VEHICLE STABILIZATION CONTROL DEVICE

• US 20100106374A1
• Filed: 09/30/2009
• Published: 04/29/2010
• Est. Priority Date: 10/28/2008
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.)
• Inventors: Kato, Toshihisa, MIYAJIMA, Takayuki, Yasui, Yoshiyuki
• Granted Patent: US 8,224,526 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60T 2201/16 Curve braking control, e.g. turn control within ABS control algorithm
• CPC Class Codes: B60T 2210/36 Global Positioning System [GPS]
• 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

Abstract

A vehicle stabilization control device includes: an actual turning state quantity acquisition unit that acquires an actual turning state quantity indicating an actual turning state of a vehicle; a curve information acquisition unit that acquires the shape of a curve ahead of the vehicle; a vehicle speed acquisition unit that acquires speed of the vehicle; and a curve traverse possibility determination unit that determines a possibility that the vehicle can stably traverse the curve, based on the curve shape and speed of the vehicle; a control quantity computation unit that, to control braking force on each wheel and suppress understeering, computes a target control quantity for each wheel, based on the actual turning state quantity and on the possibility that the vehicle can stably traverse the curve; and a control unit controlling the braking force for each wheel, based on the target control quantity for each wheel.

Claims

1. A vehicle stabilization control device that includes an actual turning state quantity acquisition unit that acquires an actual turning state quantity that indicates an actual turning state of a vehicle, a control quantity computation unit that, in order to control a braking force for each of the wheels of the vehicle such that understeer of the vehicle is suppressed, computes a target control quantity for each of the wheels, based on the actual turning state quantity, and a control unit that controls the braking force for each of the wheels, based on the target control quantity for each of the wheels, the vehicle stabilization control device comprising:

a curve information acquisition unit that acquires a shape of a curve that lies ahead in the direction of travel of the vehicle;

a vehicle speed acquisition unit that acquires a speed of the vehicle; and

a curve traverse possibility determination unit that determines a possibility that the vehicle can traverse the curve in a stable manner, based on the curve shape and the speed of the vehicle, wherein

the control quantity computation unit is configured so as to adjust the target control quantity for each of the wheels in accordance with the possibility that the vehicle can traverse the curve in a stable manner.

2. The vehicle stabilization control device according to claim 1, wherein

the curve traverse possibility determination unit is configured so as to computed a lateral acceleration that acts on the vehicle based on the curve shape and the speed of the vehicle, and to determine the possibility that the vehicle can traverse the curve in a stable manner based on the lateral acceleration.

3. The vehicle stabilization control device according to claim 2, wherein

the curve traverse possibility determination unit is configured so as to determine;

that the vehicle can traverse the curve in a stable manner, in a case where the computed lateral acceleration is not greater than a first specified value;

the possibility that the vehicle can traverse the curve in a stable manner becomes lower to the extent that the deviation between the computed lateral acceleration and the first specified value becomes greater, in a case where the computed lateral acceleration is greater than the first specified value; and

that the vehicle cannot traverse the curve in a stable manner, in a case where the computed lateral acceleration is not less than a second specified value that is greater than the first specified value.

4. The vehicle stabilization control device according to claim 2, wherein

the curve traverse possibility determination unit is configured so as to determine;

that the vehicle can traverse the curve in a stable manner, in a ease where the computed lateral acceleration is not greater than a third specified value; and

that the vehicle cannot traverse the curve in a stable manner, in a case where the computed lateral acceleration is greater than the third specified value.

5. The vehicle stabilization control device according to claim 1, wherein

the curve information acquisition unit is configured so as to acquire a position within the curve that corresponds to the curve shape,

the vehicle stabilization control device further comprising:

a vehicle position acquisition unit that acquires a position of the vehicle; and

a target vehicle speed computation unit that computes a target vehicle speed for the vehicle to traverse the curve in a stable manner, based on the position that corresponds to the curve shape, the curve shape, and the vehicle position, wherein

the curve traverse possibility determination unit is configured so as to determine the possibility that the vehicle can traverse the curve in a stable manner based on a result of a comparison of the target vehicle speed and the speed of the vehicle.

6. The vehicle stabilization control device according to claim 5, wherein

the curve traverse possibility determination unit is configured so as to determine;

that the vehicle can traverse the curve in a stable manner, in a case where a vehicle speed deviation that is computed by subtracting the target vehicle speed from the speed of the vehicle is not greater than a fourth specified value;

the possibility that the vehicle can traverse the curve in a stable manner becomes lower to the extent that the vehicle speed deviation becomes greater, in a case where the vehicle speed deviation is greater than the fourth specified value; and

that the vehicle cannot traverse the curve in a stable manner, in a case where the vehicle speed deviation is not less than a fifth specified value that is greater than the fourth specified value.

7. The vehicle stabilization control device according to claim 5, wherein

the curve traverse possibility determination unit is configured so as to determine;

that the vehicle can traverse the curve in a stable manner, in a case where a vehicle speed deviation that is computed by subtracting the target vehicle speed from the speed of the vehicle is not greater than a sixth specified value; and

that the vehicle cannot traverse the curve in a stable manner, in a case where the vehicle speed deviation is greater than the sixth specified value.

8. The vehicle stabilization control device according to claim 1, further comprising:

a steering angle acquisition unit that acquires a value that is equivalent to a steering angle of a steering control wheel of the vehicle;

a target turning state quantity computation unit that computes, based on the speed of the vehicle and the value that is equivalent to the steering angle, a target turning state quantity that corresponds to the actual turning state quantity; and

a steering characteristics computation unit that, by comparing the target turning state quantity and the actual turning state quantity, computes a steering characteristic value that indicates a steering characteristic of the vehicle, wherein

the control quantity computation unit is configured so as to compute;

the target control quantity for each of the wheels to be zero, in a case where the steering characteristic value is not greater than a threshold value;

the target control quantity for each of the wheels is computed to be greater than zero, in a case where the steering characteristic value is greater than the threshold value; and

the threshold value to be lower as the possibility that the vehicle can traverse the curve in a stable manner is lower.

9. The vehicle stabilization control device according to claim 1, wherein

the control quantity computation unit is configured so as to provide a first computation characteristic and a second computation characteristic for the computation of the target control quantity for each of the wheels, the first computation characteristic giving higher priority to an imparting of a yaw moment to the vehicle than to a deceleration of the vehicle and the second computation characteristic giving higher priority to the deceleration of the vehicle than to the imparting of the yaw moment to the vehicle;

to compute the target control quantity for each of the wheels using the first computation characteristic, in a case where the possibility that the vehicle can traverse the curve in a stable manner is high; and

to compute the target control quantity for each of the wheels is computed using the second computation characteristic, in a case where the possibility that the vehicle can traverse the curve in a stable manner is low.