VEHICLE CONTROL APPARATUS AND VEHICLE CONTROL METHOD

• US 20100262317A1
• Filed: 04/13/2010
• Published: 10/14/2010
• Est. Priority Date: 04/13/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: SUZUKI, Takashi, Nakai, Koji
• Granted Patent: US 8,706,402 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• CPC Class Codes: B60W 2552/20 Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 2552/40 Coefficient of friction
• CPC Class Codes: B60W 30/18009 related to particular drive situations
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B60W 50/0097 Predicting future conditions

Abstract

In a vehicle control, a future travel locus of a vehicle is computed by using an evaluation function, and travel road surface information regarding a travel road surface on which the Vehicle travels is stored. According to the travel road surface information stored, a convergence criterion for the evaluation function is variably set.

Claims

1. A vehicle control device comprising:

a travel locus computation portion that computes a future travel locus of a vehicle by using an evaluation function;

a travel road surface information storage portion that stores travel road surface information regarding a travel road surface on which the vehicle travels; and

a convergence criterion setting portion that variably sets a convergence criterion for the evaluation function according to the travel road surface information stored in the travel road surface information storage portion.

2. The vehicle control apparatus according to claim 1, wherein the travel road surface information includes at least one of road width information regarding a road width of the travel road surface, friction information regarding friction of the travel road surface, and curve information regarding curve of the travel road surface.

3. The vehicle control apparatus according to claim 2, wherein:

the travel road surface information includes the road width information; and

the convergence criterion setting portion sets the convergence criterion greater, as the road width in the road width information becomes greater.

4. The vehicle control apparatus according to claim 2, wherein:

the travel road surface information includes the friction information;

the friction information includes a friction coefficient of the travel road surface; and

the convergence criterion setting portion sets the convergence criterion greater, as the friction coefficient becomes greater.

5. The vehicle control apparatus according to claim 2, wherein:

the travel road surface information includes the curve information;

the curve information includes radius of the curve of the travel road surface; and

the convergence criterion setting portion sets the convergence criterion greater, as the radius of the curve becomes greater.

6. The vehicle control apparatus according to claim 1, wherein the convergence criterion setting portion computes an allowed calculation time that elapses before control of the vehicle starts, based on the travel road surface information stored in the travel road surface information storage portion, and variably sets the convergence criterion according to the allowed calculation time.

7. The vehicle control apparatus according to claim 6, wherein the convergence criterion setting portion sets the convergence criterion greater, as the allowed calculation time becomes longer.

8. The vehicle control apparatus according to claim 6, wherein in the control of the vehicle, motion of the vehicle is controlled.

9. The vehicle control apparatus according to claim 6, wherein the control of the vehicle is performed based on the travel locus computed.

10. The vehicle control apparatus according to claim 1, wherein:

the travel road surface information includes travelable width information regarding a road; and

in computation of the travel locus, an area of protrusion between a travelable width included in the travelable width information and a travel locus deviating from the travelable width is computed by a Simpson method; and

the evaluation function represents the area of protrusion, and is proportional to a length of one section of a plurality of sections that are divided in the Simpson method.

11. The vehicle control apparatus according to claim 1, wherein:

the travel road surface information includes curve information regarding curve of the travel road surface, and travelable width information regarding a road;

the curve information includes radius of the curve of the travel road surface;

the evaluation function is a function that evaluates amount by which the travel locus is protruded from the travelable width included in the travelable width information, and is proportional to a permissible error that is a predetermined permissible amount of the amount by which the travel locus is protruded; and

the permissible error is set greater, as the radius of the curve becomes greater.

12. The vehicle control apparatus according to claim 1, wherein:

the travel road surface information includes friction information regarding friction of the travel road surface, and travelable width information regarding a road;

the friction information includes a friction coefficient of the travel road surface;

the evaluation function is a function that evaluates amount by which the travel locus is protruded from the travelable width included in the travelable width information, and is proportional to a permissible error that is a predetermined permissible amount of the amount by which the travel locus is protruded; and

the permissible error is set greater, as the friction coefficient becomes greater.

13. The vehicle control apparatus according to claim 1, wherein:

the convergence criterion setting portion computes an allowed calculation time that elapses before control of the vehicle starts, based on the travel road surface information stored in the travel road surface information storage portion;

the travel road surface information includes travelable width information regarding a road;

the evaluation function is a function that evaluates amount by which the travel locus is protruded from the travelable width included in the travelable width information, and is proportional to a permissible error that is a predetermined permissible amount of the amount by which the travel locus is protruded; and

the permissible error is set greater, as the allowed calculation time becomes shorter.

14. A vehicle control method comprising:

computing a future travel locus of a vehicle by using an evaluation function;

storing travel road surface information regarding a travel road surface on which the vehicle travels; and

variably setting a convergence criterion for the evaluation function according to the travel road surface information stored.

15. The vehicle control method according to claim 14, wherein the travel road surface information includes at least one of road width information regarding a road width of the travel road surface, friction information regarding friction of the travel road surface, and curve information regarding curve of the travel road surface.

16. The vehicle control method according to claim 15, wherein:

the travel road surface information includes the road width information; and

the convergence criterion is set greater, as the road width in the road width information becomes greater.

17. The vehicle control method according to claim 15, wherein:

the travel road surface information includes the friction information;

the friction information includes a friction coefficient of the travel road surface; and

the convergence criterion is set greater, as the friction coefficient becomes greater.

18. The vehicle control method according to claim 15, wherein:

the travel road surface information includes the curve information;

the curve information includes radius of the curve of the travel road surface; and

the convergence criterion is set greater, as the radius of the curve becomes greater.

19. The vehicle control method according to claim 14, further comprising:

computing an allowed calculation time preceding start of control of motion of the vehicle based on the travel road surface information stored; and

variably setting the convergence criterion according to the allowed calculation time.

20. The vehicle control method according to claim 19, wherein the convergence criterion is set greater, as the allowed calculation time becomes longer.