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-2021095758-A1
Application number	US-202017015356-A
Country	US
Kind code	A1
Filing date	Sep 9, 2020
Priority date	Sep 30, 2019
Publication date	Apr 1, 2021
Grant date	—

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

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 drivers keeps pressing a down paddle shifter ( 25 ) for a long time.

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

• B60W2710/06

  Combustion engines, Gas turbines · CPC title

• B60W2540/12

  Brake pedal position · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60W10/10

  including control of change-speed gearings · CPC title

• B60W30/19 Primary

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