Cruise control plan evaluation device and method

• US 9,224,299 B2
• Filed: 11/01/2007
• Issued: 12/29/2015
• Est. Priority Date: 11/01/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Taguchi, Koji, Doi, Tomoyuki
• Primary Examiner(s): Algahaim, Helal A
• Assistant Examiner(s): WALLACE, DONALD JOSEPH
• Application Number:
  US12/312,001
• Publication Number:
  US 20100010699A1
• Time in Patent Office: 2,980 Days
• Field of Search: 701/1, 701/23, 701/28, 701/91, 701/93, 701/96, 701300-302, 340/901, 340/903, 340/435, 340/436, 180/170, 180/271
• US Class Current: 1/1
• CPC Class Codes: B60W 2552/05 Type of road, e.g. motorways, local streets, paved or unpaved roads
• CPC Class Codes: B60W 2552/10 Number of lanes
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2554/80 Spatial relation or speed relative to objects
• CPC Class Codes: B60W 30/08 Active safety systems predicting or avoiding probable or impending collision or attempting to minimise its consequences
• CPC Class Codes: B60W 30/0956 the prediction being responsive to traffic or environmental parameters
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: B62D 6/00 Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00
• CPC Class Codes: G08G 1/163 involving continuous checking
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Abstract

A cruise control plan evaluation device (10) that evaluates safety of a cruise control plan for an automatically-operated vehicle includes: a behavior prediction unit (16a) that predicts a behavior that may be exhibited by a nearby vehicle, which is present near the automatically-operated vehicle, at a given time point; a position prediction unit (16b) that predicts a position of the nearby vehicle after the given time point based on a position of the nearby vehicle at the given time point and the behavior predicted by the behavior prediction unit (16a); and an evaluation unit (20) that evaluates the safety of the cruise control plan based on the position of the nearby vehicle predicted by the position prediction unit (16b) and a position that is reached by the automatically-operated vehicle according to the cruise control plan.

Claims

1. A cruise control plan evaluation device that evaluates safety of a cruise control plan for an automatically-operated vehicle, comprising:

a behavior prediction unit that is configured to predict a behavior that is exhibited by a nearby vehicle, which is present near the automatically-operated vehicle, at a given time point;

a position prediction unit that is configured to predict a position of the nearby vehicle after the given time point based on a position of the nearby vehicle at the given time point and the behavior predicted by the behavior prediction unit;

a cruise control plan preparation unit that is configured to prepare multiple cruise control plans for the automatically-operated vehicle; and

an evaluation unit that is configured to evaluate the safety of each cruise control plan based on the position of the nearby vehicle predicted by the position prediction unit and a position that is reached by the automatically-operated vehicle according to the cruise control plan, wherein

the behavior prediction unit is configured to predict the behavior that is exhibited by the nearby vehicle and also configured to estimate a probability that the nearby vehicle exhibits the behavior, and

the evaluation unit includes;

a predicted vehicle-presence region drawing-up unit that is configured to draw up a predicted vehicle-presence region that indicates a region, in which the nearby vehicle is predicted to be present, using a probability distribution based on the position of the nearby vehicle predicted by the position prediction unit and the probability estimated by the behavior prediction unit;

a contact impermissible region drawing-up unit that is configured to draw up a contact impermissible region that indicates a region, which needs to be maintained to prevent contact between the automatically-operated vehicle and the nearby vehicle, using a probability distribution in a manner such that an outline of the contact impermissible region surrounds the automatically-operated vehicle;

an emergency contact-avoidance ensuring region drawing-up unit that is configured to draw up an emergency contact-avoidance ensuring region that indicates a region, which needs to be maintained to prevent contact between the automatically-operated vehicle and the nearby vehicle in an emergency and is a region that is ensured for the automatically-operated vehicle in the event of the emergency, using a probability distribution in a manner such that an outline of the emergency contact-avoidance ensuring region surrounds the automatically-operated vehicle; and

a determination unit that is configured to determine that the cruise control plan is safe when a result of multiply-and-accumulation of the predicted vehicle-presence region and the contact impermissible region is equal to or lower than a first threshold value at any time point and when a result of multiply-and-accumulation of the predicted vehicle-presence region and the emergency contact-avoidance ensuring region is equal to or lower than a second threshold value at any time point.

2. The cruise control plan evaluation device according to claim 1, wherein

the behavior prediction unit is configured to predict the behavior of the nearby vehicle based on at least information concerning a road shape.

3. The cruise control plan evaluation device according to claim 1, further comprising:

a cruise control plan selection unit that is configured to select the cruise control plan to be implemented from among the multiple cruise control plans based on results of evaluations made by the evaluation unit.

