Ground control system and ground control method

Abstract

The present invention comprises: a route search region setting unit that, when a flying body flies over a landing point, repeatedly determines a cell in which the flying body should fly within a controlled airspace while controlling the nose of the flying body so as to face upwind by using three-dimensional position information of the flying body within the controlled airspace, nose direction information relating to the nose direction of the flying body, wind direction information relating to the wind direction in individual cells, and predicted arrival time information relating to the predicted time until the flying body reaches the landing point from each cell, and sets a flight route configured from a plurality of cells that have been repeatedly determined; and a route planning unit that generates, as one packet, a command for causing the flying body to fly along the flight route, and outputs the command to the flying body.

Description

Ground control system and ground control method

[0001] The present invention is suitable for application to a ground control system and a ground control method related to a technique for controlling a flying object.

[0002] In recent years, a home delivery business using flying objects has been under consideration. In particular, the demand for home delivery services in urban areas is expected to increase. As a method of controlling a flying object, for example, Patent Document 1 discloses a technique for overall operation by creating a flight plan of a flying object in a controlled airspace and managing the state of the flying object.

[0003] International Publication No. 2018 / 155700

[0004] However, the technique disclosed in Patent Document 1 does not mention specifically what flight path the flying object should fly along to operate the flying object more safely.

[0005] The present invention has been made in consideration of the above points, and proposes a ground control system and a ground control method capable of flying a flying object in a safer flight path within a controlled airspace.

[0006] In order to solve such problems, in the present invention, a detection unit that detects in which cell of each cell that divides a controlled airspace where a flying object capable of flying from a landing point of a port is above the landing point the flying object is flying, and when the flying object flies above the landing point, using three-dimensional position information of the flying object in the controlled airspace, nose direction information regarding the nose direction of the flying object, wind direction information regarding the direction of the wind in each cell, and arrival time information regarding the estimated time until the flying object reaches the landing point from each cell, repeatedly determines the cell in which the flying object should fly in the controlled airspace while controlling the nose of the flying object to face upwind, and sets a flight path composed of a plurality of cells determined repeatedly; and a path planning unit that generates a command for flying the flying object along the flight path as one packet and outputs the command to the flying object.

[0007] Furthermore, the present invention includes a detection step in which a detection unit detects which of the cells that divide the controlled airspace above the landing point an aircraft capable of flying from the landing point is flying in; a path search area setting step in which, when the aircraft is flying above the landing point, the unit uses three-dimensional position information of the aircraft within the controlled airspace, heading information relating to the direction of the aircraft's nose, wind direction information relating to the direction of the wind in each cell, and estimated arrival time information relating to the estimated time it takes for the aircraft to reach the landing point from each cell to control the aircraft so that its nose faces into the wind, and repeatedly determines which cells the aircraft should fly in within the controlled airspace, and sets a flight path composed of a plurality of repeatedly determined cells; and a path planning step in which the path planning unit generates a command as a single packet for the aircraft to fly along the flight path and outputs the command to the aircraft.

[0008] According to the present invention, an aircraft can be flown along a safer flight path within controlled airspace.

[0009] This is a perspective view showing an example of how an aircraft flies in response to flight control by the ground control system according to this embodiment. This is a perspective view showing an example of how an aircraft takes off and lands at a landing port. This is a plan view showing an example of the configuration of an aircraft. This is a diagram showing an example of the configuration of the entire system including the ground control system according to this embodiment. This is a diagram showing an example of the arrangement of pathfinding cells that divide the airspace above a building with a point on its roof into three dimensions. This is a diagram showing an example of the arrangement of pathfinding cells that are simplified and arranged in two dimensions from the pathfinding cells shown in Figure 5. This is a diagram showing an example of a group of cells that divide the airspace above a point. This is a system configuration diagram showing an example of the configuration of the ground control system and an aircraft according to this embodiment. This is a diagram showing an example of how the flight path of an aircraft is set in the vertical direction of the airspace above a point. This is a diagram showing an example of how the flight path of an aircraft is determined when viewed from above a point. This is a diagram showing an example of how the flight path of an aircraft is set in the vertical direction of the airspace above a point. This is a diagram showing an example of a pathfinding cell shown together with the wind direction. This is a diagram showing an example of a pathfinding cell to be included in a guidance command. This is a flowchart showing an example of the procedure for the main processing according to this embodiment. This is a flowchart showing an example of the procedure for the main processing according to this embodiment. This is a flowchart showing an example of the procedure for the main processing according to this embodiment. This is a flowchart illustrating an example of the landing control process procedure. This is a diagram illustrating an example of the command data format. This is a diagram illustrating an example of a command transmission packet. This is a diagram illustrating an example of items that are part of the command transmission packet shown in Figure 19.

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 is a perspective view showing an example of how aircraft 100 and 100A fly in response to flight control by the ground control system 1 according to this embodiment. In the illustrated example, the configuration of aircraft 100 and 100A is simplified, similar to Figure 2 which will be described later.

[0011] Ground control system 1 controls the flight of unmanned aircraft 100 and 100A flying over multiple buildings 401 within Area 8. Before describing the configuration of ground control system 1, we will first explain the prerequisites for describing its configuration. Therefore, details of ground control system 1 itself will be described later.

[0012] There are multiple flight paths that aircraft 100 and 100A can take in the airspace above Area 8. Aircraft 100 and 100A are controlled by the ground control system 1 to fly along each of these flight paths.

[0013] Figure 2 is a perspective view showing an example of aircraft 100 and 100A taking off and landing at landing port 19. By supporting the cargo 5 with its underside while flying, aircraft 100 and 100A can transport the cargo 5 from the departure landing port 19 to the destination landing port 19.

[0014] The landing port 19 is located, for example, on the roof of building 401 within Area 8. Alternatively, the landing port 19 may be located on the ground within Area 8. The landing port 19 has a landing area 25 from which aircraft 100 and 100A can take off and land.

[0015] Figure 3 is a plan view showing an example configuration of the aircraft 100 and 100A. In this embodiment, the configuration of aircraft 100 is simplified in the illustration. In the following description, if it is not necessary to distinguish between multiple aircraft 100 and 100A, aircraft 100 will be referred to as an example.

