Detecting and responding to tailgaters

• US 9,050,977 B1
• Filed: 07/01/2014
• Issued: 06/09/2015
• Est. Priority Date: 07/24/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Dolgov, Dmitri A., Nemec, Philip, Aula, Anne
• Primary Examiner(s): Marc, McDieunel
• Application Number:
  US14/320,824
• Time in Patent Office: 343 Days
• Field of Search: 701/1, 701/93, 701/96, 701/301, 701/451, 340/435, 340 4- 67, 340/901, 340/903, 340/933, 340/426.16, 340/427, 180/167, 455/500
• US Class Current: 1/1
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2554/80 Spatial relation or speed relative to objects
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2554/802 Longitudinal distance
• CPC Class Codes: B60W 2754/30 Longitudinal distance
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 60/0016 of the vehicle or its occupants
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: B62D 15/0255 Automatic changing of lane, e.g. for passing another vehicle
• CPC Class Codes: G05D 1/00 Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots drive control systems specially adapted for autonomous road vehicles B60W60/00
• CPC Class Codes: G05D 1/0055 with safety arrangements
• CPC Class Codes: G05D 1/0287 involving a plurality of land vehicles, e.g. fleet or convoy travelling traffic control systems for road vehicles G08G1/00, particularly anticollision systems G08G1/16

Abstract

An autonomous vehicle detects a tailgating vehicle and uses various response mechanisms. For example, a vehicle is identified as a tailgater based on whether its characteristics meet a variable threshold. When the autonomous vehicle is traveling at slower speeds, the threshold is defined in distance. When the autonomous vehicle is traveling at faster speeds, the threshold is defined in time. The autonomous vehicle may respond to the tailgater by modifying its driving behavior. In one example, the autonomous vehicle adjusts a headway buffer (defined in time) from another vehicle in front of the autonomous vehicle. For example, if the tailgater is T seconds too close to the autonomous vehicle, the autonomous vehicle increases the headway buffer to the vehicle in front of it by some amount relative to T.

Claims

1. A system for controlling aspects of a first vehicle, the system comprising one or more processors configured to:

receive sensor data from a sensor;

detect, using the sensor data, a second vehicle driving behind a first vehicle and in a same lane as the first vehicle;

detect, using the sensor data, a third vehicle driving in front of the first vehicle and in the same lane as the first vehicle;

determine whether the second vehicle is within a threshold tailgating distance of the first vehicle;

when the second vehicle is within the threshold tailgating distance, determine a difference in distance between the threshold tailgating distance and a distance between the second vehicle and the first vehicle; and

adjust a distance between the first vehicle and the third vehicle based on the difference in distance.

2. The system of claim 1, wherein the one or more processors are further configured to adjust the distance between the first vehicle and the third vehicle by:

retrieving a minimum headway time defining a minimum driving time between the first vehicle and any vehicle immediately in front of the first vehicle;

determining an amount of time to travel the difference in distance; and

adjusting the minimum headway time based on the amount of time.

3. The system of claim 2, wherein the one or more processors are further configured to adjust the adjusted minimum headway time based on any changes to a current speed of the first vehicle.

4. The system of claim 2, wherein the one or more processors are further configured to adjust the adjusted the minimum headway time based on any changes to the difference in distance.

5. The system of claim 2, wherein the one or more processors are further configured to adjust the adjusted minimum headway time until the distance between the first vehicle and the tailgater is greater than or equal to the distance threshold.

6. The system of claim 1, wherein the one or more processors are further configured to, before determining whether the second vehicle is within a threshold tailgating distance of the first vehicle, select the threshold tailgating distance over a threshold tailgating time when a current speed of the first vehicle is less than a speed threshold.

