Vehicle motion control device

Patent metadata

Field	Value
Publication number	US-9540003-B2
Application number	US-201414780835-A
Country	US
Kind code	B2
Filing date	Jan 24, 2014
Priority date	Mar 29, 2013
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

In order to reliably assist a driver in emergency detour steering without causing a jerking forward motion of the vehicle during normal operation, a vehicle motion control device includes: a risk potential estimator that estimates a risk potential of a vehicle based on input external information and vehicle information; a vehicle longitudinal motion controller that generates a longitudinal motion control command of the vehicle based on a vehicle lateral jerk and a predetermined gain; and a gain adjustor that adjusts the gain, in which the gain adjustor adjusts the gain based on the risk potential estimated by the risk potential estimator.

First claim

The invention claimed is:

1. A vehicle motion control device comprising:
a risk potential estimator that estimates a risk potential of a vehicle based on input external information and vehicle information;
a vehicle longitudinal motion controller that generates a longitudinal motion control command of the vehicle based on a vehicle lateral jerk and a predetermined gain; and
a gain adjustor that adjusts the gain, wherein
the gain adjustor adjusts the gain based on the risk potential estimated by the risk potential estimator,
the vehicle longitudinal motion controller includes
an acceleration/deceleration controller that calculates a longitudinal acceleration command value of the vehicle based on the vehicle lateral jerk and a predetermined first gain, and outputs the longitudinal acceleration command value,
a yaw moment controller that calculates a yaw moment command value of the vehicle based on the vehicle lateral jerk and a predetermined second gain, and outputs the yaw moment command value,

the gain adjustor adjusts the first gain or the second gain based on the risk potential estimated by the risk potential estimator.

2. The vehicle motion control device according to claim 1 ,
wherein when the risk potential is detected by the risk potential estimator, the gain adjustor adjusts the gain to be large, compared with a case where the risk potential is not detected.

3. The vehicle motion control device according to claim 1 ,
wherein when the risk potential estimated by the risk potential estimator is higher than a predetermined value, the gain adjustor adjusts the first gain or the second gain to be large, compared with a case where the value is lower than the predetermined value.

4. The vehicle motion control device according to claim 1 ,
wherein the gain adjustor adjusts the first gain and the second gain based on the risk potential estimated by the risk potential estimator.

5. The vehicle motion control device according to claim 2 ,
wherein when the risk potential is not detected, the gain adjustor adjusts the gain to be zero.

6. The vehicle motion control device according to claim 1 ,
wherein the external information is host vehicle front external information obtained from a camera or a radar, and
the vehicle information is at least one piece of information among a vehicle velocity, a steering angle, an acceleration, a yaw rate, a pedal operation velocity, and a braking operation velocity.

7. The vehicle motion control device according to claim 1 ,
wherein the risk potential estimator estimates quantitative evaluation of the risk potential of the vehicle.

8. The vehicle motion control device according to claim 1 ,
wherein the quantitative evaluation of the risk potential of the vehicle is performed by quantification based on a time-to-collision or a steering angular velocity.

9. The vehicle motion control device according to claim 1 ,
wherein the gain adjustor outputs the gain corresponding to the estimated risk potential using a map in which a value of the gain depending on a risk potential which is stored in advance is written.

10. The vehicle motion control device according to claim 1 ,
wherein the vehicle longitudinal motion controller generates the longitudinal motion control command of the vehicle so that the vehicle is decelerated when an absolute value of a lateral acceleration of the vehicle increases, and is accelerated when the absolute value of the lateral acceleration of the vehicle decreases.

11. The vehicle motion control device according to claim 1 ,
wherein the vehicle longitudinal motion controller generates the longitudinal motion control command of the vehicle so that the vehicle is decelerated when an absolute value of a steering angle of the vehicle increases, and is accelerated when the absolute value of the steering angle of the vehicle decreases.

12. The vehicle motion control device according to claim 1 ,
wherein the longitudinal acceleration command value Gxc is as follows:

G
xc

=

-

sgn
⁡

(

G
y

·

G
.

y

)

⁢

C
xy

1
+
Ts

⁢



G
.

y



+

G

x
⁢

⁢
_
⁢

⁢
D
⁢

⁢
C

,

wherein Gy: vehicle lateral acceleration, Gy_dot: vehicle lateral jerk, Cxy: lateral jerk gain, T: first-order lag time constant, s: Laplace operator, Gx_DC: offset.

13. The vehicle motion control device according to claim 1 ,
wherein the yaw moment command value is generated to promote turning of the vehicle when an absolute value of a lateral acceleration of the vehicle increases, and to return the turning of the vehicle when the absolute value of the lateral acceleration of the vehicle decreases.

14. The vehicle motion control device according to claim 1 ,
wherein the yaw moment command value is generated to promote turning of the vehicle when an absolute value of a steering angle of the vehicle increases, and to return the turning of the vehicle when the absolute value of the steering angle of the vehicle decreases.

15. The vehicle motion control device according to claim 1 ,
wherein the yaw moment command value Mz+ is as follows:

M

z
+

=

sgn
⁡

(

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Yamakado Makoto
• Sasaki Mitsuhide
• Ueyama Mikio
• Nagatsuka Keiichiro

Classifications

• B60W2520/14

  Yaw · CPC title

• B60W2554/00

  Input parameters relating to objects · CPC title

• B60W2720/406

  between left and right wheel · CPC title

• B60W2510/18

  Braking system · CPC title

• B60T7/12 Primary

  for automatic initiation; for initiation not subject to will of driver or passenger {(limiting speed of vehicles other than rail vehicles B60K31/00)} · CPC title