WHEEL BRAKE/DRIVE FORCE CONTROL DEVICE

• US 20090051216A1
• Filed: 12/15/2006
• Published: 02/26/2009
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hosokawa, Akihiro, Oshiumi, Yasuhiro, Okumura, Kazuya, Maeda, Yoshinori, Sugiyama, Koji, Yoshizue, Kensuke, Tsuchida, Michitaka
• Granted Patent: US 8,714,663 B2
• Time in Patent Office: Days
• US Class Current: 303/146
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• 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 10/08 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 10/184 with wheel brakes
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/30 Wheel torque
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2720/30 Wheel torque
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: B60W 40/11 Pitch movement
• CPC Class Codes: B60W 40/112 Roll movement
• CPC Class Codes: B60W 40/114 Yaw movement
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

An object of the present invention is to achieve a braking-driving force and a yaw moment required for a vehicle to a possible extent within a range of braking-driving forces which the front and rear wheels can generate, when a target braking-driving force and a target yaw moment of the vehicle cannot be achieved by means of braking-driving forces that can be generated by the individual wheels. A target braking-driving force Fvn and a target yaw moment Mvn of the entire vehicle are calculated, and when the target braking-driving force Fvn and the target yaw moment Mvn cannot be achieved by means of the braking-driving forces of the front wheels, a target braking-driving force Fvft and a target yaw moment Mvft of the front wheels are adjusted such that the magnitudes of the braking-driving force and yaw moment of the vehicle produced by means of the braking-driving forces of the front wheels become the maximum at a ratio between Fvn and Mvn. A target braking-driving force Fvrt and a target yaw moment Mvrt of the rear wheels are calculated on the basis of Fvn, Mvn, Fvft, and Mvft, and similar adjustment is performed for them when necessarily.

Claims

1. A braking-driving-force control apparatus for a vehicle, characterized by comprising braking-driving force imparting means for imparting braking-driving forces to individual wheels;

means for detecting an amount of an occupant'"'"'s driving operation;

means for calculating a target braking-driving force of an entire vehicle and a target yaw moment of the entire vehicle, which must be generated by means of braking-driving forces of the individual wheels, on the basis of at least the amount of the occupant'"'"'s driving operation; and

control means for controlling the braking-driving forces of the individual wheels by controlling the braking-driving force imparting means such that a braking-driving force of the entire vehicle and a yaw moment of the entire vehicle approach the target braking-driving force of the entire vehicle and the target yaw moment of the entire vehicle to a possible extent, wherein one of a wheel group including front wheels and a wheel group including rear wheels is defined as a first wheel group, and the other wheel group is defined as a second wheel group, and wherein the control means comprises first adjustment means, operable when the target braking-driving force of the entire vehicle or the target yaw moment of the entire vehicle cannot be achieved by means of a braking-driving force of the first wheel group, for adjusting a target braking-driving force of the vehicle and a target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the first wheel group to values which can be achieved by means of the braking-driving force of the first wheel group;

means for calculating a target braking-driving force of the vehicle and a target yaw moment of the vehicle which are to be produced by means of a braking-driving force of the second wheel group, on the basis of the target braking-driving force of the entire vehicle and the target yaw moment of the entire vehicle, and the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the first wheel group; and

second adjustment means, operable when the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the second wheel group cannot be achieved by means of the braking-driving force of the second wheel group, for adjusting the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the second wheel group to values which can be achieved by means of the braking-driving force of the second wheel group.

2. A braking-driving-force control apparatus for a vehicle according to claim 1, wherein the first wheel group is the group of the front wheels, and the second wheel group is the group of the rear wheels.

3. A braking-driving-force control apparatus for a vehicle according to claim 1 or 2, wherein when restriction is imposed on the braking-driving force of at least one of the wheels of the first wheel group, the means for calculating the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the second wheel group calculates a shortage of the braking-driving force of the vehicle produced by means of the braking-driving force of the first wheel group, the shortage occurring due to the restriction imposed on the braking-driving force, and calculates the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the second wheel group, on the basis of the target braking-driving force of the entire vehicle and the target yaw moment of the entire vehicle, the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the first wheel group, and the shortage of the braking-driving force of the vehicle produced by means of the braking-driving force of the first wheel group.

4. A braking-driving-force control apparatus for a vehicle according to claim 1 or 2, wherein when restriction is imposed on the braking-driving force of at least one of the wheels of the first wheel group, the means for calculating the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the second wheel group calculates shortages of the braking-driving force of the vehicle and the yaw moment of the vehicle produced by means of the braking-driving force of the first wheel group, the shortages occurring due to the restriction imposed on the braking-driving force, and calculates the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the second wheel group, on the basis of the target braking-driving force of the entire vehicle and the target yaw moment of the entire vehicle, the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the first wheel group, and the shortages of the braking-driving force of the vehicle and the yaw moment of the vehicle produced by means of the braking-driving force of the first wheel group.

5. A braking-driving-force control apparatus for a vehicle according to claim 1 or 2, further comprising target-braking-driving-force correction means, operable when the target braking-driving force of the vehicle and the target yaw moment of the vehicle which are to be produced by means of the braking-driving force of the second wheel group can be achieved by means of the braking-driving force of the second wheel group in a state where restriction is imposed on the braking-driving force of one of the wheels of the first wheel group, for calculating a shortage of the target braking-driving force of the vehicle which is to be produced by means of the braking-driving force of the first wheel group, the shortage occurring due to the restriction imposed on the braking-driving force, and increasing, on the basis of the shortage, the target braking-driving force of a wheel of the second wheel group located on the same side, with respect to the lateral direction of the vehicle, as the wheel whose braking-driving force is restricted.