[0016] The aircraft 100 is a so-called multicopter. The aircraft 100 includes, for example, wings and propellers 121. In the aircraft 100, the propellers 121 are positioned almost perpendicular to the ground, but are configured to allow for some change in their direction. By controlling the direction of the propellers 121, the aircraft 100 can change its flight direction. The aircraft 100 can fly not only horizontally but also vertically.

[0017] The aircraft 100 is equipped with a flight control unit 110. The flight control unit 110 controls the flight state of the aircraft 100 by controlling the propeller 20 and actuators for changing its direction in response to received commands, and also collects and outputs flight data related to the flight state.

[0018] Figure 4 shows an example of the configuration of the overall system including the ground control system 1 according to this embodiment. Note that Figure 4 shows a simplified configuration. The ground control system 1 controls the aircraft 100 that can take off and land at the landing point 25 of the landing port 19. The ground control system 1 communicates with the aircraft 100 regarding flight control.

[0019] Figure 5 shows an example of the arrangement of pathfinding cells 24A as an example of cells obtained by dividing the airspace above building 401, which has a landing site 25 on its roof, into three dimensions. In the illustrated example, each pathfinding cell 24A is approximately square. Numerous pathfinding cells 24A are arranged in three dimensions. In the following explanation, for illustrative purposes, the pathfinding cells 24A may be illustrated as if they were arranged in two dimensions, but as mentioned above, they are arranged in three dimensions.

[0020] Figure 6 shows an example of a simplified arrangement of pathfinding cells 24A as shown in Figure 5, arranged in a two-dimensional shape when viewed from the side. In the illustrated example, a large number of pathfinding cells 24A are arranged in a matrix shape vertically and horizontally on the side above the landing port 9.

[0021] The controlled airspace 11, indicated by a thick dashed line, represents the airspace in which the aircraft 100 can fly when landing at or taking off from the landing port 19. Rectangular airspace within the controlled airspace 11 that does not overlap with the restricted flight zone outside of it is set in the pathfinding cell 24A, for example, as shown by a light fill.

[0022] As shown in the area enlarged to the right by the dashed line, a pathfinding cell 24A is set when the distance from the center of the pathfinding cell 24A, indicated by the white spot, to the edge of the controlled airspace 11, indicated by the dashed line, is d or more inward.

[0023] Figure 7 shows an example of a group of cells obtained by dividing the airspace above the landing site 25. In this example, the aircraft 100 is greatly exaggerated in the illustration, but the aircraft 100 is assumed to be flying within each cell 24.

[0024] In Figure 7, the black arrow 23A indicates the wind direction in pathfinding cell 24A, and the white arrow 23B indicates the wind direction in cells 24 other than pathfinding cells 124A to 124H. These black arrows 23A and white arrows 23B are collectively referred to as wind direction 23, as shown in the dashed line area on the right side of the figure.

[0025] In the illustrated example, the top indicates the sky and the bottom indicates near the ground. Each arrow 23A and 23B indicates, for example, that the top is north, the bottom is south, the left is west, and the right is east. The direction of each arrow is the same in Figures 9 and 10, which will be described later.

[0026] A flight path 21 is set in the controlled airspace 11, which is represented by an arrangement of multiple pathfinding cells 124A to 124H. When referring to the multiple pathfinding cells 124A to 124H separately, they are also collectively referred to as pathfinding cell 24A.

[0027] Figure 8 is a system configuration diagram showing an example of the configuration of the ground control system 1 and the aircraft 100 according to this embodiment. The ground control system 1 includes an object detection unit 210, a wind forecasting unit 220, a warning unit 230, a flight planning unit 240, a takeoff and landing guidance unit 250, and a communication unit 400B.

[0028] The object detection unit 210 is an example of a detection unit and detects which of the cells 24 that divide the controlled airspace 11, which is above the landing port 19, an aircraft 100 that can fly from the landing point 25 is flying in.

[0029] The object detection unit 210 includes a camera 211, a radar 212, a LiDAR 213, and an object detection unit 214. The camera 211 photographs objects in the airspace. The radar 212 measures the distance and direction to an object by emitting radio waves toward the object and measuring the reflected waves. The LiDAR 213 irradiates objects in the airspace with laser light and measures the distance to the object, shape, etc., from the measurement data collected by the optical sensor from the reflected light.

[0030] The object detection unit 214 detects objects in the airspace based on images of objects captured in the airspace by the camera 211. The object detection unit 214 detects objects in the airspace based on measurement data measured by the radar 212 and LiDAR 213, and outputs object information about the detected objects. These objects may include, for example, an aircraft 100.

[0031] The wind forecasting unit 220 includes a wind sensor 221, a terrain model 222, and a wind simulator 223. The wind sensor 221 measures the wind force and wind direction of the wind blowing within the controlled airspace 11. The terrain model 222 is a model of the terrain of area 8 (and its vicinity). The wind simulator 223 simulates the wind within the controlled airspace 11 based on the measurement data measured by the wind sensor 221 and the terrain model 222, and generates, for example, wind direction information and wind force information. Note that the wind direction information and wind force information may be obtained from an external system. In the following embodiment, wind direction information is shown as an example, but wind force information may also be included in addition to wind direction information.

[0032] The warning unit 230 issues a warning if there is an impediment to the flight of the aircraft 100, based on the wind simulation results within the controlled airspace 11 by the wind simulator 223.

[0033] The flight planning unit 240 creates a flight plan for the aircraft 100 within the controlled airspace 11 based on the object detection results from the object detection unit 210 and the wind forecast information within the controlled airspace 11 from the wind forecast unit 220.

[0034] The takeoff and landing guidance unit 250 guides the flight of the aircraft 100 according to the flight plan created by the flight planning unit 240. The takeoff and landing guidance unit 250 includes a command generation unit 253, a takeoff and landing path planning unit 252, and a path search area setting unit 251.

[0035] The path search area setting unit 251 sets the flight path that the aircraft 100 should take through the cells 24 within the controlled airspace 11, according to the flight plan created by the flight planning unit 240.

