APPARATUS, METHOD AND SYSTEM RELATING TO AIRCRAFT SYSTEMS

• US 20190325756A1
• Filed: 11/10/2017
• Published: 10/24/2019
• Est. Priority Date: 11/17/2016
• Status: Active Grant

• Current Assignee: University of Bath
• Original Assignee: University of Bath
• Inventors: CLEAVER, David, DU BOIS, Jonathan, IRAVANI, Pejman, LAWRENSON, Anthony
• Granted Patent: US 11,322,032 B2
• Time in Patent Office: Days
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: G06T 2207/20076 Probabilistic image processing
• CPC Class Codes: G06T 2207/30241 Trajectory
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: G08G 5/0034 Assembly of a flight plan
• CPC Class Codes: G08G 5/0039 Modification of a flight plan
• CPC Class Codes: G08G 5/0052 for cruising combined instruments indicating more than one navigational value G01C23/00
• CPC Class Codes: G08G 5/006 in accordance with predefined flight zones, e.g. to avoid prohibited zones
• CPC Class Codes: G08G 5/0078 for monitoring traffic from the aircraft radar or analogous systems specially adapted for traffic control G01S13/91
• CPC Class Codes: G08G 5/0082 for monitoring traffic from a ground station radar or analogous systems specially adapted for traffic control G01S13/91
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• CPC Class Codes: G08G 5/04 Anti-collision systems
• 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

A method for determining a flight path for an aircraft system, for example an unmanned aircraft system (UAS) comprises analysing an intensity map relating to a three dimensional space. The intensity map comprises an array of voxels, each voxel defining a volume in the three dimensional space, and each voxel having a related traffic intensity value based on historical flight data through that voxel. The method comprises determining a probability of an encounter for a preferred flight path between a start point and an end point via one or more voxels in the three dimensional space, based on traffic intensity values of the one or more voxels along the preferred flight path. The preferred flight path is selected if the probability of encounter is less than a first threshold value.

Claims

1. A method for determining a flight path for an aircraft system, the method comprising:

analysing an intensity map relating to a three dimensional space, wherein the intensity map comprises an array of voxels, each voxel defining a volume in the three dimensional space, and each voxel having a related traffic intensity value based on historical flight data through that voxel;

determining a probability of an encounter for a preferred flight path between a start point and an end point via one or more voxels in the three dimensional space, based on traffic intensity values of the one or more voxels along the preferred flight path; and

selecting the preferred flight path if the probability of encounter is less than a first threshold value.

2. A method as claimed in claim 1 wherein, if the determined probability of encounter is above the first threshold value, selecting an alternative flight path between the start point and the end point.

3. A method as claimed in claim 2, wherein selecting an alternative flight path between the start point and end point comprises:

comparing the probability of encounter along two or more different flight paths between the start point and end point, via different voxels in the three dimensional space; and

selecting a flight path which has a probability of encounter lower than the first threshold value.

4. A method as claimed in claim 2 or 3, wherein selecting an alternative flight path comprises selecting the shortest flight path which has a probability of encounter lower than the first threshold value.

5. A method as claimed in any one of claims 2 to 4, wherein selecting an alternative flight path comprises selecting the flight path which has the lowest overall probability of encounter.

6. A method as claimed in any one of claims 2 to 5, wherein selecting an alternative flight path comprises selecting a flight path which has a zero probability of encounter.

7. A method as claimed in claim 1 or 2, wherein determining a probability of encounter comprises determining if one or more voxels along the flight path comprise a traffic intensity value above a second threshold value.

8. A method as claimed in claim 1 or 2, wherein determining a probability of encounter comprises determining if one or more voxels along the flight path comprise an average traffic intensity value that is above a second threshold value.

9. A method as claimed in any one of the preceding claims, wherein determining a probability of encounter comprises:

partitioning a flight path of length D into a series of K elements, each element of length D/K;

for each of the K elements, interpolating a local intensity (p_FP,i) from the array of voxels to a point in the centre of the element; and

determining the probability of encounter for a particular element based on the local traffic intensity value multiplied by the time taken for the aircraft system to cover the element.

