AUTONOMOUS COLLISION AVOIDANCE SYSTEM FOR UNMANNED AERIAL VEHICLES

• US 20100332136A1
• Filed: 09/13/2010
• Published: 12/30/2010
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: L3 Technologies, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: L-3 Communications Geneva Aerospace, Inc. (L3Harris Technologies, Inc.)
• Inventors: Felio, David A., Askew, Craig S., Duggan, David S.
• Granted Patent: US 8,380,425 B2
• Time in Patent Office: Days
• US Class Current: 701/301
• CPC Class Codes: G05D 1/106 Change initiated in response to external conditions, e.g. avoidance of elevated terrain or of no-fly zones
• CPC Class Codes: G08G 5/0069 specially adapted for an unmanned aircraft
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933

Abstract

Autonomous collision avoidance systems for unmanned aerial vehicles are disclosed. Systems illustratively include a detect and track module, an inertial navigation system, and an auto avoidance module. The detect and track module senses a potential object of collision and generates a moving object track for the potential object of collision. The inertial navigation system provides information indicative of a position and a velocity of the unmanned aerial vehicle. The auto avoidance module receives the moving object track for the potential object of collision and the information indicative of the position and the velocity of the unmanned aerial vehicle. The auto avoidance module utilizes the information to generate a guidance maneuver that facilitates the unmanned aerial vehicle avoiding the potential object of collision.

Claims

1. An autonomous collision avoidance system for an unmanned aerial vehicle comprising:

a detect and track module that senses a potential object of collision and that generates a moving object track for the potential object of collision;

an inertial navigation system that provides information indicative of a position and a velocity of the unmanned aerial vehicle; and

an auto avoidance module that receives the moving object track for the potential object of collision and the information indicative of the position and the velocity of the unmanned aerial vehicle, the auto avoidance system utilizing the moving object track of the potential object of collision and the information indicative of the position and the velocity of the unmanned aerial vehicle to generate a guidance maneuver command that facilitates the unmanned aerial vehicle avoiding the potential object of collision.

2. The system of claim 1, further comprising:

flight controls that receive the guidance maneuver command and that utilize the guidance maneuver command to re-direct a course of the unmanned aerial vehicle to avoid the potential object of collision.

3. The system of claim 1, wherein the auto avoidance module includes a track state estimator that receives the moving object track in a form of an elevation angle and an azimuth direction finding angle.

4. The system of claim 3, wherein the elevation angle and the azimuth direction finding angle are relative to a sensor bore sight.

5. The system of claim 1, wherein the inertial navigation system includes a global positioning system and an inertial measurement unit.

6. The system of claim 1, wherein the auto avoidance module includes an auto avoid recovery unit that generates a recovery command, the recovery command returning the unmanned aerial vehicle to a previous guidance mode.

7. A method for autonomously controlling an unmanned aerial vehicle comprising:

utilizing a sensor to scan for a potential object of collision;

utilizing data collected from the sensor to generate a moving object track for the potential object of collision;

determining a position and a velocity of the unmanned aerial vehicle;

generating an estimate of a position and a velocity of the potential object of collision based at least in part on the moving object track and on the position and velocity of the unmanned aerial vehicle;

performing a calculation so as to determine whether the unmanned aerial vehicle is on a course to enter within a predetermined distance relative to the potential object of collision; and

altering the course of the unmanned aerial vehicle based at least in part on the calculation.

8. The method of claim 7, further comprising:

repeating said performing and said altering until the unmanned aerial vehicle is on course to not enter within the predetermined distance relative to the potential object of collision.

9. The method of claim 7, wherein altering the course comprises guiding the unmanned aerial vehicle away from the potential object of collision according to civilian aircraft operating rules.

10. The method of claim 7, wherein altering the course comprises calculating a waypoint leg to alter the course of the unmanned aerial vehicle.

11. The method of claim 7, further comprising:

restoring a previous course of the unmanned aerial vehicle after the unmanned aerial vehicle has avoided the potential object of collision.

12. The method of claim 7, further comprising:

sending an indication of a collision status from the unmanned aerial vehicle to a ground control station.

13. An autonomous collision avoidance system for an unmanned aerial vehicle comprising:

a sensor that detects an elevation angle and an azimuth angle of a potential object of collision;

an inertial navigation system that provides information indicative of a velocity, a position, and an angular position of the unmanned aerial vehicle; and

a track state estimator that receives information indicative of the potential object of collision elevation angle, the potential object of collision azimuth angle, the unmanned aerial vehicle velocity, the unmanned aerial vehicle position, and the unmanned aerial vehicle angular position, the track state estimator utilizing the received information to determine a line of sight rate vector, a relative range magnitude, and a relative range rate of the unmanned aerial vehicle relative to the potential object of collision.

14. The system of claim 13, further comprising:

an avoid state calculator that receives information indicative of the line of sight rate vector, the relative range magnitude, and the relative range rate, the avoid state calculator utilizing the received information to determine a zero effort miss distance of the unmanned aerial vehicle relative to the potential object of collision.

15. The system of claim 14, further comprising:

an avoid alert calculator that receives the zero effort miss distance and that compares the zero effort miss distance to a predetermined allowable miss distance, the avoid alert calculator generating an alert flag upon the zero effort miss distance being less than the predetermined allowable miss distance.

16. The system of claim 15, further comprising:

an auto avoid guidance module that, upon receiving the alert flag, generates a command to re-direct a course of the unmanned aerial vehicle to avoid the potential object of collision.

17. The system of claim 16, further comprising:

an auto avoid recovery unit that generates a recovery command that returns the unmanned aerial vehicle to a previous guidance mode.

18. The system of claim 15, wherein an indication of the alert flag is sent to a ground station.

19. The system of claim 15, wherein the alert flag indicates a head-on collision.

20. The system of claim 15, wherein the alert flag indicates a non-head-on collision.