[0036] The path search area setting unit 251, when the aircraft 100 is flying over the landing site 25 (for example, during takeoff and landing), uses the three-dimensional position information of the aircraft 100 within the controlled airspace 11, the heading information regarding the direction of the aircraft 100's nose, the wind direction information regarding the direction of the wind in each cell 24, and the estimated arrival time information regarding the estimated time it will take for the aircraft 100 to reach the landing site 25 from each cell 24 to repeatedly determine which cells 24 the aircraft 100 should fly to within the controlled airspace 11, while controlling the aircraft 100 so that its nose is facing into the wind, and sets a flight path consisting of the multiple cells 124A to 124H that have been repeatedly determined. This flight path consists of the path search cells 124A to 124H.

[0037] Based on the multiple cells 124A to 124H determined as described above, the takeoff and landing path planning unit 252 plans a path search cell 24A representing the cell 24 that the aircraft 100 should fly to within the controlled airspace 11.

[0038] The takeoff and landing path planning unit 252 is an example of a path planning unit, and generates a guidance command as a single packet, which is an example of a command for flying the aircraft 100 along the flight path (path search cells 124A to 124H), and causes the command generation unit 253 to output the guidance command to the aircraft 100. The takeoff and landing path planning unit 252 has the function of the command generation unit 253 and may output the guidance command to the aircraft 100 itself. In this embodiment, such a flight path (path search cells 124A to 124H) is also referred to as the "planned flight path (path search cell 24A)".

[0039] The command generation unit 253 outputs the generated guidance command from the communication unit 400B and transmits the guidance command to the communication unit 400A of the flying object 100.

[0040] In the present embodiment, the three-dimensional position information includes the latitude information, longitude information, and altitude information of the flying object 100 within the control airspace 11.

[0041] The route search area setting unit 251 calculates the flight route of the flying object 100 so that the change amount of the wind direction of each cell from the landing point 25 to the vertical flight start point is minimized. The vertical flight start point indicates, for example, the start point when the flying object 100 descends vertically from above when landing.

[0042] When the distance d of the horizontal line drawn from the center coordinates of each cell to the boundary of the control airspace 11 is longer than the longer one of the total length of the airframe of the flying object 100 and the span of the main wing, the route search area setting unit 251 sets the respective cells as the flight route.

[0043] When the distance of the horizontal line drawn from the center coordinates of each cell to the boundary of the control airspace 11 is shorter than the longer one of the total length of the airframe of the flying object 100 and the main wing span, the route search area setting unit 251 sets the respective cells outside the flight route.

[0044] The route search area setting unit 251 sets the flight route every time the flying object 100 enters within a predetermined distance from the landing port 9.

[0045] The route search area setting unit 251 calculates the change amount of the wind direction starting from the wind direction predicted at the predicted landing time at the landing point 25 and calculates the flight route.

[0046] The route search area setting unit 251 repeatedly selects the cell 24 used as the flight route upward starting from the landing point 25.

[0047] The route search area setting unit 251 selects the cell directly above the cell selected to be adopted as the flight route and the next cell to be used from the cells surrounding the cell directly above in the horizontal direction. When there are cells outside the flight route among the cells surrounding the cell directly above in the horizontal direction, the cells outside the flight route are excluded from the selection target.

[0048] The path search area setting unit 251 connects the center coordinates of the cell 24 to be adopted as the flight path and the cell 24 selected above the said cell 24, and extends the flight path.

[0049] The path search area setting unit 251 has information regarding the target coordinates, target time, and target azimuth angle of the landing point 25 used during landing control for each cell used in the flight path.

[0050] The path search area setting unit 251 calculates the target time for each cell from a predetermined descent speed and the center coordinate distance between cells, or calculates it by numerical analysis using a motion model of the aircraft 100.

[0051] When setting a flight path, the path search area setting unit 251 selects a specific cell from among the multiple cells where the difference in wind direction is minimized, which minimizes the flight distance of the aircraft 100 during vertical flight.

[0052] When setting a flight path, the path search area setting unit 251 selects a predetermined cell from among the multiple cells that is closest to the position where the aircraft enters the landing point 25, as the path search cell 24A, if there are multiple cells where the difference in wind direction is minimized and there are multiple cells where the flight distance in the vertical direction of the aircraft 100 is minimized.

[0053] The path search area setting unit 251, when the aircraft 100 is flying vertically through the controlled airspace 11, will switch the aircraft 100 to "hovering control" and reset the flight path if the error between the target position of the landing point 25 and the position of the aircraft 100 exceeds a predetermined threshold.

[0054] On the other hand, the aircraft 100 includes a flight control unit 110, a rotor control unit 120, an aileron control unit 130, a rudder control unit 140, and a communication unit 400A. The aircraft 100 receives guidance commands received by the communication unit 400A.

[0055] The flight control unit 110 includes a navigation unit 111, a guidance unit 112, a control unit 113, a status monitor unit 114, and a map 115.

[0056] The navigation unit 111 has a navigation function. The navigation unit 111 includes a position sensor 111A, an altitude sensor 111B, and a speed sensor 111C. The position sensor 111A measures the position of the aircraft 100 and outputs measurement data related to its position information. The altitude sensor 111B measures the altitude of the aircraft 100 and outputs measurement data. The speed sensor 111C measures the flight speed of the aircraft 100 and outputs measurement data. This measurement data is also referred to as flight data.

[0057] The status monitoring unit 114 generates navigation commands for the guidance unit 112 based on guidance commands received from the ground control system 1 via the communication unit 400A and measurement data from the navigation unit 111.

[0058] The guidance unit 112 generates guidance commands based on the received navigation commands and map 115. The guidance unit 112 includes a flight mode selection unit 112A and a course planning unit 112B.

[0059] The flight mode selection unit 112A selects one of several flight modes provided for the aircraft 100 based on the received navigation command and map 115. In this embodiment, for example, "hovering control" is provided as a flight mode.

[0060] Based on the received navigation commands and map 115, the route planning unit 112B plans the path that the aircraft 100 should fly when landing (or taking off) in the controlled airspace 11. Furthermore, based on the planned path, the route planning unit 112B determines a route search cell 24A consisting of at least one cell from among the cells 24 in the controlled airspace 11 that the aircraft 100 should fly through.

[0061] The control unit 113 redraws the aircraft 100 based on the pathfinding cell 24A from the guidance unit 112. The control unit 113 has an actuator assignment unit 113A, which assigns multiple actuators mounted on the aircraft 100. Each of the multiple actuators drives, for example, each propeller. The control unit 113 controls at least one of the rotor control unit 120, aileron control unit 130, and rudder control unit 140 according to the assignment. The rotor control unit 120 controls the drive state of the rotor for rotating the propellers of the aircraft 100.

