Search

EP-4261647-B1 - AIRCRAFT GUIDANCE TO MOVING TARGET POINT

EP4261647B1EP 4261647 B1EP4261647 B1EP 4261647B1EP-4261647-B1

Inventors

  • RYSDYK, ROLF
  • NASROULLAHI, Mohammad Ehsan

Dates

Publication Date
20260513
Application Date
20230330

Claims (15)

  1. A method (800) of guidance for an aircraft (102), the method comprising: obtaining (802), at one or more processors (1020) of a guidance system (250), first relative position data indicative of a direction from a first location (152) of the aircraft at a first time to a first location (156) of a moving target point (104) at the first time; determining (804), by the one or more processors based on the first relative position data, a first location (162) of a virtual leader based on projecting the first location of the aircraft onto a first virtual leader path (160A), wherein the first virtual leader path corresponds to a straight approach path to the first location of the moving target point (156A) along a desired approach direction; updating, by the one or more processors, the first virtual leader path to generate a second virtual leader path (160B) which extends between the current location of the virtual leader (162B) and the current location of the moving target point (156B), wherein the virtual leader follows a currently active virtual leader path; and determining (806), by the one or more processors based on the current location of the virtual leader, a guidance input (506) to cause the aircraft to follow the virtual leader, wherein the aircraft corresponds to a fixed wing aircraft.
  2. The method of claim 1, further comprising, during initialization of an approach of the aircraft to the moving target point, setting an initial virtual leader relative direction to correspond to the desired approach direction.
  3. The method of claim 1 or claim 2, wherein the first relative position data is based on data from one or more sensors (204B) onboard the aircraft.
  4. The method of claim 3, wherein the one or more sensors onboard the aircraft include one or more of a global position system (GPS) receiver, one or more passive electromagnetic sensors, one or more active electromagnetic sensors, or one or more inertial measurement sensors.
  5. The method of any of claims 1 to 4, wherein the moving target point is onboard a vehicle (106), and wherein the first relative position data is received via transmission (252) from the vehicle and is based on data from one or more sensors (204A) onboard the vehicle.
  6. The method of claim 5, wherein the one or more sensors onboard the vehicle include one or more of a global position system (GPS) receiver, one or more passive electromagnetic sensors, one or more active electromagnetic sensors, or one or more inertial measurement sensors.
  7. The method of any of claims 1 to 6, wherein the moving target point corresponds to a fuel receptacle of a refueling boom.
  8. The method of any of claims 1 to 4, wherein the moving target point corresponds to an aircraft recovery device (112) that is coupled to a vehicle (106) that is in motion (110, 120).
  9. The method of claim 8, wherein the aircraft recovery device comprises a line that extends vertically from or within a frame, and the aircraft comprises a catch member configured to engage the line to enable the aircraft recovery device to catch and retain the aircraft.
  10. The method of claim 8, wherein the aircraft recovery device comprises a net, a platform, or a basket.
  11. The method of claim 5, claim 6, claim 7 when dependent on claim 5 or claim 6, or any of claims 8 to 10, wherein the vehicle corresponds to a watercraft.
  12. The method of any of claims 8 to 10, or claim 11 when dependent on any of claims 8 to 10, wherein the motion of the vehicle is due at least in part to: external forces applied to the vehicle by its environment; and/or a propulsion system (242) of the vehicle.
  13. The method of any of claims 8 to 10, claim 11 when dependent on any of claims 8 to 10, or claim 12, wherein the motion of the vehicle includes periodic or occasional rotation about a first axis of the vehicle, and wherein the direction from the first location of the aircraft to the first location of the moving target point is substantially aligned with the first axis.
  14. The method of any of claims 1 to 13, wherein the guidance input includes a bank angle.
  15. An aircraft (102) comprising a guidance system (250), the guidance system comprising one or more processors (1020), wherein the guidance system is configured to perform the method of any of claims 1 to 14.

