Compensation of influence of transverse acceleration on braking shift-down points

Patent metadata

Field	Value
Publication number	US-10018268-B2
Application number	US-201715415898-A
Country	US
Kind code	B2
Filing date	Jan 26, 2017
Priority date	Jan 28, 2016
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A method for controlling an automatic transmission of a vehicle includes detecting a deceleration of the vehicle; detecting a cornering value of the vehicle; determining, as a function of the deceleration and as a function of the cornering value, a compensated shift-down point of a rotational speed at which shifting into a relatively low gear of the transmission occurs; and selecting a gear as a function of the compensated shift-down point.

First claim

What is claimed is:

1. A method for controlling an automatic transmission of a vehicle, the method comprising:
detecting a deceleration of the vehicle;
detecting a cornering value of the vehicle;
determining, as a function of the deceleration and as a function of the cornering value, a compensated shift-down point, the compensated shift-down point being a rotational speed at which downshifting of the transmission occurs; and
selecting a gear as a function of the compensated shift-down point,
wherein a total force is determined from the deceleration and the cornering value, and
wherein the compensated shift-down point is raised for an increasing total force.

2. The method of claim 1 , wherein a transverse acceleration is detected as a cornering value, and wherein the total force is calculated as an absolute value of a two-dimensional vector with the entries deceleration and transverse acceleration.

3. The method of claim 1 , wherein a steering angle is detected as a cornering value, and wherein the total force is determined from a division of the deceleration by the cosine of the steering angle.

4. The method of claim 1 , wherein the cornering value of the vehicle is a transverse acceleration of the vehicle.

5. The method of claim 1 , further comprising defining a regular shift-down point at which downshifting of the transmission occurs.

6. The method of claim 5 , further comprising determining a gain factor that is a function of the deceleration of the vehicle.

7. The method of claim 6 , further comprising a deceleration shift-down point based on the regular-shift down point and the gain factor.

8. The method of claim 7 , wherein the cornering value of the vehicle is a transverse acceleration of the vehicle, and
wherein the determining, as a function of the deceleration and as a function of the cornering value, the compensated shift-down point comprises:
determining a compensation factor that describes an influence of the transverse acceleration, and
determining the compensated shift-down point based on the compensation factor and the deceleration shift-down point.

9. A control unit for an automatic transmission comprising:
a first detector configured to detect a deceleration of a vehicle;
a second detector configured to detect a cornering value of the vehicle;
a computer configured to:
determine a total force from the deceleration and the cornering value,
determine, as a function of the deceleration and as a function of the cornering value, a compensated shift-down point, the compensated shift-down point being a rotational speed at which downshifting of the transmission occurs, wherein the compensated shift-down point is raised for an increasing total force, and
select a gear as a function of the compensated shift-down point; and

an output unit designed to transfer the gear to a transmission.

10. An automatic transmission for a vehicle having the control unit of claim 9 .

11. A vehicle having the automatic transmission of claim 10 .

12. A method for controlling an automatic transmission of a vehicle, the method comprising:
detecting a deceleration of the vehicle;
detecting a cornering value of the vehicle;
determining, as a function of the deceleration and as a function of the cornering value, a compensated shift-down point, the compensated shift-down point being a rotational speed at which downshifting of the transmission occurs; and
selecting a gear as a function of the compensated shift-down point,
wherein a compensation factor is determined from a characteristic curve that is a function of a transverse acceleration, and wherein the shift-down point is determined by using the compensation factor.

Assignees

• Porsche Ag

Inventors

• Hoffmeister Jan-Peter
• Mueller Torsten

Classifications

• F16H2061/0234

  Adapting the ratios to special vehicle conditions · CPC title

• B60Y2300/70

  Control of gearings · CPC title

• F16H61/21

  Providing engine brake control · CPC title

• F16H59/48 Primary

  Inputs being a function of acceleration · CPC title

• F16H2061/009

  using formulas or mathematic relations for calculating parameters · CPC title