Unisia Jecs Corporation

Japan Electronic Control Systems Company, Limited

Masuo Kashiwabara

Hiroyuki Yuasa

Yoshikazu Tanaka

Hideki Sekiguchi

Shinpei Nakaniwa

Hiromitsu Yamaura

Junichi Furuya

Yoshiki Yuzuriha

Masanobu Horiguchi

Seiichi Otani

Tomoyuki Hirose

Hirohisa Kobayashi

Masayuki Hosono

Kazuki Kamada

Kaname Suehiro

Susumu Morita

Hideyuki Kojima

Seiichi Ohtani

Takafumi Fukumoto

Akira Shimizu

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.

Gearshift pressure controller using torque ratio of oncoming/offgoing

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.

Apparatus for controlling upshifts or downshifts as a function of

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.

Method and apparatus for controlling a continuously variable transmission

Control system and method for vehicle with continuously variable

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.

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.

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.&gt;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.

Control apparatus for vehicle

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.

Apparatus for controlling continuously variable transmission and method

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'&gt; 'imax', 'itgt' is limited to 'imax'.

Control apparatus for vehicle with continuously variable transmission

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.

Apparatus and method for control of a vehicle fitted with an automatic

Method and apparatus for controlling, during N-D or P-D shift, the

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.

Apparatus and method for control of the air-fuel ratio of an automotive

Automatic transmisson controller

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.

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Atsugi, Japan

Masuo Kashiwabara