Systems, programs, and methods for controlling an aircraft

Abstract

To provide a system for controlling an aircraft to enable stable flight when the aircraft is tethered by a cable. [Solution] The system of the present invention comprises a mobile body, a flying body connected to the mobile body via a cable, a control unit for controlling the flight of the flying body, and a tension sensor for detecting the tension T applied to the cable and outputting the detected tension T to the control unit. The control unit is configured to determine whether the detected tension T is greater than or equal to a threshold, and in response to determining that the detected tension T is greater than or equal to the threshold, to control the flight of the flying body so that the detected tension T becomes less than the threshold.

Description

Technical Field

[0001] The present invention relates to a system, a program, and a method for controlling a flying object.

Background Art

[0002] With the development of unmanned aerial vehicles (so-called drones), it has become possible to perform various actions from the sky. For example, it is known that aerial photography, safety monitoring, and inspections are performed using unmanned aerial vehicles (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There are no-fly zones for flying objects, and it is also required to ensure a distance from people or objects. Therefore, in order to prevent the flying object from inadvertently entering a no-fly zone or approaching people or objects inadvertently, it is effective to moor the flying object with a cable and limit the flight range. For example, it is also possible to provide a mooring point of the flying object on a moving object. In this case, since the mooring point moves together with the moving object, the flight range of the flying object also moves accordingly.

[0005] However, when the flying object is moored with a cable, if the flying object is pulled by the cable, the free flight of the flying object may be inhibited more than necessary. In addition, if the flying object is pulled by the cable, the flying object may lose its attitude and exhibit unexpected behavior, and ultimately there is also a risk of crashing.

Means for Solving the Problems

[0006] The present invention provides a system for controlling an aircraft to enable stable flight when the aircraft is tethered by a cable. The present invention provides, for example, the following items: (Item 1) A system, wherein the system is Mobile and A flying object connected to the aforementioned moving body via a cable, A control unit that controls the flight of the aircraft, A tension sensor that detects the tension T applied to the cable and outputs the detected tension T to the control unit. Equipped with, The control unit, To determine whether the detected tension T is above a threshold, In response to determining that the detected tension T is greater than or equal to the threshold, the flight of the aircraft is controlled so that the detected tension T becomes less than the threshold. A system configured to perform the following actions. (Item 2) The threshold is a function of the control margin of the control unit and changes over time, as described in the above item. (Item 3) Determining whether the detected tension T is greater than or equal to a threshold is: To determine whether the horizontal component Tx of the detected tension T is greater than or equal to a first threshold, To determine whether the vertical component Tz of the detected tension T is greater than or equal to a second threshold. Includes, In response to determining that the detected tension T is greater than or equal to the threshold, controlling the flight of the aircraft so that the detected tension T becomes less than the threshold is: A system according to any one of the above items, comprising: determining that the horizontal component Tx of the detected tension T is greater than or equal to the first threshold; or determining that the vertical component Tz of the detected tension T is greater than or equal to the second threshold; and controlling the flight of the aircraft such that the horizontal component Tx of the detected tension T is less than the first threshold and the vertical component Tz of the detected tension T is less than the second threshold. (Item 4) The system according to any one of the above items, wherein the first threshold is a function of the horizontal control margin Ux of the control unit, and the second threshold is a function of the vertical control margin Uz of the control unit. (Item 5) The horizontal control margin Ux and the vertical control margin Uz change over time. Ux(t) = Uxmax - Udx(t) - Ufx(t) Uz(t) = Uzmax - Udz(t) - Ufz(t) Here, Uxmax is the maximum horizontal control force of the control unit, and Uzmax is the maximum vertical control force of the control unit. Udx is the horizontal control force for the aircraft to fly against disturbances, and Udz is the vertical control force for the aircraft to fly against disturbances. Ufx is the horizontal control force for the aircraft to fly in accordance with the target value, and Ufz is the vertical control force for the aircraft to fly in accordance with the target value. The system described in any one of the above items. (Item 6) The system described in any one of the above items, wherein the first threshold is α × Ux(t), the second threshold is β × Uz(t), and 0.2 ≤ α ≤ 0.3 and 0.2 ≤ β ≤ 0.3. (Item 7) Controlling the flight of the flying object such that the horizontal component Tx of the detected tension T is less than the first threshold value and the vertical component Tz of the detected tension T is less than the second threshold value includes controlling the flight of the flying object using the horizontal control margin Ux and the vertical control margin Uz, and the system according to any one of the above items. (Item 8) The moving object is a carriage capable of moving on the track along the track, and the system according to any one of the above items. (Item 9) The track is a track for a railway vehicle to run on, and the system according to any one of the above items. (Item 10) The moving object is a powered moving object or an unpowered moving object, and the system according to any one of the above items. (Item 11) The cable is a power supply cable, The moving object includes a power supply device for supplying power to the flying object via the power supply cable, and the system according to any one of the above items. (Item 12) A flying object, the flying object is coupled to a moving object via a cable, and the flying object A control unit for controlling the flight of the flying object, A tension sensor that detects the tension T applied to the cable and outputs the detected tension T to the control unit And is provided with The control unit Determining whether the detected tension T is above a threshold value, In response to determining that the detected tension T is above the threshold value, controlling the flight of the flying object so that the detected tension T is less than the threshold value And is configured to perform, a flying object. (Item 12A) The flying object according to Item 12, having the features according to any one of the above items. (Item 13) A program for controlling a flying object, wherein the flying object is coupled to a moving object via a cable, The flying object is, A control unit for controlling the flight of the flying object, A tension sensor that detects a tension T applied to the cable and outputs the detected tension T to the control unit And comprises, When the program is executed by the control unit, Determining whether the detected tension T is greater than or equal to a threshold value, In response to determining that the detected tension T is greater than or equal to the threshold value, controlling the flight of the flying object so that the detected tension T is less than the threshold value A program that causes the control unit to perform a process including. (Item 13A) The program according to item 13, comprising the features of any one of the above items. (Item 13B) A non-transitory computer-readable storage medium storing the program according to item 13 or item 13A. (Item 13C) A computer program product comprising the program according to item 13 or item 13A. (Item 14) A method for controlling a flying object, wherein the flying object is coupled to a moving object via a cable, The flying object is, A control unit for controlling the flight of the flying object, A tension sensor that detects a tension T applied to the cable and outputs the detected tension T to the control unit And comprises, The method is executed in the control unit, The method is, The control unit determines whether the detected tension T is greater than or equal to a threshold value, The control unit controls the flight of the flying object so that the detected tension T is less than the threshold value in response to determining that the detected tension T is greater than or equal to the threshold value Methods that include... (Item 14A) The method described in item 14, wherein the method has the characteristics described in any one of the above items. [Effects of the Invention]

