Abstract: A shift control system for an automatic transmission. The shift control system includes an oil temperature sensor, a hydraulic controller to operate a hydraulic clutch, and a control unit in operative communication with the oil temperature sensor and the hydraulic controller. When a gear shift is requested just after an engine restart, the control unit controls the hydraulic clutch with an adjusted shift control process, in contrast to a normal condition of the engine. This adjustment is determined based on a first oil temperature at a time point when the engine is last stopped and on a temperature difference between the first oil temperature and a second oil temperature at a time point when the engine is last restarted after the last engine stop.

Abstract: In control apparatus and method for an automatic transmission, an initial hydraulic reference value is calculated which provides a reference value of an initial hydraulic from a shift kind and a throttle opening angle or from the parameter value corresponding to the throttle opening angle and a correction quantity is calculated for the reference value of the initial hydraulic on the basis of squares of a revolution speed of a piston calculated and of the revolution speed of the piston detected, the initial hydraulic reference value being set to the initial hydraulic during the ordinary gear shift and the initial hydraulic reference value being corrected by a correction quantity to set the corrected initial hydraulic reference value to the initial hydraulic when the gear shift to a predetermined target gear shift stage is carried out at a drive point different from during the ordinary gear shift.

Abstract: In control apparatus and method for an automatic transmission, an initial hydraulic reference value is calculated which provides a reference value of an initial hydraulic from a shift kind and a throttle opening angle or from the parameter value corresponding to the throttle opening angle and a correction quantity is calculated for the reference value of the initial hydraulic on the basis of squares of a revolution speed of a piston calculated and of the revolution speed of the piston detected, the initial hydraulic reference value being set to the initial hydraulic during the ordinary gear shift and the initial hydraulic reference value being corrected by a correction quantity to set the corrected initial hydraulic reference value to the initial hydraulic when the gear shift to a predetermined target gear shift stage is carried out at a drive point different from during the ordinary gear shift.

Abstract: A shift control system for an automatic transmission. The shift control system includes an oil temperature sensor, a hydraulic controller to operate a hydraulic clutch, and a control unit in operative communication with the oil temperature sensor and the hydraulic controller. When a gear shift is requested just after an engine restart, the control unit controls the hydraulic clutch with an adjusted shift control process, in contrast to a normal condition of the engine. This adjustment is determined based on a first oil temperature at a time point when the engine is last stopped and on a temperature difference between the first oil temperature and a second oil temperature at a time point when the engine is last restarted after the last engine stop.

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 engine torque estimating apparatus is connected to an automatic transmission and an internal combustion engine. A control unit of the engine torque estimating apparatus is arranged to stop a fuel supply to the engine when a predetermined engine operating condition is satisfied, to estimate a torque generated by the engine using a first map which has defined the torque according to an engine speed and an intake air flow of the engine when the fuel supply to the engine is executed, and to estimate the torque using a second map which has defined the torque according to the engine speed when the fuel supply to the engine is stopped.

Abstract: An engine torque estimating apparatus is connected to an automatic transmission and an internal combustion engine. A control unit of the engine torque estimating apparatus is arranged to stop a fuel supply to the engine when a predetermined engine operating condition is satisfied, to estimate a torque generated by the engine using a first map which has defined the torque according to an engine speed and an intake air flow of the engine when the fuel supply to the engine is executed, and to estimate the torque using a second map which has defined the torque according to the engine speed when the fuel supply to the engine is stopped.

Abstract: A transmission control system, includes:

Abstract: A control device of an automatic transmission of a motor vehicle includes lock-up control means for controlling a coupling state between input and output elements of a torque converter clutch. This control device is used with an engine, which includes an electronic throttle control device that electrically controls a throttle valve, accelerator position detecting means for detecting an accelerator pedal position, a cruise control device that controls an opening of the throttle valve to maintain a vehicle speed at a predetermined vehicle speed, for enabling constant-speed running of the vehicle, and target throttle opening setting means for calculating a pseudo accelerator pedal position, and setting a target throttle opening based on the pseudo accelerator pedal position, when the cruise control device is in operation.

Abstract: The present invention relates to a control apparatus for a vehicle equipped with an electronic throttle control unit (drive by wire) as electronic throttle control means and an automatic transmission, and the object of the invention is to provide a control apparatus for a vehicle which is capable of ensuring stable travel even in the case where a throttle valve is stuck by a failure of an electronic throttle control unit. In a control apparatus for a vehicle equipped with electronic throttle control means for electrically driving a throttle valve by drive means and an automatic transmission having a plurality of speed change gear stages, the control apparatus is provided with sticking judgment means for judging whether or not the throttle valve has been stuck, and speed change regulation means for inhibiting use of a predetermined gear stage among the speed change gear stages of the automatic transmission in the case where the throttle valve is judged to have been stuck by the sticking judgment means.

Abstract: A shift control method for an automotive automatic transmission is provided, which reduces a shift shock particularly at the time of a skip down-shift, and shortens a required shifting time period. An electronic control unit of a shift control apparatus releases the engagement of a clutch of a subsidiary transmission mechanism and engages a one-way clutch so as to establish a gear position not used in the normal speed change when a shift command from the fifth shift position to the third shift position is issued, gradually decreasing a valve opening duty ratio of an electromagnetic valve associated with a brake of a main transmission mechanism from an initial value D.sub.HLi before this gear position is established, determines an average turbine rotation speed changing rate dD.sub.TAVE /dt from the detected turbine rotation speed (S203), and learning correction of the initial value D.sub.HLi is made if the changing rate deviates from a target range (S204-S208).

