Abstract: First, the pressure of oil within an oil passage in a control valve device is measured. Then, an amplitude and period of pressure fluctuations are detected on the basis of an obtained measurement result, and an oil vibration state or an oil non-vibration state is diagnosed. In this case, when the amplitude is greater than a reference amplitude value and when the period is less than a reference period value, the oil vibration state is diagnosed. Further, a duration time of the oil vibration state is determined on the basis of a diagnostic result. Then, when the oil vibration state continues for a period greater than or equal to a reference time, warning information is output. In this way, warning information is output stepwise in accordance with occurrence or continuation of oil vibration.

Abstract: A control method for a continuously variable transmission is disclosed to improve shifting stability. The control method may include: determining by a controller whether a shift by controlling the pulley is required, determining whether the control of the pulley for the shift generates a pressure fluctuation which is greater than or equal to a predetermined level, calculating a required hydraulic pressure varying amount for varying a hydraulic pressure to a target hydraulic pressure, adding additional hydraulic pressure to the required hydraulic pressure varying amount so as to increase the hydraulic pressure, and decreasing the increased hydraulic pressure to the target hydraulic pressure.

Abstract: A hydraulic control system for a transmission is provided. The hydraulic control system provides one or more default gears during a default condition when the transmission loses electronic control. The hydraulic control system includes a default enable valve, a default select valve, and a plurality of clutch regulation valves. The default enable valve and the default select valve feed hydraulic fluid through exhaust circuits to a set number of the clutch regulation valves during a default condition in order to provide a default gear ratio.

Abstract: A hydraulic control system for a transmission includes a reverse, a low gear ratio, and a high gear ratio during default conditions where the transmission loses electronic control. The hydraulic control system also provides neutral locked turbine capability that engages clutches to lock the transmission input shaft in order to generate heat. The hydraulic control system includes a manual valve, a default enable valve, a default select valve, and a plurality of clutch regulation valves. The neutral locked turbine capability may be engaged when the manual valve is in either a park or neutral position.

Abstract: A shift control method and apparatus for a vehicle is described. The shift control method for a vehicle having an oil pump includes determining whether the vehicle satisfies an Idle Stop and Go (ISG) learning condition, measuring, when the vehicle satisfies the ISG learning condition, a shift time of a transmission when a driving state of the vehicle is changed from an idling state to a restart state, comparing the measured shift time with a predetermined reference shift time, and adjusting a pressure of oil supplied to a solenoid of the transmission from the oil pump according to the compared result. Thus, it is possible to reduce a variation in shift time required when the ISG vehicle using a mechanical oil pump in place of an electrical oil pump is restarted.

Abstract: Provided is an engine power estimation apparatus for estimating an engine power at a gear shift completion time when making a speed change of a vehicle. The engine power estimation apparatus includes a gear shift detection unit configured to detect the speed change of the vehicle; an axle speed estimation unit configured to calculate a target axle speed at the gear shift completion time, using an axle speed and a gear shift time learning value, when the speed change of the vehicle is detected; and an engine power estimation unit configured to calculate a target engine power at the gear shift completion time, using the target axle speed and engine load information.

Abstract: A lubricating oil supply control device for delivering lubricating oil to the transmission of a vehicle is provided which overcomes disadvantages of the prior art by providing a simple and reliable configuration which does not require the addition of new sensors to an existing device. The lubricating oil supply control device includes, in part, an engine controller and a transmission controller, a lubricating oil supplying oil passage, a bypass oil passage, a relief valve or a control valve, a restrictor, and a lubricating oil supply controlling controller.

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

Abstract: An apparatus controls a vehicle having an engine including a throttle having a throttle position sensor, the throttle being adjustable to vary the speed of the vehicle, a transmission having an input shaft, an output shaft, and drive means there between providing a variable drive ratio, and a transmission controller for controlling the drive ratio between said input and output shafts, and at least one axle in driving connection with the output shaft of the said transmission, wherein the controller comprises a selector operable to select between first and second modes of operation, in said first mode the throttle and transmission are operated individually by the operator in said second mode, operation of the throttle and transmission is interconnected and performed by means of a computer program.

Abstract: A transmission line pressure controller compensates for pump speed effect on transmission line pressure. A sensor determines a pressure of a pressure control actuator. The controller determines a selected transmission range, including drive or reverse. The controller determines an effective engine speed. The controller adjusts the pressure control actuator according to the selected transmission range and the effective engine speed.

