Vehicle driving force control with operator power demand responsive correction

• US 6,330,504 B1
• Filed: 04/12/2000
• Issued: 12/11/2001
• Est. Priority Date: 04/12/1999
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yoshinoya, Daisuke, Toukura, Nobusuke, Nozaki, Mikio, Yasuoka, Masayuki
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Gibson, Eric M
• Application Number:
  US09/547,884
• Time in Patent Office: 608 Days
• Field of Search: 701/54, 701/93, 701/94, 180/170, 477/107
• US Class Current: 701/54
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/107 with endless flexible members
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2555/40 Altitude
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 30/188 Controlling power parameters of the driveline, e.g. determining the required power
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F16H 2059/142 of driving resistance calculated from weight, slope, or the like
• CPC Class Codes: F16H 2059/666 Determining road conditions by using vehicle location or position, e.g. from global navigation systems [GPS]
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38

Abstract

A driving force control system is provided for an automotive vehicle powertrain. The driving force control system has an accelerator pedal sensor to detect the vehicle'"'"'s operator depression of an accelerator pedal of the vehicle, a vehicle speed sensor to detect a vehicle speed of the vehicle, and a powertrain control module. The powertrain control modules includes a microprocessor to determine an ordinary target driving force in response to the vehicle'"'"'s operator depression of the accelerator pedal and the vehicle speed, to determine a running resistance increment, to determine a driving force correction in response to the vehicle'"'"'s operator depression and the driving force correction, and to determine a corrected target driving force after correcting the ordinary target driving force with the driving force correction.

Claims

1. A driving force control system for an automotive vehicle powertrain including a prime mover and an automatic transmission, the driving force control system comprising:

a first sensor to detect the vehicle'"'"'s operator demand on driving force to drive the vehicle;

a second sensor to detect a predetermined parameter indicative of vehicle speed of the vehicle; and

a microprocessor that is programmed to be operative

to determine a target value indicative of driving force in response to the vehicle'"'"'s operator demand on driving force and the vehicle speed,

to determine a running resistance increment,

to determine a driving force correction in response to the vehicle'"'"'s operator demand on driving force and the determined running resistance increment, and

to correct the determined target value with the determined driving force correction.

2. The driving force control system as claimed in claim 1, wherein said microprocessor is further programmed to be operative

to determine a preliminary driving force correction in response to the determined running resistance increment, and

to determine the driving force correction in response to the vehicle'"'"'s operator demand on driving force and the determined preliminary driving force correction.

3. The driving force control system as claimed in claim 2, wherein the microprocessor is further programmed to be operative

to determine a driving force correction upper limit in response to the vehicle'"'"'s operator demand on driving force, and

to select a lower one of the determined preliminary driving force correction and the determined driving force correction upper limit as the driving force correction.

4. The driving force control system as claimed in claim 3, wherein said microprocessor is further programmed to be operative

to set the driving force correction upper limit at a value correspondingly small to the vehicle'"'"'s operator depression demand on driving force as the vehicle'"'"'s operator demand on driving force becomes small.

5. The driving force control system as claimed in claim 4, wherein said microprocessor is further programmed to be operative

to set the driving force correction upper limit to zero when the vehicle'"'"'s operator demand on driving force is in the neighborhood of zero.

6. The driving force control system as claimed in claim 4, wherein said microprocessor is further programmed to be operative

to hold the driving force correction upper limit to a predetermined maximum value when the vehicle'"'"'s operator demand on driving force is greater than a predetermined value.

7. The driving force control system as claimed in claim 2, wherein said microprocessor is further programmed to be operative

to determine a correction rate in response to the vehicle'"'"'s operator demand on driving force, and

to determine the driving force correction by multiplying the determined preliminary correction with the determined correction rate.

8. The driving force control system as claimed in claim 7, wherein said microprocessor is further programmed to be operative

to set the correction rate at a value correspondingly small to the vehicle'"'"'s operator demand on driving force as the vehicle'"'"'s operator demand on driving force becomes small.

9. The driving force control system as claimed in claim 8, wherein said microprocessor is further programmed to be operative

to set the correction rate to zero when the vehicle'"'"'s operator demand on driving force is in the neighborhood of zero.

10. The driving force control system as claimed in claim 8, wherein said microprocessor is further programmed to be operative

to hold the correction rate to one when the vehicle'"'"'s operator demand on driving force is greater than a predetermined value.

11. The driving force control system as claimed in claim 2, wherein said microprocessor is further programmed to be operative

to set the preliminary driving force correction to zero when the running resistance increment is less than a first predetermined value,

to hold the preliminary driving force correction to a maximum when the running resistance increment is greater than a second predetermined value that is greater than the first predetermined value, and

to set around 50 percent of the running resistance increment as the preliminary driving force correction when the running resistance increment is not less than the first predetermined value and not greater than the second predetermined value.

12. The driving force control system as claimed in claim 1, wherein said microprocessor is further programmed to be operative

to determine a standard running resistance in response to the vehicle speed,

to determine the output torque of the prime mover in response to operation parameters of the prime mover,

to determine a driving torque in response to the determined output torque of the prime mover and operation state of the automatic transmission;

to determine an acceleration resistance in response to acceleration to which the vehicle is subject, and

to determine the running resistance increment by subtracting a sum of the acceleration resistance and the standard resistance from the determined driving torque.

13. The driving force control system as claimed in claim 1, further comprising:

a memory storing a digital map including altitude information; and

a receiver to determine vehicle'"'"'s location, and wherein said microprocessor is further programmed to be operative

to determine a road gradient in response to the determined vehicle'"'"'s location and the altitude information included by the digital map, and

to determine the running resistance increment in response to the determined road gradient.

14. The driving force control system as claimed in claim 1, wherein the target value indicative of driving force exhibits vehicle driving force needed to accomplish a desired traveling performance of the vehicle on a flat road having 0% gradient.

15. The driving force control system as claimed in claim 1, wherein the standard running resistance exhibits a resistance against which the vehicle keeps on rolling on a flat road.

16. The driving force control system as claimed in claim 1, wherein said microprocessor is further programmed to be operative

to control an operating parameter of the prime mover related to torque produced by the prime mover in response to the target value as corrected and a ratio within the automatic transmission.

17. The driving force control system as claimed in claim 16, wherein said microprocessor is further programmed to be operative

to control the ratio within the automatic transmission in response to the target value as corrected and the vehicle speed.