Flight path development for remote sensing vehicles in a moving reference frame

• US 9,266,611 B2
• Filed: 06/20/2014
• Issued: 02/23/2016
• Est. Priority Date: 06/20/2013
• Status: Active Grant

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Rambo, Thomas Jeffrey
• Primary Examiner(s): Trammell, James
• Assistant Examiner(s): Stroud, James E
• Application Number:
  US14/310,809
• Publication Number:
  US 20150226575A1
• Time in Patent Office: 613 Days
• US Class Current: 1/1
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/25 Fixed-wing aircraft VTOL aircraft B64U10/20
• CPC Class Codes: B64U 10/80 UAVs characterised by their small size, e.g. micro air vehicles [MAV]
• CPC Class Codes: B64U 2201/10 autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
• CPC Class Codes: G01C 11/00 Photogrammetry or videogrammetry, e.g. stereogrammetry; Photographic surveying
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G05D 1/0005 with arrangements to save energy
• CPC Class Codes: G05D 1/0094 involving pointing a payload, e.g. camera, weapon, sensor, towards a fixed or moving target
• CPC Class Codes: G05D 1/0202 specially adapted to aircraft
• CPC Class Codes: G08G 5/0034 Assembly of a flight plan
• CPC Class Codes: G08G 5/0069 specially adapted for an unmanned aircraft

Abstract

Embodiments of the invention relate to a method and apparatus to produce a flightplan for a sUAS. Embodiments can produce such a flightplan for a variety of environmental and/or geographical parameters. A specific embodiment produces an optimal flightplan based on one or more metrics and/or one or more assumptions or boundary conditions. Embodiments take in vehicle parameters and/or the properties of the sensor systems used for imaging, and compute a partial, or complete, flightplan. Such a flightplan can include altitude, airspeeds, flight paths encompassing the target area, and/or the direction and/or path to turn in-between flightlines. Embodiments can improve the flight planning procedure compared to a manual process, which can be completely dependent on the operator, to implement a partially, or totally, automated process. Specific embodiments can produce a flightplan that results in the optimal data collection path.

Claims

1. A method of producing a travel path for a vehicle, comprising:

providing a processor;

receiving target parameters via the processor, wherein the target parameters determine a location of a target area with respect to a first reference frame;

receiving a velocity a second reference frame is moving with respect to the first reference frame via the processor;

receiving one or more sensor parameters relating to a sensor to be transported by a vehicle traveling in the second reference frame so as to travel along a travel path with respect to the target via the processor;

determining a travel path for the vehicle with respect to the target area via the processor, wherein the travel path includes travel curves and turns, wherein when the vehicle travels along the travel curves the sensor acquires sensor data with respect to the target area to be used to provide information regarding the target area and when the vehicle travels along the turns the sensor does not acquire sensor data with respect to the target area to be used to provide information regarding the target area, wherein the turns connect the travel curves to form the travel path; and

traveling the vehicle along the travel path with respect to the target area.

2. The method according to claim 1, wherein the vehicle is an aircraft, wherein the travel path is a flight path, wherein the first reference frame is earth, wherein the sensor is an imaging device, wherein the second reference frame is airspace above the earth, wherein the flight curves are flightlines, wherein a velocity of the second reference frame is moving with respect to the first reference frame is wind.

3. The method according to claim 2, wherein determining the flight path comprises:

determining a representation of the target area based on the target parameters.

4. The method according to claim 3, wherein the representation of the target area is a convex polygon.

5. The method according to claim 2, wherein the imaging device is a still camera.

6. The method according to claim 2, wherein determining the flight path comprises determining the turns, wherein the turns are selected from a flat turn, a hook turn, and a bulb turn.

7. The method according to claim 2, wherein determining the flight path comprises determining the turns, wherein determining the turns comprises:

determining whether a width of a turn of the aircraft conducted at a desired turning radius of the vehicle is larger than a flightline width, wherein the flightline width is a distance between an i^th flightline from which the turn starts and an (i+1)^th flightline at which the turn ends.

8. The method according to claim 7, wherein the desired turning radius is a maximum turning radius of the vehicle.

9. The method according to claim 1, wherein the target parameters include one or more of the following:

location of target area in first reference frame;

geographic information regarding the target area; and

restrictions regarding aircraft flight above the target area.

10. The method according to claim 2, further comprising determining a flight plan, wherein the flight plan includes one or more of the following:

altitude of the aircraft, airspeed of the aircraft, location of flightlines, path of turns, and direction of travel along flightlines.

11. The method according to claim 4, wherein determining the flight path further comprises:

for a given distance between adjacent flightlines, determining an orientation of the flightlines to the convex polygon that minimizes a number of flightlines.

12. The method according to claim 4, wherein determining the flight path further comprises:

orienting the flightlines parallel to the wind.

