HYBRID TRAFFIC SYSTEM AND ASSOCIATED METHOD

• US 20130151135A1
• Filed: 11/15/2011
• Published: 06/13/2013
• Est. Priority Date: 11/15/2010
• Status: Active Grant

• Current Assignee: Image Sensing Systems Incorporated (Autoscope Technologies Corp.)
• Original Assignee: Image Sensing Systems Incorporated (Autoscope Technologies Corp.)
• Inventors: Aubrey, Ken, Govindarajan, Kiran, Brudevold, Bryan, Anderson, Craig, Steingrimsson, Baldur
• Granted Patent: US 8,849,554 B2
• Time in Patent Office: Days
• US Class Current: 701/118
• 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 1/0116 from roadside infrastructure, e.g. beacons

Abstract

A traffic sensing system for sensing traffic at a roadway includes a first sensor having a first field of view, a second sensor having a second field of view, and a controller. The first and second fields of view at least partially overlap in a common field of view over a portion of the roadway, and the first sensor and the second sensor provide different sensing modalities. The controller is configured to select a sensor data stream for at least a portion of the common field of view from the first and/or second sensor as a function of operating conditions at the roadway.

Claims

1. A traffic sensing system for sensing traffic at a roadway, the system comprising:

a first sensor having a first field of view;

a second sensor having a second field of view, wherein the first and second fields of view at least partially overlap in a common field of view over a portion of the roadway, and wherein the first sensor and the second sensor provide different sensing modalities; and

a controller configured to select a sensor data stream for at least a portion of the common field of view from the first and/or second sensor as a function of operating conditions at the roadway, in order to provide roadway traffic detection.

2. The system of claim 1, wherein the controller is further configured to select a sensor data stream for at least a portion of the common field of view as a function of type of detection.

3. The system of claim 1, wherein the first and second sensors are located adjacent to one another and are both commonly supported by a support structure.

4. The system of claim 1, wherein the portion of the roadway over which the respective first and second fields of view of the first and second sensors at least partially overlap include a detection region of interest within a first approach.

5. The system of claim 1, wherein the controller is configured to select a sensor data stream from the first or second sensor as a function of conditions at the roadway that include at least one of (a) presence of shadows, (b) daytime or nighttime lighting, (c) rain and wet road conditions, (d) contrast, (e) field of view occlusion, (f) traffic density, (g) lane type, (h) sensor-to-object distance, (i) roadway object speed, (j) sensor failure and (k) communication failure.

6. The system of claim 5, wherein the first sensor is a radar and the second sensor is a machine vision device, and wherein the controller is configured to select the machine vision device by default and use radar to improve detection under operating conditions that include low contrast, strong shadow, nighttime, queues, and weather conditions that decrease machine vision performance.

7. The system of claim 1, wherein the controller is configured to select a sensor data stream from the first and/or second sensor as a function of type of detection selected from the group consisting of:

(a) object count, (b) object speed, (c) stop line detection, (d) object presence in a selected area, (e) queue length, (f) turn movement detection, (g) object classification, and (h) object directional warning.

8. The system of claim 1, wherein the first sensor comprises a radar assembly, and wherein the second sensor comprises a machine vision assembly.

9. A method of normalizing a traffic sensor system for sensing traffic at a roadway, the method comprising:

positioning a first synthetic target generator device on or near the roadway;

sensing roadway data with a first sensor having a first sensor coordinate system;

sensing roadway data with a second sensor having a second sensor coordinate system, wherein the sensed roadway data of the first and second sensors overlap in a first roadway area, and wherein the first synthetic target generator is positioned in the first roadway area;

detecting a location of the first synthetic target generator device in the first sensor coordinate system with the first sensor;

displaying sensor output of the second sensor;

selecting a location of the first synthetic target generator device on the display in the second sensor coordinate system; and

correlating the first and second coordinate systems as a function of the locations of the first synthetic target generator device in the first and second sensor coordinate systems.

10. The method of claim 9 and further comprising:

positioning a second synthetic target generator device on or near the roadway;

detecting a location of the second synthetic target generator device in the first sensor coordinate system with the first sensor; and

selecting a location of the second synthetic target generator device on the display in the second sensor coordinate system,

wherein correlating the first and second coordinate systems is also performed as a function of the locations of the second synthetic target generator device in the first and second sensor coordinate systems.

11. The method of claim 10 and further comprising:

positioning a third synthetic target generator device on or near the roadway, wherein the first, second and third synthetic target generator devices are not positioned collinearly;

detecting a location of the third synthetic target generator device in the first sensor coordinate system with the first sensor; and

selecting a location of the third synthetic target generator device on the display in the second sensor coordinate system,

wherein correlating the first and second coordinate systems is also performed as a function of the locations of the third synthetic target generator device in the first and second sensor coordinate systems.

12. The method of claim 11, wherein the first, second and third synthetic target generator devices are the same device repositioned at different physical locations on the roadway.

13. The method of claim 11, wherein the first, second and third synthetic target generator devices are simultaneously positioned at different physical locations on the roadway.

14. The method of claim 9, wherein the first synthetic target generator device is held in a stationary position relative to the roadway.

15. A traffic sensing system and normalization kit for use at a roadway, the kit comprising:

a first synthetic target generator device positionable on or near the roadway;

a radar sensor having a first field of view positionable at the roadway;

a machine vision sensor having a second field of view positionable at the roadway;

a communication system configured to communicate data from the first and second sensors to a display.

16. The kit of claim 15, wherein the first synthetic target generator device comprises a mechanical or electro-mechanical device having moving element.

17. The kit of claim 15, wherein the first synthetic target generator device comprises an electrical device that generates an electromagnetic wave to simulate a reflected radar return wave.

18. The kit of claim 15, wherein the radar sensor and the machine vision sensor are secured adjacent one another in a common hybrid sensor assembly.

19. The kit of claim 15 and further comprising:

a terminal operably connectable to the communication system to allow operator input.