Patent ID: 12233439

DESCRIPTION OF EMBODIMENTS

The embodiments of the present invention are explained hereinafter with reference to the drawings.

1. Maintenance on a Blade of a Wind Turbine

FIG.1toFIG.3are used to explain a state in which a device100for performing maintenance on a blade of a wind turbine performs maintenance on a blade11of a wind turbine10.FIG.1A,FIG.2A, andFIG.3Ashow the front of the wind turbine10, andFIG.1B,FIG.2B, andFIG.3Bshow the right side of the wind turbine10.FIG.1B,FIG.2B, andFIG.3Bonly show the blade11subjected to maintenance, in which the other two blades12and13are omitted. The wind turbine shown inFIG.1A,FIG.2A, andFIG.3Ais a wind turbine that rotates clockwise on the drawings, in which a linear edge of each blade is a leading edge (front edge).

As used herein, “wind turbine” refers to a device that obtains motive power by the wind. One example of a wind turbine is a wind power generator.

As used herein, “maintenance” refers to inspection or conservation of an object. One example of maintenance is imaging the surface of an object, examining the conduction of a lightning receiving portion of an object, washing the surface of an object, polishing the surface of an object, applying paint to the surface of an object, applying a material such as putty, adhesive, and sealant to the surface of an object, or the like.

FIG.1AandFIG.1Bshow the state of a preparation stage before attaching the device100to the blade11of the wind turbine10.

Maintenance on the blade11is performed while the blade11is positioned so that the blade11extends vertically downwards. Since this is the same state as the state of a blade in a conventional method in which a worker moves on a blade along a rope stretched over the blade and performs maintenance, this state is readily accepted in existing work sites. When the blade11is positioned so as to extend vertically downwards, the leading edge is inclined by about 5 degrees relative to the vertical direction as shown inFIG.1B.

A rope20is fixed to a nacelle14of the wind turbine10in a preparation stage before attaching the device100to the blade11of the wind turbine10. The nacelle14is a case housing a generator, a gear box or the like. The rope20is fixed to, for example, a hatch of the nacelle14(seeFIG.16). The rope20extends from the nacelle14of the wind turbine10to the leading edge at the base of the blade11while going around a hub15, and extends, over the leading edge of the blade11, from the leading edge at the base of the blade11to the ground. The hub15is a member which rotatably couples the blades11,12, and13and the nacelle14.

FIG.2AandFIG.2Bshow the state of a stage for attaching the device100for performing maintenance of a blade of a wind turbine to the blade11of the wind turbine10.

The device100comprises a winch (not shown inFIG.1toFIG.3). The winch of the device100is connected with the rope20. One end of the rope20is fixed to the ground by a weight or the like. The device100can rise along the rope20by using the winch to wind the rope20.

Two ropes21are connected near the center of gravity of the device100for controlling the posture of the device100. The two ropes21extend to the ground and are held by a worker on the ground. The worker can control the rotation of the device100by appropriately adjusting the tension of the two ropes21as if, for example, navigating a sport kite. For example, when the device100is inclined to the right while rising along the rope20as shown inFIG.2A, it is possible to correct the posture of the device100by pulling the rope21on the left side. For example, when the device100is inclined to the left while rising along the rope20as shown inFIG.2A, it is possible to correct the posture of the device100by pulling the rope21on the right side.

Once the device100rises to the leading edge at the tip of the blade11, the device100attaches to the leading edge at the tip of the blade11. The device100attaches to the leading edge at the tip of the blade11by using an attaching means130described below.

FIG.3AandFIG.3Bshow a state in which the device100for performing maintenance on a blade of a wind turbine moves on the leading edge of the blade11along the rope20.

When the device100moves along the leading edge, the device100maintains an attached state by the attaching means130described below. This enables the device100to move on the leading edge of the blade11without floating up. Further, since the leading edge of the blade11is inclined by about 5 degrees relative to the vertical direction as described above, the gravity acting on the device100acts so as to push the device100against the leading edge of the blade11and prevents the device100from floating up. Furthermore, since the posture of the device100is maintained by the attaching means130during the movement, the posture does not need to be controlled by the two ropes21.

The device100performs maintenance while moving on the leading edge of the blade11. For example, the device100images the surface of the leading edge by using a camera while moving on the leading edge of the blade11. For example, the device100examines the conduction of a lightning receiving portion by using a probe while moving on the leading edge of the blade11. For example, the device100washes the surface of the leading edge by using a washing device while moving on the leading edge of the blade11. For example, the device100polishes the surface of the leading edge by using a sander while moving on the leading edge of the blade11. For example, the device100applies paint to the surface of the leading edge by using a paint applying device while moving on the leading edge of the blade11. For example, the device100applies a material such as putty, adhesive, and sealant to the surface of the leading edge by using an electric gun while moving on the leading edge of the blade11. A hole made in the blade11can be filled with an applied material. The objective of filling a hole is to cover the hole to prevent water from entering the blade11. Aesthetics or perfection do not need to be required.