10. A method as claimed claim 9, wherein the probability of an encounter for the entire flight path is determined as:

11. A method as claimed in claim 2, wherein selecting an alternative flight path comprises selecting an alternative flight path which avoids one or more voxels having a traffic intensity value above a second threshold value.

12. A method as claimed in claim 2, wherein selecting an alternative flight path comprises selecting an alternative flight path via one or more voxels having traffic intensity values below a second threshold value.

13. A method as claimed in claim 2, wherein selecting an alternative flight path comprises selecting an alternative flight path via one or more voxels having traffic intensity values of zero.

14. A method as claimed in claim 2 or 3, wherein selecting an alternative flight path comprises first attempting to selecting a flight path having a different altitude in the three dimensional space compared to the preferred flight path.

15. A method as claimed in any one of the preceding claims, wherein selecting an alternative flight path comprises selecting a flight path having a minimum altitude in the three dimensional space.

16. A method as claimed in any one of the preceding claims, wherein selecting a flight path comprises:

receiving capability data relating to one or more capabilities of the aircraft system which the flight path is being determined for; and

using the capability data as at least part of the step of selecting the flight path.

17. A method as claimed in any one of the preceding claims, wherein selecting an alternative flight path comprises:

receiving population density data relating to the population density under a voxel; and

using the population density data as at least part of the step of selecting the alternative flight path.

18. A method as claimed in any one of the preceding claims, wherein the first threshold value and/or second threshold value is set in relation to the type of aircraft system a flight path is being determined for.

19. A method as claimed in claim 18, wherein the first threshold level and/or second threshold value is linked to a collision capability of the aircraft system whose flight path is being determined.

20. A method as claimed in claim 19, wherein the first threshold level and/or second threshold level is set to be inversely proportional to the capability level and/or collision avoidance level of the aircraft system whose flight path is being controlled.

21. A method as claimed in any one of the preceding claims, wherein the first threshold value and/or second threshold value is set in relation to an experience level of an operator of the aircraft system whose flight path is being determined for.

22. A method as claimed in any one of the preceding claims, wherein the intensity map further comprises terrain data.

23. A method as claimed in any one of the preceding claims, wherein the intensity map further comprises restricted or controlled airspace data.

24. A method as claimed in claim 22 or 23, wherein a voxel relating to an area comprising terrain and/or controlled or restricted airspace is set a traffic intensity value of 100%, or a traffic intensity value ramping up from a first value on a boundary thereof towards a 100% value.

25. A method as claimed in any one of the preceding claims, further comprising the step of generating the intensity map.

26. A method as claimed in claim 25, wherein generating the intensity map comprises:

receiving transponder signals and/or automatic dependent surveillance-broadcast, ADS-B, signals and/or other flight position information from aircraft travelling through the three dimensional space, and/or from other sources, over a period of time; and

generating traffic intensity values for the plurality of voxels within the three dimensional space using the received transponder signals and/or automatic dependent surveillance-broadcast, ADS-B, signals and/or other flight position information.

27. A method as claimed in claim 26, wherein generating a traffic intensity value for a voxel comprises determining a number of aircraft that have passed through the voxel over a period of time.

28. A method as claimed in claim 26, wherein a probability value of each aircraft is distributed across the array of voxels according to the distance between an aircraft and the nearest N nodes associated with the nearest N voxels.

29. A method as claimed in claim 28, wherein the distribution is linear or non-linear with distance.

30. A method as claimed in claim 29, wherein a linear distribution for an aircraft located at point X, defined as x_ac, y_ac, z_ac at time t1 is given by:

31. A method as claimed in any one of claims 26 to 30, wherein the step of generating a traffic intensity value comprises weighting the received transponder signals and/or ADS-B signals and/or flight position information according to the type of aircraft associated with the respective transponder signal and/or ADS-B signal and/or flight position information.

32. A method as claimed in any one of claims 26 to 30, wherein generating a traffic intensity value for a voxel comprises:

receiving population density data relating to the population density in an area under the voxel; and

weighting the traffic intensity value according to the population density data.

33. A method as claimed in any one of the preceding claims, wherein each voxel defines a section of a flight path.

34. A method as claimed in any one of the preceding claims, wherein the array of voxels have the same shape and/or size.

35. A method as claimed in any one of the preceding claims, wherein at least one voxel has a different shape and/or size.

