system includes a transmission component that has an engaged condition where torque can be transferred from a vehicle engine to a drive component, and a non-engaged condition where torque is prohibited from being transferred to the drive component. A controller generates control signals to control whether the transmission component is in the engaged or non-engaged condition. The controller also identifies when a vehicle start maneuver is a coast start based on vehicle conditions existing just prior to or during the vehicle start maneuver. When a coast start is identified, the controller generates a control signal to either disengage the transmission component or to maintain the transmission component in the non-engaged condition until engine speed generally matches transmission component speed. The controller can directly control engagement by automatically actuating a movable transmission member or can indirectly control engagement by controlling engine speed.

Abstract: A transmission control system, includes: 1) a high speed side friction element for establishing a high speed side change gear; and 2) a low speed side friction element for establishing a low speed side change gear. After a disengagement of the high speed side friction element, the low speed side friction element makes an engagement for carrying out a downshift from the high speed side change gear to the low speed side change gear. When the downshift is carried out with an accelerator turned off, a stepping on the accelerator sensed in a period between the following times: i) a time for commanding a start of a transmission, and ii) a time for the low speed side friction element to start a conveyance of a torque, prevents a changeover to the low speed side change gear, thus keeping the high speed side change gear.

Abstract: An automatic shift controller for a vehicle which controls a gear-shifting mechanism to engage one of several gear trains. A sub-clutch connects and disconnects so that one of the gear trains, other than a first-speed gear train and a reverse gear train, is engaged or disengaged. By use of a controller, 1) when the vehicle is parked, then the reverse gear is engaged, the main clutch is engaged, and the sub-clutch is disengaged, and 2) when preparation for engine start-up is started in a state wherein the vehicle is parked, then the main clutch is disengaged and the sub-clutch is engaged.

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−&agr;)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−&agr;)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−&agr;)th speed.

Abstract: A vehicular transmission system is disclosed that includes a prime mover, a transmission having at least one mode of operation where the transmission is selectively shifted into a lower gear ratio as vehicle speed decreases, a master friction clutch for drivingly connecting the prime mover to the transmission, and at least one control unit. The control unit includes logic rules that selectively prohibit the transmission from being shifted into a lower gear ratio in response to a system operating condition during the at least one mode of operation. The system also includes at least one input corresponding to a system operating condition and at least one output corresponding to a command to prohibit the transmission from being shifted into a lower gear ratio in response to the sensed system operating condition. A control system and method for operating the vehicular transmission system are also disclosed.

Abstract: A method of controlling the pressure applied to the engaged clutch of a vehicle having a dual clutch transmission to control the torque transferred across the engaged clutch thereby providing engine speed control for each gear based on the engine throttle position. The method includes the steps of determining the engine throttle position, determining the currently engaged gear of the transmission, and sensing the speed of the clutch. An engine stall speed is selected for the current gear and engine throttle position from a look-up table, and then a target engine speed based on the engine stall speed and the clutch speed is continuously redetermined, the clutch speed increasing in response to the increasing engine speed.

Abstract: In automatic shift control apparatus and method for a manual transmission, at least one clutch is interposed between an engine and the manual transmission and a controller performs a feedback control for an engagement force of the clutch after a gear shift for the manual transmission is ended in such a manner that an input revolution speed of the clutch is directed toward another revolution speed thereof after the gear shift occurs at a predetermined time variation rate, the controller setting mutually different feedback control gains in a variation region of the input revolution speed of the clutch in which the input revolution speed of the clutch is directed toward the other revolution speed after the gear shift occurs and in a convergence region of the input revolution speed in which the input revolution speed of the clutch has reached to the other revolution speed after the gear shift occurs.

Abstract: A method of controlling the pressure applied to the engaged clutch of a vehicle having a dual clutch transmission to control the torque transferred across the engaged clutch thereby providing engine speed control for each gear based on the engine throttle position. The method includes the steps of determining the engine throttle position, determining the currently engaged gear of the transmission, and sensing the speed of the clutch. An engine stall speed is selected for the current gear and engine throttle position from a look-up table, and then a target engine speed based on the engine stall speed and the clutch speed is continuously redetermined, the clutch speed increasing in response to the increasing engine speed.

Abstract: A transmission system for a work vehicle, which is capable of reliably mitigating, with relatively simple arrangement, shocks caused by speed changes even in a work vehicle such as a bulldozer in which almost all operations are performed with the engine operating at full load. In the transmission system which converts the output torque of an engine into torque according to work load by operations for shifting speed gears through disengagement/engagement of friction clutches, if a downshift from a higher speed gear to a lower speed gear is effected while the engine operating at full load, the friction clutch controlling means allows the friction clutch corresponding to the higher speed gear to slide so as to enable power transmission and the engine controlling means allows the engine to perform high power operation (overload operation) during the sliding of the friction clutch.

