Vehicle stability control method and device

Patent metadata

Field	Value
Publication number	US-2021269018-A1
Application number	US-202117326006-A
Country	US
Kind code	A1
Filing date	May 20, 2021
Priority date	Aug 15, 2019
Publication date	Sep 2, 2021
Grant date	—

Abstract

A vehicle stability control method and a vehicle stability control device are provided. The method may be applied to an intelligent automobile field such as intelligent driving or autonomous driving, and is used to control lateral stability of a front axis and rear axis distributed driven vehicle. In this method, a yawing movement of the vehicle is considered, and an additional yawing moment for maintaining lateral stability of the vehicle is provided by compensating for front-axis and rear-axis slip ratios, to control lateral stability of the vehicle and therefore improve stability of the vehicle during driving.

First claim

What is claimed is:

1 . A vehicle stability control method, applied to a vehicle stability control device, the method comprising:
in response to a vehicle being in an unstable state, obtaining a required yawing moment, a front-axis actual slip ratio, a rear-axis actual slip ratio, a front-axis initial torque, and a rear-axis initial torque of the vehicle at a current time point; determining a correspondence between a yawing moment of the vehicle and a front-axis slip ratio and a rear-axis slip ratio of the vehicle; determining a front-axis target slip ratio and a rear-axis target slip ratio based on the required yawing moment and the determined correspondence between the yawing moment of the vehicle and the front-axis slip ratio and the rear-axis slip ratio of the vehicle; determining a front-axis target torque based on the front-axis initial torque and a difference between the front-axis target slip ratio and the front-axis actual slip ratio; determining a rear-axis target torque based on the rear-axis initial torque and a difference between the rear-axis target slip ratio and the actual rear-axis slip ratio; and controlling stability of the vehicle based on the front-axis target torque and the rear-axis target torque.

2 . The method according to claim 1 , further comprising:
obtaining a longitudinal driving speed, a wheel steering angle, and an actual yawing angular velocity of the vehicle at the current time point; determining a target yawing angular velocity based on the longitudinal driving speed, the wheel steering angle, and a stored steering characteristic factor, wherein the steering characteristic factor is used to represent a constant of a steering characteristic of the vehicle; determining an angular velocity error between the actual yawing angular velocity and the target yawing angular velocity; and in response to the angular velocity error not falling within a preset threshold interval, determining that the vehicle is in an unstable state, wherein the preset threshold interval is an interval formed by the first threshold and the second threshold, the first threshold is a positive number, and the second threshold is a negative number.

3 . The method according to claim 2 , wherein the target yawing angular velocity meets the following:

γ
d

⁡

(
t
)

=

v
x

⁡

(
t
)

⁢

δ
⁡

(
t
)

(

l
f

+

l
r

)

⁢

(

1
+

K
⁢

v
x

⁡

(
t
)

2

)

wherein γ d (t) is the target yawing angular velocity, v x (t) is the longitudinal driving speed, δ(t) is the wheel steering angle, l f is a distance from a center of mass of the vehicle to a front axis, l r is a distance from the center of mass of the vehicle to a rear axis, K is the steering characteristic factor, and t is the current time point.

4 . The method according to claim 2 , wherein the obtaining the required yawing moment comprises:
determining the required yawing moment based on the angular velocity error.

5 . The method according to claim 4 , wherein
in response to the angular velocity error being greater than the first threshold, the required yawing moment meets the following:

M
⁡

(
t
)

=

-

sign
⁡

(

δ
⁡

(
t
)

)

*

(

K

P
⁢
o

⁢

e
γ

⁡

(
t
)

+

K
Io

⁢

∫

t
0

t

⁢

e
γ

⁡

(
t
)

+

K

D
⁢
o

⁢

d
⁢

Assignees

• Huawei Tech Co Ltd

Inventors

• Liu Donghao
• Zhang Yongsheng
• Zhang Wei

Classifications

• Y02T10/64

  Electric machine technologies in electromobility · CPC title

• B60W40/107

  Longitudinal acceleration · CPC title

• B60T8/17552

  responsive to the tyre sideslip angle or the vehicle body slip angle · CPC title

• B60W2520/06

  Direction of travel · CPC title

• B60W40/10

  related to vehicle motion · CPC title