[0007] According to the present invention, stable flight of an aircraft is possible even when the aircraft is tethered by a cable. This allows the aircraft to fly without its free flight being unnecessarily hindered. The present invention can bring about improvements in the field of aircraft flight control. [Brief explanation of the drawing]

[0008] [Figure 1A] This diagram shows an example of how railway tracks are inspected using an aircraft tethered to a mobile vehicle by a cable. [Figure 1B] This diagram shows an example of how railway tracks are inspected using an aircraft tethered to a mobile vehicle by a cable. [Figure 1C] This diagram shows an example of how railway tracks are inspected using an aircraft tethered to a mobile vehicle by a cable. [Figure 2] A diagram showing an example of the configuration of an aircraft. [Figure 3] A flowchart showing an example of a process 300 for controlling the flight of an aircraft. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings.

[0010] Figures 1A and 1C show an example of inspecting a railway track using an aircraft tethered to a mobile body by a cable. In this example, a trolley 20 (mobile body) moves along the railway track R, and a cable 30 connected to the trolley 20 is coupled to a drone 10 (aircraft). The drone 10 then flies and inspects the railway track R from above for any abnormalities.

[0011] For example, the drone 10 may be equipped with a battery and be able to fly and perform inspections using power from the battery. Alternatively, the cable 30 may be a power supply cable, and the drone 10 may be powered via the power supply cable from a power supply device on the trolley 20 and be able to perform inspections using that power.

[0012] The drone 10 will fly within a flight range defined by the tethering point of the cable 30 on the trolley 20 and the length of the cable 30. As the trolley 20 moves along the track R, the tethering point also moves. Furthermore, for example, the tethering point of the cable 30 on the trolley 20 may be fixed to a reel, and the length of the cable 30 may be adjusted by unwinding or winding the cable 30 using the reel. In this way, the position and size of the flight range can be adjusted.