7. The system of claim 6, wherein the one or more processors are further configured to:

when the current speed of the first vehicle is greater than a speed threshold, select the threshold tailgating time over the threshold tailgating distance;

determine a difference in distance between the first vehicle and the second vehicle;

determine an amount of time for the first vehicle to travel the difference in distance between the first vehicle and the second vehicle;

when the amount of time is greater than the threshold tailgating time, determine a difference in time between the time threshold and the amount of time; and

adjust a distance between the first vehicle and the third vehicle based on the difference in time.

8. The system of claim 7, wherein the one or more processors are further configured to adjust the distance between the first vehicle and the third vehicle based on the difference in time by:

retrieving a minimum headway time defining a minimum driving time between the first vehicle and any vehicle immediately in front of the first vehicle; and

adjusting the minimum headway time based on the difference in time.

9. The system of claim 1, wherein the one or more processors are further configured to determine the threshold tailgating distance using a function of a distance threshold component, a time threshold component, and a current speed of the vehicle.

10. A system for controlling aspects of a first vehicle, the system comprising one or more processors configured to:

receive sensor data from a sensor;

detect, using the sensor data, a second vehicle driving behind the first vehicle and in a same lane as the first vehicle;

detect, using the sensor data, a third vehicle driving in front of the first vehicle and in the same lane as the first vehicle;

determine a difference in distance between the first vehicle and the second distance;

determine an amount of time for traveling the difference in distance;

when the amount of time is greater than a tailgating threshold time, determine a difference in time between the time threshold and the amount of time; and

adjust a distance between the first vehicle and the third vehicle based on the difference in time.

11. The system of claim 10, wherein the one or more processors are further configured to adjust the distance between the first vehicle and the third vehicle further by:

retrieving a minimum headway time defining a minimum driving time between the first vehicle and any vehicle immediately in front of the first vehicle; and

adjusting the minimum headway time based on the difference in time.

12. The system of claim 11, wherein the one or more processors are further configured to adjust the adjusted minimum headway time based on any changes to the current speed of the first vehicle.

13. The system of claim 11, wherein the one or more processors are further configured to adjust the adjusted the minimum headway time based on any changes to the difference.

14. The system of claim 11, wherein the one or more processors are further configured to continue to adjust the minimum headway time until the amount of time is greater than or equal to the time threshold.

15. The system of claim 10 wherein the one or more processors are further configured to select the threshold tailgating time over a threshold tailgating distance when a current speed of the first vehicle is greater than a speed threshold.

16. The system of claim 15, wherein the one or more processors are further configured to:

when the current speed of the first vehicle is less than the speed threshold, select the threshold tailgating distance over the threshold tailgating time;

use the threshold tailgating time to determine whether the second vehicle is currently tailgating; and

when the second vehicle is currently tailgating, adjust the distance between the first vehicle and the third vehicle.

17. The system of claim 16, wherein the one or more processors are further configured to adjust the distance between the first vehicle and the third vehicle by:

retrieving a minimum headway time defining a minimum driving time between the first vehicle and any vehicle immediately in front of the first vehicle;

adjusting the minimum headway time based on the determination that the second vehicle is currently tailgating.

18. A system for controlling aspects of a first vehicle, the system comprising one or more processors configured to:

receive sensor data from a sensor;

detect, using the sensor data, a second vehicle driving behind the first vehicle and in a same lane as the first vehicle;

detect, using the sensor data, a third vehicle driving in front of the first vehicle and in the same lane as the first vehicle;

select between a threshold tailgating time and a threshold tailgating distance based on a current speed of the vehicle;

use the selected threshold to determine when the second vehicle is tailgating;

when the second vehicle is tailgating, adjust a minimum threshold time defining a minimum driving time between the first vehicle and any vehicle immediately in front of the first vehicle;

use the adjusted minimum threshold time to determine a distance between the first vehicle and the third vehicle; and

controlling the first vehicle based on the distance.

19. The system of claim 18, wherein the one or more processors are further configured to adjust the minimum headway time based on any changes to the current speed of the first vehicle.

20. The system of claim 18, wherein the one or more processors are further configured to adjust the adjusted minimum headway time based on any changes to the difference.