System, program, and method for controlling an air vehicle

Abstract

To provide a system for controlling an aircraft so as to enable the aircraft to fly stably when the aircraft is tethered by a cable. [Solution] The system of the present invention comprises a moving body, an aircraft connected to the moving body via a cable, a control unit that controls the flight of the aircraft, and a tension sensor that detects tension T applied to the cable and outputs the detected tension T to the control unit, wherein the control unit is configured to determine whether the detected tension T is greater than or equal to a threshold value, and in response to determining that the detected tension T is greater than or equal to the threshold value, control the flight of the aircraft so that the detected tension T is less than the threshold value.

Description

[Technical field]

[0001] The present invention relates to a system, a program, and a method for controlling an air vehicle. [Background technology]

[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 unmanned aerial vehicles are used to take photographs, perform safety monitoring, and perform inspections from the sky (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-176425 Summary of the Invention [Problem to be solved by the invention]

[0004] No-fly zones exist for aircraft, and they are also required to maintain a distance from people or objects. Therefore, in order to prevent unintentional incursion into no-fly zones or unintentional approach to people or objects, it is effective to tether the aircraft with a cable and limit the flight range. For example, it is possible to set up a tether point for the aircraft on a moving object, and in this case, the tether point moves together with the moving object, and the flight range of the aircraft also moves accordingly.

[0005] However, when an aircraft is tethered by a cable, the aircraft's freedom of flight may be unnecessarily hindered if the aircraft is pulled by the cable, and the aircraft may lose its balance, behave in an unexpected manner, and even crash. [Means for solving the problem]

[0006] The present invention provides a system for controlling an aircraft so as to enable stable flight of the aircraft when tethered by a cable. The present invention provides, for example, the following items. (Item 1) 1. A system comprising: A moving body, an aircraft connected to the moving body via a cable; A control unit that controls the flight of the aircraft; a tension sensor that detects a tension T applied to the cable and outputs the detected tension T to the control unit; Equipped with The control unit is determining whether the detected tension T is greater than or equal to a threshold; in response to determining that the detected tension T is greater than or equal to the threshold, controlling flight of the air vehicle such that the detected tension T is less than the threshold. A system configured to: (Item 2) The system described in the preceding item, wherein the threshold value is a function of a control margin of the control unit and changes over time. (Item 3) Determining whether the detected tension T is greater than or equal to a threshold value includes: determining whether a horizontal component Tx of the detected tension T is greater than or equal to a first threshold; determining whether a vertical component Tz of the detected tension T is greater than or equal to a second threshold; Including, In response to determining that the detected tension T is greater than or equal to the threshold, controlling flight of the air vehicle such that the detected tension T is less than the threshold. The system described in any one of the above items includes, in response to determining that a horizontal component Tx of the detected tension T is greater than or equal to the first threshold or determining that a vertical component Tz of the detected tension T is greater than or equal to the second threshold, controlling the flight of the aircraft so 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 preceding claims, wherein the first threshold is a function of a horizontal control margin Ux of the control unit, and the second threshold is a function of a 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) where Uxmax is the maximum horizontal control force of the control unit, Uzmax is the maximum vertical control force of the control unit, Udx is a horizontal control force for flying the aircraft against disturbances, and Udz is a vertical control force for flying the aircraft against disturbances, Ufx is a horizontal control force for the aircraft to fly in accordance with the target value, and Ufz is a vertical control force for the aircraft to fly in accordance with the target value. A system according to any one of the preceding claims. (Item 6) The system according to any one of the preceding claims, wherein the first threshold is α×Ux(t), the second threshold is β×Uz(t), 0.2≦α≦0.3, and 0.2≦β≦0.3. (Item 7) The system described in any one of the above items, wherein controlling the flight of the aircraft so 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. (Item 8) The system according to any one of the preceding claims, wherein the moving body is a bogie capable of moving on the track along the track. (Item 9) 2. The system according to claim 1, wherein the track is a track for running railway vehicles. (Item 10) The system according to any one of the preceding claims, wherein the vehicle is a powered vehicle or a non-powered vehicle. (Item 11) the cable is a power supply cable, The system according to any one of the preceding claims, wherein the moving body is equipped with a power supply device for supplying power to the flying body via the power supply cable. (Item 12) An aircraft is connected to a moving body via a cable, and the aircraft is A control unit that controls the flight of the aircraft; a tension sensor that detects a tension T applied to the cable and outputs the detected tension T to the control unit; Equipped with The control unit is determining whether the detected tension T is greater than or equal to a threshold; in response to determining that the detected tension T is greater than or equal to the threshold, controlling flight of the air vehicle such that the detected tension T is less than the threshold. The flying object is configured to perform the above. (Item 12A) Item 13. An aircraft as described in item 12, comprising the features as described in any one of the preceding items. (Item 13) A program for controlling an aircraft, the aircraft being connected to a moving body via a cable; The flying object is A control unit that controls the flight of the aircraft; a tension sensor that detects a 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, determining whether the detected tension T is greater than or equal to a threshold; in response to determining that the detected tension T is greater than or equal to the threshold, controlling flight of the air vehicle such that the detected tension T is less than the threshold. A program causing the control unit to perform a process including the steps of: (Item 13A) Item 14. A program according to item 13, comprising the features according to any one of the preceding 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) 1. A method for controlling an air vehicle, the air vehicle being coupled to a moving body via a cable; The flying object is A control unit that controls the flight of the aircraft; a tension sensor that detects a tension T applied to the cable and outputs the detected tension T to the control unit; Equipped with The method is executed in the control unit, The method comprises: The control unit determines whether the detected tension T is greater than or equal to a threshold; In response to the control unit determining that the detected tension T is equal to or greater than the threshold, controlling the flight of the aircraft so that the detected tension T is less than the threshold. A method comprising: (Item 14A) 15. The method according to claim 14, comprising the features according to any one of the preceding claims. Effect of the Invention

