Control device and control system for unmanned aerial vehicle

Abstract

Provided is a control device for an unmanned aerial vehicle that conveys a work robot to a blade of a wind power generator by means of a hanging member having one end connected to the unmanned aerial vehicle and the other end connected to the work robot. The control device outputs: a first control signal for moving the unmanned aerial vehicle such that the one end of the hanging member is positioned at a predetermined access point upwind and above the blade; a second control signal for horizontally moving the unmanned aerial vehicle in a direction approaching the blade from upwind such that the work robot is positioned directly above the blade; and a third control signal for moving the unmanned aerial vehicle downward such that the work robot is positioned on the blade.

Description

Control device and control system for unmanned aerial vehicle

[0001] The present disclosure relates to a control device and a control system for an unmanned aerial vehicle.

[0002] Patent Document 1 discloses that in order to repair blades of a wind turbine generator by a robot maintenance device, the robot maintenance device is suspended from an unmanned aerial vehicle, conveyed, and moved to a work position on the blade of the wind turbine generator.

[0003] International Publication No. 2023 / 280360

[0004] Wind turbine generators are generally installed in places with high wind speed. For this reason, when a work robot that performs operations such as cleaning and maintenance on the blades of a wind turbine generator is suspended from an unmanned aerial vehicle and conveyed, when the work robot suspended from the unmanned aerial vehicle is placed on the blade, the work robot may move with changes in wind conditions and collide with the blade of the wind turbine generator.

[0005] An object of the present disclosure is to provide a control device and a control system for an unmanned aerial vehicle that can place a work robot suspended from the unmanned aerial vehicle on the blade of a wind turbine generator while suppressing collision of the work robot with the blade.

[0006] The present disclosure is a control device for an unmanned aerial vehicle that conveys a work robot to a blade of a wind turbine generator by suspending the work robot via a suspension member having one end connected to the unmanned aerial vehicle and the other end connected to the work robot, wherein the control device outputs: a first control signal for moving the unmanned aerial vehicle such that the one end of the suspension member is located at a predetermined access point windward and above the blade; a second control signal for horizontally moving the unmanned aerial vehicle in a direction approaching the blade from the windward side so as to arrange the work robot directly above the blade; and a third control signal for moving the unmanned aerial vehicle downward so as to arrange the work robot on the blade.

[0007] The disclosure also provides a control system for an unmanned aerial vehicle that suspends a work robot and transports it to the blades of a wind turbine, comprising: a work robot; an unmanned aerial vehicle that suspends the work robot and transports it to the blades of a wind turbine; and a control device for the unmanned aerial vehicle that controls the unmanned aerial vehicle.

[0008] According to this disclosure, when transporting a work robot to the blades of a wind turbine by suspending it from an unmanned aerial vehicle, the unmanned aerial vehicle is moved horizontally from a predetermined access point upwind and above the blade, and then moved downward. Compared to the case where the predetermined access point is set downwind and above the blade, even if the wind conditions change and the wind speed decreases when the unmanned aerial vehicle is moved horizontally from the predetermined access point, it is possible to position the work robot on the blade while suppressing collision with the blade.

[0009] This is a schematic diagram of the control system for an unmanned aerial vehicle according to the first embodiment of this disclosure. This is a side view of the unmanned aerial vehicle and wind turbine at an access point. This is a top view of the unmanned aerial vehicle and wind turbine at an access point. This is a side view of the unmanned aerial vehicle and wind turbine directly above the target. This is a side view of the unmanned aerial vehicle and wind turbine at the unloading position. This is a block diagram of the control system for an unmanned aerial vehicle. This is a flowchart illustrating the control of an unmanned aerial vehicle. This is a side view of the unmanned aerial vehicle and wind turbine at an access point in the control system for an unmanned aerial vehicle according to the second embodiment of this disclosure. This is a block diagram of the control system for an unmanned aerial vehicle according to the second embodiment of this disclosure. This is a side view of the unmanned aerial vehicle and wind turbine at an access point in the control system for an unmanned aerial vehicle according to the third embodiment of this disclosure.

[0010] The embodiments of this disclosure will be described below with reference to the attached drawings.

[0011] Figure 1 is a schematic diagram of the control system for an unmanned aerial vehicle according to the first embodiment of the present disclosure. The control system for an unmanned aerial vehicle according to the first embodiment of the present disclosure transports a work robot, which performs tasks such as cleaning and maintenance on the blades of a wind turbine, to the wind turbine blades by suspending it from the unmanned aerial vehicle using a suspension member, one end of which is connected to the unmanned aerial vehicle and the other end of which is connected to the work robot.

[0012] As shown in Figure 1, the unmanned aerial vehicle control system 1 includes a work robot 20 configured to perform tasks such as cleaning and maintenance on the blades 11 of the wind turbine 10, an unmanned aerial vehicle 30 that suspends the work robot 20 and transports it to the blades 11 of the wind turbine 10, and a control device 40 that controls the unmanned aerial vehicle 30 and the like. The control device 40 is located outside the unmanned aerial vehicle 30, away from the wind turbine 10, but it can also be located in other places, such as inside the body of the unmanned aerial vehicle 30.

[0013] The wind turbine 10 is installed in a location where there is a stable wind with high wind speed and a nearly constant wind direction. The wind turbine 10 comprises a tower 12 extending vertically, a nacelle 13 mounted on the top of the tower 12 and containing the generator and other components, and blades 11 rotatably supported on the nacelle 13. The wind turbine 10 is positioned so that the rotation surface of the blades 11 faces the wind in order to effectively receive wind flowing from upwind to downwind.

