Vehicle driving force control with different corrections for engine torque control an CVT ratio control

• US 6,389,347 B1
• Filed: 04/14/2000
• Issued: 05/14/2002
• Est. Priority Date: 04/16/1999
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Nozaki, Mikio
• Primary Examiner(s): Nguyen, Tan
• Assistant Examiner(s): Tran, Dalena
• Application Number:
  US09/550,019
• Time in Patent Office: 760 Days
• Field of Search: 701/90, 701/70, 701/95, 701/54, 701/84, 701/85, 701/53, 477/43, 477/111, 477/48, 477/107, 477/110, 477/115, 477/118
• US Class Current: 701/54
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/101 Infinitely variable gearings
• CPC Class Codes: B60W 10/109 of the toroïd type
• CPC Class Codes: B60W 2530/16 Driving resistance
• 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 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/188 Controlling power parameters of the driveline, e.g. determining the required power
• 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 59/18 dependent on the position of the accelerator pedal
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• 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. In the driving force control system, an ordinary (or base) target driving force (tTd#n) is determined in response to operator depression of an accelerator (APO) and vehicle speed (VSP). A driving force correction (ADDFCE) is determined in response to a running resistance increment. The driving force correction is added to the ordinary target driving force to provide a first corrected target driving force (tTde) to an engine torque control The driving force correction is multiplied with a correction coefficient (α) to provide a corrected driving force correction. The corrected driving force correction is add to the ordinary target driving force to provide a second corrected target driving force (tTdr) to a CVT ratio control.

Claims

1. A driving force control system for an automotive vehicle powertrain including a prime mover and a continuously variable transmission (CVT), the prime mover being operable to accomplish a target output torque, the CVT being operable to alter a CVT ratio to accomplish a target ratio, the driving force control system comprising:

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 power train controller that is operative

to determine an ordinary target driving force in response to the detected vehicle'"'"'s operator depression of the accelerator pedal and the detected vehicle speed,

to determine a driving force correction,

to determine a first corrected target driving force after correcting the determined ordinary target driving force in response to the determined driving force correction,

to determine a second corrected target driving force after correcting the determined ordinary target driving force in response to the determined driving force correction,

said first and second corrected target driving forces being different from each other, and

to determine the target output torque and the target ratio in response to the determined corrected first and second target driving forces, respectively.

2. The driving force control system as claimed in claim 1, wherein said controller is further operative

to determine said first corrected target driving force by adding said driving force correction to said ordinary target driving force, and

to determine said second corrected target driving force by adding a modification of said driving force correction to said ordinary target driving force, and

wherein said modification is less than said driving force correction.

3. The driving force control system as claimed in claim 2, wherein said controller is further operative

to hold a ratio between said modification and said driving force correction at a predetermined value.

4. The driving force control system as claimed in claim 2, wherein said controller is further operative

to vary a ratio between said modification and said driving force correction over most of the overall range of variation of the vehicle'"'"'s operator manipulation of the accelerator pedal.

5. The driving force control system as claimed in claim 4, wherein said ratio decreases as the vehicle'"'"'s operator depression of the accelerator pedal increases.

6. The driving force control system as claimed in claim 4, wherein said ratio is different depending on which one of various kinds of load that causes occurrence of driving force correction.

7. A driving force control method for an automotive vehicle powertrain including a prime mover and a continuously variable transmission (CVT), the prime mover being operable to accomplish a target output torque, the CVT being operable to alter a CVT ratio to accomplish a target ratio, the driving force control method comprising:

detecting the vehicle'"'"'s operator depression of an accelerator pedal of the vehicle;

detecting a vehicle speed of the vehicle;

determining an ordinary target driving force in response to the detected vehicle'"'"'s operator depression of the accelerator pedal and the detected vehicle speed;

determining a driving force correction;

determining a first corrected target driving force after correcting the determined ordinary target driving force in response to the determined driving force correction;

determining a second corrected target driving force after correcting the determined ordinary target driving force in response to the determined driving force correction;

said first and second corrected target driving forces being different from each other, and

determining the target output torque and the target ratio in response to the determined corrected first and second target driving forces, respectively.

8. A driving force control system for an automotive vehicle power train including a prime mover and a continuously variable transmission (CVT), the prime mover being operable to accomplish a target output torque, the CVT being operable to alter a CVT ratio to accomplish a target ratio, the driving force control system comprising:

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 power train controller that is operative to;

determine an ordinary target driving force in response to the detected vehicle'"'"'s operator depression of the accelerator pedal and the detected vehicle speed,

determine a driving force correction,

determine a first corrected target driving force by adding said driving force correction to said ordinary target driving force,

modify said driving force correction to provide a modified driving force correction,

determine a second corrected target driving force by adding said modified driving force correction to said ordinary target driving force, and

determine the target output torque and the target ratio in response to the determined first and second corrected target driving forces, respectively,

wherein said modified driving force correction is not greater than said driving force correction.