Toyota Jidosha Kabushiki Kaisha

Aisin Aw Co., Ltd.

Keisuke Ota

Norihiro Tsukamoto

Ayumu Sagawa

Yoshio Hasegawa

Seiji Masunaga

Tomohiro Asami

Tomohiro Chimbe

Daiki Fukuda

Yuji Kajiyama

Koji Oshima

Hiromasa Takai

Tomoya Iwami

Masami Kondo

Hitoshi Matsunaga

Eiji Fukushiro

Hiromichi Kimura

Shogo Tsuge

Toshimitsu Sato

Koji Hattori

Takuma Sugino

Atsuhiko Yokota

Kazuki Imanishi

Daichi Sakakibara

Masataka Hirano

A target gear stage of the automatic transmission of the own vehicle (following vehicle) is determined based on the target acceleration (=required drive torque) and the target vehicle speed of the leading vehicle by the convoy participation time speed change control unit, and when the target gear stage and the actual gear stage of the own vehicle are different, the gear stage of the automatic transmission of the own vehicle is switched to the target gear stage in advance. Thus, the speed change of the following vehicle participating in the convoy traveling can be executed in advance on the gear stage for obtaining the driving force for following the leading vehicle, and disturbance of the convoy traveling is suppressed.

Convoy travel control device

When starting a skip downshift, a controller for an automatic transmission disengages two or more engagement elements that are in an engaged state. The disengaging two or more engagement elements includes setting a first engagement element, which is one of the two or more engagement elements that are disengaged and is used to form an intermediate gear stage having a lower transmission ratio than a post-shifting gear stage, to an engagement preparation state that maintains a state immediately before the engaged state. Subsequently, the controller engages a second engagement element, which is used to form both the intermediate gear stage and the post-shifting gear stage, and temporarily increases engagement pressure of the first engagement element. The controller disengages the first engagement element and engages a third engagement element, which is used to form the post-shifting gear stage, to form the post-shifting gear stage.

Controller for automatic transmission and method for controlling automatic transmission

A control device for a vehicle includes an electronic control unit configured to increase a disengagement-side instructed pressure such that an input rotation speed decreases when overspeeding of the input shaft occurs during a coast downshift of an automatic transmission. Overspeeding of the input shaft in a disengagement-side element that forms a gear stage before a downshift having a lower gear ratio than that after the downshift is suppressed.

Control device for vehicle and control method for vehicle

An automatic transmission control device is configured to execute a first shifting between a pre-shifting gear position and an intermediate gear position, and a second shifting between the intermediate gear position and a post-shifting gear position such that each of the first and second shiftings is executed by releasing one of engagement devices and engaging one of the engagement devices, and is configured, upon transition from the first shifting to the second transition, to gradually changing an engagement torque of an engagement-maintained engagement device as one of the engagement devices which is engaged upon completion of the first shifting and is maintained in the engaged state during the second shifting, such that the engagement torque of the engagement-maintained engagement device is changed gradually from a required engagement torque required upon completion of the first shifting, to a required engagement torque which is required in the second shifting.

Control device of automatic transmission for vehicle

An electronic control unit is configured to control a hydraulic pressures of engaging element and disengaging element in accordance with a preset target output shaft torque during a power-on downshift. The electronic control unit is configured to delay a start of decrease in the hydraulic pressure of the disengaging element from a start of a torque phase while maintain the hydraulic pressure of the disengaging element at the start of the torque phase. The electronic control unit is configured to start decreasing the hydraulic pressure of the disengaging element when the electronic control unit determines that overspeed of an input shaft is occurring during the torque phase and a predetermined condition is established.

Control device for vehicle, and control method for vehicle

A control apparatus for a stepped automatic transmission in which one of a plurality of shift speeds is established by selectively engaging a plurality of frictional engagement elements, the stepped automatic transmission mounted on a vehicle, the control apparatus includes: an electronic control unit configured to perform a control of prohibiting a plurality of shift that is transitioning from an upshift speed change to a downshift speed change, for a predetermined period, when a downshift speed change requirement is requested by an occurrence of an accelerator depression operation during an inertia phase of the upshift speed change in a driven state of a vehicle.

Control apparatus and control method for automatic transmission

A control device of a vehicle including a motor and a multi-speed type automatic transmission including a plurality of engagement devices, the control device engaging the engagement device to be engaged and releasing the engagement device to be released when the shift is determined, and controlling an engagement pressure of an engagement device to be released during an upshift in a driven state and a downshift in a driving state and controlling an engagement pressure of an engagement device to be engaged during an upshift in the driving state and a downshift in the driven state so as to control a rotation speed of a rotating element of the automatic transmission, the control device increasing an instruction pressure of the engagement device to a target surge pressure for a target surge time when switching is performed during the upshift and the downshift in the driven state, to the driving state.