[0014] The blade 11 has multiple blades, such as three, and extends radially outward from the nacelle 13. The blade 11 is rotatably supported at the tip of the nacelle 13. The rotational position of the blade 11 is controlled and it is stopped in a horizontal position when work is performed by the work robot 20. The position on the blade 11 where the work robot 20 is positioned is set as the target position.

[0015] The work robot 20 is positioned, for example, at the tip of the blade 11 of the wind turbine 10 and is configured to perform tasks such as cleaning and maintenance of the blade 11. The work robot 20 is automatically controlled according to a predetermined program, but may also be operated manually by a user.

[0016] The unmanned aerial vehicle 30 is a so-called drone. The unmanned aerial vehicle 30 is a rotary-wing drone capable of horizontal movement including forward, backward, left, and right, as well as vertical movement. The unmanned aerial vehicle 30 may be other types of unmanned aerial vehicles, such as multirotor drones. The unmanned aerial vehicle 30 is automatically controlled by remote control or the like according to a predetermined program, but it may also be operated manually by a user by remote control or the like.

[0017] The unmanned aerial vehicle 30 comprises a main rotor 32 located on the upper part of the fuselage 31 and a tail rotor 33 located at the rear of the fuselage 31. The main rotor 32 and the tail rotor 33 are configured to allow control of their rotational speed and angle. The unmanned aerial vehicle 30 is equipped with actuators 34 that operate the main rotor 32 and the tail rotor 33 to move the unmanned aerial vehicle 30 horizontally and vertically. The actuators 34 may be one actuator or multiple actuators.

[0018] The position of the unmanned aerial vehicle 30 is adjusted by actuators 34, and its position is adjusted in the vertical direction, the wind direction, and in directions perpendicular to the vertical direction and the wind direction. The position of the work robot 20 is adjusted in accordance with the position of the unmanned aerial vehicle 30. The unmanned aerial vehicle 30 is configured to transport the work robot 20, which has a weight of, for example, 200 kg.

[0019] The unmanned aerial vehicle 30 suspends a work robot 20, for example, from a storage location, via a suspension device 50, and positions it above the blades 11 of the wind turbine generator 10. The suspension device 50 comprises a support cable 51 as a suspension member 51 and a coupling device 52. One end of the support cable 51 is fixed to the unmanned aerial vehicle 30, and the other end is coupled to the work robot 20. The support cable 51 is a metal cable, but it may be a cable made of other materials such as a resin cable. Other members such as ropes or slings can also be used as suspension members.

[0020] The coupling device 52 detachably connects to the work robot 20. The coupling device 52 is provided between the other end of the support cable 51 and the work robot 20 and is configured to detachably connect the work robot 20 to the support cable 51. Specifically, the suspension device 50, including the coupling device 52, may be automatically controlled by remote operation or the like according to a predetermined program, or it may be manually operated by a user by remote operation or the like.

[0021] The coupling device 52 may include, for example, a hook portion rotatably provided at the other end of the support cable 51 and a shaft portion provided on the work robot 20 and coupled to the hook portion, and the hook portion may be configured to be detachably coupled to the shaft portion. The coupling device 52 connects the work robot 20 to the support cable 51 by coupling the hook portion and the shaft portion, and disconnects the work robot 20 from the support cable 51 by releasing the coupling between the hook portion and the shaft portion. Other coupling devices can be used as long as the coupled state and the released state can be switched.

[0022] The control device 40 controls the unmanned aerial vehicle 30 and the coupling device 52, etc. When transporting the work robot 20 to the blade 11 of the wind turbine 10, the control device 40 moves the unmanned aerial vehicle 30, specifically, so that one end of the support cable 51 is positioned upwind and above a predetermined access point of the blade 11. Next, the control device 40 moves the unmanned aerial vehicle 30 horizontally from upwind towards the blade 11 so that the work robot 20 is positioned directly above the blade 11. After that, the control device 40 moves the unmanned aerial vehicle 30 downward so that the work robot 20 is positioned on the blade 11.

[0023] Figure 2 is a side view of the unmanned aerial vehicle and wind turbine at the access point. As shown in Figure 2, when transporting the work robot 20 to the blade 11 of the wind turbine 10, the unmanned aerial vehicle 30, which is suspending the work robot 20, is moved by control of the control device 40 to the access point P1, which is set to be upwind and above the horizontal blade 11. The position of the unmanned aerial vehicle 30 is set, for example, as the position where one end of the support cable 51 is fixed.

[0024] The work robot 20 is coupled to the support cable 51 and swings in accordance with the wind speed between a first position P11 where the other end of the support cable 51 extends vertically at zero wind speed and a second position P12 where the other end of the support cable 51 extends in the direction of the maximum allowable inclination angle θm relative to the vertical at the maximum allowable wind speed. The maximum allowable inclination angle θm of the support cable 51 is set to, for example, 15 degrees.

[0025] Access point P1 is set at a position where the blade 11 is not within the swing range in which the work robot 20 suspended from the unmanned aerial vehicle 30 is swung by the wind. The position where the blade 11 is not within the swing range in which the work robot 20 is swung by the wind is a position where the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11 is downwind and below the swing range S between the first position P11 and the second position P12 in which the other end of the support cable 51 fixed to the unmanned aerial vehicle 30 at access point P1 swings.

