Drive and Braking Force Control Device for Vehicle

• US 20090012685A1
• Filed: 02/02/2006
• Published: 01/08/2009
• 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: Okumura, Kazuya, Maeda, Yoshinori, Ando, Satoshi, Sugiyama, Koji, Yoshizue, Kensuke, Tsuchida, Michitaka, Uragami, Yoshio
• Granted Patent: US 8,180,541 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60G 2800/016 Yawing condition
• CPC Class Codes: B60G 2800/922 EBV - Electronic brake force distribution
• CPC Class Codes: B60G 2800/952 Electronic driving torque distribution
• CPC Class Codes: B60T 2270/311 Predefined control maps, lookup tables
• 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 10/184 with wheel brakes
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 2720/14 Yaw
• CPC Class Codes: B60W 2720/403 between front and rear axle
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability

Abstract

In a braking/driving force control apparatus according to the present invention, a vehicle target braking/driving force Fvn and a vehicle target yaw moment Mvn through the control of braking/driving forces of wheels are calculated (Step 20), and when the target braking/driving force Fvn and the target yaw moment Mvn cannot be achieved through the control of the braking/driving forces of the wheels (Step 40), it is determined which one of the braking/driving force and the yaw moment should take priority on the basis of the target braking/driving force Fvn and the target yaw moment Mvn. When it is determined that the braking/driving force should take priority, the braking/driving forces of the wheels are controlled so as to attain the target braking/driving force Fvn as much as possible, and when it is determined that the yaw moment should take priority, the braking/driving forces of the wheels are controlled so as to attain the target yaw moment Mvn as much as possible (Steps 60 to 220).

Claims

1. :

A vehicle braking/driving force control apparatus comprising;

braking/driving force applying means that can apply 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, which should be generated by the braking/driving forces of the wheels, on the basis of at least the amount of driving operation by an occupant;

determining means that determines which one of the braking/driving force and the yaw moment should take priority when said target braking/driving force and/or said target yaw moment cannot be achieved by the braking/driving forces of the wheels, said determining means determining, under the condition where the magnitude of said target yaw moment is not more than the magnitude of the maximum yaw moment attainable by the braking/driving forces of the wheels, that the yaw moment should take priority when said target braking/driving force is not less than a determination reference value, and that the braking/driving force should take priority when said target braking/driving force is less than said determination reference value; and

control means for controlling the braking/driving force applied to each wheel by said braking/driving force applying means such that, when said determining means determines that the yaw moment should take priority, the target braking/driving force after the modification and target yaw moment after the modification are respectively defined to be the braking/driving force and yaw moment, both of which are within the range of the braking/driving force and yaw moment attainable by the braking/driving forces of the wheels, and the yaw moment of which has a value that is the closest to said target yaw moment, and the vehicle braking/driving force and the yaw moment through the control of the braking/driving forces of the wheels respectively become said target braking/driving force after the modification and said target yaw moment after the modification

2. :

A vehicle braking/driving force control apparatus according to claim 1, wherein

when the magnitude of said target yaw moment exceeds the magnitude of the maximum yaw moment attainable by the braking/driving forces of the wheels, said target yaw moment is modified to said maximum yaw moment.

3. :

A vehicle braking/driving force control apparatus according to claim 1, wherein

when the magnitude of said target yaw moment is not more than the maximum yaw moment attainable by the braking/driving force of the wheels, said control means controls the braking/driving force applied to each wheel by said braking/driving force applying means such that a target point in a rectangular coordinate with the vehicle driving/braking force and the vehicle yaw moment as coordinate axes is defined to be the point of intersection which is closer to the reference point among points of intersection where a straight line, which passes a reference point representing said target braking/driving force and said target yaw moment and is parallel to the coordinate axis of the braking/driving force, crosses a line indicating the maximum values in magnitudes of the vehicle braking/driving force and the magnitude of the yaw moment by the braking/driving forces of the wheels, and the vehicle braking/driving force and the yaw moment by the braking/driving forces of the wheels take the values at said target point.

8. :

A vehicle braking/driving force control apparatus according to claim 1 or 4, wherein

said means for calculating a vehicle target braking/driving force and a vehicle target yaw moment calculates said vehicle target braking/driving force and vehicle target total yaw moment for causing the vehicle to stably run on the basis of at least the amount of the driving operation by an occupant, estimates a vehicle turning yaw moment due to a lateral force of each wheel on the basis of at least the amount of the driving operation by the occupant, and calculates the vehicle target yaw moment by subtracting said turning yaw moment from said target total yaw moment.

9. :

A vehicle braking/driving force control apparatus according to claim 3 or 6, wherein

said lines indicating the greatest values of said vehicle braking/driving force and said vehicle yaw moment are determined by the greatest value of the vehicle driving force, the greatest value of the vehicle braking force, the greatest value of the vehicle yaw moment in the leftward turning direction, and the greatest value of the vehicle yaw moment in the rightward turning direction.