The device100can move on the leading edge of the blade11in two directions in which the rope extends by controlling winding and delivering by the winch. This enables the device100to perform maintenance while reciprocatively moving on the leading edge of the blade11. Further, even if the device100comes off the blade11, the rope20to which the winch of the device100is connected serves as a lifeline, which can prevent the device100from falling down.

2. Configuration of a Device for Performing Maintenance on a Blade of a Wind Turbine

FIG.4Ashows one example of a configuration of a device100for performing maintenance on a blade of a wind turbine.

The device100comprises a maintenance means110, a transmitting and receiving means111, a memory112, a processor113, a moving means120, and an attaching means130.

The maintenance means110is a means for performing maintenance on a blade of a wind turbine. The maintenance means comprises, for example, an imaging means140, a conduction examining means150, a washing means160, a polishing means170, and an applying means180. The maintenance means110may comprise at least one of, for example, the imaging means140, the conduction examining means150, the washing means160, the polishing means170, and the applying means180. For example, the maintenance means110may comprise the imaging means140for inspection. For example, the maintenance means110may comprise at least one of the imaging means140, the conduction examining means150, the washing means160, the polishing means170, and the applying means180for inspection and conservation.

The imaging means140can be any camera that is able to image a still picture or movie of an object.

The conduction examining means150can be any means that is able to examine whether current flows in a conducting portion. For example, the conduction examining means150comprises a probe that is able to examine whether current flows in a lightning receiving portion provided to a blade of a wind turbine.

The washing means160can be any means that is able to wash an object. For example, the washing means160may be a mechanism that uses washing liquid and rag to wipe off dirt. When such a mechanism is used to wash a blade11of a wind turbine10while moving on the blade11of the wind turbine10as shown inFIG.1toFIG.3, washing is performed by the device100moving on the blade while pushing the rag against the blade.

The polishing means170can be any means that is able to polish an object. For example, the polishing means170may be a mechanism that uses a sand paper, a grinder, a disk grinder or the like for polishing. When a sand paper is used to polish the blade11of the wind turbine10while moving on the blade11of the wind turbine10as shown inFIG.1toFIG.3, polishing is performed by the device100moving on the blade while pushing the sand paper against the blade. When a grinder, a disk grinder or the like is used to polish the blade11of the wind turbine10while moving on the blade11of the wind turbine10as shown inFIG.1toFIG.3, polishing is performed by pushing the rotating grinder against the blade11. When the polishing means170is a power tool such as a grinder or a disk grinder, it is preferable that the polishing means170is attached to the body of the device100. That is because attaching the polishing means170to the body of the device100enables the body with a large mass to absorb reaction that is generated when the polishing means170is pushed against the blade11. Mechanisms shown inFIG.4BtoFIG.4Emay be used to attach the polishing means170to the body of the device100.

FIG.4BtoFIG.4Cshow one example of the polishing means170attached to the body of the device100.FIG.4D to4Eshow another example of the polishing means170attached to the body of the device100.FIG.4B(a),FIG.4C(a),FIG.4D(a), andFIG.4E(a) are figures schematically showing the bottom of the device100.FIG.4B(b),FIG.4C(b),FIG.4D(b), andFIG.4E(b) are X-X line cross sectional view ofFIG.4B(a),FIG.4C(a),FIG.4D(a), andFIG.4E(a), respectively.

As shown inFIG.4BandFIG.4C, the device100comprises an adjusting portion (circular portion172and ring portion173) in order to attach the polishing means170(e.g., a disk grinder) to the body in such a manner that the position can be adjusted. The polishing means170is attached to both the circular portion172and the ring portion173. The circular portion172and the ring portion173are each rotatable in the arrow direction inFIG.4B(a). The circular portion172and the ring portion173may be independently rotatable, or concurrently rotatable. The circular portion172is further expandable in the arrow direction inFIG.4B(b).

For example, a disk grinder needs to push the edge of the disk for polishing in order to perform polishing with a rotating disk. However, when, for example, the surface of a recessed portion on a blade is polished, the edge of the disk may not reach the surface of the recessed portion. In this case, as shown inFIG.4C(b), it is possible to adjust the expansion direction position of the disk grinder by expansion of the circular portion172, thereby it is possible to form an angle in the disk grinder, which enables polishing the surface of the recessed portion as well. Further, as shown inFIG.4C, it is possible to adjust the rotation direction position of the disk grinder by rotation of the circular portion172and the ring portion173. The position of the disk grinder can be finely adjusted by expansion of the circular portion172and rotation of the circular portion172and the ring portion173.

