Braking/Driving Force Controller of Vehicle

• US 20080221766A1
• Filed: 02/02/2006
• Published: 09/11/2008
• 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 8,655,563 B2
• Time in Patent Office: Days
• 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 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; and

control means for controlling the braking/driving force applied to each wheel by said braking/driving force applying means such that, when said vehicle target braking/driving force and/or said vehicle target yaw moment cannot be achieved by the braking/driving forces of the wheels, the vehicle braking/driving force and the vehicle yaw moment by the braking/driving forces of the wheels take the greatest values within the range where the ratio of the vehicle braking/driving force and the vehicle yaw moment through the control of the braking/driving forces of the wheels substantially coincides with the ratio of said vehicle target braking/driving force and said vehicle target yaw moment through the control of the braking/driving forces of the wheels.

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

a point of intersection of a segment, which links the point that shows said vehicle target braking/driving force and said vehicle target yaw moment and the origin, and a line indicating the greatest values of the vehicle braking/driving force and the vehicle yaw moment by the braking/driving forces of the wheels is defined as the target point in a rectangular coordinate with the vehicle driving/braking force and the vehicle yaw moment as coordinate axes, and 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 by the braking/driving forces of the wheels take the values at said target point.

3. A vehicle braking/driving force control apparatus according to claim 1 or claim 2, wherein

said braking/driving force applying means applies independently the braking/driving force to each wheel.

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

5. A vehicle braking/driving force control apparatus according to claim 1, 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 said 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 lateral forces of the wheels on the basis of at least the amount of the driving operation by an occupant, and calculates the value obtained by subtracting said turning yaw moment from said target total yaw moment as said vehicle target yaw moment.

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

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

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

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