[0013] For example, as shown in Figure 1A, when the cable 30 is slack, the drone 10 is not affected by the tension of the cable 30, or the tension of the cable 30 acting on the drone 10 is negligible. Therefore, the drone 10 can fly freely with almost no influence from the cable 30.

[0014] In contrast, as shown in Figure 1B, for example, when the cable 30 is taut, the tension T of the cable 30 acts on the drone 10, and the drone 10 is affected by the cable 30, hindering its free flight. This can lead to the drone 10's attitude becoming unexpectedly unstable, and there is a risk that the drone 10 may crash.

[0015] In this invention, the tension T of the cable 30 is monitored, and the drone 10 is controlled by feedback to prevent the tension T from becoming too large, thereby enabling the drone 10 to fly freely without being affected by the cable 30.

[0016] In one embodiment of the present invention, the tension T of the cable 30 is compared with a threshold, and if the tension T is greater than or equal to the threshold, the flight of the drone 10 is controlled so that the tension T becomes less than the threshold. Preferably, the threshold may be a value that fluctuates over time. By making the threshold a value that fluctuates over time rather than a fixed value, the tension T can be adjusted according to the flight conditions, enabling more unrestricted and free flight.

[0017] More preferably, the threshold may be a value that depends on the control force remaining to control the flight of the drone 10 (i.e., control margin), that is, the threshold may be a function of the control margin. The control margin is the remaining force after subtracting the control force necessary to stably control the drone 10 toward the target value from the maximum control force for controlling the drone 10. The control force necessary to stably control the drone 10 toward the target value includes the control force necessary to control the drone 10 toward the target value (target-following control force) and the control force necessary to stabilize the drone 10 against disturbances, etc. (disturbance-countering control force). When the control margin is exhausted (i.e., when all of the maximum control force is used to stably control the drone toward the target value), the drone 10 becomes uncontrollable.

[0018] Since the control margin will counteract the tension T of cable 30, the control margin must be sufficiently greater than the tension T. To ensure this, the threshold compared to the tension T may be 50% or less of the control margin, 40% or less of the control margin, 30% or less of the control margin, or preferably 20% to 30% of the control margin. This prevents the tension T from becoming too large and also prevents the drone 10 from becoming uncontrollable due to the tension T. This makes it possible to achieve highly versatile drone control.

[0019] In one embodiment of the present invention, the tension T of the cable 30 is decomposed into a horizontal component Tx and a vertical component Tz within the vertical plane P to which the tension T belongs (for example, within a relative coordinate system with the fixed point on the drone 10 of the cable 30 as the origin), as shown in Figure 1C. The horizontal component Tx of the tension T is compared with a first threshold, and the vertical component Tz of the tension T is compared with a second threshold. If the horizontal component Tx of the tension T is greater than or equal to the first threshold, or if the vertical component Tz of the tension T is greater than or equal to the second threshold, the flight of the drone 10 is controlled so that the horizontal component Tx of the tension T becomes less than the first threshold and the vertical component Tz of the tension T becomes less than the second threshold.

[0020] In this case, the control margin described above is also decomposed into a horizontal component and a vertical component. Furthermore, the first threshold may be a function of the horizontal component of the control margin, and the second threshold may be a function of the vertical component of the control margin.

[0021] The flight of the drone 10 is controlled using the horizontal and vertical components of the control margin so that the horizontal component Tx of tension T is less than a first threshold and the vertical component Tz of tension T is less than a second threshold. Since the horizontal and vertical components of the control margin are reliably larger than the horizontal component Tx and vertical component Tz of tension T, respectively, the flight of the drone 10 can be feedback-controlled without running out of margin.

[0022] In another embodiment of the present invention, the tension T of the cable 30 is decomposed into an X-direction component TX, a Y-direction component TY, and a Z-direction component TZ in an absolute coordinate system (i.e., a fixed coordinate system independent of the position of the drone 10) as shown in the lower left of Figure 1C. The X-direction component TX of tension T is compared with a threshold in the X direction, the Y-direction component TY of tension T is compared with a threshold in the Y direction, and the Z-direction component TZ of tension T is compared with a threshold in the Z direction. Then, if the X-direction component TX of tension T is greater than or equal to the threshold in the X direction, or the Y-direction component TY of tension T is greater than or equal to the threshold in the Y direction, or the Z-direction component TZ of tension T is greater than or equal to the threshold in the Z direction, the flight of the drone 10 is controlled so that the X-direction component TX of tension T is less than the threshold in the X direction, the Y-direction component TY of tension T is less than the threshold in the Y direction, and the Z-direction component TZ of tension T is less than the threshold in the Z direction.