[0026] The access point P1 is set so that there is at least a predetermined distance in the height direction between the lower end of the swing range in which the work robot 20 swings and the blade 11. The distance in the height direction between the lower end of the swing range in which the work robot 20 swings and the blade 11 is equal to the distance in the height direction between the swing range S in which the other end of the support cable 51 swings and the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11.

[0027] Access point P1 is set to have at least a predetermined distance in the height direction between the swing range S in which the other end of the support cable 51 swings and the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11. When the other end of the support cable 51 is in the first position P11, it is set to have a predetermined distance H1 in the height direction between it and the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11. The predetermined distance H1 is set to, for example, 1m to 2m.

[0028] The other end of the support cable 51 supporting the work robot 20 is swayed by the wind speed, and the amplitude of the sway increases, causing it to rise in the height direction. Therefore, the predetermined interval is set to a first interval when there is a first wind speed, and to a second interval which is larger than the first interval when there is a second wind speed which is greater than the first wind speed.

[0029] Access point P1 is also set to have a predetermined distance in the wind direction between the swing range in which the work robot 20 swings and the blade 11, and is set to have a predetermined distance W1 in the wind direction between the other end of the support cable 51 and the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11, when the other end of the support cable 51 is in the second position P12. Access point P1 may be in the wind direction equal to the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11, when the other end of the support cable 51 is in the second position P12. The predetermined distance W1 is set to, for example, 1 m to 2 m.

[0030] As shown in Figure 2, the control system 1 for the unmanned aerial vehicle includes a position detection sensor 45 for detecting the position of the unmanned aerial vehicle 30 and a wind detection sensor 46 for detecting wind conditions. The position detection sensor 45 can be, for example, a position detection sensor using GPS radio waves. Position accuracy can be improved by using an inertial sensor or an optical sensor as the position detection sensor 45. The wind detection sensor 46 can be, for example, a wind speed sensor for detecting wind speed. The wind detection sensor 46 may be, for example, one that detects wind speed and wind direction. The position detection sensor 45 and the wind detection sensor 46 may be provided on the unmanned aerial vehicle 30 or on something other than the unmanned aerial vehicle 30.

[0031] Figure 3 is a top view of the unmanned aerial vehicle and wind turbine at the access point. As shown by the dashed line in Figure 3, in this embodiment, a target position Pt is set on the tip 11a of the blade 11 where the work robot 20 is positioned. For example, the access point P1 is set at the same position Pe as the other end of the support cable 51 when the work robot 20 is positioned on the tip 11a of the blade 11, in a direction perpendicular to the wind direction and the vertical direction, and is set on the same plane defined by the wind direction and the vertical direction.

[0032] For example, a work robot 20 positioned at the tip 11a of the blade 11 is configured to perform cleaning and maintenance on the blade 11 while moving from the tip 11a to the base 11b of the blade 11. The tip 11a of the blade 11 is closer to the tip than the longitudinal center 11c of the blade 11, and the base 11b of the blade 11 is closer to the nacelle 13 than the longitudinal center 11c of the blade 11. As an example, the work robot 20 may be positioned in a range of one-third or one-quarter of the longitudinal length from the tip of the blade 11. The work robot 20 may be positioned in other parts of the blade 11 depending on the area on which maintenance and / or cleaning is required.

[0033] In this embodiment, the access point P1 is set upwind and above the blades 11 of the wind turbine 10, which are positioned to receive wind from the front, that is, upwind and above the blades 11 of the wind turbine 10, which are positioned perpendicular to the wind direction and extending horizontally.

[0034] Figure 4 is a side view of the unmanned aerial vehicle and wind turbine located directly above the target. After the unmanned aerial vehicle 30 is moved to access point P1, as shown in Figure 4, it is moved horizontally from upwind towards the blade 11 under the control of the control device 40 so that the work robot 20 is positioned directly above the blade 11.

[0035] The unmanned aerial vehicle 30 is moved horizontally from access point P1 to target-directly-above position P2, where the work robot 20 is directly above the blade 11. Target-directly-above position P2 is set so that the position P13 of the other end of the support cable 51 is directly above the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11. When the unmanned aerial vehicle 30 is moved horizontally to target-directly-above position P2, the position P13 of the other end of the support cable 51 is directly above the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11. Target-directly-above position P2 changes according to the wind speed, and the distance that the unmanned aerial vehicle 30 moves horizontally from access point P1 changes according to the wind speed. The distance that the unmanned aerial vehicle 30 moves from access point P1 to target-directly-above position P2 is smaller when the wind speed is high compared to when the wind speed is low.

[0036] Figure 5 is a side view of the unmanned aerial vehicle and wind turbine at the unloading position. The unmanned aerial vehicle 30 is moved to the position P2 directly above the target, and then moved downward as shown in Figure 5 to position the work robot 20 on the blade 11. The unmanned aerial vehicle 30 is moved downward from the position P2 directly above the target to the unloading position P3 where the work robot 20 is positioned on the blade 11. The unloading position P3 is set so that the position P13 of the other end of the support cable 51 becomes the position Pe of the other end of the support cable 51 when the work robot 20 is positioned on the blade 11.

