Method to control a road vehicle for the execution of a multiple downshift in a drivetrain provided with a servo-assisted transmission

Patent metadata

Field	Value
Publication number	US-11199256-B2
Application number	US-202017015356-A
Country	US
Kind code	B2
Filing date	Sep 9, 2020
Priority date	Sep 30, 2019
Publication date	Dec 14, 2021
Grant date	Dec 14, 2021

Abstract

A method to control a road vehicle for the execution of a multiple downshift in a drivetrain provided with a servo-assisted transmission; the control method comprises the steps of: detecting a condition of slowing down of the road vehicle and, simultaneously, detecting a driver's request for a multiple downshift; carrying out, in succession, a plurality of downshifts while the road vehicle is slowing down and in an autonomous manner regardless of further interventions of the driver; determining a duration of a shift time interval; and carrying out each downshift following a first downshift when said shift time interval has exactly elapsed since the previous downshift.

First claim

The invention claimed is:

1. A method to control a road vehicle ( 1 ) for the execution of a multiple downshift in a drivetrain provided with a servo-assisted transmission ( 7 ); the control method comprises the steps of:
detecting a condition of slowing down of the road vehicle ( 1 ) and, simultaneously, detecting a driver's request for a multiple downshift;
carrying out, in succession, a plurality of downshifts while the road vehicle ( 1 ) is slowing down and in an autonomous manner regardless of further interventions of the driver;
determining a duration of a single shift time interval (Δt) common to all the plurality of downshifts; and
carrying out each downshift following a first downshift when said shift time interval (Δt) has elapsed exactly since the previous downshift.

2. The control method according to claim 1 , wherein the first downshift is carried out in a same instant (T 1 ) in which the driver's request for a multiple downshift is detected.

3. The control method according to claim 1 , wherein a downshift is delayed if it would cause an excessive increase in a rotation speed (ω e ) of an internal combustion engine ( 4 ) connected to the drivetrain ( 6 ).

4. The control method according to claim 1 , wherein the duration of the shift time interval (Δt) is determined based on a rotation speed (ω e ) of an internal combustion engine ( 4 ) in an instant (T 1 ) in which the driver's request for a multiple downshift is detected.

5. The control method according to claim 1 , wherein the duration of the shift time interval (Δt) is determined based on a gear engaged in the servo-assisted transmission ( 7 ) in an instant (T 1 ) in which the driver's request for a multiple downshift is detected.

6. The control method according to claim 1 , wherein the duration of the shift time interval (Δt) is determined based on a degree of pressing of a brake pedal ( 23 ) in an instant (T 1 ) in which the driver's request for a multiple downshift is detected.

7. The control method according to claim 1 , wherein the duration of the shift time interval (Δt) always remains constant for all downshifts.

8. The control method according to claim 1 , wherein the plurality of downshifts ends when the condition of slowing down of the road vehicle ( 1 ) ceases.

9. The control method according to claim 1 , wherein the condition of slowing down of the road vehicle ( 1 ) is detected by determining a degree of pressing of a brake pedal ( 23 ).

10. The control method according to claim 1 , wherein the driver's request for a multiple downshift is detected if the driver keeps pressing a down paddle shifter ( 25 ) for a period of time exceeding a predetermined time threshold.

11. The control method according to claim 1 and comprising the further steps of:
determining a value of a comfort index in an instant (T 1 ) in which the driver's request for a multiple downshift is detected; and
adjusting a speed of execution of the downshifts based on the comfort index.

Assignees

• Ferrari Spa

Inventors

• Barone Alessandro
• Nannini Andrea
• Senserini Giacomo
• Marconi Stefano

Classifications

• F16H2059/6807

  Status of gear-change operation, e.g. clutch fully engaged · CPC title

• F16H61/0213 Primary

  characterised by the method for generating shift signals · CPC title

• F16H61/08

  Timing control · CPC title

• F16H59/70

  dependent on the ratio established · CPC title

• B60W30/19 Primary

  Improvement of gear change, e.g. by synchronisation or smoothing gear shift · CPC title