Abstract: A method for reducing oscillation in an automotive transmission system includes detecting a tip-out of an accelerator pedal position. Responsive to the detected tip-out, a pressure command is adjusted for a selected range clutch within the transmission system so as to reduce the pressure of the selected range clutch from a normal pressure level to a low pressure level, thereby producing a desired gear train slip in the transmission system. Then, the pressure command of the selected range clutch is re-adjusted after a determined period of time at the low pressure level so as to increase the pressure of the selected range clutch from the low pressure level, and thereby eliminating the gear train slip.

Abstract: An improved control method activates an electric motor to drive a torque-to-thrust converter for controlling the torque capacity of a clutch mechanism. The control utilizes a model-based feed-forward control in combination with a closed-loop position feed-back control. The desired clutch torque capacity is characterized in terms of a desired motor position, and the feed-forward control models the motor speed and position response to changes in the desired motor position. The modeled speed and position, in turn, are used to create a feed-forward command, and the feed-forward command is combined with a feedback command based on actual position error.

Abstract: A device for detecting the speed of an endless torque-transmitting member that passes around a pair of spaced conical pulley pairs of a continuously variable transmission. The device includes a sensor that is positioned adjacent the endless torque-transmitting member and that detects the speed of the endless torque-transmitting member at a point that is located relative to the movement course of the endless torque-transmitting member that is independent of the rotational speed relationship of the pulley pairs.

Abstract: A coordinated control of a drive train during a gear shift is described. The core of the control lies in establishing an optimal system trajectory for the states of the internal combustion engine and the clutch for the shift operation and in supplying this trajectory to a subordinate control and regulation. Here, the determination of the optimal system trajectory occurs as a function of the stipulations of a higher-order system for controlling the drive train. In particular, it is provided for the optimal system trajectory to be adapted to the driving situation, the driver type, the operating conditions of the assemblies, and the state of the assemblies themselves. Here, the determination of the optimal system trajectory occurs via a real-time optimization algorithm that is executed during driving operation. In this manner, optimal shift operation is attained under all operating conditions that unites a high degree of comfort with a low loss of traction.

Abstract: A vehicle driveline control system includes monitoring when the transmission is in gear and the clutch is left open. If that condition exists for a selected amount of time, the controller provides an indication to the driver regarding the open clutch status. In one example, the controller alters the RPM rate of the engine to provide audible feedback to the driver. For example, the controller raises the engine RPM rate from an idle rate to a higher rate to simulate what the driver hears upon vehicle launch. A variety of indicators and control strategies may be used with a system designed according to this invention.

Abstract: Device and method for shift control in an automatic transmission of a vehicle wherein the feedback control includes determining relative rate of change in turbine revolution during power-on up-shift, thereby preventing generation of shift impact in the shifting process. The device comprises a vehicle run state detecting unit for detecting a vehicle run state; a shift control unit for performing a power-on up-shift control, including controlling the relative rate of change in turbine revolution; and a driving unit for supplying and stopping supply of oil pressure discharged from an oil pump to perform the shifting in response to shift mode state output synchronization, throttle valve openness, revolution at output shaft, engine revolution, shift lever position and acceleration pedal operation state.

Abstract: Described is a method for controlling and regulating a drive train of a vehicle comprising one drive unit, one transmission and one output unit. The transmission has controllable free-wheel device corresponding with toothed wheel pairs for disconnecting or connecting an old or a new gear and located on the input side one clutch. In the presence of a shifting signal for carrying out a higher traction shift, an input torque of the drive unit is quickly reduced so that a first vibration is induced in the drive unit. During a subsequent shifting, an operative connection is abruptly created between a free-wheel device and a toothed wheel pair corresponding therewith in a manner such that a second vibration counteracting the first vibration is produced in the drive train. With the engagement of the new gear the operative connection of the old gear is canceled as a result of a torque reversal from a pull torque to a push torque.

Abstract: A torque transfer system of a motor vehicle has a clutch, a transmission, a control device, and a traction load detecting device. The traction load is the variable resistance that a vehicle has to overcome to start or to keep moving, e.g., going uphill or downhill, with a heavy or light load, with or without a trailer or a roof load. The control device controls the torque transfer system, in particular the clutch, dependent on input signals received from the traction load detecting device.

Abstract: An automatic transmission system for a vehicle includes a rotational speed detecting means for detecting a variation of a rotation number of driving torque transmitting member when a friction engagement element, which has been disengaged based upon oil pressure controlled by a control unit, a side of which has been transmitted with the rotation of the driving torque transmitting member, and the other side of which is locked not to be rotated during the vehicle at a stationary condition, is controlled to be engaged, wherein an oil pressure characteristic value of the friction engagement element is learned by the control unit based upon the variation of the rotation number of the driving torque transmitting member when the friction engagement element is initially engaged.

