Upshift control method for DCT vehicle

Patent metadata

Field	Value
Publication number	US-10508736-B2
Application number	US-201815984978-A
Country	US
Kind code	B2
Filing date	May 21, 2018
Priority date	Dec 6, 2017
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

An upshift control method for a dual clutch transmission (DCT) for a vehicle includes: determining, by a controller, whether or not an inertia phase begins when a driver accelerator pedal depression amount increases during power-on upshifting; calculating, by the controller, a first control amount, which is a first final clutch torque for controlling an engaging clutch, when the inner phase begins, in consideration of a difference between a current accelerator pedal depression amount and an accelerator pedal depression amount at beginning of the inertia phase, a difference between the current accelerator pedal depression amount and a maximum value of an accelerator pedal depression amount during the inertia phase elapsed until a present time, and a target engine torque, and controlling, by the controller, the engaging clutch with the final clutch torque calculated in the calculating.

First claim

What is claimed is:

1. An upshift control method for a dual clutch transmission (DCT) in a vehicle, the method comprising the steps of:
determining, by a controller, whether or not an inertia phase begins when an accelerator pedal depression amount increases during power-on upshifting;
calculating, by the controller when the inertia phase begins, a first control amount including a first final clutch torque for an engaging clutch based on a difference between a current acceleration amount and an inertia phase acceleration amount at the beginning of the inertia phase, a difference between the current acceleration amount and a maximum inertia phase acceleration amount during the inertia phase, and a target engine torque; and
controlling, by the controller, the engaging clutch with the first final clutch torque calculated in the calculating step.

2. The method according to claim 1 , wherein the current acceleration amount corresponds to a current acceleration pedal depression amount, the inertia phase acceleration amount and the maximum inertia phase acceleration amount correspond to acceleration pedal depression amounts detected at the beginning of the inertia phase and during the inertia phase, respectively.

3. The method according to claim 1 , further comprising: determining, by the controller, whether or not a current shifting progress rate is equal to or greater than a predetermined reference value after the determining step and before the calculating step; and
when the current shifting progress rate is equal to or greater than the predetermined reference value, calculating, by the controller, a second control amount, including a second final clutch torque for the engaging clutch, wherein the second final clutch torque is calculated based on a slip change rate corresponding to a difference between an engine speed and a target shift-stage input shaft speed, and
controlling the engaging clutch using the second final clutch torque.

4. The method according to claim 3 , wherein the second final clutch torque is further calculated based the difference between the current acceleration amount and the inertia phase acceleration amount at the beginning of the inertia phase, the difference between the current acceleration amount and the maximum inertia phase acceleration amount during the inertia phase, and the target engine torque, which are used in calculating the first final clutch torque.

5. The method according to claim 3 , wherein the first final clutch torque is calculated as:
Final Clutch Torque(t)=Final Clutch Torque(t−1)+f{Target Clutch Torque−Final Clutch Torque(t−1), Difference between Current Accelerator Pedal Depression Amount and Maximum Value of Accelerator Pedal Depression Amount during Elapsed Inertia Phase}
where,
Target Clutch Torque=Target Engine Torque−Gap Torque+f(Target Engine Torque, Difference between Current Accelerator Pedal Depression Amount and Accelerator Pedal Depression Amount at beginning of inertia phase), and
Gap Torque=Difference between Target Engine Torque and Engaging Clutch Torque upon completion of torque phase.

6. The method according to claim 3 , wherein the second final clutch torque is calculated as:
Final Clutch Torque(t)=Final Clutch Torque(t−1)+f{Target Clutch Torque−Final Clutch Torque(t−1), Difference between Current Accelerator Pedal Depression Amount and Maximum Value of Accelerator Pedal Depression Amount during Elapsed Inertia Phase}
where,
Target Clutch Torque=Target Engine Torque−Gap Torque+f(Target Engine Torque, Difference between Current Accelerator Pedal Depression Amount and Accelerator Pedal Depression Amount at beginning of inertia phase)+Slip Change Rate Compensation Torque,
where, Gap Torque is difference between Target Engine Torque and Engaging Clutch Torque upon completion of torque phase, and

Slip
⁢

⁢
Chage
⁢

⁢
Rate
⁢

⁢
Compensation
⁢

⁢
Torque

=

Je
*

[

dNi
dt

+

(

dSlip
target

dt

-

dSlip
actual

dt

)

]

where, Je is Engine Rotational Inertial Moment,
Ni is Engaging Input Shaft Speed (Number of Revolutions),
Slip is difference between Engine Speed and Target Shift-stage Input

Shaft Speed (=Engaging Input Shaft Speed), Slip target is Target Slip, and
Slip actual is Actual Slip (=Measured Slip).

7. The method according to claim 1 , wherein the controller ends shifting when slip is equal to or less than a predetermined reference slip amount while performing the controlling step.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Cho Sung Hyun
• Kang Dong Hyup

Classifications

• F16H61/688 Primary

  with two inputs, e.g. selection of one of two torque-flow paths by clutches · CPC title

• F16D2500/70426

  Clutch slip · CPC title

• F16D2500/30412

  Torque of the input shaft · CPC title

• F16H59/18

  dependent on the position of the accelerator pedal · CPC title

• F16H59/48

  Inputs being a function of acceleration · CPC title