Method for Controlling Gear Change During Shifting Rule or Variogram Switching

• US 20080262684A1
• Filed: 07/13/2005
• Published: 10/23/2008
• Est. Priority Date: 07/21/2004
• Status: Active Grant

• Current Assignee: Renault Sas (Renault)
• Original Assignee: Renault Sas (Renault)
• Inventors: Poisson, Carine, Taffin, Christian
• Granted Patent: US 8,180,535 B2
• Time in Patent Office: Days
• US Class Current: 701/57
• CPC Class Codes: B60W 2540/30 Driving style
• CPC Class Codes: F16H 2059/003 Detecting or using driving style of a driver, e.g. for adapting shift schedules
• CPC Class Codes: F16H 2059/082 with different modes
• CPC Class Codes: F16H 2061/0227 Shift map selection, i.e. methods for controlling selection between different shift maps, e.g. to initiate switch to a map for up-hill driving
• CPC Class Codes: F16H 59/18 dependent on the position of the accelerator pedal
• CPC Class Codes: F16H 59/46 dependent on a comparison between speeds
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 61/16 Inhibiting or initiating shift during unfavourable conditions, e.g. preventing forward reverse shift at high vehicle speed, preventing engine over speed unintentional control input F16H61/18
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38
• CPC Class Codes: F16H 61/66254 controlling of shifting being influenced by a signal derived from the engine and the main coupling

Abstract

The inventive method for controlling the gear change of an automatic gearbox provided with distinct shifting rules or variograms used according to a vehicle operating conditions consists in detecting and carrying out gear shifting requests sequential to the shifting rule or variogram switching, subject to the application of specific conditions only.

Claims

1-11. -11. (canceled)

12. :

A method for control of changes of gear ratio of an automatic transmission programmed with distinct shifting rules or variograms including a plurality of shifting curves, and applied according to operating conditions of the vehicle, comprising;

detecting and executing requests for gear ratio changes following a switch of shifting rule or of variogram solely subject to application of special conditions.

13. :

A control method according to claim 12, wherein requests to shift to a lower or higher gear ratio following a switch of shifting rule of the automatic transmission with discrete gear ratios are temporarily suspended.

14. :

A control method according to claim 13, wherein requests to shift to a lower gear ratio following a switch of shifting rule are authorized if one of the following conditions is met;

the vehicle is undergoing a speed reduction that in absolute value is larger than a specified speed difference threshold, or

the vehicle is undergoing significant positive acceleration.

15. :

A control method according to claim 14, wherein the shift to the lower gear ratio is authorized if depression of the accelerator pedal is greater in absolute value than a specified displacement threshold.

16. :

A control method according to claim 14, wherein the shift to the lower gear ratio is authorized if the derivative of depression of the pedal is greater in absolute value than a pre-established rate of displacement threshold.

17. :

A control method according to claim 13, wherein shifts to higher gear ratio following a switch of shifting rules are authorized if one of the following conditions is met;

a predetermined time has elapsed since the switch exceeds a pre-established duration threshold,

relaxation of the accelerator pedal is smaller in absolute value than a predetermined displacement threshold, or

engine speed exceeds a pre-established speed threshold.

18. :

A control method according to claim 12, wherein the gear ratio requested following a switch of variogram of a transmission with continuous variation is subjected to filtering with a relatively long time constant.

21. :

A control method according to claim 14, wherein the time constant is shortened if the derivative of depression of the pedal exceeds, in absolute value, a pre-established rate of displacement threshold.

22. :

A control method according to claim 18, wherein, in the case of a request for an increase of gear ratio, the time constant is shortened if one of the following conditions is met;

relaxation of the accelerator pedal is smaller in absolute value than a predetermined displacement threshold, or

engine speed exceeds a pre-established speed threshold.

19. :

A control method according to clam 18, wherein, in the case of a request for a reduction of gear ratio, the time constant is shortened if one of the following conditions is met;

the vehicle has experienced, since the switch of variogram, a reduction of speed such that the difference between its instantaneous speed and its speed during the switch is larger in absolute value than a pre-established threshold, or

the vehicle is undergoing significant positive acceleration.

20. :

A control method according to claim 19, wherein the time constant is shortened if depression of the accelerator pedal exceeds, in absolute value, a specified displacement threshold.