[0023] In this case, the control margin described above is also decomposed into components in the X, Y, and Z directions. Furthermore, the threshold in the X direction may be a function of the X component of the control margin, the threshold in the Y direction may be a function of the Y component of the control margin, and the threshold in the Z direction may be a function of the Z component of the control margin.

[0024] The flight of the drone 10 is controlled using the X, Y, and Z components of the control margin so that the X component TX of tension T is less than the threshold in the X direction, the Y component TY of tension T is less than the threshold in the Y direction, and the Z component TZ of tension T is less than the threshold in the Z direction. Since the X, Y, and Z components of the control margin are each reliably larger than the X component TX, Y component TY, and Z component TZ of tension T, the flight of the drone 10 can be feedback-controlled without running out of margin.

[0025] In the example described above, the mobile body moves along the track R on which the railway vehicle runs. However, in the present invention, the mobile body can move in any manner and is not limited to moving along the track R. The mobile body may, for example, move along a road, move freely on land, or move freely on the sea.

[0026] In the example described above, a trolley 20 was used as an example of a mobile body, but in the present invention, the mobile body can be any movable object and is not limited to a trolley 20. The mobile body may be, for example, a powered mobile body or an unpowered mobile body. For example, the mobile body may be able to move on a railway track R or the like, or it may be able to move on a railway track R or the like by being towed by a drone 10.

[0027] In the example described above, a drone 10 was used as an example of the flying object, but in the present invention, the flying object can be any flyable object and is not limited to a multi-rotor type drone 10. The drone 10 may be, for example, a fixed-wing type drone.

[0028] Figure 2 shows an example of the configuration of an aircraft. In Figure 2, an aircraft, which is a multi-rotor drone 10, is shown.

[0029] The aircraft 10 may include a control unit 100 and a tension sensor 110. The aircraft 10 may also include a propulsion mechanism 120. A cable 30 is connected to the aircraft 10, and the cable 30 is connected to the mobile body 20.

[0030] The tension sensor 110 is configured to detect the tension T applied to the cable 30. The tension sensor 110 can output the detected tension T to the control unit.

[0031] The propulsion mechanism 120 can be any mechanism that provides thrust to the aircraft 10. For example, if the aircraft 10 is a multi-rotor drone, the propulsion mechanism 120 can be multiple propellers. For example, if the aircraft 10 is a fixed-wing drone, the propulsion mechanism 120 may be multiple propellers or a jet engine. If the aircraft 10 is a fixed-wing drone, in addition to the propulsion mechanism 120, the aircraft 10 may be equipped with control surfaces for attitude control (e.g., ailerons, rudders, elevators, etc.).

[0032] The control unit 100 is configured to control the flight of the aircraft 10, and the control unit 100 may be a so-called flight controller. The control unit 100 may consist of, for example, a processor and memory. The processor reads a program stored in memory and executes that program. This makes it possible to make the control unit 100 function as a system that executes desired steps. The memory stores programs required to execute the processing of the control unit 100, and data required to execute those programs. The memory may also store a program that causes the processor to perform processing to control the flight of the aircraft (for example, a program that implements the processing shown in Figure 3, which will be described later). Here, it is not relevant how the program is stored in memory. For example, the program may be pre-installed in memory. Alternatively, the program may be stored in a non-transient computer-readable storage medium and installed by reading the storage medium, or it may be configured as a computer program product. Alternatively, the program may be installed in memory by being downloaded over a network.

[0033] For example, if the aircraft 10 is a multi-rotor drone having multiple propellers as a propulsion mechanism 120, the control unit 100 can control the flight of the aircraft 10 by controlling the multiple propellers as the propulsion mechanism 120. The control unit 100 can control six degrees of freedom (up-down, left-right, forward-backward, roll, pitch, and yaw) by controlling the rotation speed of the multiple propellers. For example, if the aircraft is a fixed-wing drone having fixed wings, the control unit 100 can control the flight of the aircraft 10 by, for example, controlling the propulsion mechanism and the control surfaces. The control unit 100 can control six degrees of freedom (up-down, left-right, forward-backward, roll, pitch, and yaw) by controlling the output of the propulsion mechanism and controlling the angle of the control surfaces.