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

[0008] [Figure 1A] A diagram showing an example of how a railroad track is inspected using an aircraft tethered to a moving object by a cable. [Figure 1B] A diagram showing an example of how a railroad track is inspected using an aircraft tethered to a moving object by a cable. [Figure 1C] A diagram showing an example of how a railroad track is inspected using an aircraft tethered to a moving object by a cable. [Diagram 2] FIG. 1 is a diagram showing an example of a configuration of an aircraft; [Diagram 3] 1 is a flowchart illustrating an example of a process 300 for controlling the flight of an air vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] 1A to 1C show an example of how a track is inspected using an aircraft tethered to a moving body by a cable. In this example, a bogie 20 (moving body) moves along a track R on which railroad cars run, and a cable 30 connected to the bogie 20 is connected to a drone 10 (aircraft body). While flying, the drone 10 inspects the track R from the sky to see if there are any abnormalities.

[0011] For example, the drone 10 is equipped with a battery and can fly and perform inspections using power from the battery. Alternatively, the cable 30 can be a power supply cable, and the drone 10 can be powered from a power supply device provided in the dolly 20 via the power supply cable and can perform inspections using that power.

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

[0013] For example, as shown in Fig. 1A, when the cable 30 is slack, the drone 10 is not subjected to tension of the cable 30 or the tension of the cable 30 acting on the drone 10 is very small. Therefore, the drone 10 can fly freely without being affected by the cable 30.

[0014] 1B, when the cable 30 is taut, the drone 10 is subjected to a tension T of the cable 30, and the drone 10 is affected by the cable 30 and is prevented from flying freely. This can cause the attitude of the drone 10 to become unexpectedly unstable, and there is a risk of the drone 10 crashing.

[0015] In the present invention, the tension T of the cable 30 is monitored, and the drone 10 is feedback controlled to prevent the tension T from becoming too large, thereby allowing 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 value, and if the tension T is equal to or greater than the threshold value, the flight of the drone 10 is controlled so that the tension T is less than the threshold value. Preferably, the threshold value may be a value that varies over time. By setting the threshold value to a value that varies over time rather than a fixed value, the tension T can be set according to the flight situation, and a more free and unrestricted flight can be realized.

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

[0018] Since the tension T of the cable 30 is countered by the control margin, the control margin needs to be sufficiently larger than the tension T. To ensure this, the threshold value compared with the tension T can 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 can also prevent the drone 10 from becoming uncontrollable due to the tension T. This makes it possible to realize highly versatile drone control.

