Nissan Motor Company Limited

Jatco Corporation

Ryoji Kadono

Tatsuo Ochiai

Hideaki Suzuki

Masaaki Uchida

Masato Koga

Seiichiro Takahashi

Mamiko Inoue

Ryousuke Nonomura

Tateki Jozaki

Yusuke Kimura

Kenichiro Murakami

Atsufumi Kobayashi

Akihiro Makiyama

Yuzo Kageyama

Tetsunobu Morita

Shuusaku Katakura

Shuichi Wakabayashi

An abnormality diagnostic method is provided for a driving force control system in which an automatic transmission is interposed between an engine and a drive wheel, and a target driving force that is transmitted to the drive wheel is calculated based on a driver's output request. The automatic transmission and the engine are controlled based on the target driving force. The abnormality diagnostic method includes calculating a target engine torque based on the target driving force, detecting an actual engine torque of the engine, and detecting an intake temperature of the engine. Upon determining the automatic transmission has been operating normally, abnormality diagnostic method determines an abnormality of the driving force control system exists that is caused by the engine upon determining a difference between the target engine torque and the actual engine torque has exceeded a predetermined threshold value.

Abnormality diagnostic method and abnormality diagnostic device for driving force control system

A vehicle control device includes an engine stop/start determination unit and an engine controller and a re-acceleration scene predicting unit. The engine stop/start determination unit determines stopping and starting of the engine based on a magnitude of the accelerator position opening amount unit. The engine controller carries out the stopping/starting of the engine in accordance with the determination of the engine stop/start determination unit. The re-acceleration scene predicting unit predicts a re-acceleration scene in which an accelerator is depressed after the accelerator has been released based on the accelerator position opening amount. When the re-acceleration scene predicting unit predicts a re-acceleration scene of the engine, the engine stop/start determination unit prohibits the stopping of the engine while the engine is running, and the starting of the engine is carried out by the accelerator being depressed while the engine is stopped.

Vehicle control device

A transmission controller permits a 2-1 shift, in which a gear position of a subtransmission mechanism is changed from a second speed to a first speed, when an accelerator pedal has been depressed to or above a predetermined opening. The gear position of the subtransmission mechanism is changed from the second speed to the first speed when an actual through speed ratio passes a mode switch line from a High side to a Low side while the 2-1 shift is permitted in the subtransmission mechanism.

Continuously variable transmission and control method thereof

A control apparatus for an automatic transmission includes a stepwise variable transmission mechanism; a power ON/OFF state judging section; and a shift control section configured to control the stepwise variable transmission mechanism to a target rotational speed by disengaging the first engagement portion and engaging the second engagement portion in accordance with a torque inputted to the stepwise variable transmission mechanism, the shift control section being configured to engage one of the first engagement portion and the second engagement portion which has a function to suppress a variation of an input rotational speed of the stepwise variable transmission mechanism which is generated by a switching of the power ON/OFF state when the power ON/OFF state is switched at the shift control of the stepwise variable transmission mechanism, and to disengage the other of the first engagement portion and the second engagement portion.

Control apparatus and method for automatic transmission

A control system of an automatic transmission including a stepwise variable transmission section and a continuously variable transmission section makes a speed change control of the continuously variable transmission section cooperate with a change of an input rotation speed of the stepwise variable transmission section and is configured to judge, during the shift change of the stepwise variable transmission section, whether a delivery of a torque from one of a plurality of disengaging side frictional elements to one of a plurality of engaging side frictional elements is completed, and to start the speed change control of the continuously variable transmission section upon judgment that the delivery of the torque is completed and that an inertial phase has started.

Control system of automatic transmission

The transmission controller changes the gear position of the subtransmission mechanism and varies the speed ratio of the variator in an opposite direction to a speed ratio variation direction of the subtransmission mechanism when the actual through speed ratio passes a predetermined mode switch line. When the improvement in the shift response of the continuously variable transmission is determined to be required and the actual through speed ratio passes the mode switch line from a Low side to the High side, the transmission controller increases a shift speed of the subtransmission mechanism compared with a normal coordinated shift.

A control apparatus for an automatic transmission system having a serial arrangement of a stepwise variable automatic transmission mechanism and a continuously variable automatic transmission mechanism, the control apparatus being disposed in the automatic transmission system and performing a shift control of the continuously variable automatic transmission mechanism in accordance with variation in transmission ratio of the stepwise variable automatic transmission mechanism, the control apparatus including a control section configured to execute a retardation processing upon shift control of one of the continuously variable transmission mechanism and the stepwise variable transmission mechanism which has a smaller response delay of an actual transmission ratio from a target transmission ratio than that of the other transmission mechanism.

Control apparatus and method for automatic transmission system

In control apparatus and method for an automatic transmission, a gear shift state of a stepwise variable transmission mechanism is controlled to a target gear shift state by releasing a first engagement section according to a reduction in a capacity of the first engagement section and, simultaneously, by engaging a second engagement section according to an increase in the capacity of the second engagement section, in accordance with a torque inputted to the stepwise variable transmission mechanism and, during an inertia phase, either one of the first and second engagement sections functions as a gear shift state control side engagement section and the capacity of a gear shift state non-control side engagement section which is the other engagement section is increased when determining that it is impossible to make the gear shift state follow up the target gear shift state at the gear shift state control side engagement section.

A continuously variable transmission includes a variator capable of varying a speed ratio continuously, and a subtransmission mechanism provided in series with the variator. On the basis of an operating condition of a vehicle, a transmission controller sets a destination through speed ratio, which is an overall speed ratio of the variator and the subtransmission mechanism to be realized in accordance with the operating condition, and controls the variator and the subtransmission mechanism on the basis thereof. When shifts are prohibited in the subtransmission mechanism, the destination through speed ratio is limited to a speed ratio range that can be realized only by a shift in the variator.

A control apparatus of an automatic transmission has an engagement part, a power-ON/OFF state judgment section and a control section controlling a capacity of the engagement part. The control section compares an actual input revolution speed difference absolute value of an absolute value of a difference between an input revolution speed when engaged and an actual input revolution speed with a target input revolution speed difference absolute value of an absolute value of a difference between the input revolution speed when engaged and a target input revolution speed, then a deviation is determined by subtracting the target input revolution speed difference absolute value from the actual input revolution speed difference absolute value. When the deviation is positive, the capacity is increased. When the deviation is negative, the capacity is reduced. When the deviation is zero, a previous capacity that is set before the comparison of the both absolute values is maintained.

Control apparatus of automatic transmission

A continuously variable transmission includes a variator capable of varying a speed ratio continuously, and a subtransmission mechanism provided in series with the variator. When an actual through speed ratio passes a predetermined mode switch speed ratio, a transmission controller performs a coordinated shift in which a gear position of the subtransmission mechanism is changed and a speed ratio of the variator is varied in an opposite direction to a speed ratio variation direction of the subtransmission mechanism. When the rapid deceleration is determined to be underway, the transmission controller decreases a speed ratio variation amount of the variator in the direction of a High side accompanied by a downshift of the subtransmission mechanism compared with the coordinated shift.

A speed change control device for an automatic transmission according to this invention determines whether or not a request to downshift a gear position of the transmission exists during traveling in a manual speed change mode (S, S), and calculates an input shaft rotation speed of the transmission following a downshift based on the downshift request (S). When it is determined that the calculated rotation speed is higher than a rotation speed limit value (S), the speed change control device performs a downshift to a gear position at which the input shaft rotation speed of the transmission is lower than the calculated rotation speed (S, S).

Growing community of inventors

Kawasaki, Japan

Ryoji Kadono