[0034] The control unit 100 has a maximum control force Umax. The maximum control force Umax is the maximum force available to control the flight of the aircraft 10 and may be determined by the specifications of the aircraft. The maximum control force Umax may be, for example, the maximum output of the propulsion mechanism 120, or a value dependent on the maximum output. If the control unit 10 attempts to control the aircraft 10 with a force exceeding the maximum control force Umax, the aircraft 10 will become uncontrollable; therefore, the control unit 10 must control the aircraft 10 with a control force less than or equal to the maximum control force Umax. The control force Uc (Uc ≤ Umax) for controlling the aircraft at time t is: Uc(t) = Ud(t) + Uf(t) + Ut(t) This is expressed as follows: Ud is the control force necessary to stabilize the aircraft 10 against disturbances, etc. (disturbance-resistant control force), Uf is the control force necessary to control the aircraft 10 toward a target value (target-following control force), and Ut is the control force to counteract tension.

[0035] The control force Ut(t) to counteract tension is, Ut(t)=Uc(t)-Ud(t)-Uf(t) It is expressed as follows, and Uc(t) is at most Umax, Utmax(t) = Umax - Ud(t) - Uf(t) Therefore, Utmax is the maximum control force to counteract the tension. Utmax can also be said to be the control margin U provided by the control unit 100.

[0036] The control unit 100 determines whether the tension T detected by the tension sensor is greater than or equal to a threshold, and in response to determining that the tension T is greater than or equal to the threshold, controls the flight of the aircraft 10 so that the tension T becomes less than the threshold. As described above, with a control force less than or equal to Utmax, the control unit 100 controls the flight of the aircraft 10 so that the tension T becomes less than the threshold. Therefore, the tension T must be sufficiently smaller than Utmax. To ensure this, the threshold is a function of Utmax (= control margin U), and specifically, the threshold can be expressed as α × U (where α is a positive number less than 1). Preferably, α = 0.5, 0.4, 0.3, or 0.2, and more preferably, 0.2 ≤ α ≤ 0.3.

[0037] In one embodiment, when tension T and control force Uc are considered within the vertical plane to which tension T belongs, the control unit 100 determines whether the horizontal component Tx of tension T is greater than or equal to a first threshold, and whether the vertical component Tz of tension T is greater than or equal to a second threshold. In response to the determination that the horizontal component Tx of tension T is greater than or equal to the first threshold or the vertical component Tz of tension T is greater than or equal to the second threshold, the control unit 100 controls the flight of the aircraft 10 such that the horizontal component Tx of tension T is less than the first threshold and the vertical component Tz of tension T is less than the second threshold.

[0038] The first threshold is a function of the horizontal control margin Ux, for example, the control margin Ux at time t is Ux(t) = Uxmax - Udx(t) - Ufx(t) The second threshold is expressed as follows: the second threshold is a function of the vertical control margin Uz, for example, the control margin Uz at time t is Uz(t) = Uzmax - Udz(t) - Ufz(t) This is expressed as follows: Uxmax is the maximum horizontal control force of the control unit 100, Uzmax is the maximum vertical control force of the control unit 100, Udx is the horizontal disturbance-counter control force, Udz is the vertical disturbance-counter control force, Ufx is the horizontal target-following control force, and Ufz is the vertical target-following control force.

[0039] The first threshold is, for example, α × Ux(t), and the second threshold is, for example, β × Uz(t). The control unit 100 controls the flight of the aircraft 10 such that the horizontal component of tension Tx < α × Ux(t) and the vertical component of tension Tz < β × Uz(t). Here, α and β are 0.5, 0.4, 0.3, or 0.2, and more preferably 0.2 ≤ α ≤ 0.3 and 0.2 ≤ β ≤ 0.3. The control unit 100 controls the flight of the aircraft 10 using Ux(t) and Uz(t).