[0037] When the unmanned aerial vehicle 30 moves from access point P1 to position P2 directly above the target, the distance between the work robot 20 and the blade 11 in the vertical direction increases as the wind speed increases from zero. Therefore, even when the wind speed decreases due to a change in wind conditions and the work robot 20 moves, collisions with the blade 11 can be suppressed according to the wind speed.

[0038] If the access point is set downwind and above the blade 11, when the unmanned aerial vehicle 30 is moved horizontally from the access point to the target position P2, approaching the blade 11 from downwind, so that the work robot 20 is positioned directly above the blade 11, if the wind speed decreases due to a change in wind conditions, the work robot 20 may move downwards as it moves towards the blade 11, and there is a risk that the work robot 20 will collide with the blade 11.

[0039] In this embodiment, when transporting the work robot 20 to the blade 11 of the wind turbine generator 10 by suspending it from the unmanned aerial vehicle 30, the unmanned aerial vehicle 20 is moved horizontally from an access point P1 that is upwind and above the blade 11, and then moved downwards. Compared to the case where the access point is set downwind and above the blade 11, even if the wind conditions change and the wind speed decreases when the unmanned aerial vehicle 30 is moved horizontally from the access point P1, the work robot 20 can be positioned on the blade while suppressing the risk of collision with the blade 11.

[0040] Figure 6 is a block diagram of the control system for an unmanned aerial vehicle. As shown in Figure 6, the unmanned aerial vehicle control system 1 includes a work robot 20, an unmanned aerial vehicle 30 that suspends the work robot 20 and transports it to the blades 11 of the wind turbine 10, and an unmanned aerial vehicle control device 40 that controls the unmanned aerial vehicle 30 and the like. The control device 40 controls the unmanned aerial vehicle 30 and also controls the coupling device 52 and the like.

[0041] The control device 40 includes a control unit 41 that controls the operation of the unmanned aerial vehicle 30, coupling device 52, etc. by executing a predetermined program; a storage unit 42 that stores a program for controlling the operation of the unmanned aerial vehicle 30 and coupling device 52, etc. in order to transport the work robot 20 onto the blade 11, as well as data such as access point P1, target directly above position P2, and unloading position P3; an input / output unit 43 that inputs data such as access point P1, target directly above position P2, and unloading position P3 and outputs it to a display device, etc.; and a transmitting / receiving unit 44 that transmits and receives data between the unmanned aerial vehicle 30, coupling device 52, position detection sensor 45, wind detection sensor 46, etc.

[0042] The control device 40 receives the position and wind speed of the unmanned aerial vehicle 30, as detected by the position detection sensor 45 and the wind detection sensor 46, as input to the transmitting / receiving unit 44 of the control device 40 using wireless communication or the like. The control device 40 is configured, for example, with a microcomputer as its main component. The control unit 41 includes an arithmetic processing unit, the storage unit 42 includes a storage device, the input / output unit 43 includes an input / output device, and the transmitting / receiving unit 44 includes a transmitting / receiving device including a communication device. The control unit 41, storage unit 42, input / output unit 43, and transmitting / receiving unit 44 are interconnected.

[0043] When the control device 40 suspends the work robot 20 from the unmanned aerial vehicle 30 and transports it to the blade 11 of the wind turbine generator 10, it sequentially outputs the following control signals to the unmanned aerial vehicle 30 via the transmitting and receiving unit 44: a control signal to move the unmanned aerial vehicle 30 so that one end of the support cable 51 is located upwind and above the access point P1 of the blade 11; a control signal to move the unmanned aerial vehicle 30 horizontally from upwind towards the blade 11 so that the work robot 20 is positioned directly above the blade 11; and a control signal to move the unmanned aerial vehicle 30 downward so that the work robot 20 is positioned on the blade 11.

[0044] When the swing amplitude of the working robot 20 exceeds a predetermined threshold, the control device 40 also outputs a control signal to move the working robot 20 in a direction away from the blade 11. As the threshold for the swing amplitude of the working robot 20, for example, the allowable maximum inclination angle θm of the support cable 51 when the wind speed is at the allowable maximum wind speed is set.

[0045] For the unmanned aerial vehicle 30, the actuator 34 is controlled in response to a control signal from the control device 40. The coupling device 52 is also configured to be controlled in response to a control signal from the control device 40. When performing work, the working robot 20 may be operationally controlled in response to a control signal from the control device 40, or may be controlled using an operation device or the like separate from the control device 40.

[0046] FIG. 7 is a flowchart showing control of an unmanned aerial vehicle. When transporting the working robot 20 to the blade 11 of the wind turbine generator 10, first, the working robot 20 is suspended by the unmanned aerial vehicle 30 using the suspension device 50. Control of the unmanned aerial vehicle 30 that transports the working robot 20 suspended by the unmanned aerial vehicle 30 to the blade 11 of the wind turbine generator 10 is executed by the control device 40.

[0047] The control device 40 reads data of the access point P1, the position P2 directly above the target corresponding to the wind speed, and the unloading position P3, and also reads information such as data of the position and wind speed of the unmanned aerial vehicle 30 detected by the position detection sensor 45 and the wind detection sensor 46.

[0048] Then, as shown in FIG. 7, the control device 40 outputs a control signal to the unmanned aerial vehicle 30 with the working robot 20 suspended thereon, so that the unmanned aerial vehicle 30 is moved such that one end of the support cable 51 is located at the access point P1 which is on the windward side and above the blade 11 (step S1). In the unmanned aerial vehicle 30, the actuator 34 is operated according to the control signal, and the unmanned aerial vehicle 30 is moved to the access point P1. Whether the unmanned aerial vehicle 30 has moved to the access point P1 is determined based on the position of the unmanned aerial vehicle 30 detected by the position detection sensor 45.