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

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

[0021] The flight of the drone 10 is controlled using the horizontal component of the control margin and the vertical component of the control margin so that the horizontal component Tx of the tension T is less than the first threshold value and the vertical component Tz of the tension T is less than the second threshold value. Since the horizontal component and the vertical component of the control margin are reliably greater than the horizontal component Tx and the vertical component Tz of the 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 as shown in the lower left of FIG. 1C (i.e., in a fixed coordinate system that does not depend on the position of the drone 10), and the X-direction component TX of the tension T is compared with a threshold in the X direction, the Y-direction component TY of the tension T is compared with a threshold in the Y direction, and the Z-direction component TZ of the tension T is compared with a threshold in the Z direction. Then, when the X-direction component TX of the tension T is equal to or greater than the threshold in the X direction, or the Y-direction component TY of the tension T is equal to or greater than the threshold in the Y direction, or the Z-direction component TZ of the tension T is equal to or greater than the threshold in the Z direction, the flight of the drone 10 is controlled so that the X-direction component TX of the tension T is less than the threshold in the X direction, the Y-direction component TY of the tension T is less than the threshold in the Y direction, and the Z-direction component TZ of the tension T is less than the threshold in the Z direction.

[0023] At this time, the above-mentioned control margin is also decomposed into an X-direction component, a Y-direction component, and a Z-direction component. Furthermore, the X-direction threshold value may be a function of the X-direction component of the control margin, the Y-direction threshold value may be a function of the Y-direction component of the control margin, and the Z-direction threshold value may be a function of the Z-direction component of the control margin.

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

[0025] In the above example, the moving body moves on the track R along the track R on which the railroad vehicles run, but in the present invention, the moving body can move in any manner and is not limited to moving along the track R. The moving body may, for example, move on a road along a road, or may move freely on the ground or over the sea.

[0026] In the above example, the dolly 20 is exemplified as the moving body, but in the present invention, the moving body may be any movable object and is not limited to the dolly 20. The moving body may be, for example, a powered moving body or a non-powered moving body. For example, the moving body may be capable of self-propelling on a track R or the like, or the moving body may be towed by the drone 10 and move on a track R or the like.

[0027] In the above example, the drone 10 is exemplified as an air vehicle, but in the present invention, the air vehicle may be any object capable of flight and is not limited to the multicopter type drone 10. The drone 10 may be, for example, a fixed-wing type drone.

[0028] Fig. 2 shows an example of a configuration of an aircraft, which is a multicopter type drone 10.

[0029] The flying object 10 may include a control unit 100 and a tension sensor 110. The flying object 10 may further include a propulsion mechanism 120. A cable 30 is connected to the flying object 10, and the cable 30 is connected to the moving object 20.

[0030] The tension sensor 110 is configured to detect a 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 may be any mechanism that provides propulsive force to the aircraft 10. For example, if the aircraft 10 is a multicopter drone, the propulsion mechanism 120 may 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, the aircraft 10 may be equipped with moving surfaces (e.g., ailerons, rudders, elevators, etc.) for attitude control in addition to the propulsion mechanism 120.

[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 be configured, for example, by a processor and a memory. The processor, for example, reads a program stored in the memory and executes the program. This allows the control unit 100 to function as a system that executes desired steps. The memory stores a program required to execute the processing of the control unit 100 and data required to execute the program. The memory may store a program for causing the processor to perform processing for controlling the flight of the aircraft (for example, a program for realizing the processing shown in FIG. 3 described later). Here, there is no restriction on how the program is stored in the memory. For example, the program may be pre-installed in the memory. Alternatively, the program may be stored in a non-transient computer-readable storage medium and installed by reading the storage medium, or may be configured as a computer program product. Alternatively, the program may be installed in the memory by being downloaded via a network.

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

[0034] The control unit 100 has a maximum control force Umax. The maximum control force Umax is the maximum force available for controlling 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 an attempt is made to control the aircraft 10 beyond the maximum control force Umax, the aircraft 10 will become uncontrollable, and therefore the control unit 10 must control the aircraft 10 with a control force equal to or less than the maximum control force Umax. The control force Uc (Uc≦Umax) for controlling the aircraft at time t is given by Uc(t)=Ud(t)+Uf(t)+Ut(t) where Ud is the control force required to stabilize the aircraft 10 against disturbances etc. (disturbance-facing control force), Uf is the control force required to control the aircraft 10 toward the target value (target tracking control force), and Ut is the control force for countering tension.

[0035] The control force Ut(t) to counter the tension is Ut(t)=Uc(t)-Ud(t)-Uf(t) Since Uc(t) is at most Umax, Utmax(t)=Umax-Ud(t)-Uf(t) where Utmax is the maximum control force to counter the tension. Utmax can also be said to be the control margin U by the control unit 100.