[0040] In another embodiment, when the tension T and control force Uc are considered in a fixed XYZ coordinate system, the control unit 100 determines whether the X-direction component TX of tension T is greater than or equal to a threshold in the X direction, whether the Y-direction component TY of tension T is greater than or equal to a threshold in the Y direction, and whether the Z-direction component TZ of tension T is greater than or equal to a threshold in the Z direction. In response to the determination that the X-direction component TX of tension T is greater than or equal to a threshold in the X direction, or the Y-direction component TY of tension T is greater than or equal to a threshold in the Y direction, or the Z-direction component TZ of tension T is greater than or equal to a threshold in the Z direction, the control unit 100 controls the flight of the aircraft 10 such that the X-direction component TX of tension T is less than the threshold in the X direction, the Y-direction component TY of tension T is less than the threshold in the Y direction, and the Z-direction component TZ of tension T is less than the threshold in the Z direction.

[0041] The threshold in the X direction is a function of the control margin UX in the X direction, for example, the control margin UX at time t is: UX(t) = UXmax - UdX(t) - UfX(t) This is expressed as follows: The threshold in the Y direction is a function of the control margin UY in the Y direction, for example, the control margin UY at time t is UY(t) = UYmax - UdY(t) - UfY(t) is expressed as, and the threshold value in the Z direction is a function of the control margin UZ in the Z direction. For example, the control margin UZ at time t is UZ(t) = UZmax - UdZ(t) - UfZ(t) is expressed as. UXmax is the maximum control force in the X direction of the control unit 100, UYmax is the maximum control force in the Y direction of the control unit 100, UZmax is the maximum control force in the Z direction of the control unit 100, UdX is the disturbance opposing control force in the X direction, UdY is the disturbance opposing control force in the Y direction, UdZ is the disturbance opposing control force in the Z direction, UfX is the target tracking control force in the X direction, UfY is the target tracking control force in the Y direction, and UfZ is the target tracking control force in the Z direction.

[0042] The threshold value in the X direction is, for example, a×UX(t), the threshold value in the Y direction is, for example, b×UY(t), and the threshold value in the Z direction is, for example, c×UZ(t). The control unit 100 controls the flight of the flying object 10 so that the X - direction component TX of the tension T < a×UX(t), the Y - direction component TY of the tension T < b×UY(t), and the Z - direction component TZ of the tension T < c×UZ(t). Here, a, b, and c are 0.5, 0.4, 0.3, or 0.2, and more preferably, 0.2 ≤ a ≤ 0.3, 0.2 ≤ b ≤ 0.3, 0.2 ≤ c ≤ 0.3. The control unit 100 controls the flight of the flying object 10 using UX(t), UY(t), and UZ(t).

[0043] In the above - described example, it has been described that the control unit 100 is provided inside the flying object 10, but the present invention is not limited thereto. A system in which the control unit 100 is provided outside the flying object 10 and the flying object 10 is remotely controlled from the external control unit 100 is also within the scope of the present invention. In this case, the flying object 10 and the control unit 100 can communicate in any manner. For example, the flying object 10 and the control unit 100 may communicate wired (e.g., via the cable 30) or wirelessly.

[0044] In the example described above, the tension sensor 110 is provided inside the aircraft 10, but the present invention is not limited to this. Systems in which the tension sensor 110 is provided outside the aircraft 10 (i.e., on a moving body) are also within the scope of the present invention. For example, if the control unit 100 is inside the aircraft 10, the control unit 100 can communicate remotely with the tension sensor 110. For example, the control unit 100 may communicate with the tension sensor 110 via a wired connection (e.g., via a cable 30) or wirelessly.

[0045] Figure 3 is a flowchart showing an example of a process 300 for controlling the flight of an aircraft. The process 300 is performed by the control unit 100.

[0046] In step S301, the control unit 100 receives the output from the tension sensor 110. The control unit 301 may receive the output from the tension sensor 110 continuously or intermittently. When receiving the output intermittently, the output can be received at any time interval (for example, every 1 second, every 5 seconds, every 10 seconds, etc.).

[0047] In step S302, the control unit 100 determines whether the tension T received in step S301 is greater than or equal to a threshold. The threshold may be a function of the control margin of the control unit 100, and the control margin U(t) at time t is: U(t) = Umax - Ud(t) - Uf(t) The threshold can be expressed as α × Uc(t) (where α is a positive number less than 1). Therefore, the control unit 100 determines whether T(t) ≥ α × Uc(t). If it is determined that T(t) ≥ α × Uc(t) (Yes), control of the aircraft 10 to reduce the tension T is required, so the unit proceeds to step S303. If it is determined that T(t) < α × Uc(t) (No), control of the aircraft 10 to reduce the tension T is not required, so the unit returns to step S301 and continues to monitor the tension T.

