Jatco Corporation

Nissan Motor Company Limited

Hideshi Wakayama

Kousuke Waku

Keichi Tatewaki

Masayuki Miyazono

Naohiro Yamada

Noritaka Aoyama

Hiroyasu Tanaka

Mamiko Inoue

Yuzuru Tohta

Seiji Kasahara

Seiichiro Takahashi

Daisuke Matsumoto

Takashi Matsuda

Toshimitsu Araki

Tatsuo Ochiai

Takuichiro Inoue

Yoshinobu Kawamoto

Kouji Saitou

Naohiro Hoshi

Yusuke Kimura

Tateki Jozaki

Shinichiro Watanabe

Tetsuya Izumi

Hiroshi Sekiya

Koji Dohi

Hyuk Park

Katsumi Doihara

Toshiaki Noda

Kunihiro Takahashi

Takashi Koguchi

Makoto Komatsu

Azusa Shimoda

Koutarou Tagami

Tatsuya Ozone

Yuuji Nagase

Sho Okutani

Kyounggon Choi

Shoichi Sekiguchi

Yoshinori Ishimori

Ruofeng Liu

Masashi Sato

Tomonari Uchiyama

Hideaki Sasaki

Toshio Saitou

In a vehicle equipped with a torque converterhaving a lock-up clutch (), learning control for obtaining a learning value (L_n) on the basis of meet-point information, with which the lock-up clutch () initiates torque transmission, is carried out. When the lock-up clutch () experiences a transition to an engaged state during travel, a meet-point learning control unit () calculates an LU transmission torque estimate on the basis of the difference between the engine torque (engine torque signal value Te) and the torque converter transmission torque (&#x3c4;&#xb7;Ne). Excess clutch capacity is detected when the LU transmission torque estimate is greater than an excess capacity determination transmission torque threshold within a prescribed amount of time after an initial pressure (P_n) based on the learning value (L_n) is instructed. When excess clutch capacity is detected, a learning value correction that reduces the learning value (L_n) is carried out.

Lock-up clutch control device for vehicle, and lock-up clutch control method

A transmission includes a sub-transmission mechanism, a variator having lower shift responsiveness than the sub-transmission mechanism, and a controller configured to carry out a coordinated shift for changing a speed ratio of the variator in a direction opposite to a changing direction of a speed ratio of the sub-transmission mechanism as the sub-transmission mechanism is shifted so that a through speed ratio reaches a target through speed ratio. The controller sets a target speed ratio of the sub-transmission mechanism on the basis of the target through speed ratio and an actual speed ratio of the variator in carrying out the coordinated shift.

Transmission and control method for transmission

In a drive control device, a controller automatically stops an engine if an execution condition of an idling stop is satisfied, and an electric oil pump is driven during an automatic stop of the engine. A first friction engaging element establishes a starting gear position and a second friction engaging element is released when a vehicle starts. A second solenoid drains oil to be supplied to the second friction engaging element according to an indicator current. A drain degree becomes smaller by reducing the indicator current. The controller reduces the indicator current below a minimum value during the automatic stop of the engine.

Vehicle drive control device and control method for vehicle drive control device

In a vehicle equipped with a torque converter () having a lock-up clutch (), learning control for obtaining a learning value (L_n) on the basis of meet-point information, with which the lock-up clutch () initiates torque transmission, is carried out. After acquiring the current learning detection value (M_n), a meet-point learning control unit () calculates the current detection error (E_n) on the basis of the difference between the current learning detection value (M_n) and the previous learning value (L_(n&#x2212;1)) that is stored. When the current and previous detection errors (E_n) and (E_n&#x2212;1) have the same plus/minus sign, the current learning value correction amount is set to a larger value if the absolute value |(E_n&#x2212;1)| of the previous detection error (E_n&#x2212;1) is large than if the absolute value |(E_n&#x2212;1)| is small. The sum of the previous learning value (L_(n&#x2212;1)) and the current learning value correction amount is set as the present learning value (L_n).

In a transmission, a controller sets a target line pressure to an offset target value, which is a value obtained by adding a positive offset amount to one of a target PRI pressure and a target SEC pressure, in a speed ratio range in which the offset target value is higher than the other at least during an inertia phase in a sub-transmission mechanism when a coordinated shift is carried out. At that time, the one of the target PRI pressure and the target SEC pressure is the target SEC pressure when a variator is downshifted by the coordinated shift while being the target PRI pressure when the variator is upshifted by the coordinated shift.

In a vehicle on which a torque converter having a lock-up clutch is mounted between an engine and a transmission, a meet point learning controller is provided to perform learning control for obtaining a learning value based on information on a meet point at which the lock-up clutch starts torque transmission. The meet point learning controller estimates a LU transmission torque based on a difference between an engine torque signal value and a torque converter transmission torque when the lock-up clutch moves from a non-engaged state to an engaged state during traveling of the vehicle, and uses, as the meet point information, a meet point detection pressure at a time when the LU transmission torque estimated value is determined to have entered an upward trend.

Vehicle lock-up clutch control device and lock-up clutch control method

The present invention relates to a control device and a control method for a vehicle in which a lockup clutch is disengaged when a rotation speed of an engine falls below a disengagement rotation speed. The device/method changes a speed ratio of a variator on the basis of a shifting map in which a primary pulley rotation speed on a coast line is set higher than a primary pulley rotation speed on a drive line and sets a target input rotation speed of the variator to a predetermined target input rotation speed higher than the primary pulley rotation speed on the drive line when an operation of an accelerator pedal is performed such that an accelerator pedal opening falls to a first predetermined opening or less. As a result, the present invention can suppress drop of fuel efficiency of the engine caused by disengagement of the lockup clutch which is a friction engagement element.