Control device of vehicle

When a jump downshift via an intermediate shift stage is requested and a rotation speed of an input shaft approaches a synchronous rotation speed of the intermediate shift stage, a target torque phase time when the gear shift via the intermediate shift stage is performed with input switching is set to be shorter than that when the gear shift via the intermediate shift stage is performed without using input switching and torque phase control is performed. Accordingly, it is possible to promptly perform engagement of an engagement-side frictional engagement element at the time of passing through the intermediate shift stage and to rapidly perform the gear shift after passing through the intermediate shift stage.

Controller for automatic transmission

When an engagement-side clutch taking charge of rotation control in a downshift is the same as a rotation control clutch in the previous gear shift or a clutch of which the engagement has been switched in the previous gear shift, there is a likelihood that clutch hydraulic controllability will decrease and the clutch hydraulic controllability is secured by delaying start of the gear shift. It is possible to execute a gear shift which is a downshift without unnecessary waiting by setting a delay time by which the start of the gear shift is delayed depending on an accelerator depression amount such that the delay time is shorter when the accelerator depression amount is small than when the accelerator depression amount is large.

Controller for vehicle

An electronic control unit is configured to set a target torque phase time which is used in torque phase control based on an output shaft torque difference. The electronic control unit sets the target torque phase time to be longer when the output shaft torque difference is large than when the output shaft torque difference is small. Accordingly, since the target torque phase time can be appropriately set, it is possible to achieve both of preventing a sudden change in driving force and torsion vibration of an output shaft and preventing a decrease in drivability due to hesitation at the same time. Sudden change in driving force and torsion vibration of the output shaft occur when the difference in driving force between before and after a gear shift is large. Hesitation occurs when the difference in driving force between before and after the gear shift is small.

In a controller for an automatic transmission, when a jump gear shift via a plurality of intermediate shift stages is executed, a first and a second target intermediate shift stages are extracted, and a target input shaft rotation speed change rate is calculated from a difference in synchronous rotation speed between a shift stage before a current gear shift and the second target intermediate shift stage as a target shift stage of a gear shift which is executed after the current gear shift. Accordingly, it is possible to avoid a situation in which a shifting time in the gear shift control of the step before the second target intermediate shift stage becomes very short and thus packing of a clutch pack is not executed in a timely manner.

An electronic control unit updates a target gear shift characteristic value to a target gear shift characteristic value which is set at a gear shift start time with a first predetermined torque based on the first predetermined torque and performs gear shift control from a degree of progress in gear shift based on the updated target gear shift characteristic value, when an input torque becomes equal to or less than the first predetermined torque due to an accelerator returning operation or the like during a gear shift (during a power-on upshift). Accordingly, it is possible to perform stable gear shift control to cope with a decrease in input torque during the gear shift and to suppress occurrence of a shock.

When an input torque becomes greater by a predetermined value or more due to an operation of increasing an amount of accelerator depression amount or the like during a gear shift, a controller for an automatic transmission updates a target gear shift characteristic value to a target gear shift characteristic value which is set when the gear shift is started with the input torque based on the input torque at the updating time, and performs gear shift control from a degree of progress in gear shift at the updating time based on the updated target gear shift characteristic value. Since the target gear shift characteristic value can be changed with respect to an increase in the input torque during the gear shift by this control, it is possible to prevent a decrease in durability of frictional engagement elements.

When a power-on downshift via an intermediate shift stage accompanied by input switching control is required and a predetermined shift stage is a shift stage lower than the intermediate shift stage, an electronic control unit performs torque phase control in a torque phase control time shorter than the torque phase control time that is set when the predetermined shift stage is a shift stage higher than the intermediate shift stage. Accordingly, it is possible to complete disengagement of a disengagement-side element early and to suppress a rapid increase of an input shaft rotation speed due to a clutch torque remaining.

When an engagement-side clutch taking charge of rotation control in an upshift is the same as a rotation control clutch of a previous gear shift, it is determined that there is a likelihood that a thermal load of a clutch friction material will increase, and the thermal load of the clutch friction material is decreased by delaying gear shift start. By setting a delay time by which the gear shift start is delayed when an accelerator depression amount is small to be shorter than when the accelerator depression amount is large depending on the accelerator depression amount, a gear shift which is an upshift can be performed without unnecessary waiting.

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Toyota, Japan

Keisuke Ota