[0036] The control unit 100 determines whether the tension T detected by the tension sensor is equal to or greater than a threshold, and in response to determining that the tension T is equal to or greater than the threshold, controls the flight of the aircraft 10 so that the tension T is less than the threshold. As described above, with a control force equal to or less than Utmax, the control unit 100 controls the flight of the aircraft 10 so that the tension T is less than the threshold. Therefore, the tension T needs to 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 (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 the tension T and the control force Uc are considered within the vertical plane to which the tension T belongs, the control unit 100 determines whether the horizontal component Tx of the tension T is greater than or equal to a first threshold, determines whether the vertical component Tz of the tension T is greater than or equal to a second threshold, and, in response to determining that the horizontal component Tx of the tension T is greater than or equal to the first threshold or the vertical component Tz of the tension T is greater than or equal to the second threshold, controls the flight of the aircraft 10 so that the horizontal component Tx of the tension T is less than the first threshold and the vertical component Tz of the 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 expressed as follows: Ux(t) = Uxmax - Udx(t) - Ufx(t) The second threshold is a function of the vertical control margin Uz. For example, the control margin Uz at time t is expressed as follows: Uz(t) = Uzmax - Udz(t) - Ufz(t) Uxmax is the maximum control force of the control unit 100 in the horizontal direction, Uzmax is the maximum control force of the control unit 100 in the vertical direction, Udx is the disturbance facing control force in the horizontal direction, Udz is the disturbance facing control force in the vertical direction, Ufx is the target tracking control force in the horizontal direction, and Ufz is the target tracking control force in the vertical direction.

[0039] The first threshold is, for example, α×Ux(t), and the second threshold is, for example, β×Uz(t), and the control unit 100 controls the flight of the aircraft 10 so that the horizontal component of the tension T is Tx<α×Ux(t) and the vertical component of the tension T is Tz<β×Uz(t). Here, α and β can be 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 the control force Uc are considered in a fixed coordinate system of XYZ, the control unit 100 determines whether the X-direction component TX of the tension T is greater than or equal to a threshold in the X direction, determines whether the Y-direction component TY of the tension T is greater than or equal to a threshold in the Y direction, and determines whether the Z-direction component TZ of the tension T is greater than or equal to a threshold in the Z direction; and, in response to determining that the X-direction component TX of the tension T is greater than or equal to the threshold in the X direction or the Y-direction component TY of the tension T is greater than or equal to the threshold in the Y direction, or the Z-direction component TZ of the tension T is greater than or equal to the threshold in the Z direction, controls the flight of the flying body 10 so that the X-direction component TX of the tension T is less than the threshold in the X direction, and the Y-direction component TY of the tension T is less than the threshold in the Y direction, and the Z-direction component TZ of the 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) The threshold value 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 expressed as follows: 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 counteracting control force in the X direction, UdY is the disturbance counteracting control force in the Y direction, UdZ is the disturbance counteracting 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 aircraft 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, and 0.2 ≤ c ≤ 0.3. The control unit 100 controls the flight of the aircraft 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 aircraft 10, but the present invention is not limited thereto. A system in which the control unit 100 is provided outside the aircraft 10 and the aircraft 10 is remotely controlled by the external control unit 100 is also within the scope of the present invention. In this case, the aircraft 10 and the control unit 100 can communicate in any manner. For example, the aircraft 10 and the control unit 100 may communicate wired (e.g., via the cable 30) or wirelessly.

[0044] In the above example, the tension sensor 110 is described as being provided inside the flying object 10, but the present invention is not limited thereto. A system in which the tension sensor 110 is provided outside the flying object 10 (i.e., on a moving object) is also within the scope of the present invention. For example, when the control unit 100 is inside the flying object 10, the control unit 100 may remotely communicate with the tension sensor 110. For example, the control unit 100 may communicate with the tension sensor 110 in a wired manner (e.g., via the cable 30) or wirelessly.

[0045] 3 is a flowchart showing an example of a process 300 for controlling the flight of an aircraft. The process 300 is executed 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, 1 second intervals, 5 second intervals, 10 second intervals, etc.).

[0047] In step S302, the control unit 100 determines whether the tension T received in step S301 is equal to or greater than 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 expressed as follows: U(t) = Umax - Ud(t) - Uf(t) and the threshold value can be expressed as α×Uc(t) (α is a positive number less than 1). Therefore, the control unit 100 judges whether T(t)≧α×Uc(t). If it is judged that T(t)≧α×Uc(t) (Yes), control of the aircraft 10 to reduce the tension T is necessary, and so the process proceeds to step S303. If it is judged that T(t)<α×Uc(t) (No), control of the aircraft 10 to reduce the tension T is not necessary, and so the process returns to step S301, and the tension T continues to be monitored.