Abstract: An ECT-ECU includes an abrupt turbine speed increase learning control circuit which prevents simultaneous release of both a frictional engagement element to be released and a frictional engagement element to be engaged, a tie-up learning control circuit which prevents simultaneous engagement of both the frictional engagement element to be released and the frictional engagement element to be engaged, a determination circuit that determines whether one of tie-up learning control and abrupt turbine speed increase learning control is necessary based on the turbine speed, and a control circuit that prohibits execution of the tie-up learning control unless the number of trips after the abrupt turbine speed increase learning control has been executed is at least equal to a predetermined number, when it has been determined that the tie-up learning control is necessary.

Abstract: The hydraulic control system includes a driving condition detection unit, a transmission control unit, and a driving unit. The driving condition detection unit detects driving conditions of a vehicle. The transmission control unit performs variable line pressure control using a minimum line pressure and a line-pressure-decreasing gradient calculated based on driving condition data detected by the driving condition detection unit when the driving conditions satisfy variable line pressure control entrance conditions. The driving unit adjusts a duty ratio of line pressure applied to friction elements according to a line pressure control signal generated by the transmission control unit.

Abstract: In a constitution where a hydraulic pressure is delivered periodically to friction engagement elements in released states to discharge air mixed into a hydraulic circuit a duty ratio in the hydraulic pressure delivery is switched to a plurality of different values according to operating conditions, a ratio of an actual total time to a target total time is switched per each of duty ratios; and the air discharge control is terminated when a sum of the ratios becomes a predetermined value or above.

Abstract: A method for controlling hydraulic pressure of an automatic transmission for a vehicle is provided. The automatic transmission has a clutch element engaged by a solenoid pressure to perform speed change. The solenoid pressure is generated by a solenoid that is driven by a solenoid drive current. The method calculates a required clutch engagement pressure and a required solenoid pressure corresponding to the required clutch engagement pressure based on a relationship between the clutch engagement pressure and the solenoid pressure. The method outputs a required solenoid drive current corresponding to the required solenoid pressure based on a relationship between the solenoid pressure and the solenoid drive current. The solenoid outputs the solenoid pressure corresponding to the required solenoid drive current.

Abstract: The hydraulic control system includes a driving condition detection unit, a transmission control unit, and a driving unit. The driving condition detection unit detects driving conditions of a vehicle. The transmission control unit performs variable line pressure control using a minimum line pressure and a line-pressure-decreasing gradient calculated based on driving condition data detected by the driving condition detection unit when the driving conditions satisfy variable line pressure control entrance conditions. The driving unit adjusts a duty ratio of line pressure applied to friction elements according to a line pressure control signal generated by the transmission control unit.

Abstract: A kick down shift control apparatus of an automatic transmission of a vehicle comprising: vehicle running state sensing means for checking a running state of the vehicle; engine control means for controlling engine outputs in response to a signal sensed by the vehicle running state sensing means and outputting information on the temperature of intake air and the operational state of an air conditioner; shift control means for outputting a control signal to correct the pressure of transmission oil according to the temperature of absorbed air and the operational state of the air conditioner input from the engine control means, if conditions for a kick down shift are met with reception of the signal checked by the vehicle running state sensing means; and driving means for controlling the oil pressure discharged out by the oil pump according to the control signal output from the shift control means and performing a shift by providing the oil pressure for a relevant friction factor, thus relieving an shifting shoc

Abstract: A shift control method for an automatic transmission which includes converting to a lean-burn mode from a normal mode if throttle voltage is less than a first predetermined value; determining if tip-in has occurred in the lean-burn mode using accelerator pedal signals; increasing the throttle valve opening if it is determined that the throttle voltage has increased by a second predetermined value such that engine rpm is increased; determining if the difference between engine rpm and turbine rpm is greater than a predetermined number of rpm; and converting from the lean-burn mode to the normal mode if the engine rpm are greater than the turbine rpm by the predetermined number of rpm.

Abstract: A forced downshift control method for automatic transmissions, wherein, if shift signals of a forced 4-2 downshift are input, a first shift control solenoid valve (SCSV-A) is controlled to OFF; a second shift control solenoid valve SCSV-B is maintained in an OFF state for a predetermined period of time (t1) then controlled to ON; a third shift control solenoid valve (SCSV-C) is continuously maintained in an ON state, then is immediately controlled to OFF and first and second pressure control solenoid valves (PCSV-A) and (PCSV-B) are duty controlled.

Abstract: Disclosed is a shift control method for automatic transmissions.

