Rotor safety system

• US 10,139,493 B1
• Filed: 07/06/2017
• Issued: 11/27/2018
• Est. Priority Date: 07/06/2016
• Status: Active Grant

• Current Assignee: Near Earth Autonomy, Inc.
• Original Assignee: Near Earth Autonomy, Inc.
• Inventors: Chamberlain, Lyle, Singh, Sanjiv, Stambler, Adam, Cover, Hugh, Hamner, Bradley
• Primary Examiner(s): Paige, Tyler D
• Application Number:
  US15/642,744
• Time in Patent Office: 509 Days
• Field of Search: 701 3
• CPC Class Codes: B64C 27/006 Safety devices
• CPC Class Codes: B64C 27/06 with single rotor
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/933 of aircraft or spacecraft
• CPC Class Codes: G01S 19/13 Receivers
• CPC Class Codes: G01S 19/14 specially adapted for specific applications

Abstract

Piloted or autonomous rotorcraft includes a rotor safety system. The rotor safety system comprises a lidar scanner toward a rotor of the rotorcraft, e.g., the tail rotor, that scans the 3D space in the vicinity of the rotor. Objects in the vicinity of the rotor are detected from the lidar point data. In a piloted rotorcraft, predictive warnings can be provided to the helicopter'"'"'s flight crew when a detected object presents a hazard to the rotor of the rotorcraft.

Claims

1. A rotorcraft comprising:

a rotor; and

a rotor safety system that comprises;

a lidar scanner attached to the rotorcraft for continuously scanning a space around the rotor during a near-ground operation of the rotorcraft;

a computer system in communication with the lidar scanner for detecting objects that pose a threat of contacting the rotor during the near-ground operation of the rotorcraft based on time-stamped lidar point data from the lidar scanner, wherein the computer system detects whether an object poses a threat of contacting the rotor by;

generating a series of time-stamped point clouds from the time-stamped lidar point data, wherein the series of time-stamped point clouds indicate a location of the object in a vicinity of the rotor at different time stamp instances;

determining a relative velocity of the object relative to the rotor based on movement of the object relative to the rotor over the series of time-stamped point clouds; and

determining, based on the determined relative velocity of object, that the object poses a threat of contacting the rotor when it is determined that the object will be within a threshold distance of the rotor within a threshold time period; and

reaction means in communication with the computer system for taking a reaction in response to detection by the computer system that the object poses a threat of contacting the rotor.

2. The rotorcraft of claim 1, wherein the near-ground operation comprises take-off or landing of the rotorcraft.

3. The rotorcraft of claim 1, wherein the rotor comprises a tail rotor of the rotorcraft.

4. The rotorcraft of claim 3, wherein the lidar scanner is attached to a tail portion of the rotorcraft.

5. The rotorcraft of claim 4, wherein the lidar scanner is attached to an underside of the tail portion.

6. The rotorcraft of claim 1, wherein:

the rotorcraft further comprises an altitude sensor;

the computer system is in communication with the altitude sensor; and

the computer system inactivates the rotor safety system when the rotorcraft is a threshold distance above ground as determined by the altitude sensor.

7. The rotorcraft of claim 6, wherein:

the rotorcraft comprises at least one motion sensor that is in communication with the computer system; and

the computer system continuously registers the time-stamped point clouds into a three-dimensional space based on time-stamped position data for the rotorcraft from the at least one motion sensor.

8. The rotorcraft of claim 7, wherein the computer system detects objects that pose a threat of contacting the rotor during the near-ground operation of the rotorcraft by performing steps that comprise:

generating a three-dimensional evidence grid representative of the space around the rotor, wherein the three-dimensional evidence grid comprises a number of three-dimensional cells, and wherein the three-dimensional evidence grid is continuously updated based on the time-stamped, registered point data;

determining a likelihood that a potentially hazardous object is located in the space corresponding to each three-dimensional cell in an ongoing manner during the near-ground operation based on the registered lidar point data; and

determining that a potentially hazardous object is in one of the cells when the likelihood of a potentially hazardous object in the cell is greater that a threshold likelihood for a threshold period of time.

9. The rotorcraft of claim 8, wherein the at least one motion sensor comprises an IMU.

10. The rotorcraft of claim 8, wherein the at least one motion sensor comprises an IMU and a GPS system.

11. The rotorcraft of claim 1, wherein:

the rotorcraft comprises a piloted rotorcraft; and

the reaction means comprises a flight crew interface that indicates when a potentially hazardous object is detected in the vicinity of the rotor during the near-ground operation.

12. The rotorcraft of claim 11, wherein the flight crew interface is located in a cockpit of the rotorcraft.

13. The rotorcraft of claim 11, wherein the flight crew interface comprises a warning system selected from the group consisting of:

at least one electroacoustic transducer that emits sound when a potentially hazardous object is detected in the vicinity of the rotor during the near-ground operation;

at least one light source that emits light when a potentially hazardous object is detected in the vicinity of the rotor during the near-ground operation; and

at least one vibrator that vibrates when a potentially hazardous object is detected in the vicinity of the rotor during the near-ground operation.

14. The rotorcraft of claim 11, wherein:

the flight crew interface comprises a video monitor that displays continuously updated graphics of the space around the rail rotor during the near-ground operation; and

the computer system generates the continuously updated graphics based on the lidar point data from the lidar scanner.