[0049] When the unmanned aerial vehicle 30 is moved to access point P1, the control device 40 outputs a control signal that moves the unmanned aerial vehicle 30 horizontally from upwind towards the blade 11 so that the work robot 20 is positioned directly above the blade 11 (step S2). The actuator 34 of the unmanned aerial vehicle 30 is activated according to the control signal and the unmanned aerial vehicle 30 is moved horizontally to a position directly above the target P2 according to the wind speed. The position directly above the target P2 is set to a position that is further upwind from the blade 11 as the wind speed increases from zero. Whether or not the unmanned aerial vehicle 30 has moved to the position directly above the target P2 is determined by the position of the unmanned aerial vehicle 30 as detected by the position detection sensor 45.

[0050] When the unmanned aerial vehicle 30 moves to the position P2 directly above the target, the control device 40 outputs a control signal to move the unmanned aerial vehicle 30 downward to the unloading position P3 so that the work robot 20 is positioned on the blade 11 (step S3). The unmanned aerial vehicle 30 moves downward to the unloading position P3 as the actuator 34 is activated in accordance with the control signal. Whether or not the unmanned aerial vehicle 30 has moved to the unloading position P3 is determined by the position of the unmanned aerial vehicle 30 as determined by the position detection sensor 45.

[0051] When the unmanned aerial vehicle 30 is moved to the unloading position P3, the control device 40 outputs a control signal to disconnect the work robot 20 from the unmanned aerial vehicle 30 so that the coupling device 52 releases the coupling between the work robot 20 and the support cable 51 (step S4). The coupling device 52 releases the coupling between the work robot 20 and the support cable 51 in accordance with the control signal.

[0052] When the coupling device 52 releases the coupling between the work robot 20 and the support cable 51, the control device 40 outputs a control signal to move the unmanned aerial vehicle 30 to a safe position (not shown) located above the unloading position P3 so as to move away from the blades 11 of the wind turbine 10 (step S5). The actuator 34 of the unmanned aerial vehicle 30 is activated in accordance with the control signal and moved to the safe position located above the unloading position P3. The safe position is set to a predetermined position above the target position P2, for example, but it may also be set to a predetermined position upwind from the access point P1. In this way, the control device 40 controls the unmanned aerial vehicle 30 and the coupling device 52 to transport the work robot 20 to the blades 11 of the wind turbine 10.

[0053] The control device 40 also outputs a control signal to move the work robot 20 away from the blade 11 when the amplitude of the swing of the work robot 20 exceeds a predetermined threshold, i.e., when the wind speed exceeds the maximum allowable wind speed, while suspending the work robot 20 and transporting it to the blade 11 of the wind turbine 10. The unmanned aerial vehicle 30 is moved in accordance with the control signal by at least one upward movement and horizontal movement in the direction away from the blade 11.

[0054] Thus, in this embodiment, when the unmanned aerial vehicle 30 suspends the work robot 20 and transports it to the blade 11 of the wind turbine generator 10, it is moved horizontally from a predetermined access point P1 upwind and above the blade 11, and then moved downward. Compared to the case where the predetermined access point P1 is set downwind and above the blade 11, even if the wind conditions change and the wind speed decreases when the unmanned aerial vehicle 30 is moved horizontally from the predetermined access point P1, the work robot 20 can be positioned on the blade while suppressing collision with the blade 11.

[0055] Figure 8 is a side view of an unmanned transporter and a wind turbine at an access point in a control system for an unmanned aerial vehicle according to a second embodiment of the present disclosure. Figure 9 is a block diagram of the control system for the unmanned aerial vehicle. The control system for the unmanned aerial vehicle according to the second embodiment is the same as the control system for the unmanned aerial vehicle 1 according to the first embodiment, except that the unmanned aerial vehicle 30 is equipped with a collision avoidance device that moves the work robot 20 to avoid collision with the blade 11, so the description of the similar parts will be omitted.

[0056] As shown in Figure 8, in the control system for the unmanned aerial vehicle according to the second embodiment, the unmanned aerial vehicle 30 is equipped with a collision avoidance device 55 that moves the work robot 20 to avoid collision with the blade 11. As the collision avoidance device 55, a collision avoidance device can be used that adjusts the position of the work robot 20 and moves the work robot 20 to avoid collision with the blade 11 when predetermined conditions are met, for example, when the wind speed changes to above a threshold.

[0057] The collision avoidance device 55 is, for example, located at the other end of the support cable 51 and is configured to adjust the position of the work robot 20. The collision avoidance device 55 includes, for example, a fan 57 located inside a cylindrical duct 56, and is configured to adjust the position of the work robot 20 by generating thrust by rotating the fan 57.

[0058] As shown in Figure 9, in the unmanned aerial vehicle control system according to the second embodiment, the control device 40 outputs a control signal to the collision avoidance device 55 via the transmitting / receiving unit 44 to move the unmanned aerial vehicle 30 so that one end of the support cable 51 is located upwind and above the access point P1 of the blade 11. After that, if a predetermined condition is met, such as when the wind speed changes to a threshold value or higher after the unmanned aerial vehicle 30 has moved to the access point P1, the control device 40 outputs a control signal to activate the collision avoidance device 55, which moves the work robot 20 to avoid a collision with the blade 11. The threshold value is set to a predetermined wind speed that is smaller than the maximum allowable wind speed.