Abstract: A control system for a CVT comprises a controller arranged to compute an engine revolution condition on the basis of an engine revolution speed indicative signal, to compute actual and estimated engine outputs on the basis of the engine revolution condition, to compute a rotational change condition of the drive system, to compute an actual input load change amount caused by the inertia by multiplying the actual rotational change condition detection value by a predetermined inertial constant, to compute an estimated input load change amount by multiplying the estimated rotational change condition detection value by a predetermined inertia coefficient, to select larger one of the actual input load change amount and the estimated input load change amount as the input load change amount for outputting a command signal, and to output the command signal to a line pressure duty valve on the basis of the engine output and the selected input load change amount so as to further accurately control a line pressure.

Abstract: Automotive vehicle control apparatus including a running stability control device for reducing engine output and/or applying brake to vehicle wheels for improving vehicle running stability, a shift control device for shifting an automatic transmission by engagement of at least one hydraulically operated frictional coupling device, depending upon a detected vehicle running condition as compared with a predetermined shift boundary pattern, a running stability control detecting device for detecting an operation of said running stability control device, and one of (a) a coupling pressure control device for controlling a hydraulic pressure of the frictional coupling device to be engaged to shift the automatic transmission, such that a rate of rise of the hydraulic pressure is lower when the operation of running stability control device is detected by the running stability control detecting device, than when the operation of the running stability control device is not detected, and (b) a shift point changing device

Abstract: The method of controlling a pressure control solenoid valve which controls hydraulic pressure in a hydraulic control system for an automatic transmission of a vehicle first senses a plurality of vehicle operating conditions, and detects a power-on vehicle operating state based on the sensed vehicle operating conditions. Next, the method controls a duty ratio of the pressure control solenoid valve according to predetermined values corresponding to the power-on state when the power-on state detected. The method then detects a change in the vehicle operating state from the power-on state to a power-off state. Upon detection, the method generates an initial duty ratio for the pressure control solenoid valve based on a predetermined duty ratio corresponding to the power-off state and duty ratios supplied to the pressure control solenoid valve during the power-on state. The pressure control solenoid valve is then controlled according to this initial duty ratio during the power-off state.

Abstract: A control system for downshifting an automatic transmission provides reduced shift shock by controlling pressure fed to a kickdown servo brake. A throttle valve sensor, an input shaft rpm sensor, an output shaft rpm sensor, and a transmission control unit are used. The transmission control unit outputs a control signal for a second-to-first speed shift after reducing hydraulic pressure fed in accordance with a duty pattern when the vehicle is in the state of a second-to-first downshift. Alternatively, the transmission control units outputs a control signal for a second-to-first speed shift after the third-to-second speed shift is completed when the vehicle is in the state of a third-to-first speed shift. In any case, the transmission control units controls first and second transmission control solenoid valves, and a hydraulic pressure control solenoid valve for changing the state of hydraulic pressure fed to every friction member.

Abstract: A hydraulic control system of an automatic transmission. A pressure regulator valve of the hydraulic control system includes a pressure reducing valve for reducing oil pressure created in an oil pump to a predetermined level; a duty solenoid valve for creating a solenoid pressure by draining the oil reduced in the pressure reducing valve according to duty level of a transmission control unit based on open level of a throttle valve; and a pressure regulator valve for supplying the controlled oil to a manual valve acting in relation to a shift lever by controlling pressure of the oil supplied directly from the oil pump based on the reduction of the fluctuation in shock in the pressure accumulating valve.

Abstract: An automatic transmission of a vehicle including a speed change gear mechanism including rotary members such as gears and gear carriers and hydraulically operated friction engaging means and adapted to provide various speed stages according to selective engagement and disengagement of the friction engaging means is controlled by such steps as detecting rotation speed of at least one of the rotary members during a shifting between the speed stages, changing hydraulic pressure of at least one of the friction engaging means during a first phase of the speed stage shifting so as to make the rotation speed of the one rotary member follow a first change performance curve calculated according to a first feedback control program, and changing the hydraulic pressure of the one friction engaging means during a second phase of the speed stage shifting so as to make the rotation speed of the one rotary member follow a second change performance curve calculated according to a second feedback control program in continuity

Abstract: The present invention provides a method and apparatus for controlling the hydraulic line pressure in an automatic transmission for a vehicle in response to the torque transmitted through the transmission such that a minimum hydraulic line pressure is provided to the frictional elements to achieve a no-slip condition through the transmission increasing transmission efficiency, thereby increasing the fuel economy of the vehicle. Hydraulic line pressure is controlled by activating a solenoid activated valve which allows fluid recirculation from the high-pressure side of the hydraulic pump to the low-pressure side of the pump. Control signals are generated based on engine speed, turbine speed, output speed (vehicle speed), hydraulic line pressures, driver selected gear, the operating gear and the torque converter operating condition for energizing the solenoid-actuated valve.

