Behavior control device of vehicle against drift-out with watching of rear wheel slide

• US 5,882,092 A
• Filed: 02/10/1997
• Issued: 03/16/1999
• Est. Priority Date: 02/23/1996
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Koibuchi, Ken
• Primary Examiner(s): Butler, Douglas C.
• Application Number:
  US08/798,465
• Time in Patent Office: 764 Days
• Field of Search: 303/146, 303/147, 303/139, 303/140, 303/141, 303/163, 303/165, 180/197, 701/72, 701/82, 701/84, 701/83, 701/188, 188/181 A, 188/181 C
• US Class Current: 303/146
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/17552 responsive to the tire sideslip angle or the vehicle body slip angle
• CPC Class Codes: B60T 8/246 Change of direction
• CPC Class Codes: B60T 8/4827 in hydraulic brake systems

Abstract

A behavior control device of a vehicle having a device for estimating a drift-out value representative of drifting out state of the vehicle; a device for estimating slip angle of rear wheels; and a controller for controlling a brake system such that, when the drift-out value is greater than a threshold value determined therefor, a moment for yawing the vehicle body in a direction of suppressing the drifting out of the vehicle represented by the drift-out value is generated in accordance with the slip angle of the rear wheels, the yaw moment increases as the slip angle of the rear wheels increases, with a restriction that the yaw moment is no longer increased when the slip angle reaches a limit value representing a state that the cornering force of the rear wheels is substantially at a maximum.

Claims

1. A behavior control device of a vehicle having a vehicle body, front left, front right, rear left and rear right wheels, an engine and a brake system comprising:

means for estimating a drift-out value representative of drifting out state of the vehicle;

means for estimating slip angle of the rear wheels; and

means for controlling said brake system such that, when said drift-out value is greater than a drift-out threshold value determined therefor for braking, a moment for yawing the vehicle body in a direction of suppressing the drifting out of the vehicle represented by said drift-out value is generated in accordance with the slip angle of the rear wheels, said yaw moment increases as said slip angle of the rear wheels increases, with a restriction that said yaw moment is no longer increased when said slip angle reaches a limit value representing a state that the cornering force of the rear wheels is substantially at a maximum.

2. A behavior control device according to claim 1, wherein said control means controls said brake system such that, when said drift-out value increases to be greater than said drift-out threshold value for braking, only one of the rear wheels at the inside of a turn of the vehicle is braked for a predetermined time duration.

3. A behavior control device according to claim 1, wherein the behavior control means further comprises a means for estimating a spin value representative of spinning state of the vehicle, and said control means controls said brake system such that, when said spin value is greater than a spin threshold value determined therefor for braking, a front wheel at the outside of a turn of the vehicle is braked.

4. A behavior control device according to claim 1, wherein the vehicle is a front drive vehicle, and the behavior control device further comprises a means for controlling said engine such that, when said drift-out value is greater than a drift-out threshold value determined therefor for lowering engine output torque, output torque of the engine is lowered.

5. A behavior control device according to claim 4, wherein the behavior control device further comprises a means for estimating a spin value representative of spinning state of the vehicle, and said engine control means controls said engine further such that, when said spin value is greater than a spin threshold value determined therefor for increasing engine output torque, output torque of the engine is increased.

6. A behavior control device according to claim 4, wherein said engine control means delays said lowering of the engine output torque for a predetermined period after said drift-out value crosses said drift-out threshold value for lowering engine output.