Using Driving Behavior to Determine Gear Changes of an Automatic Transmission

• US 20090312926A1
• Filed: 06/12/2008
• Published: 12/17/2009
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Wong, Andrew, Wiethe, Philip J. JR., Henriksen, Alan, Bradley, Peter J., Rebandt, Henry A., MacFarlane, Kevin
• Granted Patent: US 8,380,406 B2
• Time in Patent Office: Days
• US Class Current: 701/59
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: F16H 2059/003 Detecting or using driving style of a driver, e.g. for adapting shift schedules

Abstract

A method for changing the timing of gear changes of an automatic transmission for a motor vehicle including repetitively updating a current value of a count whose value is a measure of driving behavior, performing an evaluation of driving behavior and updating the current value by a value determined from the evaluation, determining shift schedules that define the occurrence of a gear change to be produced by the transmission, and using the updated current value to establish from among the shift schedules a shift schedule that defines a gear change to be produced by the transmission.

Claims

1. A method for changing the timing of gear changes of an automatic transmission for a motor vehicle, comprising the steps of:

(a) repetitively updating a current value of a count that is a measure of driving behavior;

(b) using manual control of a gear selector to determine a desired transmission range and a base value for the desired range;

(c) updating of the current value on the basis of a difference between the current value and the base value for the desired range;

(d) performing at least one evaluation of driving behavior and updating the current value by a value determined from the evaluation; and

(e) using the updated current value to establish a shift schedule that defines a gear change to be produced by the transmission.

2. The method of claim 1 further comprising the step of producing a gear change defined by the established shift schedule.

3. The method of claim 1 wherein step (c) further comprises the steps of:

determining a rate of change of the current value on the basis of the difference;

determining a change of the current value from a product produced by multiplying the rate of change and the current value;

determining a reference value on the basis of the difference;

producing a sum by adding the reference value and the product; and

updating of the current value by a magnitude of the sum.

4. The method of claim 1 wherein step (c) further comprises the steps of:

the updating the current value of the count by the value of an entry offset in response to a change between desired ranges of the transmission;

determining a rate of change of the current value on the basis of the difference;

determining a change of the current value from a product produced by multiplying the rate of change and the current value;

determining a reference value on the basis of the difference;

producing a sum by adding the reference value and the product; and

updating of the current value by a magnitude of the sum.

5. The method of claim 1 wherein step (d) further comprises the steps of:

performing a drive-off evaluation of driving behavior; and

updating the current value of the count by a value determined from a magnitude of accelerator pedal displacement.

6. The method of claim 1 wherein step (d) further comprises the steps of:

performing a pedal-rate evaluation of driving behavior; and

updating the current value of the count by a value determined from a rate of accelerator pedal displacement.

7. The method of claim 1 wherein step (d) further comprises the steps of:

determining that an accelerator pedal has been depressed at a relatively high rate;

performing a pedal-level evaluation of driving behavior; and

updating the current value of the count by a value determined from the rate of accelerator pedal displacement and that produces a downshift between gears of the transmission.

8. The method of claim 1 wherein step (d) further comprises the steps of:

determining that an accelerator pedal has been depressed to a relatively large displacement;

performing a pedal-level evaluation of driving behavior; and

updating the current value of the count by a value determined from the displacement of accelerator pedal and that produces a downshift between gears of the transmission.

9. The method of claim 1 wherein step (d) further comprises the steps of:

operating an engine to produce a magnitude of engine torque that is transmitted to the transmission;

updating the current value of the count by a value determined from the magnitude of engine torque and a reserve capacity of the engine to produce torque in excess of the produced magnitude of engine torque.

10. The method of claim 1 wherein step (d) further comprises the steps of:

determining a lateral acceleration of the vehicle and a speed of the vehicle;

using the lateral acceleration of the vehicle and the speed of the vehicle to determine a potential change in the current value of the count;

using the difference to determine a modifier; and

updating the current value of the count by a second product produced by multiplying the potential change in the current value of the count and the modifier.

11. The method of claim 1 wherein step (d) further comprises the steps of:

determining a longitudinal acceleration of the vehicle and a speed of an output shaft of the transmission;

using the longitudinal acceleration of the vehicle and the speed of the output shaft to determine a change in the current value of the count associated with longitudinal acceleration of the vehicle;

updating the current value of the count by the change in the current value of the count associated with longitudinal acceleration of the vehicle.

12. The method of claim 1 wherein step (d) further comprises the steps of:

increasing the current value of the count when a gear selected by manual control of the gear selector is a lower gear than a gear in which the transmission is operating; and

decreasing the current value of the count when a gear selected by manual control of the gear selector is a higher gear than a gear in which the transmission is operating.