10. :

A vehicle braking/driving force control apparatus according to claim 3 or 6, wherein

said lines indicating the greatest values of said vehicle braking/driving force and said vehicle yaw moment are variably set in accordance with a road friction coefficient.

11. :

A vehicle braking/driving force control apparatus according to claim 2, wherein

when the magnitude of said vehicle target yaw moment is not more than the maximum yaw moment attainable by the braking/driving forces of the wheels, said vehicle target yaw moment after the modification is set to the value equal to the target yaw moment before the modification.

12. :

A vehicle braking/driving force control apparatus according to claim 2, wherein

when the magnitude of said vehicle target braking/driving force is not more than said maximum braking/driving force attainable by the braking/driving forces of the wheels, said vehicle target braking/driving force after the modification is set to the value equal to said vehicle target braking/driving force before the modification.

13. :

A vehicle braking/driving force control apparatus according to claim 1, wherein

when the magnitude of the target yaw moment before the modification exceeds the magnitude of the maximum yaw moment attainable by the braking/driving forces of the wheels, the determining means determines that the yaw moment should take priority.

14. :

A vehicle braking/driving force control apparatus according to claim 1, wherein

when the magnitude of the target braking/driving force before the modification exceeds the magnitude of the maximum braking/driving force attainable by the braking/driving forces of the wheels, the determining means determines that the braking/driving force should take priority.

15. :

A vehicle braking/driving force control apparatus according to claim 8, wherein

said means for calculating the vehicle target braking/driving force and the vehicle target yaw moment calculates a vehicle target longitudinal acceleration and a vehicle target yaw rate for stably running the vehicle on the basis of at least the amount of the driving operation by an occupant, and calculates said vehicle target driving/braking force and the vehicle target total yaw moment on the basis of said vehicle target longitudinal acceleration and said vehicle target yaw rate, respectively.

16. :

A vehicle braking/driving force control apparatus according to claim 1 or 4, wherein

said control means calculates the target braking/driving force of each wheel on the basis of said vehicle target braking/driving force, said vehicle target yaw moment, and the distribution ratio of the braking/driving force to the front and rear wheels, and controls the braking/driving force applied to each wheel on the basis of the target braking/driving force of each wheel.

4. :

A vehicle braking/driving force control apparatus comprising;

braking/driving force applying means that can apply 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, which should be generated by the braking/driving forces of the wheels, on the basis of at least the amount of driving operation by an occupant;

determining means that determines which one of the braking/driving force and the yaw moment should take priority when said target braking/driving force and/or said target yaw moment cannot be achieved by the braking/driving forces of the wheels, said determining means determining, under the condition where the magnitude of said target yaw moment is not more than the magnitude of the maximum yaw moment attainable by the braking/driving forces of the wheels, that the yaw moment should take priority when said target braking/driving force is not less than a determination reference value, and that the braking/driving force should take priority when said target braking/driving force is less than said determination reference value; and

control means for controlling the braking/driving force applied to each wheel by said braking/driving force applying means such that, when said determining means determines that the braking/driving force should take priority, the target braking/driving force after the modification and target yaw moment after the modification are respectively defined to be the braking/driving force and yaw moment, both of which are within the range of the braking/driving force and yaw moment attainable by the braking/driving forces of the wheels, and the braking/driving force of which has a value that is the closest to said target braking/driving force, and the vehicle braking/driving force and the yaw moment through the control of the braking/driving forces of the wheels respectively become said target braking/driving force after the modification and said target yaw moment after the modification.

5. :

A vehicle braking/driving force control apparatus according to claim 4, wherein

when the magnitude of said target braking/driving force exceeds the magnitude of the maximum braking/driving force attainable by the braking/driving forces of the wheels, said target braking/driving force is modified to said maximum braking/driving force.

6. :

A vehicle braking/driving force control apparatus according to claim 4, wherein

when the magnitude of said target braking/driving force is not more than the maximum braking/driving force attainable by the braking/driving force of the wheels, said control means controls the braking/driving force applied to each wheel by said braking/driving force applying means such that a target point in a rectangular coordinate with the vehicle driving/braking force and the vehicle yaw moment as coordinate axes is defined to be the point of intersection closer to a reference point representing said target braking/driving force and said target yaw moment among points of intersection where a straight line, which passes the reference point and is parallel to the coordinate axis of the yaw moment, crosses a line indicating the maximum values in magnitudes of the vehicle braking/driving force and the yaw moment by the braking/driving forces of the wheels, and the vehicle braking/driving force and the yaw moment by the braking/driving forces of the wheels take the values at said target point.

7. (canceled)