[0062] Figure 9 shows an example of how the flight path of the aircraft 100 is determined in the vertical direction of the controlled airspace 11 above the landing site 25. Figure 10 shows an example of how the flight path of the aircraft 100 is determined when viewed from above the landing site 25.

[0063] Figure 9 shows an example of how the flight path of the aircraft 100 is set based on the arrival time in the vertical direction of the airspace above the landing site 25. Figure 10 shows an example of how the flight path of the aircraft 100 is set based on the wind direction in the vertical direction of the airspace above the landing site 25.

[0064] Figure 11 shows an example of selecting the cell with the minimum wind force that is closest in wind direction to the currently located cell. In the example shown, each θ of the white arrow indicates the wind direction. In Figures 9 to 11 described above, the direction of each arrow is, for example, north at the top, south at the bottom, east to the right, and west to the left.

[0065] First, in Figure 9, each numerical value (seconds) such as "-1.0s" shown in each cell 24A represents the estimated time it will take for the aircraft 100 to land at landing site 25, assuming the scheduled landing time at landing site 25 is 0.0s. For example, cell 124G, which is shown as "-1.0s", indicates that, assuming the landing time at landing site 25 is 0.0s, it will take 1.0s for the aircraft 100 to land at landing site 25 from its current position in cell 124G at its current flight speed. The same applies to each numerical value (seconds) shown in each cell 24A in Figures 10 to 13.

[0066] In the range R1 shown in Figure 10, the three cells in the lower row correspond to the three cells in the second row from the bottom shown in Figure 9, that is, the three cells in range R1. On the other hand, the three cells in the upper row shown in Figure 10 are three other cells that are adjacent to and parallel to the three cells in the lower row.

[0067] The aforementioned pathfinding area setting unit 251 sets as part of the pathfinding cell 24A a cell where the time required to travel from the cell where the aircraft 100 is currently located to, for example, the adjacent cell that it must pass through to reach the landing point 25 is shorter, and where it is easier to fly safely from the perspective of the wind direction in the cell where the aircraft is currently located (hereinafter referred to as the "next cell").

[0068] The next cell and the cell where the aircraft is currently located are set as cells 124H and 124G, as shown by the thick black border in Figure 11, for example, when the aircraft 100 takes off from landing site 25.

[0069] Furthermore, as shown in Figure 12, the path search area setting unit 251 repeatedly sets cells as part of the path search cell 24A, starting from the set next cell, for example, the cell after that up to the landing point 25, where the time required to fly is shorter and the wind direction in that cell is easier to fly safely.

[0070] As a result, the next cell and the currently located cell that are repeatedly set are similarly set, for example, when the aircraft 100 takes off from the landing point 25, as shown by the thick black border in Figure 12, as cells 124H to 124A. In this embodiment, these cells 124H to 124A are set as the pathfinding cells 24A described above, and the flight path 21 that the aircraft 100 should fly is set along the line connecting the adjacent centers of these cells 124H to 124A, as shown by the thick black border in Figure 13. Each center is illustrated by a black dot.

[0071] In the explanation regarding the determination of flight paths based on wind direction, etc., as described in Figures 9 to 11 above, the following equation holds: θ_error(i+1) = |θ （ｉ＋１）ｊ = θＣｉ i ∈ 1, 2, 3 and j ∈ 1, 2, 3, where i and j represent coordinates used to identify the position of each cell.

[0072] Furthermore, in the explanation regarding the determination of the next cell related to Figures 9 to 11 mentioned above, the following equation holds true: C ｉ＋１ |min(θ) ｉｊ＿ｅｒｒｏｒ )

[0073] Figure 13 shows an example of a pathfinding cell 24A represented with wind direction indicated by a white arrow. The takeoff and landing path planning unit 252 creates a guidance command 104 that includes information about a pathfinding cell 24A in which a plurality of cells 124A to 124H set by the pathfinding area setting unit 251 are consecutive, as shown by the thick rectangle in Figure 13, from the landing point 25 toward the controlled airspace 11.

[0074] Figure 13 shows an example of a pathfinding cell 24A represented with a central path line connecting the centers of each cell 124A to 124H. Each cell 124A to 124H constitutes a pathfinding cell 24A.

[0075] The path search area setting unit 251 creates a guidance command 104 that includes a path search cell 24A in which multiple cells 124A to 124H are consecutive in the controlled airspace 11, extending upward from the landing point 25, as shown by the thick rectangle in Figure 12.

[0076] Guidance command 104 is expressed by the following formula, where the leading edge of the aircraft 100 is facing into the wind. Guidance command = {Cell_ID(i), Time(i), Position(i), Heading(i)} where Time(i) indicates the time in cell i, Position(i) indicates the position of i, and Heading(i) indicates the direction the leading edge of the aircraft is facing.

[0077] Figures 14 to 16 are flowcharts illustrating an example of the main processing procedure as an example of the ground control method according to this embodiment. Figure 15 is a continuation of the flowchart shown in Figure 14, and Figure 16 is a continuation of the flowchart shown in Figure 15.

[0078] The ground control method includes a detection step in which an object detection unit 210, as an example of a detection unit, detects which of the cells 24 that divide the controlled airspace 11, which is above the landing point 25, is flying in, and a path search area setting unit 251 of a takeoff and landing guidance unit 250, as an example of a path search area setting unit, sets the three-dimensional position information of the aircraft 100 within the controlled airspace 11, the heading information of the aircraft 100, the wind direction information of the wind in each cell 24, and the estimated time until the aircraft 100 reaches the landing point 25 from each cell 24 when the aircraft 100 is flying above the landing point 25. The system includes a path search area setting step in which, using arrival time information, the system repeatedly determines the cells 24 that the aircraft 100 should fly to within the controlled airspace 11 while controlling the aircraft 100 so that its nose faces into the wind, and sets path search cells 124A to 124H as an example of a flight path composed of the multiple cells 24 that have been repeatedly determined, and a path planning step in which the takeoff and landing path planning unit 252 and command generation unit 253 of the takeoff and landing guidance unit 250, which is an example of a path planning unit, generate a guidance command 104 as a single packet as an example of a command to fly the aircraft 100 along the path search cells 124A to 124H, and outputs the guidance command 104 to the aircraft 100.