15. The rotorcraft of claim 14, wherein the graphics comprise a representation of the rotorcraft from a viewing angle.

16. The rotorcraft of claim 14, wherein:

the rotorcraft comprises at least one camera system pointed at the space around the rotor that is scanned by the lidar scanner; and

the graphics generated by the computer system comprise hybrid video image-graphical representations that combine images from the camera system and graphics generated based on the lidar data.

17. The rotorcraft of claim 14 wherein:

the rotorcraft comprises a plurality wide-field camera systems each pointing from a different side of the rotorcraft;

the plurality of wide-field cameras are in communication with the computer system; and

the graphics generated by the computer system comprise omniviews of the rotorcraft with a representation of the rotorcraft in the omniviews.

18. The rotorcraft of claim 1, wherein:

the rotorcraft comprises an autonomous rotorcraft; and

the reaction means comprises a navigation system that navigates the rotorcraft based on any potentially hazardous objects in the space around the rotor.

19. The rotorcraft of claim 1, wherein the computer system additional determines that an object poses a threat of contacting the rotor when, based on the time-stamped point clouds, the computer system determines that a non-moving object is within a threshold distance of the rotor.

20. A method comprising:

continuously scanning, by a lidar scanner that is attached to a rotorcraft, a space around the rotor during a near-ground operation of the rotorcraft;

detecting, by a rotor safety system that comprises a computer system that is in communication with the lidar scanner, objects that pose a threat of contacting the rotor during the near-ground operation of the rotorcraft based on time-stamped lidar point data from the lidar scanner, wherein detecting whether an object poses a threat of contacting the rotor comprises;

generating, by the computer system, a series of time-stamped point clouds from the time-stamped lidar point data, wherein the series of time-stamped point clouds indicate locations of the object in a vicinity of the rotor at different time stamp instances;

determining, by the computer system, a relative velocity of the object relative to the rotor based on movement of the object relative to the rotor over the series of time-stamped point clouds; and

determining, by the computer system, based on the determined relative velocity of object, that the object poses a threat of contacting the rotor when it is determined that the object will be within a threshold distance of the rotor within a threshold time period; and

performing a reaction, by a reaction means of the rotorcraft that is in communication with the computer system, in response to detection of a potentially hazardous object in the vicinity of the rotor.

21. The method of claim 20, wherein:

the rotorcraft further comprises an altitude sensor that is in communication with the computer system; and

the method further comprises inactivating, by the computer system, the rotor safety system when the rotorcraft is a threshold distance about ground as determined by the altitude sensor.

22. The method of claim 21, wherein:

the rotorcraft comprises at least one motion sensor that is in communication with the computer system;

the step of detecting potentially hazardous objects comprises;

continuously registering, by the computer system, the time-stamped lidar point data from the lidar scanner into a three-dimensional space based on time-stamped position data for the rotorcraft from the at least one motion sensor; and

detecting, by the computer system, potentially hazardous objects in the vicinity of the rotor during the near-ground operation of the rotorcraft based on the time-stamped, registered point data.

23. The method of claim 22, wherein the step of detecting potentially hazardous objects in the vicinity of the rotor during the near-ground operation of the rotorcraft further comprises, by the computer system:

generating a three-dimensional evidence grid representative of the space around the rotor, wherein the three-dimensional evidence grid comprises a number of three-dimensional cells, and wherein the three-dimensional evidence grid is continuously updated based on the time-stamped, registered point data;

determining a likelihood that a potentially hazardous object is located in the space corresponding to each three-dimensional cell in an ongoing manner during the near-ground operation based on the registered lidar point data; and

determining that a potentially hazardous object is in one of the cells when the likelihood of a potentially hazardous object in the cell is greater that a threshold likelihood for a threshold period of time.

24. The method of claim 20, wherein:

the rotorcraft comprises a piloted rotorcraft; and

the reaction means comprises a flight crew interface that indicates when a potentially hazardous object is detected in the vicinity of the rotor during the near-ground operation.

25. The method of claim 20, wherein:

the rotorcraft comprises an autonomous rotorcraft; and

the reaction means comprises a navigation system that navigates the rotorcraft based on any potentially hazardous objects in the space around the rotor.

26. A rotor safety retrofit kit for a rotorcraft, the kit comprising:

a lidar scanner for attachment to the rotorcraft such that, when attached, the lidar scanner is for continuously scanning a space around the rotor during a near-ground operation of the rotorcraft;

computer software for execution by a computer system of the rotorcraft, wherein execution of the computer software by the computer system cause the computer system to;

detect objects that poses a threat of contacting the rotor during the near-ground operation of the rotorcraft based on time-stamped lidar point data from the lidar scanner, wherein the computer software configures the computer system to detect whether an object poses a threat of contacting the rotor by;

generating a series of time-stamped point clouds from the time-stamped lidar point data, wherein the series of time-stamped point clouds indicate locations of the object in a vicinity of the rotor at different time stamp instances;

determining a relative velocity of the object relative to the rotor based on movement of the object relative to the rotor over the series of time-stamped point clouds; and

determining, based on the determined relative velocity of object, that the object poses a threat of contacting the rotor when it is determined that the object will be within a threshold distance of the rotor within a threshold time period; and

generate continuously updated graphics of the space around the rail rotor during the near-ground operation based on the lidar point data from the lidar scanner, wherein the graphic are for display by a flight crew interface of the rotorcraft.