[0059] As a predetermined condition, if the wind direction changes by more than a threshold after the unmanned aerial vehicle 30 has moved horizontally from the access point P1, or if the work robot 20 moves unexpectedly and the distance from the blade 11 falls below a threshold, the collision avoidance device 55 may move the work robot 20 away from the blade 11 to avoid a collision with the blade 11. Also, if the predetermined condition is met when the unmanned aerial vehicle 30 moves downward after moving horizontally from the access point P1, the collision avoidance device 55 may move the work robot 20 to avoid a collision with the blade 11.

[0060] As a result, when predetermined conditions are met, such as when the wind speed changes above a threshold, when the wind direction changes above a threshold, or when the work robot 20 moves unexpectedly and the distance from the blade 11 falls below a threshold, the collision avoidance device 55 is activated to move the work robot 20 to avoid a collision with the blade 11. Therefore, the collision avoidance device 55 can avoid a collision when there is a possibility that the work robot 20 will collide with the blade 11.

[0061] In the embodiment described above, the unmanned aerial vehicle 30 suspending the work robot 20 transports the work robot 20 to a blade 11 of the wind turbine 10 where the tip of the nacelle 13 supporting the blade 11 is located upwind. However, the unmanned aerial vehicle 30 suspending the work robot 20 can similarly transport the work robot 20 to a blade of the wind turbine 10 where the tip of the nacelle 13 supporting the blade 11 is located downwind.

[0062] Figure 10 is a side view of an unmanned aerial vehicle and a wind turbine at an access point in a control system for an unmanned aerial vehicle according to a third embodiment of the present disclosure. The control system for an unmanned aerial vehicle according to the third embodiment is the same as the control system for an unmanned aerial vehicle 1 according to the first embodiment, except that the rotation surface of the blade 11 of the wind turbine 10 to which the work robot 20 is transported is parallel to the direction of the wind, so the explanation of the similar parts will be omitted.

[0063] As shown in Figure 10, in the control system for an unmanned aerial vehicle according to the third embodiment, the unmanned aerial vehicle 30 transports the work robot 20 to the blades 11 of the wind turbine 60, where the rotation plane of the blades 11 is parallel to the direction of the wind. The blades 11 of the wind turbine 60 are rotatably supported at the tip of the nacelle 13, and when the work robot 20 is transported, they are stopped in a horizontal position, and the longitudinal direction of the blades 11 is positioned horizontally in the direction of the wind, that is, from upwind to downwind.

[0064] Even when transporting the work robot 20 to the blades 11 of the wind turbine 60 arranged in this manner, the unmanned aerial vehicle 30 suspending the work robot 20 moves the unmanned aerial vehicle 30 so that one end of the support cable 51 is located at an access point P1 upwind and above the blade 11. Next, the unmanned aerial vehicle 30 is moved horizontally from upwind towards the blade 11 so that the work robot 20 is positioned directly above the blade 11. After that, the unmanned aerial vehicle 30 is moved downward so that the work robot 20 is positioned on the blade 11.

[0065] As a result, when the work robot 20 is suspended and transported to the blade 11 of the wind turbine 60, it is moved horizontally from the access point P1 which is upwind and above the blade 11, and then moved downwards. Compared to the case where the access point P1 is set downwind and above the blade 11, even if the wind conditions change when the unmanned aerial vehicle 30 is moved horizontally from the access point P1, the work robot 20 can be positioned on the blade 11 while suppressing the risk of collision between the work robot 20 and the blade 11.

[0066] In the control systems for unmanned aerial vehicles according to the first to third embodiments, when transporting a work robot 20 suspended from an unmanned aerial vehicle 30 to the blades 11 of a wind turbine generator 10, the unmanned aerial vehicle 30 is moved horizontally from a predetermined access point P1 to a position where the work robot 20 is directly above the blades 11. However, if an abnormal situation occurs during horizontal movement, such as another aircraft approaching, the control device 40 can output a control signal to move the unmanned aerial vehicle 30 away from the blades 11 so that the work robot 20 moves away from the blades 11, thereby allowing the unmanned aerial vehicle 30 to move away from the blades 11.

[0067] Furthermore, when transporting the work robot 20 suspended from the unmanned aerial vehicle 30 to the blade 11 of the wind turbine generator 10, the unmanned aerial vehicle 30 is moved downward from a position where the work robot 20 is directly above the blade 11. However, if an abnormal situation occurs, such as another aircraft approaching, the control device 40 can output a control signal to move the unmanned aerial vehicle 30 away from the blade 11 so that the work robot 20 moves away from the blade 11, and also output a control signal to activate a collision avoidance device 55 that moves the work robot 20 to avoid a collision with the blade 11, thereby moving the unmanned aerial vehicle 30 away from the blade 11.

[0068] In the control systems for unmanned aerial vehicles according to the first to third embodiments, for example, a case is described in which a work robot 20 located in a storage position is suspended from the unmanned aerial vehicle 30 and then moved to an access point P1 for transport to the blade 11 of a wind turbine generator 10. However, in cases such as transporting a work robot located on the blade of one wind turbine generator to the blade of another wind turbine generator, the work robot on the blade of a wind turbine generator may be suspended and transported, or a work robot located in a storage area set near the control device may be suspended and transported.