[0079] In step S1 shown in Figure 14, the object detection unit 210 monitors the position of the flying object 100. The object detection unit 210 continuously performs step S1, and each of the subsequent steps from step S2 onward is performed each time the object detection unit 210 detects the flying object 100.

[0080] In step S2, the object detection unit 210 determines whether the aircraft 100 has approached within a specific distance of the landing port 19. If in step S2 it is determined that the aircraft 100 has not approached within a specific distance of the landing port 19, the object detection unit 210 terminates the main process. On the other hand, if in step S2 it is determined that the aircraft 100 has approached within a specific distance of the landing port 19, the object detection unit 210 executes step S3.

[0081] In step S3, the route search area setting unit 251 acquires the terrain model 222 and the object information from the wind forecasting unit 220. In step S4, the route search area setting unit 251 sets the controlled airspace 11 based on the terrain model 222 and object information.

[0082] In step S5, the route search area setting unit 251 sets the cells that constitute the controlled airspace 11. In step S6, the route search area setting unit 251 selects an available cell. Specifically, it is preferable that the route search area setting unit 251 satisfies the following relationship with respect to the distance D shown in Figure 6.

[0083] As described above, the path search area setting unit 251 sets each cell as a flight path if the distance d of the horizontal line drawn from the center coordinates of each cell to the boundary of the controlled airspace 11 is longer than the longer of the overall length of the aircraft 100 or the wingspan.

[0084] On the other hand, the path search area setting unit 251 determines that if the distance of the horizontal line drawn from the center coordinates of each cell to the boundary of the controlled airspace 11 is shorter than the longer of the overall length of the aircraft 100 or the wingspan, then each cell is outside the flight path.

[0085] In step S7 shown in Figure 15, the takeoff and landing path planning unit 252 acquires wind direction information and the like from the wind simulator 223 of the wind forecasting unit 220. In step S8, the takeoff and landing path planning unit 252 sets the wind direction of the landing cell (initial cell) at the predicted landing time, which is predicted according to the flight speed of the aircraft 100 and the distance from the current position to the landing site 25. Here, setting the wind direction is shown as an example, but wind force may also be set.

[0086] In step S9, the takeoff and landing path planning unit 252 estimates the expected arrival time for each cell on the flight path, including the selected cell. In step S10, the takeoff and landing path planning unit 252 stores wind direction information for the cell directly above the selected cell in the vertical direction in a memory (not shown).

[0087] In step S11, the takeoff and landing path planning unit 252 searches for a new cell from the selected cells that is predicted to have the smallest difference in wind direction. In step S12, the takeoff and landing path planning unit 252 determines whether or not there is a new cell that is predicted to have the smallest difference in wind direction. If in step S12 it is determined that there is no new cell that is predicted to have the smallest difference in wind direction, the takeoff and landing path planning unit 252 terminates the main process. On the other hand, if in step S12 it is determined that there is a new cell that is predicted to have the smallest difference in wind direction, the takeoff and landing path planning unit 252 executes step S13.

[0088] In step S13, the takeoff and landing path planning unit 252 selects the cell with the shortest flight distance (hereinafter referred to as the "shortest cell") from among a new set of cells where the wind direction difference is predicted to be the smallest. In step S14, the takeoff and landing path planning unit 252 selects the cell with the shortest flight distance to the landing point 25, which will be the entry position for the landing port 19 of the aircraft 100.

[0089] The takeoff and landing path planning unit 252 repeatedly executes steps S9 to S15 described above until the shortest selected cell reaches the starting altitude for vertical flight of the aircraft 100 (step S16).

[0090] In step S16, when the shortest selected cell reaches the starting altitude for vertical flight of the aircraft 100, in step S17, the takeoff and landing path planning unit 252 causes the command generation unit 253 to send a guidance command to change the flight mode of the aircraft 100 to automatic landing. In step S18, the command generation unit 253 sends a guidance command to the aircraft 100 that includes the information of the planned flight path described above.

[0091] In step S19, the command generation unit 253 waits until it receives a response signal from the aircraft 100. If a response signal is received from the aircraft 100 in step S19, the object detection unit 210 executes step S20.

[0092] In step S20, the object detection unit 210 acquires the position information of the aircraft 100 obtained by the position sensor 111A. In step S21, the takeoff and landing path planning unit 252 calculates the difference between the landing port 19 and the aircraft 100.

[0093] In step S22, the takeoff and landing path planning unit 252 determines whether the deviation exceeds a predetermined threshold. If it is determined in step S22 that the deviation does not exceed a predetermined threshold, the takeoff and landing path planning unit 252 executes step S25.

[0094] In step S25, the takeoff and landing path planning unit 252 instructs the command generation unit 253 to send a guidance command to the aircraft 100 to change the flight mode to "hovering control". In step S26, the takeoff and landing path planning unit 252 replans the cells and flight path of the landing point 25 so that it is directly below the aircraft 100. In step S27, the takeoff and landing path planning unit 252 instructs the command generation unit 253 to send a guidance command to the aircraft 100 to guide it along the replanned flight path. The takeoff and landing path planning unit 252 returns to step S20 and repeats each step from step S20 onward. That is, the takeoff and landing path planning unit 252 calculates the flight path so that it passes through the path search cells 24A, which consist of consecutive cells 124A to 128H within the controlled airspace 11.

[0095] On the other hand, if in step S22 it is determined that the deviation exceeds a predetermined threshold, the takeoff and landing path planning unit 252 executes step S23. In step S23, the takeoff and landing path planning unit 252 determines whether or not the aircraft 100 has landed at the landing port 19 based on the position information of the aircraft 100 acquired by the object detection unit 210.

[0096] In step S24, the takeoff and landing path planning unit 252 stores the landing control history of the aircraft 100 in a memory (not shown). The storage location may be a device capable of non-volatile storage, other than memory. The above description may be applied, for example, when the aircraft 100 is landing or when it is taking off.

[0097] Figure 17 is a flowchart showing an example of the landing control process procedure. This landing control process is performed on the aircraft 100. In step S101, the guidance unit 112 waits until it receives a command from the ground control system 1 that includes the planned flight path or the replanned flight path.

