Vehicle steering control apparatus

Patent metadata

Field	Value
Publication number	US-8996254-B2
Application number	US-201013991083-A
Country	US
Kind code	B2
Filing date	Dec 1, 2010
Priority date	Dec 1, 2010
Publication date	Mar 31, 2015
Grant date	Mar 31, 2015

Abstract

A vehicle motion control apparatus which is configured to control a motion of a vehicle comprising a plurality of apparatuses, each of which is configured to selectively control a slip angle or a yaw rate, is provided with: a behavior controlling device which is configured to perform behavior control in which a plurality of apparatuses are controlled such that a slip angle and a yaw rate are a set target slip angle and a target yaw rate, respectively; a turning state quantity specifying device which is configured to specify a turning state quantity of the vehicle; and a selecting device which is configured to select at least one of the slip angle and the yaw rate to be prioritized, on the basis of the specified turning state quantity in a case where the behavior control needs to be performed by one of the plurality of apparatuses. The behavior controlling device controls the one apparatus such that the selected one has the target value corresponding to the selected one, in the case where the behavior control needs to be performed by the one apparatus.

First claim

The invention claimed is:

1. A vehicle motion control apparatus which is configured to control a motion of a vehicle,
the vehicle comprising a plurality of apparatuses, each of which is configured to selectively control a slip angle or a yaw rate,
said vehicle motion control apparatus comprising:
a controller which is configured to set a target slip angle as a target value of the slip angle, set a target yaw rate as a target value of the yaw rate, perform behavior control in which the plurality of apparatuses are controlled such that the slip angle and the yaw rate are the set target slip angle and the target yaw rate, respectively, specify a turning state quantity of the vehicle, select at least one of the slip angle and the yaw rate to be prioritized, on the basis of the specified turning state quantity in a case where the behavior control needs to be performed by one of the plurality of apparatuses and control the one apparatus such that the selected one has the target value corresponding to the selected one, in the case where the behavior control needs to be performed by the one apparatus.

2. The vehicle motion control apparatus according to claim 1 , wherein
the plurality of apparatuses include a first apparatus and a second apparatus, each of which is configured to selectively control the slip angle or the yaw rate,
said controller is further configured to determine whether or not at least one of the first and second apparatuses is in a function restricted state, select the one to be prioritized in a case where it is determined that the first or second apparatus is in the function restricted state, as the case where the behavior control needs to be performed by the one apparatus, and control one of the first and second apparatuses which is not in the function restricted state, as the one apparatus, such that the selected one has the target value corresponding to the selected one.

3. The vehicle motion control apparatus according to claim 2 , wherein
the first apparatus is a front-wheel steering angle varying apparatus which is configured to change a front-wheel steering angle, independently of a driver's operation which promotes a change in the front-wheel steering angle, and
the second apparatus is a rear-wheel steering angle varying apparatus which is configured to change a rear-wheel steering angle, independently of a driver's operation which promotes a change in the rear-wheel steering angle.

4. The vehicle motion control apparatus according to claim 2 , wherein
the plurality of apparatuses further include a third apparatus which is different from the first and second apparatus, each of which is configured to selectively control the slip angle or the yaw rate, and
said controller is further configured to control the third apparatus such that the selected one has the target value corresponding to the selected one if both the first and second apparatuses are in the function restricted state.

5. The vehicle motion control apparatus according to claim 4 , wherein the third apparatus is a braking/driving force varying apparatus which is configured to change a front-wheel or rear-wheel left-right braking/driving force difference.

6. The vehicle motion control apparatus according to claim 2 , wherein the function restricted state includes at least one of a failure state and a state in which selection of controlled variables is restricted.

7. The vehicle motion control apparatus according to claim 1 , wherein said controller is further configured to specify degree of turning of the vehicle as the turning state quantity.

8. The vehicle motion control apparatus according to claim 7 , wherein said controller is further configured to select the yaw rate as the one to be prioritized if the specified degree of turning is greater than or equal to a reference value, and select the slip angle as the one to be prioritized if the specified degree of turning is less than the reference value.

9. The vehicle motion control apparatus according to claim 1 , wherein said controller is configured to specify a change rate of degree of turning of the vehicle as the turning state quantity.

10. The vehicle motion control apparatus according to claim 9 , wherein said controller is configured to select the yaw rate as the one to be prioritized if the specified change rate of degree of turning is greater than or equal to a reference value, and select the slip angle as the one to be prioritized if the specified change rate of degree of turning is less than the reference value.

11. The vehicle motion control apparatus according to claim 1 , wherein said controller is further configured to specify a steering characteristic of the vehicle as the turning state quantity.

12. The vehicle motion control apparatus according to claim 11 , wherein said controller is further configured to select the yaw rate as the one to be prioritized if the specified steering characteristic corresponds to a strong under-steering state, and select the slip angle as the one to be prioritized if the specified steering characteristic does not correspond to the strong under-steering state.

13. The vehicle motion control apparatus according to claim 1 , wherein said controller is further configured to specify a stability state quantity for defining degree of stability of vehicle behavior, and select the one to be prioritized on the basis of the specified stability sate quantity, in preference to the selection based on the turning state quantity.

14. The vehicle motion control apparatus according to claim 13 , wherein said controller is further configured to specify the slip angle as the stability state quantity, and select the slip angle as the one to be prioritized if the specified slip angle is greater than or equal to a reference value.

15. The vehicle motion control apparatus according to claim 13 , wherein said controller is further configured to specify degree of friction of a driving route as the stability state quantity, and select the slip angle as the one to be prioritized if the specified degree of friction is less than a reference value.

16. The vehicle motion control apparatus according to claim 1 , wherein said controller is further configured to set the target slip angle such that the vehicle follows a target driving route, set the target yaw rate such that the vehicle follows the target driving route, perform, as the behavior control, trajectory following control in which the plurality of apparatuses are controlled such that the slip angle and the yaw rate are the target slip angle and the target yaw rate, respectively, each of which is set to follow the target driving route,
the vehicle further comprises a steering reaction force control apparatus which is configured to control a steering reaction force,
said controller is further configured to set a target steering reaction force as a target value of the steering reaction force, perform coordinated control in which the steering reaction force control apparatus is controlled such that the steering reaction force is the set target steering reaction force, cooperatively with the trajectory following control, continue the trajectory following control by controlling the one apparatus such that the selected one has the target value corresponding to the selected one, in the case where the behavior control needs to be performed by the one apparatus, and continue the coordinated control in a period in which the trajectory following control is continued.

17. The vehicle motion control apparatus according to claim 16 , wherein
said controller is further configured to determi

Assignees

• Nishikawa Norihisa
• Tanimoto Mitsutaka
• Fujita Yoshitaka
• Takashima Toru
• Narita Tetsuhiro
• Inoue Go
• Kojo Takahiro
• Toyota Motor Co Ltd

Inventors

• Nishikawa Norihisa
• Tanimoto Mitsutaka
• Fujita Yoshitaka
• Takashima Toru
• Narita Tetsuhiro
• Inoue Go
• Kojo Takahiro

Classifications

• B62D7/159

  characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition · CPC title

• B62D6/003 Primary

  in order to control vehicle yaw movement, i.e. around a vertical axis (B62D6/007 takes precedence) · CPC title

• B60W30/045

  Improving turning performance · CPC title

• B60W50/023

  Avoiding failures by using redundant parts · CPC title

• B60W10/188

  hydraulic brakes · CPC title