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

[0049] The control unit 100 performs feedback control of the flying object 10 by repeating steps S301 to S303, for example, until a No determination is made in step S302.

[0050] In the above-described embodiment in which the tension T and the 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 outputs from the tension sensor 110.

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

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

[0053] In the above-described embodiment in which the tension T and the control force Uc are considered in a fixed coordinate system of XYZ, 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 the tension T is equal to or greater than the X-direction threshold (e.g., a×UX(t)), whether the Y-direction component TY of the tension T is equal to or greater than the Y-direction threshold (e.g., b×UY(t)), and whether the Z-direction component TZ of the tension T is equal to or greater than the Z-direction threshold (e.g., c×UZ(t)). If it is determined that the X-direction component TX of the tension T is equal to or greater than the X-direction threshold, or the Y-direction component TY of the tension T is equal to or greater than the Y-direction threshold, or the Z-direction component TZ of the tension T is equal to or greater than the Z-direction threshold, the process proceeds to step S303. If it is determined that the X-direction component TX of the tension T is less than the X-direction threshold, and the Y-direction component TY of the tension T is less than the Y-direction threshold, and the Z-direction component TZ of the tension T is less than the Z-direction threshold, the process returns to step S301, and the tension T continues to be monitored.

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

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

[0057] The present invention is not limited to the above-mentioned embodiment. It is understood that the scope of the present invention should be interpreted only by the claims. It is understood that a person skilled in the art can implement an equivalent scope based on the description of the present invention and technical common sense from the description of the specific preferred embodiment of the present invention. [Industrial Applicability]

[0058] The present invention is useful for providing a system for controlling the flight of an aircraft, etc. [Explanation of symbols]

[0059] 10 Flying Objects 20 Mobile 30 Cable 100 Control section 110 Tension sensor R Rail T tension

Claims

1. 1. A system comprising: A moving body, an aircraft connected to the moving body via a cable; A control unit that controls the flight of the aircraft; a tension sensor that detects a tension T applied to the cable and outputs the detected tension T to the control unit; Equipped with The control unit is determining whether a horizontal component Tx of the detected tension T is greater than or equal to a first threshold; determining whether a vertical component Tz of the detected tension T is greater than or equal to a second threshold; in response to determining that a horizontal component Tx of the detected tension T is equal to or greater than the first threshold or determining that a vertical component Tz of the detected tension T is equal to or greater than the second threshold, controlling 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; the first threshold is a function of a time-varying control margin Ux(t) of the control unit in a horizontal direction, the first threshold being expressed as α×Ux(t); the second threshold is a function of a time-varying control margin Uz(t) of the control unit in a vertical direction, the second threshold being expressed as β×Uz(t), 0.2≦α≦0.3 and 0.2≦β≦0.3; The horizontal control margin Ux(t) and the vertical control margin Uz(t) are expressed as follows: Ux(t)=Uxmax-Udx(t)-Ufx(t) Uz(t)=Uzmax-Udz(t)-Ufz(t) where Uxmax is the maximum horizontal control force of the control unit, Uzmax is the maximum vertical control force of the control unit, Udx is a horizontal control force for flying the aircraft against disturbances, and Udz is a vertical control force for flying the aircraft against disturbances, A system in which Ufx is a horizontal control force for causing the aircraft to fly in a manner that tracks a target value, and Ufz is a vertical control force for causing the aircraft to fly in a manner that tracks a target value.

2. The system of claim 1, wherein controlling the flight of the aircraft so that a horizontal component Tx of the detected tension T is less than the first threshold and a 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.

3. The system of claim 1 , wherein the moving object is a cart capable of moving on the track along the track.

4. The system of claim 3 , wherein the track is a track for running rail vehicles.

5. The system of claim 1 , wherein the vehicle is a powered vehicle or a non-powered vehicle.

6. the cable is a power supply cable, The system according to claim 1 , wherein the moving body includes a power supply device for supplying power to the flying body via the power supply cable.