[0098] In step S101, when the guidance unit 112 receives a guidance command including the planned flight path or the replanned flight path, it performs tracking control to the cell at the starting point of the planned flight path. In step S103, the guidance unit 112 sends a reply command to the ground control system 1 via the communication unit 400A.

[0099] In step S104, the control unit 113 performs follow-up control along the planned flight path. In step S105, the control unit 113 determines whether or not it has received a guidance command to change the flight mode to "hovering control".

[0100] In step S105, if the control unit 113 determines that it has received a guidance command to change the flight mode to "hovering control", it performs hovering control. The control unit 113 then returns to step S101 described above and repeats each step.

[0101] If, in step S105, the control unit 113 does not determine that it has received a guidance command to change the flight mode to "hovering control", it executes step S107. In step S107, the control unit 113 determines whether or not the aircraft 100 has landed. If, in step S107, it determines that the aircraft 100 has landed, the control unit 113 executes step S108. Alternatively, if, in step S107, it determines that the aircraft 100 has landed, the control unit 113 executes step S108. In step S108, the control unit 113 stores the landing control history in a memory (not shown).

[0102] Figure 18 shows an example of the data format for a guidance command 104. A guidance command 104 is a record that includes item name 401A, property name 401B, and meaning 401C. Item name 401A indicates the item name of each property. The flight plan ID represents the identifier (hereinafter also referred to as "ID") assigned to the flight plan of the aircraft 100.

[0103] Property name 401B represents the names of the properties "flightplanId" 402, "userId" 403, "aircraftId" 404, and "route" 405, which constitute the command transmission packet described later.

[0104] Meaning 401C represents the meaning of each property. Meaning 401C corresponding to item name 401A "Flight Plan ID" indicates, for example, that it is an ID assigned individually to each flight plan. Meaning 401C corresponding to item name 401A "User ID" indicates, for example, that it is an ID assigned to each operator performing the flight. Meaning 401C corresponding to item name 401A "Aircraft ID" indicates, for example, that it is an ID assigned to each aircraft of aircraft 100. Meaning 401C corresponding to item name 401A "Flight Rulo Information" indicates, for example, that it is waypoint information that is referenced when aircraft 100 uses it for flight control.

[0105] The guidance command 104 is transmitted as a command from the ground control system 1 to the aircraft 100 in a data format such as the following. The guidance command 104 begins with a description of the flight plan properties, followed by the waypoint (WP) information, which is described in array format. A distinctive feature of this embodiment is the addition of the heading angle during vertical descent.

[0106] Guidance command 104 is written in an array format like the following, for example: { flightplanId: r_xxxx, userId: u_xxxx, aircraftId: a_xxxx, route:{ coordinate:[ { latitude: xxx.xxxx, longitude: yyy.yyyy, altitude: zzz.zzzz, heading: rrr.rrrr, time: YYYY.MM.DD.hh.mm.ss,}, { latitude: xxx.xxxx, longitude: yyy.yyyy, altitude: zzz.zzzz, heading: rrr.rrrr, time: YYYY.MM.DD.hh.mm.ss,} (This is repeated until the end point of the WP (landing point))}}

[0107] Figure 19 shows an example of a command transmission packet 400. Figure 20 shows an example of item 405F, which is part of the command transmission packet 400 shown in Figure 19. As shown in Figure 19, the command transmission packet 400 includes at least the property "flightplanId" 402, the property "userId" 403, the property "aircraftId" 404, and the property "route" 405, as shown by property name 401B in Figure 18.

[0108] The property "route" 405 includes, for example, at least items 405A to 405J. The property "route" 405 is obtained by calculating, for example, latitude information, longitude information, altitude information, azimuth information of the aircraft's nose, and time information as a set, repeating from the cell of the aircraft's current position to the cell of the landing site 25. The time information may be transmitted in Coordinated Universal Time, for example, YYYY.MM.DD.hh.mm.ss. In that case, by fixing the number of packets in the property "route" 405 and setting all data after arrival to a predetermined number (for example, a series of 9s), the aircraft 100 can grasp the time set of the expected arrival time at the landing site 25, and can ignore, for example, data thereafter.

[0109] Here, for example, by using time information as data of the number of seconds calculated from the expected arrival time set to 0.0s, the aircraft 100 can grasp the information set upon arrival at the landing point 25. Alternatively, information specifying the number of information sets may be added to the header information of the command transmission packet 400, etc., which constitutes the value of the property "route" 405 (or, if the only variation in the number of packets is the property "route" 405, the total number of packets). In this case, the transmission packet length of the command transmission packet 400 can be made variable.

[0110] As shown in Figure 20, the command transmission packet 400 has columns such as LAT1 405A, LON 405B, ALT1 405C, HEAD1 405D, TIME1 405E, TIME1 405E, LAT2 405F, LON2 405G, ALT2 305H, HEAD2 405I, TIME2 405J, etc., and contains data for each column.

[0111] The ground control system 1 according to this embodiment includes an object detection unit 210 as an example of a detection unit that detects which of the cells 24 that divide the controlled airspace 11, which is the airspace above the landing point 25, an aircraft 100 that can fly from the landing point 25 of the landing port 19 is flying in, and when the aircraft 100 is flying above the landing point 25, it uses the three-dimensional position information of the aircraft 100 within the controlled airspace 11, the heading information regarding the direction of the aircraft 100's nose, the wind direction information regarding the direction of the wind in each cell 24, and the estimated arrival time information regarding the estimated time it will take for the aircraft 100 to reach the landing point 25 from each cell 24, to perform the operation. The system includes a path search area setting unit 251, which is an example of a path search area setting unit, that repeatedly determines the cells 24 that the aircraft 100 should fly to within the controlled airspace 11 while controlling the aircraft 100 so that its nose faces into the wind, and sets path search cells 124A to 124H as an example of a flight path composed of the multiple cells 24 that have been repeatedly determined, and a takeoff and landing path planning unit 252, which is an example of a path planning unit, that generates a guidance command 104 as a single packet as an example of a command for the aircraft 100 to fly along the path search cells 124A to 124H, and outputs the guidance command 104 to the aircraft 100. The above-described flight includes, for example, at least one of takeoff and landing.

