Method of setting transmission shift points in real-time based upon an engine performance curve

• US 8,788,424 B2
• Filed: 04/22/2011
• Issued: 07/22/2014
• Est. Priority Date: 04/22/2011
• Status: Active Grant

• Current Assignee: Allison Transmission Incorporated (Allison Transmission Holdings Incorporated)
• Original Assignee: Allison Transmission Incorporated (Allison Transmission Holdings Incorporated)
• Inventors: Etchason, Edmond M.
• Primary Examiner(s): Badii, Behrang
• Application Number:
  US13/092,470
• Publication Number:
  US 20120271520A1
• Time in Patent Office: 1,187 Days
• Field of Search: 477/3, 477/5, 477/49, 477/34, 475/205, 475/269, 475/284, 475/219, 475/5, 701/61, 701/55, 701/95, 701/51, 701/85, 701/60, 701/58, 180/197, 180/65.265, 180/65.285, 180/65.21, 474/69
• US Class Current: 705/55
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60Y 2300/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: F16H 2059/743 using engine performance or power for control of gearing transmission input torque F16H2059/147
• CPC Class Codes: F16H 2061/0216 Calculation or estimation of post shift values for different gear ratios, e.g. by using engine performance tables
• CPC Class Codes: F16H 2061/022 Calculation or estimation of optimal gear ratio, e.g. best ratio for economy drive or performance according driver preference, or to optimise exhaust emissions
• CPC Class Codes: F16H 2061/0223 Generating of new shift maps, i.e. methods for determining shift points for a schedule by taking into account driveline and vehicle conditions
• CPC Class Codes: F16H 59/14 Inputs being a function of torque or torque demand
• CPC Class Codes: F16H 59/24 dependent on the throttle opening
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 61/061 using electric control means

Abstract

The present invention provides a method for setting a shift point for shifting a transmission for a powered vehicle between a first gear ratio and a second gear ratio. The method includes determining input power data points based on real-time input torque data. The input torque data includes a maximum input torque. The method also includes calculating a gear step value based on the first gear ratio and second gear ratio. The method further includes determining a first power value and computing a second power value based on the gear step value. The first power value and second power value are compared to one another and adjustments are incrementally made in the first power value speed until the difference between first and second power values meets a threshold. The shift point is therefore based on the result of comparing the first power value and the second power value and the corresponding speed associated with the first power value.

Claims

1. A method for setting a shift point for shifting a transmission for a powered vehicle between a first gear ratio and a second gear ratio, the transmission having a controller electrically coupled to a data bus, comprising:

determining input power data points based on input torque data;

calculating a gear step value based on the first gear ratio and second gear ratio;

determining a first power value;

computing a second power value based on the gear step value;

comparing the first power value and the second power value to one another; and

setting the shift point based on the result of comparing the first power value and the second power value.

2. The method of claim 1, further comprising receiving the input torque data from the data bus.

3. The method of claim 1, wherein the calculating a gear step comprises dividing the first gear ratio by the second gear ratio.

4. The method of claim 1, further comprising determining the first power value at a first speed value.

5. The method of claim 4, wherein the first speed value is based on the gear step.

6. The method of claim 4, further comprising comparing the first speed value to a full load governing speed value of the powered vehicle.

7. The method of claim 6, further comprising setting the shift point to approximately the full load governing speed when the first speed value exceeds the full load governing speed.

8. The method of claim 4, further comprising determining a second speed value based on the first speed value.

9. The method of claim 8, wherein the determining a second speed value comprises dividing the first speed value by the gear step value.

10. The method of claim 8, wherein the computing a second power value comprises interpolating between at least two input power data points at the second speed value.

11. The method of claim 1, wherein the comparing step comprises:

multiplying the first power value by a threshold value; and

determining if the second power value is equal to or greater than the result of multiplying the first power value by the threshold value.

12. The method of claim 11, further comprising adjusting the first speed value if the second power value is less than the result of multiplying the first power value by the threshold value.

13. The method of claim 12, wherein the first speed value is adjusted by a constant value up to a full load governing speed of the powered vehicle.