Braking/driving force controller of vehicle

• US 8,655,563 B2
• Filed: 02/02/2006
• Issued: 02/18/2014
• Est. Priority Date: 02/02/2005
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Maeda, Yoshinori, Okumura, Kazuya, Tsuchida, Michitaka, Uragami, Yoshio, Yoshizue, Kensuke, Ando, Satoshi, Sugiyama, Koji
• Primary Examiner(s): Dager, Jonathan M
• Application Number:
  US11/815,367
• Publication Number:
  US 20080221766A1
• Time in Patent Office: 2,938 Days
• Field of Search: 701/1, 701/22, 701 36- 45, 701 69-109, 303146-150, 303/152, 303/162, 180/197, 477/35, 361/238
• US Class Current: 701/70
• CPC Class Codes: B60T 2270/613 ESP features related thereto
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2050/0057 Frequency analysis, spectral techniques or transforms
• CPC Class Codes: B60W 2510/18 Braking system
• CPC Class Codes: B60W 2510/182 Brake pressure, e.g. of fluid or between pad and disc
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability

Abstract

In a braking/driving force control apparatus, a vehicle target braking/driving force and a vehicle target yaw moment through the control of braking/driving forces of wheels are calculated, and when the target braking/driving force and the target yaw moment cannot be achieved through the control of the braking/driving forces of the wheels, the vehicle target braking/driving force after the modification and the vehicle target yaw moment after the modification are calculated such that, within the range where the ratio of the vehicle target braking/driving force after the modification and the vehicle target yaw moment after the modification coincides with the ratio of the target braking/driving force and the target yaw moment, the vehicle braking/driving force and the vehicle yaw moment by the target braking/driving forces of the wheels take the greatest values.

Claims

1. A vehicle braking/driving force control apparatus comprising:

braking/driving force applying means that applies braking/driving forces to wheels;

means for detecting an amount of driving operation by an occupant;

means for calculating a vehicle target braking/driving force and a vehicle target yaw moment, based on at least the amount of driving operation by the occupant; and

control means for controlling the braking/driving force applied to each wheel by said braking/driving force applying means such that, when at least one of said vehicle target braking/driving force and said vehicle target yaw moment is not within an achievable range by the braking/driving forces of the wheels, a vehicle braking/driving force and a vehicle yaw moment are set to maximum values, respectively, within the achievable range, where a ratio of the maximum value of the vehicle braking/driving force and the maximum value of the vehicle yaw moment substantially coincides with a ratio of said vehicle target braking/driving force and said vehicle target yaw moment.

2. A vehicle braking/driving force control apparatus according to claim 1, wherein the means for calculating calculates the maximum values to which the vehicle braking/driving force and the vehicle yaw moment are set, such that, in terms of graphically plotting the maximum values and the achievable range of the vehicle braking/driving force and the vehicle yaw moment in a rectangular coordinate system, a target point in the rectangular coordinate system correlates to the maximum values,

wherein the rectangular system includes

an origin,

a horizontal axis corresponding to a vehicle driving/braking force, and

a vertical axis corresponding to a vehicle yaw moment,

wherein a line extending between the vertical axis and the horizontal axis is an outer boundary of the achievable range indicating potential maximum values of the vehicle braking/driving force and the vehicle yaw moment,

wherein a segment extends between the origin and a calculated point, which coincides with the calculated vehicle target braking/driving force and the vehicle target yaw moment,

wherein a point of intersection of the segment and the line is the target point, and

wherein said control means controls the braking/driving force applied to each wheel by said braking/driving force applying means such that the vehicle braking/driving force and the vehicle yaw moment are set to the maximum values at said target point.

3. A vehicle braking/driving force control apparatus according to claim 1, wherein said braking/driving force applying means applies the braking/driving force to each wheel independently.

4. A vehicle braking/driving force control apparatus according to claim 1, wherein said braking/driving force applying means applies the braking force to each wheel independently, and applies a driving force from driving means, which is common to right and left wheels, to the right and left wheels in such a manner that a distribution of the driving forces to the right and left wheels is variable.

5. A vehicle braking/driving force control apparatus according to claim 1, wherein said means for calculating calculates said vehicle target braking/driving force and a vehicle target total yaw moment for causing the vehicle to stably run based on at least the amount of the driving operation by the occupant, estimates a vehicle turning yaw moment due to lateral forces of the wheels based on at least the amount of the driving operation by the occupant, and calculates a value obtained by subtracting said vehicle turning yaw moment from said vehicle target total yaw moment as said vehicle target yaw moment.

6. A vehicle braking/driving force control apparatus according to claim 2, wherein the line is determined by a greatest value of a vehicle driving force, a greatest value of a vehicle braking force, a greatest value of a vehicle yaw moment in a leftward turning direction, and a greatest value of a vehicle yaw moment in a rightward turning direction.

7. A vehicle braking/driving force control apparatus according to claim 2, wherein the line is variably set in accordance with a road friction coefficient.

8. A vehicle braking/driving force control apparatus according to claim 2, wherein said means for calculating calculates a vehicle target longitudinal acceleration and a vehicle target yaw rate for stably running the vehicle based on at least the amount of the driving operation by the occupant, and calculates said vehicle target driving/braking force and a vehicle target total yaw moment based on said vehicle target longitudinal acceleration and said vehicle target yaw rate, respectively.

9. A vehicle braking/driving force control apparatus according to claim 2, wherein said control means calculates a target braking/driving force of each wheel based on said vehicle target braking/driving force, said vehicle target yaw moment, and a distribution ratio of the braking/driving force to front and rear wheels, and

wherein the control means controls the braking/driving force applied to each wheel based on the target braking/driving force of each wheel.

10. A vehicle braking/driving force control apparatus according to claim 2, wherein said braking/driving force applying means applies the braking/driving force to each wheel independently.

11. A vehicle braking/driving force control apparatus according to claim 2, wherein said braking/driving force applying means applies independently the braking force to each wheel, and applies a driving force from driving means, which is common to right and left wheels, to the right and left wheels in such a manner that the distribution of the driving forces to the right and left wheels is variable.

12. An apparatus comprising:

a braking/driving force applying member that apply braking/driving forces to wheels;

a detection unit that detects an amount of driving operation by an occupant; and

an electronic controller configured to calculate a vehicle target braking/driving force and a vehicle target yaw moment, based on at least the amount of driving operation by the occupant, and is configured to control the braking/driving force applied to each wheel by the braking/driving force applying member such that, when at least one of the vehicle target braking/driving force and the vehicle target yaw moment is not within an achievable range by the braking/driving forces of the wheels, a vehicle braking/driving force and a vehicle yaw moment are set to maximum values, respectively, within the achievable range, where a ratio of the maximum value of the vehicle braking/driving force and the maximum value of the vehicle yaw moment substantially coincides with a ratio of the vehicle target braking/driving force and the vehicle target yaw moment.