[0112] The ground control method according to this embodiment includes a detection step in which the object detection unit 210 detects which of the cells 24 that divide the controlled airspace 11, which is above the landing point 25, the aircraft 100 that can fly from the landing point 25 of the landing port 19 is flying in; and a path search area setting unit 251 sets the three-dimensional position information of the aircraft 100 within the controlled airspace 11, the heading information regarding the direction of the aircraft 100's nose, the wind direction information regarding the direction of the wind in each cell 24, and the estimated arrival time information regarding the estimated time it will take for the aircraft 100 to reach the landing point 25 from each cell 24. The system includes a path search area setting step in which, using information, the aircraft 100 is controlled so that its nose faces into the wind, and the cells 24 to which the aircraft 100 should fly within the controlled airspace 11 are repeatedly determined, and path search cells 124A to 124H composed of the multiple cells 24 that have been repeatedly determined are set; and a path planning step in which a takeoff and landing path planning unit 252, as an example of a path planning unit, generates a guidance command 104 as a single packet, as an example of a command to cause the aircraft 100 to fly along the path search cells 124A to 124H as an example of a flight path, and outputs the guidance command 104 to the aircraft 100. Here, the flight includes at least one of takeoff and landing.

[0113] The ground control method of the ground control system 1 according to this embodiment includes a detection step in which an object detection unit 210, as an example of a detection unit, detects which of the cells 24 that divide the controlled airspace 11, which is above the landing point 25, is flying in, and a path search area setting unit 251, as an example of a path search area setting unit, sets the three-dimensional position information of the aircraft 100 within the controlled airspace 11, the heading information of the aircraft 100, the wind direction information of the wind in each cell 24, and the estimated time until the aircraft 100 reaches the landing point 25 from each cell 24 when the aircraft 100 is flying above the landing point 25. The system includes a path search area setting step in which, using predicted arrival time information, the system repeatedly determines the cell 24 that the aircraft 100 should fly to within the controlled airspace 11 while controlling the aircraft 100 so that its nose faces into the wind, and sets path search cells 124A to 124H as an example of a flight path composed of the multiple cells 24 that have been repeatedly determined, and a path planning step in which the takeoff and landing path planning unit 252 and command generation unit 253 of the takeoff and landing guidance unit 250, which is an example of a path planning unit, generate a guidance command 104 as a single packet as an example of a command to fly the aircraft 100 along the flight path, and output the guidance command 104 to the aircraft 100.

[0114] With this configuration, the flight path is divided into multiple cells, and the heading information regarding the aircraft's heading in each cell is included in the guidance command 104. As a result, the aircraft 100 can fly while directing the heading information included in the guidance command 104 in the optimal direction for each cell, thereby achieving stable flight within the controlled airspace 11. Therefore, the aircraft 100 can fly along a safer flight path within the controlled airspace 11. In addition, since the guidance command 104 is transmitted as a single packet, the number of communications between the ground control system 1 and the aircraft 100 can be reduced.

[0115] In this embodiment, the three-dimensional position information includes latitude, longitude, and altitude information of the aircraft 100 within the controlled airspace 11. This allows the aircraft 100 to fly along a safer flight path within the controlled airspace 11 based on this three-dimensional position information.

[0116] In this embodiment, the path search area setting unit 251 calculates the flight path of the aircraft 100 so that the amount of change in wind direction in each cell from the landing point 25 to the vertical flight start point is minimized. In this way, since the amount of change in wind direction in each cell of the flight path is minimized, the aircraft 100 can be flown along a safer flight path within the controlled airspace 11.

[0117] In this embodiment, the path search area setting unit 251 sets each cell as a flight path if the distance d of the horizontal line drawn from the center coordinates of each cell to the boundary of the controlled airspace 11 is longer than the longer of the overall length of the aircraft 100 or the wingspan. In this way, the aircraft 100 can fly along a safer flight path within the controlled airspace 11 which is set with a margin of safety.

[0118] In this embodiment, the pathfinding area setting unit 251 determines that if the distance of the horizontal line drawn from the center coordinates of each cell to the boundary of the controlled airspace 11 is shorter than the longer of the overall length of the aircraft 100 or the wingspan, then that cell is considered outside the flight path. This eliminates the need to consider such outside flight paths, and consequently allows the aircraft 100 to fly along a safer flight path within the controlled airspace 11.

[0119] In this embodiment, the path search area setting unit 251 sets the flight path each time the aircraft 11 enters a predetermined distance from the landing port 9. This allows the aircraft 100 to fly along a safer flight path within the controlled airspace 11.

[0120] In this embodiment, the path search area setting unit 251 calculates the amount of change in wind direction starting from the wind direction predicted at the estimated landing time at the landing point 25, and calculates the flight path. In this way, the aircraft 100 can be flown along a safer flight path within the controlled airspace 11.

[0121] In this embodiment, the path search area setting unit 251 starts from the landing point 25 and repeatedly selects cells to be used as the flight path, pointing upwards. In this way, the aircraft 100 can fly along a safer flight path within the controlled airspace 11 which has a flight path composed of the repeatedly selected group of cells.

[0122] The path search area setting unit 251 selects the next cell to be used from the cell directly above the cell selected as the flight path, and from the cells that horizontally surround the cell directly above. If the cells that horizontally surround the cell directly above include cells outside the flight path, those cells outside the flight path are excluded from selection. In this way, it is not necessary to consider cells outside the flight path, and the aircraft 100 can fly along a safer flight path within the controlled airspace 11.

[0123] In this embodiment, the path search area setting unit 251 connects the center coordinates of the cell to be adopted as the flight path and the cell selected above that cell, thereby extending the flight path. In this way, the aircraft 100 can be flown along a safer flight path within the controlled airspace 11.

[0124] In this embodiment, the path search area setting unit 251 has information regarding the target coordinates, target time, and target azimuth angle of the landing point 25 used during landing control for each cell (cells 124A to 124H described later) used in the flight path. This allows the aircraft 100 to fly along a safer flight path within the controlled airspace 11.

[0125] In this embodiment, the path search area setting unit 251 calculates the target time for each cell from a predetermined descent speed and the center coordinate distance between cells, or calculates it by numerical analysis using a motion model of the aircraft 100. This allows the aircraft 100 to fly along a safer flight path within the controlled airspace 11.