13. The method according to claim 11, wherein determining the flight path comprises determining the turns, wherein determining the turns comprises:

determining whether a width of a turn of the aircraft conducted at a desired turning radius of the vehicle is larger than a flightline width, wherein the flightline width is a distance between an i^th flightline from which the turn starts and an (i+1)^th flightline at which the turn ends.

14. The method according to claim 13, wherein if the width of the turn is larger than the flightline width and the wind is a crosswind or the aircraft is traveling upwind, the turn starts away from the (i+1)^th flightline, wherein if the width of the turn is not larger than the flightline width, or the width of the turn is larger than the flightline width and the aircraft is flying downwind, the turn starts toward the (i+1)^th flightline.

15. The method according to claim 14, wherein if a height of the turn is greater than a flightline height, post-turn length is added to the turn, wherein if the height of the turn is less than the flightline height, pre-turn length is added to the turn.

16. The method according to claim 14, wherein if the width of the turn is larger than the flightline width and the wind is a crosswind or the aircraft is traveling upwind, the turn is a bulb turn, wherein if the width of the turn is larger than the flightline width and the aircraft is traveling upwind, the turn is a hook turn, wherein if the width of the turn is larger than the flightline width and the aircraft is flying downwind, the turn is a hook turn, wherein if the width of the turn is not larger than the flightline width the turn is a flat turn.

17. A method of acquiring sensor data with respect to a target area, comprising:

traveling a vehicle along a travel path with respect to a target area, wherein a sensor is transported by the vehicle and acquires sensor data with respect to the target area while the vehicle travels along the travel path, wherein the travel path is produced via;

receiving target parameters, wherein the target parameters determine a location of a target area with respect to a first reference frame;

receiving a velocity a second reference frame is moving with respect to the first reference frame;

receiving one or more sensor parameters relating to a sensor to be transported by a vehicle traveling in the second reference frame so as to travel along a travel path with respect to the target, and

determining a travel path for the vehicle with respect to the target area, wherein the travel path includes travel curves and turns, wherein when the vehicle travels along the travel curves the sensor acquires sensor data with respect to the target area to be used to provide information regarding the target area and when the vehicle travels along the turns the sensor does not acquire sensor data with respect to the target area to be used to provide information regarding the target area, wherein the turns connect the travel curves to form the travel path.

18. The method according to claim 17, wherein the vehicle is an aircraft, wherein the travel path is a flight path, wherein the first reference frame is earth, wherein the sensor is an imaging device, wherein the second reference frame is airspace above the earth, wherein the flight curves are flightlines, wherein a velocity of the second reference frame is moving with respect to the first reference frame is wind.

21. The method according to claim 18, wherein determining the flight path comprises:

determining a representation of the target area based on the target parameters.

22. The method according to claim 21, wherein the representation of the target area is a convex polygon.

23. The method according to claim 18, wherein the imaging device is a still camera.

24. The method according to claim 18, wherein determining the flight path comprises determining the turns, wherein the turns are selected from a flat turn, a hook turn, and a bulb turn.

25. The method according to claim 18, wherein determining the flight path comprises determining the turns, wherein determining the turns comprises:

determining whether a width of a turn of the aircraft conducted at a desired turning radius of the vehicle is larger than a flightline width, wherein the flightline width is a distance between an ith flightline from which the turn starts and an (i+1)th flightline at which the turn ends.

26. The method according to claim 25, wherein the desired turning radius is a maximum turning radius of the vehicle.

27. The method according to claim 17, wherein the target parameters include one or more of the following:

location of target area in first reference frame;

geographic information regarding the target area; and

restrictions regarding aircraft flight above the target area.

28. The method according to claim 18, further comprising determining a flight plan, wherein the flight plan includes one or more of the following:

altitude of the aircraft, airspeed of the aircraft, location of flightlines, path of turns, and direction of travel along flightlines.

29. The method according to claim 22, wherein determining the flight path further comprises:

for a given distance between adjacent flightlines, determining an orientation of the flightlines to the convex polygon that minimizes a number of flightlines.

30. The method according to claim 22, wherein determining the flight path further comprises:

orienting the flightlines parallel to the wind.

31. The method according to claim 29, wherein determining the flight path comprises determining the turns, wherein determining the turns comprises:

determining whether a width of a turn of the aircraft conducted at a desired turning radius of the vehicle is larger than a flightline width, wherein the flightline width is a distance between an ith flightline from which the turn starts and an (i+1)th flightline at which the turn ends.

32. The method according to claim 31, wherein if the width of the turn is larger than the flightline width and the wind is a crosswind or the aircraft is traveling upwind, the turn starts away from the (i+1)th flightline, wherein if the width of the turn is not larger than the flightline width, or the width of the turn is larger than the flightline width and the aircraft is flying downwind, the turn starts toward the (i+1)th flightline.