Abstract: A speed change mechanism (1) constructed by connecting in tandem a hydraulic type speed change unit (17) having a plurality of hydraulic clutches (57, 58, 59) to be alternatively engaged and a hydraulic type speed change unit (20) having a plurality of hydraulic clutches (66, 67, 68) to be alternatively engaged, wherein a time-varying region (common slip region) is secured in which the two clutches slip in common such that during speed change, when the working hydraulic pressure in a clutch to be engaged is on its way to gradual increase, the working hydraulic pressure in a clutch to be disengaged lowers.

Abstract: Many vehicles designed for running on rough terrain include an automatic transmission for performing speed change by connecting or disconnecting an oil hydraulic clutch provided alongside each speed change gear. However, depending on the posture of the driver, it may be impossible to step on the brake. As a result, it may be impossible to achieve creep prevention with a creep preventive mechanism dependent on a brake signal. Therefore, a creep preventive mechanism which operates independently from a brake signal is required. The present invention provides an oil pressure control system operating independently from a brake signal. The system includes an oil pressure supply source with a linear solenoid valve for supplying working oil or interrupting the supply of the working oil to the oil hydraulic clutches. The supply of the working oil to the clutches is interrupted when the vehicle is stopped under an idling condition of an engine.

Abstract: A controller for an exhaust brake device is provided whereby the braking force of the exhaust brake device can be ensured sufficiently, even at low vehicle speeds. A controller for an exhaust brake device (73) used in combination with a power transmission device comprising a fluid coupling (2) connected to the output shaft (1a) of an engine (E), a clutch (3) interposed between the fluid coupling (2) and a gearbox (T/M), and a lock-up clutch (7) for mechanically disengaging and engaging the fluid coupling (2), is provided, and this controller is provided with an electronic control unit (22) for controlling the engagement and disengagement of the lock-up clutch (7) and the operation of the exhaust brake device (73). The electronic control unit (22) permits operation of the exhaust brake device (73) in the range of engagement of the lock-up clutch (7).

Abstract: In a method of shifting a vehicle transmission from an old ratio to a new ratio, the output torque of the transmission is managed by controlling the engine torque and/or the transmittable torque of the main clutch, and by also controlling the transmittable torque of at least one of the gear-shifting clutches of the transmission.

Abstract: A coordinated control of a drive train during a gear shift is described. The core of the control lies in establishing an optimal system trajectory for the states of the internal combustion engine and the clutch for the shift operation and in supplying this trajectory to a subordinate control and regulation. Here, the determination of the optimal system trajectory occurs as a function of the stipulations of a higher-order system for controlling the drive train. In particular, it is provided for the optimal system trajectory to be adapted to the driving situation, the driver type, the operating conditions of the assemblies, and the state of the assemblies themselves. Here, the determination of the optimal system trajectory occurs via a real-time optimization algorithm that is executed during driving operation. In this manner, optimal shift operation is attained under all operating conditions that unites a high degree of comfort with a low loss of traction.

Abstract: A method for changing gear in an automated change-speed gearbox of a motor vehicle with an automated clutch arranged between an engine and the change-speed gearbox includes engaging the clutch up to a slip limit during a downshift from an original gear to a target gear to increase the rotational speed of an input shaft of the change-speed gearbox.

Abstract: A control unit is provided for controlling a twin clutch mechanism which includes first and second automatic clutches respectively incorporated with first and second groups of gears. The control unit is configured to carry out establishing a condition wherein both the first and second automatic clutches are in their engaged conditions and wherein one of the first and second groups of gears is operated to select a certain speed gearing with the aid of a corresponding selection mechanism while leaving the other of the first and second groups of gears in a neutral condition with the aid of the other corresponding selection mechanism; and releasing the engaged condition of the automatic clutch incorporated with the other of the first and second groups of gears when the other of the first and second groups of gears is in a critical condition to induce a gear hit noise.

Abstract: Device and method for shift control in an automatic transmission of a vehicle wherein the feedback control includes determining relative rate of change in turbine revolution during power-on up-shift, thereby preventing generation of shift impact in the shifting process. The device comprises a vehicle run state detecting unit for detecting a vehicle run state; a shift control unit for performing a power-on up-shift control, including the controlling the relative rate of change in turbine revolution; and a driving unit for supplying and stopping supply of oil pressure discharged from an oil pump to perform the shifting in response to shift mode state output synchronization, throttle valve openness, revolution at output shaft, engine revolution, shift lever position and acceleration pedal operation state.