Abstract: A speed change control apparatus for an automatic transmission includes a transmission control unit for controlling gear-changing. The control unit discriminates a fluid temperature/rotational speed zone based on the hydraulic fluid temperature and the engine speed at the start of gear-changing, and detects a time period from the end of dead-stroke elimination of an engagement-side hydraulic clutch to the start of actual gear-changing. In the case that a condition for executing learning correction is satisfied and if a time period from the end of the dead-stroke elimination to the start of the actual gear-changing is longer than an upper limit, the control unit increases a learning-correction time with which a dead-stroke-elimination time for the discriminated temperature/speed zone is calculated. The learning-correction time is decreased if such a time period is shorter than a lower limit.

Abstract: In a shift control method, when a speed ratio of an automatic transmission is shifted from a third speed ratio to a first speed ratio before stoppage of a vehicle, a down shift line 3-1 in a shift pattern is shifted to a high-speed side to initiate shifting under a power-OFF condition. A third brake is released by setting the duty ratio of an electromagnetic valve of the third brake at 0% to establish a free condition (neutral condition) in an output shaft of a second transmission. While the duty ratio of an electromagnetic valve of a second clutch in a first transmission mechanism is set at 0%, the duty ratio of an electromagnetic valve of a second brake is gradually increased, so that the shifting from the second clutch to the second brake is made, and the first transmission mechanism is operatively shifted from the third speed ratio to a speed ratio corresponding to the first speed ratio.

Abstract: A speed change control method for an automatic transmission is provided, which is capable of reducing a shift shock and a required shifting time period. A skip down-shift from a first shift position to a second shift position is effected by way of a third shift position which is not used in a normal shifting. If it is determined that a difference (N.sub.TM -N.sub.T) between the present turbine rotation speed N.sub.T and the synchronous rotation speed N.sub.TM for the third shift position becomes smaller than a threshold value .DELTA.N.sub.FM during the shifting from the first shift position to the third shift position, a control for releasing a friction engaging element 23, corresponding to a releasing side speed-changing element of the third shift position, is started prior to establishment of the third shift position, whereby a time period for establishing the third shift position is shortened, so that a shift shock and a required shifting time period are reduced.

Abstract: A speed change control method for an automatic transmission, which can achieve a smooth skip downshifting even when a driver depresses an accelerator pedal slowly in kickdown. An electronic control unit 6 calculates, at the time when a predetermined time period elapses from the time when a downshifting command from a fourth speed to a third speed is outputted, a difference between the throttle valve opening degree .theta..sub.t1 at that time and the throttle valve opening degree .theta..sub.ts at the time when the downshifting command is outputted, and a change rate (.dwnarw..sub.t1)' of the throttle valve opening degree at the time when the predetermined time period elapses. If the calculated difference is larger than the threshold value .DELTA..theta. and the calculated change rate is higher than the threshold value .DELTA.(.theta.

Abstract: A speed change control apparatus of an automatic transmission has a transmission control unit. When determining a fault of a power-on/off determining section on the basis of engine load information from an engine control unit, the transmission control unit controls an oil pressure controller by regarding an engine as being in a power-on state in upshifting and by regarding the engine as being in a power-off state in downshifting. As a result, in either of upshifting and downshifting, the moment when a disengagement-side friction element of the transmission begins to slip and the moment when an engagement-side friction element is engaged are made proper. This makes it possible to surely prevent undesired rise in the engine rotation during the speed change in upshifting and inability in speed change in downshifting, which are caused by a fault of the power-on/off determining section.

Abstract: An automatic transmission control method and apparatus for a vehicle includes a first gear change mechanism in which an input shaft is connected to an output shaft of a fluid coupling and a rotational speed of the output shaft of the first gear change mechanism is changed by selectively controlling hydraulic oil supplied to and discharged from a plurality of first frictional engaging elements. It further includes a second gear change mechanism in which an input shaft is connected to the output shaft of the first gear change mechanism, the output shaft is connected to a driving wheel member and an output shaft rotational speed of the second gear change mechanism is controlled by selectively controlling the hydraulic oil supplied to and discharged from a plurality of second frictional engaging elements.

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: During downshift operation of an automotive automatic transmission in which a lower-speed clutch for establishing a lower-speed gear is engaged while a higher-speed clutch, which has established a higher-speed gear, is disengaged, to increase the turbine rotational speed Nt toward a synchronous rotation speed Ntj associated with the lower-speed gear, speed change control is carried out according to the same control method regardless of whether the engine is in a power-on or power-off state. A target change rate (Nir)' of turbine rotational speed associated with the higher-speed clutch and a target change rate (Nia)' of turbine rotational speed associated with the lower-speed clutch are set, and a change rate (Nt)' of the turbine rotational speed is detected.

Abstract: During downshift operation of an automotive automatic transmission in which a lower-speed clutch for establishing a lower-speed gear is engaged while a higher-speed clutch, which has established a higher-speed gear, is disengaged, to increase the turbine rotational speed Nt toward a synchronous rotation speed Ntj associated with the lower-speed gear, speed change control is carried out according to the same control method regardless of whether the engine is in a power-on or power-off state. A target change rate (Nir)' of turbine rotational speed associated with the higher-speed clutch and a target change rate (Nia)' of turbine rotational speed associated with the lower-speed clutch are set, and a change rate (Nt)' of the turbine rotational speed is detected. The transmission torque through the higher-speed clutch is controlled in a feedback manner such that the detected change rate (Nt)' coincides with the change rate (Nir)'.