[0069] As described above, the control device 40 of the unmanned aerial vehicle according to the first to third embodiments outputs a first control signal that moves the unmanned aerial vehicle 30 so that one end of the suspension member 51 is located upwind and above a predetermined access point P1 of the blade 11; a second control signal that moves the unmanned aerial vehicle 30 horizontally from upwind towards the blade 11 so that the work robot 20 is positioned directly above the blade 11; and a third control signal that moves the unmanned aerial vehicle 30 downward so that the work robot 20 is positioned on the blade 11.

[0070] As a result, when the work robot 20 is suspended from the unmanned aerial vehicle 30 and transported to the blade 11 of the wind turbine generator 10, the unmanned aerial vehicle 30 is moved horizontally from a predetermined access point P1 upwind and above the blade 11, and then moved downwards. Compared to the case where the predetermined access point is set downwind and above the blade 11, even if the wind conditions change and the wind speed decreases when the unmanned aerial vehicle 30 is moved horizontally from the predetermined access point P1, the work robot 20 can be positioned on the blade 11 while suppressing the risk of collision between the work robot 20 and the blade 11.

[0071] The predetermined access point P1 can be set at a position where the blade 11 is not within the swing range in which the work robot 20 suspended from the unmanned aerial vehicle 30 is swung by the wind. This makes it possible to suppress the work robot 20 from colliding with the blade 11 even when the wind conditions change.

[0072] The predetermined access point P1 can be set such that there is at least a predetermined distance in the height direction between the lower end of the swing range and the blade 11. This makes it possible to suppress the work robot 20 from colliding with the blade 11 even when the wind conditions change when the unmanned aerial vehicle 30 moves to the predetermined access point P1.

[0073] The predetermined interval can be set to a first interval when the wind speed is first, and to a second interval that is larger than the first interval when the wind speed is second, which is greater than the first interval. By making the predetermined height distance between the lower end of the swing range and the blade 11 larger when the wind speed is high compared to when the wind speed is low, it is possible to suppress the working robot 20 from colliding with the blade 11 even if the displacement of the working robot 20 is larger when the wind conditions change compared to when the wind speed is low.

[0074] The control device 40 can output a fourth control signal to detach the work robot 20 from the unmanned aerial vehicle 30. This allows the work robot 20 to be detached from the unmanned aerial vehicle 30 after it has been positioned on the blade 11, thereby preventing the work robot 20 from moving in conjunction with the movement of the unmanned aerial vehicle 30 due to changes in wind conditions.

[0075] The control device 40 can output a fifth control signal that moves the work robot 20 away from the blade 11 when the amplitude of the work robot 20's oscillation exceeds a predetermined threshold. This prevents the work robot 20 from colliding with the blade 11 when the amplitude of the work robot 20's oscillation exceeds a predetermined threshold, making it difficult to safely position the work robot 20 on the blade 11.

[0076] After outputting the first control signal, the control device 40 may output a sixth control signal that activates a collision avoidance device 55, which moves the work robot 20 to avoid collision with the blade 11, when predetermined conditions are met. As a result, when predetermined conditions are met, such as when the wind speed changes above a threshold, when the wind direction changes above a threshold, or when the work robot 20 moves unexpectedly and the distance from the blade 11 falls below a threshold, the collision avoidance device 55 is activated to move the work robot 20 to avoid collision with the blade 11. Therefore, the collision avoidance device 55 can be activated to avoid a collision when there is a possibility that the work robot 20 will collide with the blade 11.

[0077] The control device 40 can output a first control signal that moves the unmanned aerial vehicle 30 to a predetermined access point P1 located upwind and above the blade 11, which is positioned to receive wind from the front. As a result, the unmanned aerial vehicle 30 is moved to the predetermined access point P1 located upwind and above the blade 11, which is positioned to receive wind from the front, thereby suppressing collisions between the work robot 20 and the blade 11, which is positioned to receive wind from the front, while allowing the work robot 20 to be positioned on the blade 11.

[0078] The control device 40 can output a third control signal that moves the unmanned aerial vehicle 30 downward so that the work robot 20 is positioned on the tip portion 11a of the blade 11. As a result, the work robot 20 is positioned on the tip portion 11a of the blade 11, which requires more maintenance than the base portion 11b of the blade 11, allowing the work robot 20 to perform work on the blade 11 efficiently.

[0079] Furthermore, the control system 1 of the unmanned aerial vehicle according to this embodiment is a control system 1 for an unmanned aerial vehicle that suspends a work robot 20 and transports it to the blade 11 of a wind turbine generator 10, and comprises a work robot 20, an unmanned aerial vehicle 30 that suspends the work robot 20 and transports it to the blade 11 of a wind turbine generator 10, and a control device 40 for the unmanned aerial vehicle that controls the unmanned aerial vehicle 30.

[0080] As a result, when the work robot 20 is suspended and transported to the blade 11 of the wind turbine 10, the unmanned aerial vehicle 30 is moved horizontally from a predetermined access point P1 upwind and above the blade 11, and then moved downwards. Compared to the case where the predetermined access point P1 is set downwind and above the blade 11, even if the wind conditions change when the unmanned aerial vehicle 30 is moved horizontally from the predetermined access point P1, the work robot 20 can be positioned on the blade 11 while suppressing the risk of collision between the work robot 20 and the blade 11.