[0048] In step S303, the control unit 100 controls the flight of the aircraft 10 so that the tension T is less than a threshold. The control unit 100 controls the flight of the aircraft 10 so that, for example, T(t) < α × Uc(t). The control unit 100 may, for example, control the propulsion mechanism 120, or control the propulsion mechanism 120 and the control surfaces.

[0049] The control unit 100 performs feedback control of the aircraft 10 by repeating steps S301 to S303, for example, until it determines No in step S302.

[0050] In the above embodiment in which the tension T and control force Uc are considered within the vertical plane to which the tension T belongs, in step S301, the control unit 100 receives the horizontal component Tx and the vertical component Tz of the tension T as output from the tension sensor 110.

[0051] In step S302, the control unit 100 determines whether the horizontal component Tx of tension T is greater than or equal to a first threshold (e.g., α × Ux(t)) and whether the vertical component Tz of tension T is greater than or equal to a second threshold (e.g., β × Uz(t)). If it is determined that the horizontal component Tx of tension T is greater than or equal to the first threshold or the vertical component Tz of tension T is greater than or equal to the second threshold, the process proceeds to step S303. If it is determined that the horizontal component Tx of tension T is less than the first threshold and the vertical component Tz of tension T is less than the second threshold, the process returns to step S301 and continues to monitor the tension T.

[0052] In step S303, the control unit 100 controls the flight of the aircraft 10 such that the horizontal component Tx of tension T is less than a first threshold and the vertical component Tz of tension T is less than a second threshold.

[0053] In the above embodiment in which the tension T and control force Uc are considered in a fixed XYZ coordinate system, in step S301, the control unit 100 receives the X-direction component TX, the Y-direction component TY, and the Z-direction component TZ of the tension T as outputs from the tension sensor 110.

[0054] In step S302, the control unit 100 determines whether the X-direction component TX of tension T is greater than or equal to the X-direction threshold (e.g., a × UX(t)), whether the Y-direction component TY of tension T is greater than or equal to the Y-direction threshold (e.g., b × UY(t)), and whether the Z-direction component TZ of tension T is greater than or equal to the Z-direction threshold (e.g., c × UZ(t)). If it is determined that the X-direction component TX of tension T is greater than or equal to the X-direction threshold, or the Y-direction component TY of tension T is greater than or equal to the Y-direction threshold, or the Z-direction component TZ of tension T is greater than or equal to the Z-direction threshold, the process proceeds to step S303. If it is determined that the X-direction component TX of tension T is less than the X-direction threshold, and the Y-direction component TY of tension T is less than the Y-direction threshold, and the Z-direction component TZ of tension T is less than the Z-direction threshold, the process returns to step S301 and continues to monitor tension T.

[0055] In step S303, the control unit 100 controls the flight of the aircraft 10 such that the X-direction component TX of tension T is less than the threshold in the X direction, the Y-direction component TY of tension T is less than the threshold in the Y direction, and the Z-direction component TZ of tension T is less than the threshold in the Z direction.

[0056] Referring to the example described above with reference to Figure 3, the processing of each step shown in Figure 3 can be realized by the processor and program stored in memory of the control unit 100, but the present invention is not limited thereto. At least one of the processing of each step shown in Figure 3 may be realized by a hardware configuration such as a control circuit.

[0057] The present invention is not limited to the embodiments described above. It is understood that the scope of the present invention should be interpreted solely by the claims. Those skilled in the art will understand that, based on the description of specific preferred embodiments of the present invention and common technical knowledge, an equivalent scope can be practiced. [Industrial applicability]

[0058] This invention is useful as it provides a system for controlling the flight of an aircraft. [Explanation of Symbols]

[0059] 10 flying objects 20 Mobile Units 30 Cables 100 Control Unit 110 Tension Sensor R Railway T tension

Claims

1. A system, wherein the system is Mobile and A flying object connected to the aforementioned moving body via a cable, A control unit that controls the flight of the aircraft, A tension sensor that detects the tension T applied to the cable and outputs the detected tension T to the control unit. Equipped with, The control unit, To determine whether the detected tension T is above a threshold, In response to determining that the detected tension T is greater than or equal to the threshold, the flight of the aircraft is controlled so that the detected tension T becomes less than the threshold. A system configured to perform the following actions.