6. A braking-driving-force control apparatus for a vehicle according to one of claims 1 to 5, wherein at least one of the first and second adjustment means performs the adjustment such that the magnitudes of the braking-driving force and yaw moment of the vehicle produced by means of the braking-driving forces of the wheels become the maximum within a range in which a ratio between the braking-driving force and yaw moment of the vehicle produced by means of the braking-driving forces of the wheels substantially coincides with a ratio between the target braking-driving force and the target yaw moment.

7. A braking-driving-force control apparatus for a vehicle according to one of claims 1 to 5, wherein at least one of the first and second adjustment means determines, as a corrected target braking-driving force and a corrected target yaw moment, a braking-driving force and a yaw moment which fall within the ranges of the braking-driving force and yaw moment of the vehicle which can be achieved by means of the braking-driving forces of the wheels, such that the determined yaw moment assumes a value substantially equal to a value closest to the target yaw moment;

and performs adjustment such that the braking-driving force and yaw moment of the vehicle produced by means of the braking-driving forces of the wheels become equal to the corrected target braking-driving force and the corrected target yaw moment, respectively.

8. A braking-driving-force control apparatus for a vehicle according to one of claims 1 to 5, wherein at least one of the first and second adjustment means determines, as a corrected target braking-driving force and a corrected target yaw moment, a braking-driving force and a yaw moment which fall within the ranges of the braking-driving force and yaw moment of the vehicle which can be achieved by means of the braking-driving forces of the wheels, such that the determined braking-driving force assumes a value substantially equal to a value closest to the target braking-driving force;

and performs adjustment such that the braking-driving force and yaw moment of the vehicle produced by means of the braking-driving forces of the wheels become equal to the corrected target braking-driving force and the corrected target yaw moment, respectively.

9. A braking-driving-force control apparatus for a vehicle according to one of claims 1 to 5, wherein at least one of the first and second adjustment means determines a ratio of correction to the target braking-driving force and the target yaw moment on the basis of a driver'"'"'s driving operation;

increases or decreases the target braking-driving force or the target yaw moment on the basis of the ratio of correction such that the corrected target braking-driving force and the corrected target yaw moment assume values which can be achieved by means of the braking-driving forces of the individual wheels; and

performs adjustment such that the braking-driving force and yaw moment of the vehicle, which can be achieved by means of the braking-driving forces of the individual wheels become equal to the corrected target braking-driving force and the corrected target yaw moment, respectively.

10. A braking-driving-force control apparatus for a vehicle according to one of claims 1 to 5, wherein the braking-driving force imparting means imparts braking forces to the individual wheels independently of one another and impart a driving force to left and right wheels by use of drive means shared by the left and right wheels while changing the distribution of the driving force between the left and right wheels, and wherein at least one of the first and second adjustment means determines, as a reference yaw moment, the maximum value of the magnitude of the yaw moment of the vehicle which can be achieved by means of the braking-driving forces of the individual wheels when the magnitude of the braking-driving force of the vehicle is the maximum value which can be achieved by means of the braking-driving forces of the individual wheels;

corrects the magnitude of the target braking-driving force to the maximum value when the magnitude of the target yaw moment is equal to or less than the reference yaw moment and the magnitude of the target braking-driving force is greater than the maximum value;

corrects the magnitude of the target yaw moment to a value which can be achieved by means of the braking-driving forces of the individual wheels, when the magnitude of the target braking-driving force is equal to or less than the maximum value and the magnitude of the target yaw moment is greater than the value which can be achieved by means of the braking-driving forces of the individual wheels; and

corrects the magnitude of the target braking-driving force to the maximum value and the magnitude of the target yaw moment to the reference yaw moment when the magnitude of the target braking-driving force is greater than the maximum value and the magnitude of the target yaw moment is greater than the reference yaw moment.

11. A braking-driving-force control apparatus for a vehicle according to one of claims 1 to 5, wherein at least one of the first and second adjustment means corrects the target braking-driving force or the target yaw moment such that the corrected target braking-driving force and the corrected target yaw moment assume values which can be achieved by means of the braking-driving forces of the individual wheels;

and suppresses a change in the corrected target yaw moment attributable at least to a change in the target braking-driving force in a state where the target braking-driving force or the target yaw moment cannot be achieved by means of the braking-driving forces of the wheels.

12. A braking-driving-force control apparatus for a vehicle according to one of claims 1 to 5, wherein at least one of the first and second adjustment means corrects the target braking-driving force or the target yaw moment such that the corrected target braking-driving force and the corrected target yaw moment assume values which can be achieved by means of the braking-driving forces of the individual wheels;

and suppresses a change in the corrected target braking-driving force attributable at least to a change in the target yaw moment in a state where the target braking-driving force or the target yaw moment cannot be achieved by means of the braking-driving forces of the wheels.

13. A braking-driving-force control apparatus for a vehicle according to one of claims 1 to 5, wherein at least one of the first and second adjustment means corrects the target braking-driving force or the target yaw moment to a value which is within ranges of the braking-driving force and yaw moment of the vehicle which can be achieved by means of the braking-driving forces of the wheels, and which is within an ellipse defined in an orthogonal coordinate system whose two axes correspond to the braking-driving force and yaw moment of the vehicle, the ellipse having a center on the axis of the orthogonal coordinate system corresponding to the braking-driving force, and the directions of the major and minor radius of the ellipse coinciding with the axes of the orthogonal coordinate system.