[0126] In this embodiment, when setting a flight path, if there are multiple cells where the difference in wind direction is minimized, the path search area setting unit 251 selects a specific cell from among these multiple cells that minimizes the flight distance of the aircraft 100 during vertical flight. In this way, the aircraft 100 can be flown along a safer flight path within the controlled airspace 11 by selecting the specific cell.

[0127] In this embodiment, when setting a flight path, the path search area setting unit 251 selects a predetermined cell as the path search cell 24A if there are multiple cells where the difference in wind direction is minimized and multiple cells where the flight distance of the aircraft 100 in the vertical direction is minimized. This predetermined cell allows the aircraft 100 to fly along a safer flight path within the controlled airspace 11.

[0128] In this embodiment, when the aircraft 100 is flying vertically through the controlled airspace 11, if the error between the target position of the landing point 25 and the position of the aircraft 100 exceeds a predetermined threshold, the path search area setting unit 251 switches the aircraft 100 to "hovering control" and resets the flight path. In this way, the aircraft 100 can be flown along a safer flight path within the controlled airspace 11 by the reset flight path.

[0129] It should be noted that the present invention is not limited to the embodiments described above, but includes various modifications and equivalent configurations within the spirit of the appended claims. For example, the embodiments described above are described in detail for the purpose of clearly illustrating the present invention, and the present invention is not necessarily limited to having all the configurations described. Also, each element described in parallel in this embodiment may be configured such that at least one of the elements is connected in series with respect to the other elements.

[0130] The present invention can be applied, for example, to ground control systems related to the technology of controlling aircraft.

[0131] 1...Ground control system, 250...Takeoff and landing guidance unit, 251...Route search area setting unit, 252...Takeoff and landing route planning unit

Claims

1. A ground control system comprising: a detection unit that detects which of the cells that divide the controlled airspace above the landing site an aircraft capable of flying from the landing site is flying in; a path search area setting unit that, when the aircraft is flying above the landing site, repeatedly determines which cells the aircraft should fly in within the controlled airspace while controlling the aircraft so that its nose faces into the wind, using three-dimensional position information of the aircraft within the controlled airspace, heading information regarding the direction of the aircraft's nose, wind direction information regarding the direction of the wind in each cell, and estimated arrival time information regarding the estimated time it takes for the aircraft to reach the landing site from each cell, and sets a flight path composed of a plurality of repeatedly determined cells; and a path planning unit that generates a command as a single packet for the aircraft to fly along the flight path and outputs the command to the aircraft.

2. The ground control system according to claim 1, characterized in that the three-dimensional position information includes latitude information, longitude information, and altitude information of the aircraft within the controlled airspace.

3. The ground control system according to claim 1, characterized in that the path search area setting unit calculates the flight path of the aircraft so that the amount of change in wind direction in each cell from the landing point to the vertical flight start point is minimized.

4. The ground control system according to claim 1, characterized in that the path search area setting unit sets each cell as a flight path if the distance of the horizontal line drawn from the center coordinates of each cell to the boundary of the controlled airspace is longer than the longer of the overall length of the aircraft's fuselage or the wingspan of its main wings.

5. The ground control system according to claim 1, characterized in that the path search area setting unit determines each cell to be outside the flight path if the distance of the horizontal line drawn from the center coordinates of each cell to the boundary of the controlled airspace is shorter than the longer of the overall length of the aircraft or the wingspan.

6. The ground control system according to claim 1, characterized in that the path search area setting unit sets the flight path each time the aircraft enters a predetermined distance from the landing port.

7. The ground control system according to claim 1, characterized in that the path search area setting unit calculates the amount of change in wind direction starting from the wind direction predicted at the estimated landing time at the landing site, and calculates the flight path.

8. The ground control system according to claim 1, characterized in that the path search area setting unit starts from the landing point and repeatedly selects cells to be used as the flight path, with the cells facing upwards.

9. The ground control system according to claim 1, characterized in that the path search area setting unit selects the next cell to be used from the cell directly above the cell selected to be adopted as the flight path, and from the cells that horizontally surround the cell directly above, and if the cells that horizontally surround the cell directly above include a cell outside the flight path, the cell outside the flight path is excluded from selection.

10. The ground control system according to claim 1, characterized in that the path search area setting unit connects the center coordinates of the cell to be adopted as the flight path and the cell selected above the cell, and extends the flight path.

11. The ground control system according to claim 1, characterized in that the path search area setting unit has information regarding the target coordinates, target time, and target azimuth angle of the landing point used during landing control for each cell used in the flight path.

12. The ground control system according to claim 1, characterized in that the path search area setting unit calculates the target time for each cell from a predetermined descent speed and the center coordinate distance between cells, or calculates it by numerical analysis using a motion model of the aircraft.

13. The ground control system according to claim 1, characterized in that when setting the flight path, if there are multiple cells where the difference in wind direction is minimized, the path search area setting unit selects a specific cell from among the multiple cells that minimizes the flight distance of the aircraft during vertical flight.

14. The ground control system according to claim 1, characterized in that when setting the flight path, the path search area setting unit selects a predetermined cell from among the multiple cells that is closest to the position where the aircraft will enter the landing site, when there are multiple cells where the difference in wind direction is minimized and there are multiple cells where the flight distance in the vertical direction of the aircraft is minimized, as the path search cell.

15. The ground control system according to claim 1, characterized in that, when the aircraft is flying vertically through the controlled airspace, if the error between the target position of the landing site and the position of the aircraft is greater than or equal to a predetermined threshold, the aircraft switches to hover control and resets the flight path.

16. Ground control method comprising: a detection step in which a detection unit detects which of the cells that divide the controlled airspace above the landing point an aircraft capable of flying from the landing point is flying in; a path search area setting step in which, when the aircraft is flying above the landing point, the unit repeatedly determines which cells the aircraft should fly in within the controlled airspace while controlling the aircraft so that its nose faces into the wind, using three-dimensional position information of the aircraft within the controlled airspace, heading information relating to the direction of the aircraft's nose, wind direction information relating to the direction of the wind in each cell, and estimated arrival time information relating to the estimated time it takes for the aircraft to reach the landing point from each cell, and sets a flight path composed of a plurality of repeatedly determined cells; and a path planning step in which the path planning unit generates a command as a single packet for the aircraft to fly along the flight path and outputs the command to the aircraft.

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