Method for controlling gear change during shifting rule or variogram switching

• US 8,180,535 B2
• Filed: 07/13/2005
• Issued: 05/15/2012
• Est. Priority Date: 07/21/2004
• Status: Expired due to Fees

• Current Assignee: Renault Sas (Renault)
• Original Assignee: Renault Sas (Renault)
• Inventors: Taffin, Christian, Poisson, Carine
• Primary Examiner(s): Nguyen, Cuong H
• Application Number:
  US11/658,078
• Publication Number:
  US 20080262684A1
• Time in Patent Office: 2,498 Days
• Field of Search: 701/51, 701/57, 701/60, 701 54- 56, 701/61, 701/102, 477/34, 477/43, 477/174, 477/120, 477/46, 477/121, 477/125, 744/732.1, 743/36.R
• US Class Current: 701/51
• 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. A method for control of a gear ratio of a transmission of a vehicle, the transmission being a continuously variable transmission programmed with variograms including a plurality of shifting curves, and applied according to operating conditions of the vehicle, comprising:

detecting a request for an increase of a gear ratio following a switch of variogram;

after the detecting the request for the increase of the gear ratio, filtering the request for the gear ratio change such that the gear ratio change is delayed by a time constant relaxation of an accelerator pedal is smaller in absolute value than a predetermined displacement threshold, or engine speed exceeds a pre-established speed threshold; and

authorizing the request for the increase of the gear ratio once the relaxation of the accelerator pedal is smaller than the predetermined displacement threshold, or the engine speed exceeds the pre-established speed threshold.

2. A method for control of changes of a gear ratio of an automatic transmission of a vehicle programmed with distinct shifting rules, and applied according to operating conditions of the vehicle, comprising:

detecting a request for a gear ratio change to a lower gear ratio following a switch of shifting rule;

after the detecting the request for the gear ratio change, delaying the gear ratio change until depression of an accelerator pedal is greater in absolute value than a specified displacement threshold or a derivative of the depression of the accelerator pedal is greater in absolute value than a pre-established rate of displacement threshold; and

authorizing the gear ratio change to the lower gear once the depression of the accelerator pedal is greater than the specified displacement threshold or the derivative of the depression of the accelerator pedal is greater than the pre-established rate of displacement threshold.

3. A method for control of changes of a gear ratio of an automatic transmission of a vehicle programmed with distinct shifting rules, and applied according to operating conditions of the vehicle, comprising:

detecting a request for a gear ratio change to a lower gear ratio following a switch of shifting rule;

after the detecting the request for the gear ratio change, delaying the gear ratio change until the vehicle is undergoing a speed reduction that in absolute value is larger than a specified speed difference threshold, or the vehicle is undergoing positive acceleration greater than a predetermined threshold; and

authorizing the gear ratio change to the lower gear once vehicle is undergoing the speed reduction that is larger than the specified speed difference threshold, or the vehicle is undergoing the positive acceleration greater than the predetermined threshold.

4. A method for control of changes of a gear ratio of an automatic transmission of a vehicle programmed with distinct shifting rules, and applied according to operating conditions of the vehicle, comprising:

detecting a request for a gear ratio change to a higher gear following a switch of shifting rule;

after the detecting the request for the gear ratio change, delaying the gear ratio change until a predetermined time has elapsed since the switch exceeds a pre-established duration threshold, or relaxation of an accelerator pedal is smaller in absolute value than a predetermined displacement threshold, or engine speed exceeds a pre-established speed threshold; and

authorizing the request for the gear ratio change once the predetermined time has elapsed since the switch exceeds the pre-established duration threshold, or relaxation of the accelerator pedal is smaller in absolute value than the predetermined displacement threshold, or the engine speed exceeds the pre-established speed threshold.

5. A method for control of a gear ratio of a transmission of a vehicle, the transmission being a continuously variable transmission programmed with variograms including a plurality of shifting curves, and applied according to operating conditions of the vehicle, comprising:

detecting a request for a reduction of a gear ratio following a switch of variogram;

after the detecting the request for the reduction of the gear ratio, filtering the request for the gear ratio change such that the gear ratio change is delayed until the vehicle has experienced, since the switch of variogram, a reduction of speed such that a difference between an instantaneous speed and a speed of the vehicle during the switch is larger in absolute value than a pre-established threshold, or the vehicle is undergoing positive acceleration above a predetermined threshold; and

authorizing the request for the reduction of the gear ratio once the vehicle has experienced, since the switch of variogram, the reduction of speed larger than the pre-established threshold, or the vehicle is undergoing positive acceleration above the predetermined threshold.

6. A method for control of a gear ratio of a transmission of a vehicle, the transmission being a continuously variable transmission programmed with variograms including a plurality of shifting curves, and applied according to operating conditions of the vehicle, comprising:

detecting a request for a reduction of a gear ratio following a switch of variogram;

after the detecting the request for the reduction of the gear ratio, filtering the request for the gear ratio change such that the gear ratio change is delayed until depression of an accelerator pedal exceeds, in absolute value, a specified displacement threshold; and

authorizing the request for the reduction of the gear ratio once the depression of the accelerator pedal exceeds the specified displacement threshold.