On-board traffic density estimator

• US 9,117,098 B2
• Filed: 06/03/2013
• Issued: 08/25/2015
• Est. Priority Date: 06/03/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Trombley, Roger A., Plutti, Thomas E., Prakah-Asante, Kwaku O.
• Primary Examiner(s): Nguyen, John Q
• Assistant Examiner(s): ODEH, NADEEM N
• Application Number:
  US13/908,386
• Publication Number:
  US 20140358413A1
• Time in Patent Office: 813 Days
• Field of Search: 701/118, 701/300, 342/454, 340/934
• US Class Current: 1/1
• CPC Class Codes: G06G 1/00 Hand manipulated computing devices planimeters G01B5/26
• CPC Class Codes: G08G 1/00 Traffic control systems for road vehicles arrangement of road signs or traffic signals E01F9/00 ; automatic vehicle control B62D
• CPC Class Codes: G08G 1/0112 from the vehicle, e.g. floating car data [FCD]
• CPC Class Codes: G08G 1/0129 for creating historical data or processing based on historical data
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors

Abstract

Traffic density is estimated around a host vehicle moving on a roadway. An object detection system remotely senses and identifies the positions of nearby vehicles. A controller a) predicts a path of a host lane being driven by the host vehicle, b) bins the nearby vehicles into a plurality of lanes including the host lane and one or more adjacent lanes flanking the predicted path, c) determines a host lane distance in response to a position of a farthest vehicle that is binned to the host lane, d) determines an adjacent lane distance in response to a difference between a closest position in an adjacent lane that is within the field of view and a position of a farthest vehicle binned to the adjacent lane, and e) indicates a traffic density in response to a ratio between a count of the binned vehicles and a sum of the distances.

Claims

1. A method for an electronic controller in a host vehicle to determine a traffic density, comprising the steps of:

a sensor remotely sensing objects within a field of view around the host vehicle;

identifying positions of nearby vehicles from among the sensed objects;

predicting a path of a host lane being driven by the host vehicle;

the electronic controller binning the nearby vehicles into a plurality of lanes including the host lane and at least one adjacent lane flanking the predicted path;

the electronic controller determining a host lane distance in response to a position of a farthest vehicle relative to the host vehicle that is binned to the host lane;

the electronic controller determining an adjacent lane distance in response to a difference between a closest position in an adjacent lane that is within the field of view and a position of a farthest vehicle binned to the adjacent lane;

the electronic controller indicating a traffic density in response to a ratio between a count of the binned vehicles and a sum of the distances.

2. The method of claim 1 wherein the host lane distance includes a length of the farthest vehicle binned to the host lane and a length of the host vehicle.

3. The method of claim 1 wherein the adjacent lane distance includes a length of the farthest vehicle binned to the adjacent lane.

4. The method of claim 1 wherein if no nearby vehicles are identified in the host lane, then the host lane distance is comprised of a maximum detection distance of the sensor along the predicted path.

5. The method of claim 1 wherein if no nearby vehicles are identified in the adjacent lane, then the adjacent lane distance defaults to a predetermined maximum detection distance.

6. The method of claim 1 further comprising the step of normalizing the ratio into a predetermined range prior to indicating the traffic density.

7. The method of claim 1 further comprising the step of classifying the indicated traffic density according to a light, medium, or heavy density.

8. The method of claim 1 wherein the electronic controller indicates individual traffic lane densities for the host lane and the adjacent lane.

9. The method of claim 1 further comprising the step of:

the electronic controller periodically determining validity of adjacent lanes along each side of the host lane, wherein an adjacent lane path is determined as a valid adjacent lane whenever a moving vehicle is coincident with the adjacent lane path.

10. The method of claim 9 wherein an adjacent lane path is determined not to be a valid adjacent lane whenever no moving vehicle is coincident with the adjacent lane path over a predetermined time period.

11. Apparatus comprising:

sensor in a host vehicle; and

a controller receiving identification of nearby vehicles from the sensor, predicting a host lane path, binning vehicles into a host lane and adjacent lanes, determining a host lane distance and adjacent lane distances in response to positions of farthest vehicles in the respective lanes, and indicating a traffic density in response to a ratio between a count of binned vehicles and a sum of the distances.

12. An apparatus for monitoring traffic density around a host vehicle, comprising:

an object detection system, in the host vehicle, using remote sensing within a field of view around the host vehicle to identify positions of nearby vehicles; and

a controller, in the host vehicle, coupled to the object detection system for a) predicting a path of a host lane being driven by the host vehicle, b) binning the nearby vehicles into a plurality of lanes including the host lane and at least one adjacent lane flanking the predicted path, c) determining a host lane distance in response to a position of a farthest vehicle relative to the host vehicle that is binned to the host lane, d) determining an adjacent lane distance in response to a difference between a closest position in an adjacent lane that is within the field of view and a position of a farthest vehicle binned to the adjacent lane, and e) indicating a traffic density in response to a ratio between a count of the binned vehicles and a sum of the distances.

13. The apparatus of claim 12 wherein if no nearby vehicles are identified in the host lane, then the host lane distance is comprised of a maximum detection distance in the field of view along the predicted path.

14. The apparatus of claim 12 wherein if no nearby vehicles are identified in the adjacent lane, then the adjacent lane distance defaults to a predetermined maximum detection distance.

15. The apparatus of claim 12 wherein the controller indicates individual traffic lane densities for the host lane and the adjacent lane.

16. The apparatus of claim 12 wherein the controller is further adapted for f) periodically determining validity of adjacent lanes along each side of the host lane, wherein an adjacent lane path is determined as a valid adjacent lane whenever a moving vehicle is coincident with the adjacent lane path.

17. The apparatus of claim 16 wherein an adjacent lane path is determined not to be a valid adjacent lane whenever no moving vehicle is coincident with the adjacent lane path over a predetermined time period.