13. A method for changing the timing of gear changes of an automatic transmission for a motor vehicle, comprising the steps of:

(a) repetitively updating a current value of a count whose value is a measure of driving behavior;

(b) performing an evaluation of driving behavior and updating the current value by a value determined from the evaluation;

(c) determining shift schedules that define the occurrence of a gear change to be produced by the transmission; and

(d) using the updated current value to establish from among the shift schedules a shift schedule that defines a gear change to be produced by the transmission.

14. The method of claim 13 further comprises the steps of:

using manual control of a gear selector to determine a desired transmission range and a base value for the desired range; and

updating of the current value on the basis of a difference between the current value and the base value for the desired range.

15. The method of claim 14 wherein step (b) further comprises the steps of:

determining a rate of change of the current value on the basis of the difference;

determining a change of the current value from a product produced by multiplying the rate of change and the current value;

determining a reference value on the basis of the difference;

producing a sum by adding the reference value and the product; and

updating of the current value by a magnitude of the sum.

16. The method of claim 14 wherein step (b) further comprises the steps of:

the updating the current value of the count by the value of an entry offset in response to a change between desired ranges of the transmission;

determining a rate of change of the current value on the basis of the difference;

determining a change of the current value from a product produced by multiplying the rate of change and the current value;

determining a reference value on the basis of the difference;

producing a sum by adding the reference value and the product; and

updating of the current value by a magnitude of the sum.

17. The method of claim 13 wherein step (c) further comprises the steps of:

determining shift schedules representing a range that extends from conservative driving behavior to aggressive driving behavior and indexed by the updated current value, each shift schedule defining the occurrence of desired gear changes at an indexed position within said range in response to a vehicle speed and a degree of displacement of an accelerator pedal.

18. The method of claim 13 wherein:

step (c) further comprises the step of determining shift schedules representing a range that extends from conservative driving behavior to aggressive driving behavior, each shift schedule defining the occurrence of desired gear changes within said range in response to a vehicle speed and a degree of displacement of an accelerator pedal; and

step (d) further comprises the steps of using the updated current value to determine a performance normalizer that that extends over a range from conservative driving behavior to aggressive driving behavior; and

interpolating the timing of the gear changes that are defined by two shift schedules indexed by the performance equalizer.

19. The method of claim 13 wherein step (b) further comprises the steps of:

performing a drive-off evaluation of driving behavior; and

updating the current value of the count by a value determined from a magnitude of accelerator pedal displacement.

20. The method of claim 13 wherein step (b) further comprises the steps of:

performing a pedal-rate evaluation of driving behavior; and

updating the current value of the count by a value determined from a rate of accelerator pedal displacement.

21. The method of claim 13 wherein step (b) further comprises the steps of:

determining that an accelerator pedal has been depressed at a relatively high rate;

performing a pedal-level evaluation of driving behavior; and

updating the current value of the count by a value determined from the rate of accelerator pedal displacement and that produces a downshift between gears of the transmission.

22. The method of claim 13 wherein step (b) further comprises the steps of:

determining that an accelerator pedal has been depressed to a relatively large displacement;

performing a pedal-level evaluation of driving behavior; and

updating the current value of the count by a value determined from the displacement of accelerator pedal and that produces a downshift between gears of the transmission.

23. The method of claim 13 wherein step (b) further comprises the steps of:

operating an engine to produce a magnitude of engine torque that is transmitted to the transmission;

updating the current value of the count by a value determined from the magnitude of engine torque and a reserve capacity of the engine to produce torque in excess of the produced magnitude of engine torque.

24. The method of claim 13 wherein step (b) further comprises the steps of:

determining a lateral acceleration of the vehicle and a speed of the vehicle;

using the lateral acceleration of the vehicle and the speed of the vehicle to determine a potential change in the current value of the count;

using manual control of a gear selector to determine a desired transmission range and a base value for the desired range;

using the difference to determine a modifier; and

updating the current value of the count by a second product produced by multiplying the potential change in the current value of the count and the modifier.

25. The method of claim 13 wherein step (b) further comprises the steps of:

determining a longitudinal acceleration of the vehicle and a speed of an output shaft of the transmission;

using the longitudinal acceleration of the vehicle and the speed of the output shaft to determine a change in the current value of the count associated with longitudinal acceleration of the vehicle;

updating the current value of the count by the change in the current value of the count associated with longitudinal acceleration of the vehicle.

26. The method of claim 13 wherein step (b) further comprises the steps of:

increasing the current value of the count when a gear selected by manual control of the gear selector is a lower gear than a gear in which the transmission is operating; and

decreasing the current value of the count when a gear selected by manual control of the gear selector is a higher gear than a gear in which the transmission is operating.