Abstract: A gearshift controller for an automatic transmission comprises an input shaft torque estimating portion for estimating the input shaft torque, a torque dividing ratio setting portion for setting the torque dividing ratio for each friction member of each gear range, and a desired torque calculating portion for calculating the desired torque of each friction member on the basis of the input shaft torque and the torque dividing ratio, and a desired hydraulic fluid calculating portion for calculating the desired hydraulic fluid pressure for each friction member on the basis of the desired torque of the each friction member, and a hydraulic fluid controlling portion for providing the desired hydraulic fluid pressure to each friction member.

Abstract: The up-shift is discriminated to be in any one of a first up-shift mode in which the throttle opening degree remains nearly constant, a second up-shift mode accompanying the operation for nearly fully closing the throttle or a third up-shift mode accompanying the operation for closing the throttle to a half opened state. On the other hand, the down-shift is discriminated to be either in a first down-shift mode which accompanies the operation for opening the throttle or in a second down-shift mode accompanying the decrease in the vehicle speed. The rate of changing the speed is set for each of the speed change modes, and the speed change ratio of the continuously variable transmission is so controlled that the actual speed change ratio is gradually brought to the basic speed change ratio based upon said rate of changing the speed.

Abstract: A basic speed change ratio is set on the basis of vehicle speed and throttle valve opening, and a control target speed change ratio is made to gradually approach the basic speed change ratio in accordance with a speed change speed. Feedback control is then carried out so that the actual speed change ratio coincides with the control target speed change ratio. When there is an up-shift requirement with a rate of change in throttle valve opening equal to or less than a predetermined value, and a rate of change in the basic speed change ratio, which is set on the basis of operating conditions, equal to or less than a predetermined value, the speed change speed is faster than at the time of an up-shift requirement with throttle valve closure.

Abstract: A steady state transmission ratio Base i is computed from a vehicle speed VPS and a throttle opening TVO (S1). An output shaft revolution speed No of the transmission and a current transmission ratio i are detected (S2, S3). A coefficient TTINR is computed from a difference or a ratio or the like between the steady state transmission ratio Base i and the current transmission ratio i (S4). Then, from the current transmission ratio i, the output shaft revolution speed No and the coefficient TTINR, a shift speed SV=TTINR/(IE.times.i.times.No) is computed (S5). Then a shift control is performed in accordance with the shift speed SV so as to approach to the steady state transmission ratio Base i (S6.about.S9). Thus, the shift speed during shifting in a continuously variable transmission is controlled in consideration of inertia torque.

Abstract: In order to optimize the speed change control of a continuously variable transmission, a necessary minimum primary pressure (Ppmin) for achieving a target speed change ratio is computed, and also a necessary minimum line pressure (Plmin) for the non occurrence of slippage between a secondary pulley 5 and a belt 6 is computed, and a required speed change ratio line pressure (Plratio) which can realize a target speed change ratio without slippage on the primary pulley 4 side is computed. The highest of these is then selected. The selected line pressure (Pl base) is then corrected by a transition line pressure (Pl add) determined from engine torque (TQ.sub.ENG) and speed change speed (SV), to obtain a final output line pressure (Plprs) which is then used to control a secondary pulley actuator 5a. In this way, speed change control can be optimized, for example by controlling slipping of the belt 6 at the time of rapid speed change.

Abstract: In order to optimize the speed change control of a continuously variable transmission, a necessary minimum primary pressure (Ppmin) for achieving speed change ratio control, a necessary minimum line pressure (Plmin) for the non occurrence of slippage between a secondary pulley 3 and a belt 4, and a required speed change ratio line pressure (Plratio) which can realize a target speed change ratio without slippage on the primary pulley 2 side are computed. The highest of these is then selected, and a final output line pressure (Plprs) then obtained based on the selected line pressure. By using this line pressure (Plprs) to control a secondary pulley actuator 3a, slipping of the belt 4 can be prevented and a target speed change ratio achieved, with an extremely simple construction compared to that of conventional arrangements.

