Detecting roadway targets across beams

• US 9,240,125 B2
• Filed: 01/24/2014
• Issued: 01/19/2016
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: Wavetronix
• Original Assignee: Wavetronix
• Inventors: Arnold, David V., Jarrett, Bryan R., Karlinsey, Thomas W., Waite, Jonathan L., Giles, Brad, St. John, Randy
• Primary Examiner(s): HOFSASS, JEFFERY A
• Application Number:
  US14/164,102
• Publication Number:
  US 20140139361A1
• Time in Patent Office: 725 Days
• Field of Search: 340/907, 340/916, 340/917, 340/933, 340941-943, 343/700.MS, 342/104, 342/118, 342/147
• US Class Current: 1/1
• CPC Class Codes: G01S 13/48 using multiple beams at emission or reception
• CPC Class Codes: G01S 13/726 Multiple target tracking
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors
• CPC Class Codes: G08G 1/08 according to detected number or speed of vehicles

Abstract

The present invention extends to methods, systems, and computer program products for detecting targets across beams at roadway intersections. Embodiments of the invention include tracking a target across a plurality of beams of a multiple beam radar system in a roadway intersection and updating track files for targets within a roadway intersection. Returns from a plurality of radar beams monitoring a roadway intersection are divided into range bins. Identified energy in the range bins is used to compute the position of targets within a roadway intersection. When the position of a target is computed, it is determined if the position is a new position for an existing target or if the position is the position of a new target.

Claims

1. A traffic sensor for monitoring a roadway, the traffic sensor comprising:

a radar system including a plurality of beams and configured to transmit signals into a roadway and to receive reflections of signals off of objects in the roadway using the plurality of beams;

a target identifying module configured to;

divide received reflections of signals into a plurality of range bins;

compute a position of at least one target in the roadway based on at least one received reflection and at least one corresponding range bin;

and

create a track file for the at least one target in the roadway.

2. The traffic sensor recited in claim 1, wherein the track file includes target position data for the at least one target in the roadway, and the target position data is selected from a group consisting of:

a last known position for the at least one target and a predicted future position for the at least one target.

3. The traffic sensor recited in claim 1, wherein the target identifying module further comprises a track file maintenance module configured to maintain the track file for the at least one target in the roadway.

4. The traffic sensor recited in claim 3, wherein the track file maintenance module is configured to update the track file for the at least one target in the roadway when a new position has been computed for the at least one target and the new position is determined to correspond to either the last known position or the predicted future position of the at least one target.

5. The traffic sensor recited in claim 3, wherein the track file maintenance module is further configured to:

create a new track file for a second target when a new position of a target has been computed and the new position does not correspond to the last known position or the predicted future position of a previously detected target.

6. The traffic sensor recited in claim 3, wherein the track file maintenance module is configured to access all existing track files and to update at least one of the existing track files or create a new track file depending on the correspondence or lack of correspondence of a new position to the position data included in the existing track files.

7. The traffic sensor recited in claim 1, wherein the radar system further comprises:

transmit antennas for transmitting signals into the roadway using the plurality of beams, the signals being frequency modulated continuous wave radio frequency signals; and

receive antennas for receiving the reflections of the signals.

8. The traffic sensor recited in claim 1, wherein the target identifying module is further configured to:

detect a multi-beam image, the multi-beam image representing the at least one target within the roadway, the multi-beam image spanning one or more beams of the plurality of beams, the multi-beam image also spanning a plurality of range bins;

identify an energy peak within the multi-beam image, by determining, for a specified range bin in at least one of the plurality of beams, that the magnitude of the radio frequency energy in the specified range bin is above a specified threshold; and

that the magnitude of the radio frequency energy in the specified range bin is greater than the magnitude of the radio frequency energy in any adjacent range bins.

9. The traffic sensor recited in claim 1, further comprising:

one or more computer storage media having computer-executable instructions stored thereon, such instructions comprising the target identifying module; and

one or more processors electronically coupled to system memory and the one or more computer storage media, the one or more processors being configured to execute the computer-executable instructions.

10. The traffic sensor recited in claim 1, wherein the range bins are arranged in a grid.

11. The traffic sensor recited in claim 9, wherein the one or more computer storage media having computer-executable instructions stored thereon further comprises instructions comprising a track file maintenance module.

12. A traffic control system comprising:

a traffic sensor for monitoring a roadway, the traffic sensor comprising;

a radar system including a plurality of beams configured to transmit a signal into the roadway and to receive reflections of the signal off of objects in the roadway using the plurality of beams; and

a computer system coupled to the radar system and configured to;

detect one or more targets using the received reflections of the signal off of objects in the roadway;

access a target list for the roadway, the target list including currently computed positions for the one or more targets in the roadway, the currently computed positions being derived from a grid of range bins dividing returns from the plurality of beams;

maintain a track file for each target in the roadway, each track file including target data for a target that is within the roadway, the target data including target position data for the target, the target position data including at least one of;

a last known position for the target and a predicted future position for the target.

13. The traffic control system recited in claim 12, wherein the computer system is further configured to:

access the track file for an existing target, the track file having target position data that may correspond to one of the currently computed positions;

determine if the one of the currently computed positions is a position of the existing target by comparing the one of the currently computed positions to the target position data in the accessed track file;

update the accessed track file for the existing target when the one of the currently computed positions is determined to correspond to the position of the existing target; and

create a new track file for a new target when the one of the currently computed positions is determined not to correspond to the position of the existing target.