2. The system according to claim 1, wherein the threshold is a function of the control margin of the control unit and changes over time.

3. Determining whether the detected tension T is above a threshold is: To determine whether the horizontal component Tx of the detected tension T is greater than or equal to a first threshold, To determine whether the vertical component Tz of the detected tension T is greater than or equal to a second threshold. Includes, In response to determining that the detected tension T is greater than or equal to the threshold, controlling the flight of the aircraft so that the detected tension T becomes less than the threshold is: The system according to claim 1, comprising determining that the horizontal component Tx of the detected tension T is greater than or equal to the first threshold, or determining that the vertical component Tz of the detected tension T is greater than or equal to the second threshold, and controlling the flight of the aircraft such that the horizontal component Tx of the detected tension T becomes less than the first threshold and the vertical component Tz of the detected tension T becomes less than the second threshold.

4. The system according to claim 3, wherein the first threshold is a function of the horizontal control margin Ux of the control unit, and the second threshold is a function of the vertical control margin Uz of the control unit.

5. The horizontal control margin Ux and the vertical control margin Uz change over time. Ux(t)=Uxmax-Udx(t)-Ufx(t) Uz(t)=Uzmax-Udz(t)-Ufz(t) Here, Uxmax is the maximum horizontal control force of the control unit, and Uzmax is the maximum vertical control force of the control unit. Udx is the horizontal control force for the aircraft to fly against disturbances, and Udz is the vertical control force for the aircraft to fly against disturbances. Ufx is the horizontal control force for the aircraft to fly in accordance with the target value, and Ufz is the vertical control force for the aircraft to fly in accordance with the target value. The system according to claim 4.

6. The system according to claim 5, wherein the first threshold is α × Ux(t), the second threshold is β × Uz(t), and 0.2 ≤ α ≤ 0.3 and 0.2 ≤ β ≤ 0.

3.

7. The system according to any one of claims 4 to 6, wherein controlling the flight of the aircraft such that the horizontal component Tx of the detected tension T is less than the first threshold and the vertical component Tz of the detected tension T is less than the second threshold includes controlling the flight of the aircraft using the horizontal control margin Ux and the vertical control margin Uz.

8. The system according to claim 1, wherein the moving body is a trolley capable of moving along the railway tracks.

9. The system according to claim 8, wherein the aforementioned track is a track for a railway vehicle to run on.

10. The system according to claim 1, wherein the mobile body is a powered mobile body or an unpowered mobile body.

11. The cable in question is a power supply cable. The system according to claim 1, wherein the mobile body is equipped with a power supply device for supplying power to the flying body via the power supply cable.

12. An aircraft, wherein the aircraft is connected to a mobile body via a cable, and the aircraft is A control unit that controls the flight of the aircraft, A tension sensor that detects the tension T applied to the cable and outputs the detected tension T to the control unit. Equipped with, The control unit, To determine whether the detected tension T is above a threshold, In response to determining that the detected tension T is greater than or equal to the threshold, the flight of the aircraft is controlled so that the detected tension T becomes less than the threshold. An aircraft configured to perform the following actions.

13. A program for controlling an aircraft, wherein the aircraft is connected to a mobile body via a cable. The aforementioned flying object A control unit that controls the flight of the aircraft, A tension sensor that detects the tension T applied to the cable and outputs the detected tension T to the control unit. Equipped with, When the program is executed by the control unit, To determine whether the detected tension T is above a threshold, In response to determining that the detected tension T is greater than or equal to the threshold, the flight of the aircraft is controlled so that the detected tension T becomes less than the threshold. A program that causes the control unit to perform processing including the following.

14. A method for controlling an aircraft, wherein the aircraft is connected to a mobile body via a cable, The aforementioned flying object A control unit that controls the flight of the aircraft, A tension sensor that detects the tension T applied to the cable and outputs the detected tension T to the control unit. Equipped with, The above method is performed in the control unit, The aforementioned method, The control unit determines whether the detected tension T is equal to or greater than a threshold, In response to the control unit determining that the detected tension T is greater than or equal to the threshold, the control unit controls the flight of the aircraft so that the detected tension T becomes less than the threshold. Methods that include...

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