Abstract: A basic speed change ratio is set on the basis of vehicle speed and throttle valve opening, and a control target speed change ratio is made to gradually approach the basic speed change ratio in accordance with a speed change speed. Feedback control is then carried out so that the actual speed change ratio coincides with the control target speed change ratio. When there is an up-shift requirement with a rate of change in throttle valve opening equal to or less than a predetermined value, and a rate of change in the basic speed change ratio, which is set on the basis of operating conditions, equal to or less than a predetermined value, the speed change speed is faster than at the time of an up-shift requirement with throttle valve closure.

Abstract: With the present invention, it is possible for a vehicle to run on an uphill road at substantially the same throttle opening as on a horizontal road.When the road is uphill (hill-climbing resistance R.theta.>0), a maximum acceleration Amax for a full throttle opening is obtained according to a vehicle speed, and a maximum driving force Fmax=m.multidot.Amax+RL is calculated based on the mass of the vehicle m and the rolling and air resistance RL of the vehicle. Then, a correction coefficient HOS is obtained according to a throttle opening to calculale a required driving force Ftgt=Fmax.multidot.HOS. According to the required driving force Ftgt, hill-climbing resistance R.theta., and vehicle speed VSP, a target horsepower Ptgt=(Ftgt+R.theta.).multidot.VSP is calculated. To attain the target horsepower Ptgt, a target speed change ratio "itgt" for a continuously variable transmission is calculated to control the transmission.

Abstract: The speed change ratio of a continuously variable transmission is controlled so that the actual speed change ratio approaches the basic speed change ratio at a predetermined rate of changing the speed by setting the basic speed change ratio based upon the opening degree of the accelerator and the vehicle speed. Here, when a change in the basic speed change ratio accompanying the accelerator operation is against the direction in which the actual speed change ratio approaches the basic speed change ratio, the speed is forcibly and temporarily changed to follow the change in the basic speed change ratio.

Abstract: A control apparatus for a vehicle having a continuously variable transmission between an engine and a drive shaft prevents the transmission from shifting up when an accelerator is released on a curved uphill road, which also prevents transmission-gear-ratio hunting. A high-speed-side upper limit "imax" on the speed change ratio of the transmission is set according to a decreasing function with respect to the absolute value .vertline.R.THETA..vertline. of a hill-climbing resistance and a vehicle speed VSP. A target transmission speed change ratio "itgt", which is determined according to a target horsepower calculated from the hill-climbing resistance, is compared with the upper limit "imax", and if "itgt"> "imax", "itgt" is limited to "imax".

Abstract: With an engine wherein the setting of a target air-fuel ratio is changed in accordance with operating conditions, and the air-fuel ratio of the engine intake mixture is controlled in accordance with the target air-fuel ratio, a gear ratio in an automatic continuously variable transmission fitted to the engine is forcibly changed towards a ratio which suppresses changes in vehicle drive torque, at the time of changing the setting of the target air-fuel ratio. As a result even with a rapid change in engine output torque following a change in the target air-fuel ratio, a rapid change in the vehicle drive torque can be suppressed, so that vehicle driving stability can be improved.

Abstract: The present invention involves control of an increase in engine output of a vehicle fitted with an automatic transmission incorporating a torque converter, during a period from transmission selector operation from a stop range to a drive range up until a speed ratio (Nt/Ne) of engine rotational speed Ne to torque converter output shaft rotational speed Nt falls below a predetermined value. Control is effected by a method involving for example, maintaining a second control valve used for traction control fully closed. As a result of the invention, completion of the gear selecting operation can be accurately judged, and effects due to alleviation of gear selection shock and reduction in the load on components such as the differential can be reliably achieved.

