METHOD TO DETERMINE AN OPTIMIZED SHIFT POINT, IN PARTICULAR UPSHIFT POINT, FOR A MANUAL TRANSMISSION

• US 20090076692A1
• Filed: 09/15/2008
• Published: 03/19/2009
• Est. Priority Date: 09/18/2007
• Status: Active Grant

• Current Assignee: Vitesco Technologies GmbH (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Bailliard, Laurent, Schopp, Gerhard, Aigner, Stefan
• Granted Patent: US 7,917,267 B2
• Time in Patent Office: Days
• US Class Current: 701/55
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: F16H 2063/426 with means for advising the driver for proper shift action, e.g. prompting the driver with allowable selection range of ratios
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 63/42 Ratio indicator devices
• CPC Class Codes: Y10T 70/5018 Robes
• CPC Class Codes: Y10T 70/5022 Tools
• CPC Class Codes: Y10T 70/5035 Bag

Abstract

In order to determine an optimized upshift point, it is proposed that a control circuit, on the basis of a current engine operating point (TQ_CUR;N) calculates a new engine operating point (TQ_NEW; N_NEW) produced when shifting up at approximately the same vehicle speed, wherein the current engine operating point is determined as the optimized upshift point if the calculated new engine operating point is below a preset upper torque limit (TQ_MAX_LIM) and is at the same time above a preset lower engine speed limit (N_MIN_x+1) for the higher gear.

Claims

1. A method for determining an optimized upshift point for a combustion engined vehicle with manual transmission, comprising the step of:

calculating a new engine operating point by a control circuit on the basis of a current engine operating point produced by a clutch torque and an engine speed and using preset gear ratios in the transmission, wherein the new engine operating point is produced when shifting up to the next higher gear at approximately the same vehicle speed, wherein the current engine operating point is determined by the control circuit as the optimized upshift point if the calculated new engine operating point is below a preset upper torque limit and is at the same time above a preset lower engine speed limit for the higher gear.

2. The method according to claim 1, wherein the preset upper torque limit in the engine characteristic graph runs at a presettable, essentially constant distance below a line representing the maximum available clutch torque.

3. The method according to claim 1, wherein the control circuit regularly calculates whether the respective current engine operating point is valid as the optimized shift point to be determined.

4. The method according to claim 3, wherein the control circuit calculates whether the respective current engine operating point is valid at an interval of about 100 ms.

5. The method according to claim 1, wherein the control circuit issues a shift recommendation in the form of an optical signal by means of a display connected to one of its outputs, if the current engine operating point is determined by the control circuit as an optimized shift point.

6. The method according to claim 5, wherein the control circuit only issues a shift recommendation if at least one additional activation condition is met, containing a limit value relating to the driving style and/or the current engine operation.

7. The method according to claim 5, wherein the switching on and/or switching off of the shift recommendation is linked to an additional condition, containing a time criterion.

8. The method according to claim 7, wherein a shift recommendation issued remains switched on for the duration of a minimum and maximum, both presettable, period of time, even if the shift recommendation were to be forestalled owing to the next engine operating point.

9. The method according to claim 7, wherein, after each new engine start, the first shift recommendation is only allowed to be switched on after an adjustable delay period.

10. A method for determining an optimized downshift point for a combustion engined vehicle with manual transmission, comprising the step of:

calculating a new engine operating point by a control circuit on the basis of a current engine operating point produced by a clutch torque and an engine speed and using preset gear ratios in the transmission, wherein the new engine operating point is produced when shifting down to the next lower gear at approximately the same vehicle speed, wherein the current engine operating point is determined by the control circuit as the optimized downshift point if the calculated new engine operating point is above a preset lower torque limit and is at the same time below a preset upper engine speed limit.

11. The method according to claim 10, wherein the preset lower torque limit in the engine characteristic graph runs at a presettable, essentially constant distance above a line representing the minimum available clutch torque.

12. The method according to claim 10, wherein the control circuit regularly calculates whether the respective current engine operating point is valid as the optimized shift point to be determined.

13. The method according to claim 12, wherein the control circuit calculates whether the respective current engine operating point is valid at an interval of about 100 ms.

14. The method according to claim 10, wherein the control circuit issues a shift recommendation in the form of an optical signal by means of a display connected to one of its outputs, if the current engine operating point is determined by the control circuit as an optimized shift point.

15. The method according to claim 14, wherein the control circuit only issues a shift recommendation if at least one additional activation condition is met, containing a limit value relating to the driving style and/or the current engine operation.

16. The method according to claim 14, wherein the switching on and/or switching off of the shift recommendation is linked to an additional condition, containing a time criterion.

17. The method according to claim 16, wherein a shift recommendation issued remains switched on for the duration of a minimum and maximum, both presettable, period of time, even if the shift recommendation were to be forestalled owing to the next engine operating point.

18. The method according to claim 16, wherein, after each new engine start, the first shift recommendation is only allowed to be switched on after an adjustable delay period.