Vehicle control device and vehicle control method

An automatic transmission control device implements a downshift by disengagement of a clutch that is engaged in a gear position before the downshift. It is determined whether an engine state is in a predetermined region in which a change of an engine torque per a change of an accelerator pedal opening is smaller than that in another region, and the engine torque is within a predetermined range, and an engine rotational speed is within a predetermined range. It is determined whether an operating state is in a predetermined state of accelerator operation in which the accelerator pedal opening is larger than a predetermined value, and an accelerator pedal opening change rate has an absolute value smaller than a predetermined value. The downshift is inhibited in response to determination that the engine state is in the predetermined region and the operating state is in the predetermined state of accelerator operation.

Automatic transmission control device

An engine control device for a vehicle including a power train where a continuously variable transmission is coupled to an engine, includes engine torque control means configured to control the engine so as to obtain an basic engine torque corresponding to an operating state of the vehicle, and command means configured to command engine torque control means to increase an engine torque from the basic engine torque during a gear shifting from a first speed stage to a second speed stage. The continuously variable transmission includes a continuously variable transmission mechanism, an auxiliary transmission mechanism that includes at least a first engagement portion and a second engagement portion to achieve the gear shifting from the first speed stage to the second speed stage, and shift control means configured to set a target value of a transmission gear ratio of the entire continuously variable transmission mechanism and the auxiliary transmission mechanism based on the operating state of the vehicle to control the continuously variable transmission mechanism such that the target value is achieved.

Engine control device for vehicle and engine control method for vehicle

A transmission including a variator capable of continuously changing a speed ratio, a stepped transmission mechanism arranged in series with the variator and in which a gear position is switched and a shilling control unit executing stepped shifting repeatedly performing a shifting suppression phase and an upshift phase when a stepped upshift shifting condition is satisfied is provided, and the shifting control unit completes a change from an n-th gear position of the stepped transmission mechanism to an n+1 gear position if the stepped transmission mechanism is at the n-th gear position before the through speed ratio reaches a Highest speed ratio of the variator when the stepped shifting is performed.

Transmission and control method of transmission

In a control apparatus for an automatic transmission including a continuously variable transmission mechanism continuously modifying speed ratio and a stepped transmission mechanism that is disposed on a downstream side of the continuously variable transmission mechanism and being switched between a plurality of gear positions by engaging and disengaging a plurality of frictional engagement elements, the control apparatus comprises a control unit that performs a coordinated shift by shifting the stepped transmission mechanism and simultaneously shifting the continuously variable transmission mechanism in an opposite direction to a shift direction of the stepped transmission mechanism in order to suppress variation in a through speed ratio, which is an overall speed ratio of the automatic transmission, when the stepped transmission mechanism is upshifted and the control unit predicts, on the basis of an increase in an accelerator opening, that judder will occur in the frictional engagement element during the upshift, the control unit reduces a shift speed of the continuously variable transmission mechanism while shudder is predicted to occur in the frictional engagement element in comparison with a shift speed of the continuously variable transmission mechanism during the coordinated shift, the coordinated shift being executed at an accelerator opening corresponding to the increased accelerator opening.

Control apparatus and control method for automatic transmission

A vehicle control device for controlling a vehicle with a drive source, a friction transmission mechanism provided between the drive source and drive wheels and a fluid transmission mechanism provided between the friction transmission mechanism and the drive source includes a suppression unit configured to suppress a decrease of a speed ratio of the fluid transmission mechanism if the speed ratio becomes negative when the vehicle starts.

A vehicle control device calculates a target line pressure based on an instructed torque capacity of a friction engaging element and a belt capacity when the friction engaging element is determined as not engaging. Belt capacity is calculated using an input torque of a continuously variable transmission mechanism. The device calculates torque down in a driving source based on an upper limit line pressure when the calculated target line pressure exceeds such line pressure. A limit torque capacity of the friction engaging element is calculated using the input torque and a belt capacity when the friction engaging element is determined as not engaging. The belt capacity is calculated using an actual line pressure. The device restrains a slip between pulleys and a power transmitting member using the target line pressure, the torque down, and the limit torque capacity when the friction engaging element is determined as not engaging.

Vehicle control device and method for controlling the same

A vehicle control device controls a vehicle that has an electric oil pump, executes idling stop control for stopping a drive source when predetermined conditions are satisfied, and is capable of applying a braking force in a state where a brake pedal is released. The vehicle control device determines whether or not the vehicle is stopped, determines whether or not the electric oil pump is driven, and executes the idling stop control when stop of the vehicle is determined, driving of the electric oil pump is determined, and the braking force is applied to the vehicle. Application of the braking force is started after the vehicle is determined to be stopped and the electric oil pump is determined to be driven.

A control device () for a stepped transmission mechanism is configured to perform an interlock by engaging a first clutch () and increasing hydraulic pressure of a second clutch () up to a first predetermined pressure (P) such that an output shaft of the transmission mechanism is fixed, after an idle-stop condition including at least a requirement that a vehicle is stationary was satisfied and before a stop of an engine (). The control device includes a gradient detecting section () that detects a gradient (R) of a road surface on which the vehicle is stationary; and a hydraulic control section () that performs a slipping interlock by reducing the hydraulic pressure to a second predetermined pressure (P), if the gradient R detected by the gradient detecting section is lower than or equal to a predetermined value (R) during the interlock and before the stop of the engine.

Growing community of inventors

Hadano, Japan

Hideshi Wakayama