Abstract: With an internal combustion engine wherein a target air-fuel ratio is set on the basis of engine load and engine rotational speed, a setting for a lean air-fuel ratio for improving fuel consumptions prohibited, when an increase in grade resistance is detected or when winding road conditions are estimated, and sets a target air-fuel ratio to ensure drive power is forcibly set. As a result, lean combustion can be avoided under running conditions requiring drive power, so that the vehicle power performance can be ensured as required.

Abstract: The present invention relates to technology wherein the torque input to an automatic transmission is estimated using an intake flow rate corrected by eliminating an intake flow rate friction component, the invention enabling the intake flow rate at the time of cool down to be accurately corrected. The characteristics of warm-up intake flow rate friction component versus engine rotational speed are pre-stored, and a warm-up intake flow rate friction component retrieved from an actual engine speed. A ratio for when the automatic transmission is in a non driving range, between the actual intake flow rate and the retrieved warm-up intake flow rate friction component is then obtained to set a correction coefficient. The warm-up intake flow rate friction component is then corrected by the most recently set correction coefficient, and this becomes the intake flow rate friction component.

Abstract: A speed change controller for vehicle automatic transmission is constructed such that a speed change range is selected on the basis of vehicle speed and throttle valve opening, and a speed change position for either a low speed change step or a high speed change step is selected from the speed change range by recognizing/judging the vehicle driving conditions. As a result speed change timing can be appropriately controlled to suit to environmental changes, and speed change control catering equally to the individual needs of a large variety of drivers is possible.

Abstract: In an anti-lock braking apparatus, by detecting brake torque at a wheel and controlling the braking force of a wheel brake unit, a locked state of the wheel can be quickly detected to thus enable braking control with fast response characteristics. Also, based on direction of a variation of the brake torque on the wheel, the road friction coefficient is predicted to perform feedback control for the braking force and to adjust the brake torque to a target brake torque, whereby the braking performance can be optimized.

Abstract: In a driving zone where a torque converter is to be locked up, a lockup force of a lockup clutch is weakened in the deceleration driving state compared with that in the non-deceleration driving state. Moreover, during transition from the deceleration driving state to the non-deceleration driving state, increase control of the lockup force is forcedly delayed for a predetermined time. By this, during acceleration from the deceleration driving state, the clutch is made to slip with a rapid increase in engine output torque and a rise in the engine output torque is buffered by the lockup clutch.

Abstract: In an automatic transmission provided with a hydraulic lockup clutch which can directly and mechanically engage an input shaft with an output shaft of a torque converter, input torque of the above torque converter is detected and an working oil pressure supplied to said lockup clutch is detected. And a target oil pressure for said lockup clutch is set based on said input torque, supply of the oil pressure is feedback controlled so that an actual working oil pressure gets close to said target oil pressure, and said lockup clutch is controlled to the semi-clutch state.

Abstract: A speed-changing hydraulic oil pressure control apparatus for controlling speed-changing hydraulic oil pressure according to a transition state of the speed change in an automatic transmission. The controllability is improved by detecting in advance the transfer from a torque phase to an inertia phase by detecting the output torque of the transmission and the input revolution number and output revolution number of a torque converter. The input torque of the transmission is estimated from the input revolution number and output revolution number of the torque converter, and the transition state of the speed change is detected from the input torque and output torque of the transmission. By comparing input torque and output torque of the transmission, the transfer from the torque phase to the inertia passe is detected in advance by utilizing the phenomenon of a large fall of the output torque of the transmission just before the transfer to the inertia phase from the torque phase.

Abstract: A control system for automatic transmission is provided in a motor vehicle having an internal combustion engine and an automatic transmission associated with the engine. The engine is operable on a fuel which is a mixture of gasoline and alcohol. The control system comprises an alcohol sensor for sensing the alcohol concentration in the fuel; a first device for deriving an engine load parameter which represents the load applied to the engine; a second device for correcting the engine load parameter with reference to the alcohol concentration sensed by the alcohol sensor; and a third device for controlling a line pressure of the transmission in accordance with the corrected engine load parameter.