[0081] This disclosure is not limited to the embodiments described herein, and various improvements and design modifications are possible without departing from the spirit of this disclosure.

[0082] [Note 1] A control device for an unmanned aerial vehicle that suspends a work robot and transports it to the blade of a wind turbine by a suspension member, one end of which is connected to the unmanned aerial vehicle and the other end of which is connected to the work robot, wherein the control device outputs: a first control signal that moves the unmanned aerial vehicle so that the one end of the suspension member is located upwind and above the blade; a second control signal that moves the unmanned aerial vehicle horizontally from upwind towards the blade so that the work robot is positioned directly above the blade; and a third control signal that moves the unmanned aerial vehicle downward so that the work robot is positioned on the blade. [Note 2] The control device for an unmanned aerial vehicle according to Note 1, wherein the predetermined access point is set to a position where the blade is not within the swing range in which the work robot suspended from the unmanned aerial vehicle swings due to the wind. [Note 3] The control device for an unmanned aerial vehicle according to Note 2, wherein the predetermined access point is set to have at least a predetermined distance in the height direction between the lower end of the swing range in which the work robot swings and the blade. [Note 4] The control device for an unmanned aerial vehicle according to Note 3, wherein the predetermined distance is set to a first distance in the case of a first wind speed, and is set to a second distance which is greater than the first distance in the case of a second wind speed which is greater than the first wind speed. [Note 5] The control device for an unmanned aerial vehicle according to any one of Notes 1 to 4, wherein the control device outputs a fourth control signal which separates the work robot from the unmanned aerial vehicle. [Note 6] The control device for an unmanned aerial vehicle according to any one of Notes 1 to 5, wherein when the amplitude of the swing of the work robot exceeds a predetermined threshold, the control device outputs a fifth control signal which moves the work robot away from the blade. [Note 7] The control device for an unmanned aerial vehicle as described in any of Notes 1 to 6, wherein the control device outputs a sixth control signal after outputting the first control signal, which activates a collision avoidance device that moves the work robot to avoid collision with the blade when predetermined conditions are met.[Note 8] The control device outputs a first control signal that moves the unmanned aerial vehicle so that one end of the suspension member is positioned at a predetermined access point upwind and above the blade, which is arranged to receive wind from the front, as described in any of Notes 1 to 6. [Note 9] The control device outputs a third control signal that moves the unmanned aerial vehicle downward so that the work robot is positioned on the tip of the blade, as described in any of Notes 1 to 8. [Note 10] An unmanned aerial vehicle control system for transporting a work robot to the blade of a wind turbine, comprising: a work robot; an unmanned aerial vehicle for transporting the work robot to the blade of a wind turbine; and an unmanned aerial vehicle control device according to any of Notes 1 to 9 for controlling the unmanned aerial vehicle.

[0083] 1. Control system for unmanned aerial vehicles 10, 60 Wind turbine 11 Blades 20 Work robot 30 Unmanned aerial vehicle 40 Control device 51 Suspension member 55 Collision avoidance device

Claims

1. A control device for an unmanned aerial vehicle (UAV) that suspends a work robot and transports it to the blade of a wind turbine by a suspension member, one end of which is connected to the UAV and the other end of which is connected to the work robot, wherein the control device outputs: a first control signal that moves the UAV so that the one end of the suspension member is located upwind and above a predetermined access point of the blade; a second control signal that moves the UAV horizontally from upwind towards the blade so that the work robot is positioned directly above the blade; and a third control signal that moves the UAV downward so that the work robot is positioned on the blade.

2. The control device for an unmanned aerial vehicle according to claim 1, wherein the predetermined access point is set at a position where the blade is not within the swing range in which the work robot suspended from the unmanned aerial vehicle is swung by the wind.

3. The control device for an unmanned aerial vehicle according to claim 2, wherein the predetermined access point is set to have at least a predetermined distance in the height direction between the lower end of the swing range in which the work robot swings and the blade.

4. The control device for an unmanned aerial vehicle according to claim 3, wherein the predetermined interval is set to a first interval when there is a first wind speed, and is set to a second interval which is larger than the first interval when there is a second wind speed which is greater than the first wind speed.

5. The control device for an unmanned aerial vehicle according to claim 1, wherein the control device outputs a fourth control signal for separating the work robot from the unmanned aerial vehicle.

6. The control device for an unmanned aerial vehicle according to claim 1, wherein the control device outputs a fifth control signal that moves the work robot away from the blade when the amplitude of the swing of the work robot exceeds a predetermined threshold.

7. The control device for an unmanned aerial vehicle according to claim 1, wherein the control device outputs a sixth control signal after outputting the first control signal, which activates a collision avoidance device that moves the work robot to avoid collision with the blade when predetermined conditions are met.

8. The control device for an unmanned aerial vehicle according to claim 1, wherein the control device outputs a first control signal that moves the unmanned aerial vehicle to a predetermined access point upwind and above the blade, which is positioned to receive wind from the front.

9. The control device for an unmanned aerial vehicle according to claim 1, wherein the control device outputs a third control signal that moves the unmanned aerial vehicle downward so that the work robot is positioned on the tip of the blade.

10. A control system for an unmanned aerial vehicle that suspends a work robot and transports it to the blades of a wind turbine, comprising: a work robot; an unmanned aerial vehicle that suspends the work robot and transports it to the blades of a wind turbine; and a control device for the unmanned aerial vehicle according to claim 1, which controls the unmanned aerial vehicle.

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