7. An aircraft is connected to a moving body via a cable, and the aircraft is A control unit that controls the flight of the aircraft; a tension sensor that detects a tension T applied to the cable and outputs the detected tension T to the control unit; Equipped with The control unit is determining whether a horizontal component Tx of the detected tension T is greater than or equal to a first threshold; determining whether a vertical component Tz of the detected tension T is greater than or equal to a second threshold; in response to determining that a horizontal component Tx of the detected tension T is equal to or greater than the first threshold or determining that a vertical component Tz of the detected tension T is equal to or greater than the second threshold, controlling 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; the first threshold is a function of a time-varying control margin Ux(t) of the control unit in a horizontal direction, the first threshold being expressed as α×Ux(t); the second threshold is a function of a time-varying control margin Uz(t) of the control unit in a vertical direction, the second threshold being expressed as β×Uz(t), 0.2≦α≦0.3 and 0.2≦β≦0.3; The horizontal control margin Ux(t) and the vertical control margin Uz(t) are expressed as follows: Ux(t)=Uxmax-Udx(t)-Ufx(t) Uz(t)=Uzmax-Udz(t)-Ufz(t) where Uxmax is the maximum horizontal control force of the control unit, Uzmax is the maximum vertical control force of the control unit, Udx is a horizontal control force for flying the aircraft against disturbances, and Udz is a vertical control force for flying the aircraft against disturbances, An aircraft, wherein Ufx is a horizontal control force for causing the aircraft to fly in a manner that tracks a target value, and Ufz is a vertical control force for causing the aircraft to fly in a manner that tracks a target value.

8. A program for controlling an aircraft, the aircraft being connected to a moving body via a cable; The flying object is A control unit that controls the flight of the aircraft; a tension sensor that detects a 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, determining whether a horizontal component Tx of the detected tension T is greater than or equal to a first threshold; determining whether a vertical component Tz of the detected tension T is greater than or equal to a second threshold; in response to determining that a horizontal component Tx of the detected tension T is equal to or greater than the first threshold or determining that a vertical component Tz of the detected tension T is equal to or greater than the second threshold, controlling 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; the first threshold is a function of a horizontal control margin Ux(t) of the control unit which changes over time, the first threshold being expressed as α×Ux(t); the second threshold is a function of a vertical control margin Uz(t) of the control unit which changes over time, the second threshold being expressed as β×Uz(t), 0.2≦α≦0.3 and 0.2≦β≦0.3; The horizontal control margin Ux(t) and the vertical control margin Uz(t) are expressed as follows: Ux(t)=Uxmax-Udx(t)-Ufx(t) Uz(t)=Uzmax-Udz(t)-Ufz(t) where Uxmax is the maximum horizontal control force of the control unit, Uzmax is the maximum vertical control force of the control unit, Udx is a horizontal control force for flying the aircraft against disturbances, and Udz is a vertical control force for flying the aircraft against disturbances, A program, wherein Ufx is a horizontal control force for causing the aircraft to fly in a manner that tracks a target value, and Ufz is a vertical control force for causing the aircraft to fly in a manner that tracks a target value.

9. 1. A method for controlling an air vehicle, the air vehicle being coupled to a moving body via a cable; The flying object is A control unit that controls the flight of the aircraft; a tension sensor that detects a tension T applied to the cable and outputs the detected tension T to the control unit; Equipped with The method is executed in the control unit, The method comprises: The control unit determines whether a horizontal component Tx of the detected tension T is greater than or equal to a first threshold; The control unit determines whether a vertical component Tz of the detected tension T is greater than or equal to a second threshold; in response to the control unit determining that a horizontal component Tx of the detected tension T is equal to or greater than the first threshold value, or determining that a vertical component Tz of the detected tension T is equal to or greater than the second threshold value, controlling the flight of the aircraft 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; the first threshold is a function of a horizontal control margin Ux(t) of the control unit that changes over time, and the first threshold is expressed as α×Ux(t); the second threshold is a function of a vertical control margin Uz(t) of the control unit that changes over time, and the second threshold is expressed as β×Uz(t), where 0.2≦α≦0.3 and 0.2≦β≦0.3; The horizontal control margin Ux(t) and the vertical control margin Uz(t) are expressed as follows: Ux(t)=Uxmax-Udx(t)-Ufx(t) Uz(t)=Uzmax-Udz(t)-Ufz(t) where Uxmax is the maximum horizontal control force of the control unit, Uzmax is the maximum vertical control force of the control unit, Udx is a horizontal control force for flying the aircraft against disturbances, and Udz is a vertical control force for flying the aircraft against disturbances, A method according to claim 1, wherein Ufx is a horizontal control force for causing the flying object to fly in a manner that tracks a target value, and Ufz is a vertical control force for causing the flying object to fly in a manner that tracks a target value.

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