Vehicle driving force control

• US 20030074124A1
• Filed: 09/17/2002
• Published: 04/17/2003
• Est. Priority Date: 09/26/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Ashizawa, Hiroyuki, Ono, Tatsuya, Higashimata, Akira, Ishizu, Takeshi
• Granted Patent: US 7,050,898 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60K 31/04 and means for comparing one electrical quantity, e.g. voltage, pulse, waveform, flux, or the like, with another quantity of a like kind, which comparison means is involved in the development of an electrical signal which is fed into the controlling means
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/101 Infinitely variable gearings
• CPC Class Codes: B60W 2050/001 Proportional integral [PI] controller
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: F16H 2059/663 Road slope
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

In a vehicle driving force control apparatus for controlling a driving force of the vehicle to achieve a target acceleration or a target vehicle speed, a running resistance estimating section calculates an estimated running resistance. A target acceleration modifying section modifies the target acceleration with the estimated running resistance and thereby decreases the target acceleration with increase in the estimated running resistance.

Claims

1. A vehicle driving force control apparatus for a vehicle, comprising:

an actuating section to control a driving force of the vehicle to achieve a target acceleration;

a running resistance estimating section to calculate an estimated running resistance; and

a target acceleration modifying section to modify the target acceleration with the estimated running resistance and thereby to decrease the target acceleration with increase in the estimated running resistance.

2. The vehicle driving force control apparatus as claimed in claim 1, further comprising a target acceleration calculating section to calculate the target acceleration from a target engine torque and a target transmission ratio determined in accordance with an accelerator input.

3. The vehicle driving force control apparatus as claimed in claim 1, further comprising a target vehicle speed calculating section to calculate a target vehicle speed by integrating the target acceleration, wherein the actuating section controls the driving force of the vehicle to achieve the target vehicle speed.

4. The vehicle driving force control apparatus as claimed in claim 3, wherein the running resistance estimating section is configured to calculate a flat road running resistance from the target vehicle speed, and to determine the estimated running resistance by modifying the flat road running resistance with a road gradient.

5. The vehicle driving force control apparatus as claimed in claim 4, wherein the running resistance estimating section is configured to determine the estimated running resistance by multiplying the flat road running resistance by a running resistance correction coefficient determined in accordance with the road gradient.

6. The vehicle driving force control apparatus as claimed in claim 5, wherein the running resistance correction coefficient is held equal to one when the road gradient is in a small gradient region.

7. The vehicle driving force control apparatus as claimed in claim 4, wherein the running resistance estimating section is configured to determine the estimated running resistance by modifying the flat road running resistance by a running resistance correction quantity determined in accordance with the road gradient.

8. The vehicle driving force control apparatus as claimed in claim 7, wherein the running resistance correction quantity is held equal to zero when the road gradient is in a small gradient region.

9. The vehicle driving force control apparatus as claimed in claim 4, the running resistance estimating section is configured to determine the estimated running resistance by modifying the flat road running resistance with the road gradient when the accelerator input is in a minimum setting region, and to set the estimated running resistance equal to the flat road running resistance without modification when the accelerator input is greater than the minimum setting region.

10. The vehicle driving force control apparatus as claimed in claim 1, wherein the running resistance estimating section is configured to calculate the estimated running resistance of the vehicle in accordance with a first parameter representing a vehicle speed and a second parameter representing a road gradient.

11. The vehicle driving force control apparatus as claimed in claim 10, further comprising a target acceleration calculating section to calculate an unmodified target acceleration in accordance with a driver'"'"'s accelerator input represented by an accelerator pedal depression quantity, and wherein the target acceleration modifying section determines a modified target acceleration by subtracting the estimated running resistance from the unmodified target acceleration, and the actuating section controls the driving force of the vehicle to achieve the modified target acceleration.

12. The vehicle driving force control apparatus as claimed in claim 11, further comprises a road gradient estimating section to calculate the second parameter representing the road gradient in accordance with an actual vehicle speed.

13. The vehicle driving force control apparatus as claimed in claim 12, further comprises a target driving force calculating section to calculate a target driving force to control the actuating section so as to achieve the target acceleration, and the road gradient estimating section calculates the second parameter representing the road gradient in accordance with the target driving force and the actual vehicle speed.

14. The vehicle driving force control apparatus as claimed in claim 13, further comprising a target vehicle speed calculating section to calculate a target vehicle speed in accordance with the target acceleration;

wherein the road gradient estimating section is a robust compensator in the target driving force calculating section and the target driving force calculating section further comprises a model matching compensator to calculate a command driving force in accordance with the target vehicle speed, and the target driving force calculating section determines the target driving force by adding the second parameter representing the road gradient determined by the robust compensator, to the command driving force determined by the model matching compensator.

15. A vehicle driving force control apparatus for controlling a driving force of a vehicle:

first means for calculating a target acceleration in accordance with a driver'"'"'s accelerator input;

second means for calculating an estimated running resistance;

third means for calculating a modified target acceleration by modifying the target acceleration determined by the first means, with the estimated running resistance so that the modified target acceleration decreases as the estimated running resistance increases; and

fourth means for controlling the driving force of the vehicle so as to achieve the modified target acceleration.

16. A vehicle driving force control process for controlling a driving force of a vehicle, comprising:

calculating a target acceleration in accordance with a driver'"'"'s accelerator input;

determining an estimated running resistance;

modifying the target acceleration with the estimated running resistance, to determine a modified target acceleration such that the modified target acceleration decreases as the estimated running resistance increases; and

controlling the driving force of the vehicle so as to achieve the modified target acceleration.