4. The cruise control plan evaluation device according to claim 3, wherein the cruise control plan selection unit is configured to select the cruise control plan to be implemented from among the multiple cruise control plans based on the results of evaluations made by the evaluation unit such that:

when there is only one cruise control plan that is determined to be safe, this cruise control plan is selected as the cruise control plan that will be implemented,

when there are multiple cruise control plans that are determined to be safe, the cruise control plan having a lower multiply-and-accumulation value and a higher level of safety is selected as the cruise control plan that will be implemented, and

when there is no cruise control plan that is determined to be safe, the cruise control plan having a highest level of safety is selected.

5. The cruise control plan evaluation device according to claim 1, wherein requests from a driver of the automatically-operated vehicle are taken into account in preparation of the multiple cruise control plans.

6. The cruise control plan evaluation device according to claim 1, wherein the emergency contact-avoidance ensuring region is drawn so that the area behind the automatically-operated vehicle is set to be wide.

7. The cruise control plan evaluation device according to claim 1, wherein when the automatically-operated vehicle is decelerating, the area behind the automatically-operated vehicle is set to be wide and the area in front of the automatically-operated vehicle is set to be narrow.

8. The cruise control plan evaluation device according to claim 1, wherein when a lateral velocity is generated, the area in the moving direction of the automatically-operated vehicle is set to be wide and the area in the direction opposite to the moving direction is set to be narrow.

9. A cruise control plan evaluation method for evaluating safety of a cruise control plan for an automatically-operated vehicle, comprising:

predicting a behavior that is exhibited by a nearby vehicle, which is present near the automatically-operated vehicle, at a given time point;

predicting a position of the nearby vehicle after the given time point based on a position of the nearby vehicle at the given time point and the predicted behavior;

preparing multiple cruise control plans for the automatically-operated vehicle; and

evaluating the safety of each cruise control plan based on the predicted position of the nearby vehicle and a position that is reached by the automatically-operated vehicle according to the cruise control plan, wherein

the behavior that is exhibited by the nearby vehicle is predicted and a probability that the nearby vehicle exhibits the behavior is also estimated, and

a step of evaluating the cruise control plan includes;

drawing up a predicted vehicle-presence region that indicates a region, in which the nearby vehicle is predicted to be present, using a probability distribution based on the predicted position of the nearby vehicle and the estimated probability;

drawing up a contact impermissible region that indicates a region, which needs to be maintained to prevent contact between the automatically-operated vehicle and the nearby vehicle, using a probability distribution in a manner such that an outline of the contact impermissible region surrounds the automatically-operated vehicle;

drawing up an emergency contact-avoidance ensuring region that indicates a region, which needs to be maintained to prevent contact between the automatically-operated vehicle and the nearby vehicle in an emergency and is a region that is ensured for the automatically-operated vehicle in the event of the emergency, using a probability distribution in a manner such that an outline of the emergency contact-avoidance ensuring region surrounds the automatically-operated vehicle; and

determining that the cruise control plan is safe when a result of multiply-and-accumulation of the predicted vehicle-presence region and the contact impermissible region is equal to or lower than a first threshold value at any time point and when a result of multiply-and-accumulation of the predicted vehicle-presence region and the emergency contact-avoidance ensuring region is equal to or lower than a second threshold value at any time point.

10. The cruise control plan evaluation method according to claim 9, wherein

the behavior of the nearby vehicle is predicted based on at least information concerning a road shape.

11. The cruise control plan evaluation method according to claim 9, further comprising:

selecting the cruise control plan to be implemented from among the multiple cruise control plans based on results of evaluations.

12. The cruise control plan evaluation method according to claim 11, wherein the cruise control plan to be implemented is selected from among the multiple cruise control plans based on the results of evaluations such that:

when there is only one cruise control plan that is determined to be safe, this cruise control plan is selected as the cruise control plan that will be implemented,

when there are multiple cruise control plans that are determined to be safe, the cruise control plan having a lower multiply-and-accumulation value and a higher level of safety is selected as the cruise control plan that will be implemented, and

when there is no cruise control plan that is determined to be safe, the cruise control plan having a highest level of safety is selected.

13. The cruise control plan evaluation method according to claim 9, wherein requests from a driver of the automatically-operated vehicle are taken into account in preparation of the multiple cruise control plans.

14. The cruise control plan evaluation method according to claim 9, wherein the emergency contact-avoidance ensuring region is drawn so that the area behind the automatically-operated vehicle is set to be wide.

15. The cruise control plan evaluation method according to claim 9, wherein when the automatically-operated vehicle is decelerating, the area behind the automatically-operated vehicle is set to be wide and the area in front of the automatically-operated vehicle is set to be narrow.

16. The cruise control plan evaluation method according to claim 9, wherein when a lateral velocity is generated, the area in the moving direction of the automatically-operated vehicle is set to be wide and the area in the direction opposite to the moving direction is set to be narrow.