33. The method according to claim 32, wherein if a height of the turn is greater than a flightline height, post-turn length is added to the turn, wherein if the height of the turn is less than the flightline height, pre-turn length is added to the turn.

34. The method according to claim 32, wherein if the width of the turn is larger than the flightline width and the wind is a crosswind or the aircraft is traveling upwind, the turn is a bulb turn, wherein if the width of the turn is larger than the flightline width and the aircraft is traveling upwind, the turn is a hook turn, wherein if the width of the turn is larger than the flightline width and the aircraft is flying downwind, the turn is a hook turn, wherein if the width of the turn is not larger than the flightline width the turn is a flat turn.

19. A non-transitory computer-readable medium containing a set of instructions that when executed cause a computer to perform a method, the method comprising:

receiving target parameters, wherein the target parameters determine a location of a target area with respect to a first reference frame;

receiving a velocity a second reference frame is moving with respect to the first reference frame;

receiving one or more sensor parameters relating to a sensor to be transported by a vehicle traveling in the second reference frame so as to travel along a travel path with respect to the target, and

determining a travel path for the vehicle with respect to the target area, wherein the travel path includes travel curves and turns, wherein when the vehicle travels along the travel curves the sensor acquires sensor data with respect to the target area to be used to provide information regarding the target area and when the vehicle travels along the turns the sensor does not acquire sensor data with respect to the target area to be used to provide information regarding the target area, wherein the turns connect the travel curves to form the travel path.

20. The medium according to claim 19, wherein the vehicle is an aircraft, wherein the travel path is a flight path, wherein the first reference frame is earth, wherein the sensor is an imaging device, wherein the second reference frame is airspace above the earth, wherein the flight curves are flightlines, wherein a velocity of the second reference frame is moving with respect to the first reference frame is wind.

35. The method according to claim 20, wherein determining the flight path comprises:

determining a representation of the target area based on the target parameters.

36. The method according to claim 35, wherein the representation of the target area is a convex polygon.

37. The method according to claim 20, wherein the imaging device is a still camera.

38. The method according to claim 20, wherein determining the flight path comprises determining the turns, wherein the turns are selected from a flat turn, a hook turn, and a bulb turn.

39. The method according to claim 20, wherein determining the flight path comprises determining the turns, wherein determining the turns comprises:

determining whether a width of a turn of the aircraft conducted at a desired turning radius of the vehicle is larger than a flightline width, wherein the flightline width is a distance between an ith flightline from which the turn starts and an (i+1)th flightline at which the turn ends.

40. The method according to claim 39, wherein the desired turning radius is a maximum turning radius of the vehicle.

41. The method according to claim 19, wherein the target parameters include one or more of the following:

location of target area in first reference frame;

geographic information regarding the target area; and

restrictions regarding aircraft flight above the target area.

42. The method according to claim 20, further comprising determining a flight plan, wherein the flight plan includes one or more of the following:

altitude of the aircraft, airspeed of the aircraft, location of flightlines, path of turns, and direction of travel along flightlines.

43. The method according to claim 36, wherein determining the flight path further comprises:

for a given distance between adjacent flightlines, determining an orientation of the flightlines to the convex polygon that minimizes a number of flightlines.

44. The method according to claim 36, wherein determining the flight path further comprises:

orienting the flightlines parallel to the wind.

45. The method according to claim 43, wherein determining the flight path comprises determining the turns, wherein determining the turns comprises:

determining whether a width of a turn of the aircraft conducted at a desired turning radius of the vehicle is larger than a flightline width, wherein the flightline width is a distance between an ith flightline from which the turn starts and an (i+1)th flightline at which the turn ends.

46. The method according to claim 45, wherein if the width of the turn is larger than the flightline width and the wind is a crosswind or the aircraft is traveling upwind, the turn starts away from the (i+1)th flightline, wherein if the width of the turn is not larger than the flightline width, or the width of the turn is larger than the flightline width and the aircraft is flying downwind, the turn starts toward the (i+1)th flightline.

47. The method according to claim 46, wherein if a height of the turn is greater than a flightline height, post-turn length is added to the turn, wherein if the height of the turn is less than the flightline height, pre-turn length is added to the turn.

48. The method according to claim 46, wherein if the width of the turn is larger than the flightline width and the wind is a crosswind or the aircraft is traveling upwind, the turn is a bulb turn, wherein if the width of the turn is larger than the flightline width and the aircraft is traveling upwind, the turn is a hook turn, wherein if the width of the turn is larger than the flightline width and the aircraft is flying downwind, the turn is a hook turn, wherein if the width of the turn is not larger than the flightline width the turn is a flat turn.