Abstract: A method for controlling shifting of a powershift transmission of an agricultural vehicle in accordance with a boost pressure developed by a turbocharger of an engine associated with said vehicle. The turbocharger generates a turbo boost pressure which is indicative of the engine torque being produced by the engine at a given time. The turbo boost pressure is monitored by a sensor which generates a boost pressure signal in accordance with the sensed boost pressure. This signal is then modified in accordance with the sensed engine speed of the vehicle to produce a compensated turbo boost signal. The compensated turbo boost signal is compared against predetermined full-load and no-load turbo boost values to determine the percentage value of full-load boost pressure, and thus the load on the engine, at a given time.

Abstract: A speed change control method and apparatus for a vehicular automatic transmission having a first-speed clutch for establishing a first speed and a second-speed clutch for establishing a second speed, includes subjection of at least a duty ratio Dr of a second-speed solenoid valve for supplying oil pressure to the second-speed clutch to feedback control, so that the first-speed clutch is engaged while disengaging the second-speed clutch. This thereby increases a turbine rotational speed Nt toward the first-speed synchronous rotational speed. Further, an upper limit value Dmax of the duty ratio Dr is set, and the duty ratio Dr is subject to feedback control within a resultant duty ratio range. This thereby prevents the duty ratio Dr from being set at an excessive value caused by a delay in the rise of the oil pressure. As a result, even if a depression of an accelerator pedal is suddenly increased during a downshifting process, an interlock problem can be prevented, thereby ensuring smooth speed change.

Abstract: An improved adaptive transmission pressure control in which cumulative adaptive corrections are stored in a multi-cell memory array, the cells being associated with specified contiguous ranges of a vehicle operating parameter, such as engine throttle position. Periodically determined adaptive correction amounts are applied to a selected cell which includes the engine throttle setting measured at the initiation of the shift and to two or more cells associated with contiguous engine throttle ranges. In this way, a relatively large number of cells may be employed to minimize approximation errors, while maintaining a cell-to-cell continuum of pressure correction values. In operation, an electro-hydraulic pressure regulator is controlled as a combined function of a predefined pressure command obtained from a normal table look-up and a cumulative correction amount obtained from the memory array.

Abstract: Pulse frequency modulation is used to control brakes and clutches which are operated by fluid pressure actuators controlled by electrically actuated solenoid valves. Short pulse periods for all duty cycles are generated by feedback from the solenoid valve or from the actuator. In one circuit an electrical control triggers a flip-flop which starts solenoid current. Solenoid movement results in back-emf and its effects on the solenoid flux field or current is detected and used as a feedback signal to reset the flip-flop to thereby turn off the current as soon as the valve is operated. In another circuit, a computer control emits a command for a certain pulse period. Actuator pressure or position is monitored to produce a feedback signal to the computer. If the signal is not received, the pulse period is increased for the next pulse command so that a sufficient pulse period will be found. If the magnitude of the actuator response exceeds a threshold, the pulse period is decreased for the next pulse command.

Abstract: A control apparatus for controlling a hydraulic pressure to be applied to a hydraulic operated frictional coupling device of an automatic transmission for a motor vehicle, for an engaging action of the coupling device to establish a given operating position of the transmission. The apparatus includes a detector for detecting a rate of change in a parameter indicative of a progress of the engaging action of the frictional coupling device, and a pressure control device for regulating the hydraulic pressure so that the rate of change in the parameter detected by the detector coincides with a target value. The apparatus further includes an inhibiting device. The execution of a vehicle control function which influences the detected rate of change in the parameter is inhibited by the inhibiting device, while the rate of change in the parameter is detected by the detector.

Abstract: In an electronically controlled automatic power transmission of an automotive vehicle in which an electronic control unit is installed at a predetermined position of the vehicle remote from a main frame of the automatic power transmission, a characteristic storage unit is installed on the main frame of the automatic power transmission, the characteristic storage unit has a memory which stores inherent characteristics of controllable devices and components such as frictional engagement elements, solenoids, and sensors installed in the main frame of the automatic power transmission and is electrically connected to the electronic control unit.

Abstract: A lubrication system for multi-plate clutch assemblies is controlled to provide increased lube flow. During steady state operation, lube flow is increased periodically for a short time interval. At other times during steady state operation, the lube flow is maintained at a level requiring minimum fluid flow for the system.