Abstract: Transmission system, in which a single double-effect actuator, used to engage/release the gears, comprises a piston which is mobile with reciprocating motion, and has different areas which face first and second chambers of the actuator. The first and second chambers are supplied respectively, directly by a source of pressurised fluid, and by a valve of the proportional type, which is interposed between the source of pressurised fluid and the actuator.

Abstract: The present invention provides a creep-control method for an automatic transmission of a vehicle comprising: creep-entering, in which a hydraulic circuit of the automatic transmission is controlled to form hydraulic pressure supply lines of a second shift-speed when a predetermined creep-entrance condition is satisfied; creep-maintaining, in which the formed hydraulic pressure supply lines of the second shift-speed are maintained and a hydraulic supply pressure of the formed hydraulic pressure supply lines is maintained at a predetermined creep duty ratio; and creep-escaping, in which one of controlling the hydraulic circuit to engage the second shift-speed shift mechanism of the automatic transmission and controlling the hydraulic circuit to engage a first shift-speed shift mechanism of the automatic transmission is selectively performed based on a vehicle speed and throttle valve open-angle when, a predetermined creep-escape condition is satisfied.

Abstract: By preventing engagement of an engaging part (clutch) under appropriate conditions, it is possible to effectively avoid the so-called surging phenomenon. When there is an engaging directive for the clutch, the rotational speed of the engaging element positioned at the output shaft side of the drive/regeneration motor (the clutch output rotational speed) is detected, and the gear ratio of the CVT is detected, and when the product of the rotational speed of the engaging element and the gear ratio of the CVT is equal to or below a predetermined value, complete engagement between the engaging elements is prevented, and control is conducted which makes the gear ratio large.

Abstract: The invention proceeds from a vehicle having a clutch and a transmission. The clutch is mounted in the drive train of the motor vehicle and the transmission is mounted in the drive train and is changeable with respect to its transmission ratio. Furthermore, means are provided which generate a clutch signal which represents the actuation of the clutch. The essence of the invention is that a change of the transmission ratio is detected. According to the invention, monitoring means are provided by means of which a fault signal is generated in dependence upon the recognized change and the generated clutch signal. The fault signal indicates whether the means, which generates the clutch signal, operates properly. A further variation of the invention evaluates the clutch actuation with the first start of movement of the vehicle after the engine start.

Abstract: A vehicle clutch control system that can prevent an engine (222) from racing when a friction clutch (304) is disengaged and engaged. When a driver stamps an accelerator pedal (206) over a predetermined depth at the time of completion of transmission gear speed change, clutch engagement is prohibited if a clutch rotation speed is slower than a prescribed speed, or an accelerator is maintained to a 0% opening position.

Abstract: A lock-up control device is provided to control the engaging and release of a lock-up clutch, which is arranged in parallel with a torque converter to transmit driving force of an engine of a car. Herein, target driving force is calculated based on accelerator pedal opening and car velocity. A present shift position is detected using a shift map based on accelerator pedal opening, car velocity and engine speed. Target engine torque is calculated based on the target driving force and present shift position as well as a torque amplification ratio, which is detected when the torque converter is placed in a torque amplification state. A lock-up release instruction is issued under conditions that the torque converter is placed in the torque amplification state while the target engine torque is greater than a preset value, which is determined in advance based on a torque characteristic of the engine.

Abstract: An adaptive control system and method for direct clutch engagement control for an automatic transmission including a micro-controller that receives and stores input data from driveline sensors and executes transmission clutch control logic. The micro-controller develops output signals in real time and transfers the signals to a driver circuit that controls solenoids that enable clutch engagement. The signals for establishing clutch pressure buildup are delivered to a driver circuit that produces hydraulic pressure at the clutch to achieve a smooth torque and speed transition for the torque input elements of the transmission. Adaptive pressure values are stored in a keep-alive memory. The pressure values are adjusted values based on the result of previous engagements. This compensates for driveline variables such as changes in coefficients of friction, spring loads, clutch wear, etc.

Abstract: A multiple-ratio transmission with planetary gearing and a friction clutch and brake for controlling relative motion of the gearing to establish multiple driving ratios between an internal combustion engine and vehicle traction wheels, the clutch and brake include a forward drive clutch and a reverse drive clutch for establishing torque flow paths through the gearing. The forward drive clutch establishes a torque flow path through the gearing from the engine through a torque output element of the transmission during vehicle startup in forward drive range, and the reverse clutch establishes a corresponding torque flow path during startup in reverse. A mechanical connection between the torque input shaft of the gearing and the crankshaft is characterized by minimal rotating mass, thereby reducing the inertia of rotating mass of the elements of the transmission.