Description

FIELD The present disclosure is generally related to guidance to direct an aircraft to a moving target point. BACKGROUND Path following dynamics of many aircraft (e.g., fixed wing aircraft) are limited due to the inability of such aircraft to move directly laterally. For example, rather than moving directly to the side, such aircraft turn while moving forward (e.g., by rolling to a particular bank angle). This inability to move directly sideward limits some path following capabilities of such aircraft. For example, when approaching a moving target point along a desired approach path, the aircraft is not able to shift side-to-side in response to the target point moving side-to-side. Rather, if the target point moves to the left, the aircraft generally has to bank to turn toward the left to move toward alignment with the desired approach path and then bank again toward the right to turn into alignment with a desired approach direction. If the location of the target point is dynamic (e.g., frequently or continuously moving), a guidance system of the aircraft may have to continuously or frequently change guidance input resulting in a wildly varying approach to the target point. WO2022001748, in accordance with its abstract, states a target tracking method and apparatus, and an electronic device and a mobile carrier. The target tracking method comprises: collecting position information of a tracked target; determining whether the tracked target is beyond a known three-dimensional map; if not, planning a first tracking path according to a three-dimensional position of the tracked target in the three-dimensional map; if so, generating, at a boundary of the three-dimensional map, a virtual target point in the same direction as the tracked target; planning a second tracking path according to a three-dimensional position of the virtual target point; and moving along the second or first tracking path. SUMMARY According to a first aspect, there is provided a method as defined in claim 1. According to a second aspect, there is provided an aircraft as defined in claim 15. The features, functions, and advantages described herein can be achieved independently in various implementations or may be combined in yet other implementations, further details of which can be found with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a diagram that illustrates a rear view of a system including an aircraft and a moving target point according to a particular aspect.FIG. 1B is a diagram that illustrates a top view of the system of FIG. 1A according to a particular aspect.FIG. 1C is a diagram that illustrates aspects of approach of the aircraft of FIGS. 1A and 1B toward the moving target point over a period of time according to a particular aspect.FIG. 2 is a block diagram of aspects of the system of FIGS. 1A and 1B.FIG. 3A is a diagram illustrating aspects of the approach of the aircraft of FIGS. 1A and 1B toward the moving target point at a first time according to a particular aspect.FIG. 3B is a diagram illustrating aspects of the approach of the aircraft of FIGS. 1A and 1B toward the moving target point at a second time subsequent to the first time of FIG. 3A according to a particular aspect.FIG. 3C is a diagram illustrating aspects of the approach of the aircraft of FIGS. 1A and 1B toward the moving target point at a third time subsequent to the second time of FIG. 3B according to a particular aspect.FIG. 4 is a first diagram that illustrates a flight path and guidance input of an aircraft approaching a moving target.FIG. 5 is a second diagram that illustrates a flight path and guidance input of an aircraft approaching a moving target according to a particular aspect.FIG. 6 is a histogram of results of Monte Carlo simulation of approaches of an aircraft to a moving target point.FIG. 7 shows two diagrams contrasting control effort for direct and virtual leader approaches.FIG. 8 is a diagram that illustrates a flow chart of an example of a method of guiding an aircraft to a moving target point according to a particular aspect.FIG. 9 is a flowchart illustrating a life cycle of an aircraft according to a particular aspect.FIG. 10 is a block diagram of a computing environment including a computing device configured to support aspects of computer-implemented methods and computer-executable program instructions (or code) according to a particular aspect. DETAILED DESCRIPTION Aspects of the subject disclosure use path following logic to facilitate approach of an aircraft to a moving target point, such as an aircraft recovery device onboard a moving vehicle. The aircraft may include a fixed wing aircraft or another nonholonomic aircraft, such as a quadcopter. Although the disclosure focuses primarily on aircraft, aspects disclosed herein may also be used to facilitate approach of other vehicles to a moving target point. To illustrate, aspects disclosed herein may be used to facilitate approac