Control device and control method for continuously variable transmission
AssigneeAisin Aw Co., Ltd.
InventorsAkihiro Kikkawa, Masaki Ueda, Masachika Kato
Life of this patent
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Abstract
A control device for a continuously variable transmission, which sets a target input rotational speed, or a target value of an input rotational speed of the continuously variable transmission mounted on a vehicle, such that a speed ratio is changed in a stepped manner and which controls the continuously variable transmission such that the input rotational speed becomes equal to the target input rotational speed.
Claims20
A control device for a continuously variable transmission, which sets a target input rotational speed, or a target value of an input rotational speed of the continuously variable transmission mounted on a vehicle, such that a speed ratio is changed in a stepped manner and which controls the continuously variable transmission such that the input rotational speed becomes equal to the target input rotational speed, the control device comprising:
- an electronic control unit that includes control logic, which when executed:
- obtains a current accelerator operation amount and a current vehicle speed;
- obtains a current vehicle speed range corresponding to the current accelerator operation amount and the current vehicle speed from a plurality of vehicle speed ranges that are determined for each accelerator operation amount by dividing a possible vehicle speed range for the accelerator operation amount into a plurality of ranges;
- obtains an increase gradient corresponding to the current accelerator operation amount and the current vehicle speed range from increase gradients of the input rotational speed which are determined for the plurality of vehicle speed ranges for each accelerator operation amount;
- sets, at a timing the speed ratio is changed to an upshift side in a stepped manner, the target input rotational speed to a value lower than a current input rotational speed;
- and
- sets, after the input rotational speed is set, the target input rotational speed such that the input rotational speed changes according to the increase gradient obtained.
A control method for a continuously variable transmission, in which a target input rotational speed, or a target value of an input rotational speed of the continuously variable transmission mounted on a vehicle, is set such that a speed ratio is changed in a stepped manner and in which the continuously variable transmission is controlled such that the input rotational speed becomes equal to the target input rotational speed, the method comprising the steps of:
- (a) setting, via an electronic control unit, at a timing the speed ratio is changed to an upshift side in a stepped manner, the target input rotational speed to a value lower than a current input rotational speed;
- (b) obtaining, via the electronic control unit, a current vehicle speed range corresponding to a current accelerator operation amount and a current vehicle speed from a plurality of vehicle speed ranges that are determined for each accelerator operation amount by dividing a possible vehicle speed range for the accelerator operation amount into a plurality of ranges;
- (c) obtaining, via the electronic control unit, an increase gradient corresponding to the current accelerator operation amount and the current vehicle speed range obtained in the step (b) from increase gradients of the input rotational speed which are determined for the plurality of vehicle speed ranges for each accelerator operation amount;
- and
- (d) setting, via the electronic control unit, the target input rotational speed such that the input rotational speed changes according to the increase gradient obtained in the step (c), wherein
- the steps (b), (c), and (d) are performed at predetermined time intervals after the target input rotational speed is set in the step (a).
Dependencies are inferred from the claim text.