36. A method as claimed in any one of the preceding claims, wherein different regions within the three dimensional space have voxels of different shape and/or size.

37. A method as claimed in any one of the preceding claims, wherein:

the intensity map comprises a plurality of time slices, each time slice comprising traffic intensity values for each of the voxels in the array for that time slice; and

wherein

analysing the intensity map relating to the three dimensional space comprises analysis the intensity map of one or more time slices relating to a time period during which the flight path is being determined.

38. A method as claimed in claim 37, wherein each voxel comprises a series of traffic intensity values relating to a series of time slices.

39. A method as claimed in any one of the preceding claims, wherein the preferred flight path is along a direct line of sight between the start point and the end point.

40. A method as claimed in any one of the preceding claims, wherein the traffic intensity values are updated in real time.

41. A method as claimed in any one of the preceding claims, wherein selecting the flight path or an alternative flight path comprises defining a flight corridor through which the aircraft system is to travel.

42. A method as claimed in claim 41, wherein:

a first aircraft system to be allocated the flight path in the flight corridor is set to travel along a first channel within the flight corridor; and

a second aircraft system to be allocated a flight path in the flight corridor is set to travel along a second channel within the flight corridor, the second channel being physically separate from the first channel.

43. A method as claimed in any one of claims 1 to 42, wherein the aircraft system is an unmanned aircraft system, UAS.

45. An aircraft system 1000 as claimed in claim 44, wherein said aircraft system 1000 is operative to perform the method as defined in any one of claims 2 to 43.

48. A flight control system 1100 as claimed in claim 47, wherein said flight control system 1100 is operative to perform the method as defined in any one of claims 2 to 43.

50. An aircraft system configured to receive a flight path as determined in any one of claims 1 to 43, wherein the aircraft system is configured to control its fight path according to the received flight path.

51. An aircraft system as claimed in claim 50, wherein the aircraft system is an unmanned aircraft system, UAS.

44. An aircraft system 1000 comprising a processor 1001 and a memory 1003, said memory 1003 containing instructions executable by said processor 1001, whereby said aircraft system 1000 is operative to:

analyse an intensity map relating to a three dimensional space, wherein the intensity map comprises an array of voxels, each voxel defining a volume in the three dimensional space, and each voxel having a related traffic intensity value based on historical flight data through that voxel;

determine a probability of an encounter for a preferred flight path between a start point and an end point via one or more voxels in the three dimensional space, based on traffic intensity values of the one or more voxels along the preferred flight path; and

select the preferred flight path if the probability of encounter is less than a first threshold value.

46. An aircraft system 1000 as claimed in claim 44 or 45, wherein the aircraft system 1000 is an unmanned aircraft system, UAS.

47. A flight control system 1100 for controlling an aircraft system, and comprising a processor 1101 and a memory 1103, said memory 1103 containing instructions executable by said processor 1101, whereby said flight control system 1100 is operative to:

analyse an intensity map relating to a three dimensional space, wherein the intensity map comprises an array of voxels, each voxel defining a volume in the three dimensional space, and each voxel having a related traffic intensity value based on historical flight data through that voxel;

determine a probability of an encounter for a preferred flight path between a start point and an end point via one or more voxels in the three dimensional space, based on traffic intensity values of the one or more voxels along the preferred flight path; and

select the preferred flight path if the probability of encounter is less than a first threshold value.

49. A flight control system as claimed in claim 47 or 48, wherein the aircraft system is an unmanned aircraft system, UAS.

52. A method for assessing a risk associated with a flight path for an aircraft system, the method comprising:

analysing an intensity map relating to a three dimensional space, wherein the intensity map comprises an array of voxels, each voxel defining a volume in the three dimensional space, and each voxel having a related traffic intensity value based on historical flight data through that voxel;

determining a probability of an encounter for a preferred flight path between a start point and an end point via one or more voxels in the three dimensional space, based on traffic intensity values of the one or more voxels along the preferred flight path; and

assessing the risk associated with the preferred flight path based on the determined probability of encounter.