As shown inFIG.4DandFIG.4E, the device100comprises an adjusting portion (circular portion172) in order to attach the polishing means170(e.g., a grinder) to the body in such a manner that the position can be adjusted. The polishing means170is attached to the circular portion172. The circular portion172is rotatable in the arrow direction inFIG.4D(a). The circular portion172is further expandable in the arrow direction inFIG.4D(b).

For example, since a grinder performs polishing with a rotating sphere, the grinder needs to push the sphere for polishing. However, when, for example, the surface of a recessed portion on a blade is polished, the sphere may not reach the surface of the recessed portion. In this case, as shown inFIG.4E(b), it is possible to adjust the expansion direction position of the grinder by expansion of the circular portion172, thereby it is possible to polish the surface of the recessed portion as well. Further, as shown inFIG.4E, it is possible to adjust the rotation direction position of the grinder by rotation of the circular portion172. The position of the grinder can be finely adjusted by expansion of the circular portion172and rotation of the circular portion172. Furthermore, an angle does not need to be formed in a grinder that performs polishing with a rotating sphere like a disk grinder because said grinder does not perform polishing with a limited portion such as the edge of a disk like a disk grinder but can perform polishing with a wider portion.

The above-described examples explain attaching a disk grinder to the adjusting portion (circular portion172and ring portion173) shown inFIG.4BandFIG.4C. However, a grinder may be attached to the adjusting portion (circular portion172) shown inFIG.4BandFIG.4C.

With reference toFIG.4Aagain, the applying means180can be any means that is able to apply a material to an object. A material applied by the applying means180includes, for example, paint, putty, adhesive, and sealant. For example, the applying means180may be a spraying device that is able to spray paint. When such a spraying device is used to apply paint to the blade11of the wind turbine10while moving on the blade11of the wind turbine10as shown inFIG.1toFIG.3, the paint is applied by the device100moving on the blade while spraying the paint from the spraying device. For example, the applying means180may be a caulking gun that is able to extrude putty, adhesive, sealant or the like. When such a caulking gun is used to apply a material such as putty, adhesive, or sealant to the blade11of the wind turbine10while moving on the blade11of the wind turbine10as shown inFIG.1toFIG.3, the material is applied by identifying a part to which the material should be applied with the imaging means140or the like in advance, moving the device100on the blade11, and extruding the material when the device100reaches the part to which the material should be applied.

It should be noted that the maintenance means110is not limited to the imaging means140, the conduction examining means150, the washing means160, the polishing means170, and the applying means180. The device100may comprise another means for performing maintenance on an object as the maintenance means110instead of or in addition to the above-described means.

The transmitting and receiving means111is a means for receiving a signal from outside the device100and transmitting a signal to outside the device100. The transmitting and receiving means111may receive a signal from outside the device100by wire or wireless. The transmitting and receiving means111may transmit a signal to outside the device100by wire or wireless. The transmitting and receiving means111receives, for example, a signal for controlling each action of the device100from outside the device100(e.g., a terminal for operation used by an operator). The transmitting and receiving means111transmits, for example, image data obtained by an imaging means to outside the device100(e.g., a terminal for operation used by an operator). For example, the transmitting and receiving means111may use a LAN interface to communicate with outside the device100. Since this enables supplying a plurality of types of signals via the LAN interface, it will be easier to remotely operate the device100.

The memory112stores a program necessary for execution of processing of the device100, data necessary for execution of the program, or the like. The memory112can be implemented by any storage means.

The processor113controls the action of the whole device100. For example, the processor113controls the action of the moving means120or the maintenance means110in accordance with a control signal received by the transmitting and receiving means111. This executes each action for performing maintenance on an object. The processor113is also able to read out a program stored in the memory112, execute the program, and cause the device100to function as a device executing a desired step.

Although it was explained that each action for performing maintenance on an object is executed in accordance with a signal from outside the device100, the present invention is not limited to the above. For example, a program for realizing a series of actions for performing maintenance on an object may be stored in the memory112, and the processor113can read out and execute the program, thereby causing the device100to function as a device automatically performing maintenance on an object.

The moving means120is a means that enables the device100to move on a blade. The moving means120comprises, for example, a winch121, a wheel for travelling on leading edge122, and a wheel for travelling on blade side surface123. The device100is able to move on a blade in the horizontal direction ofFIG.4Aalong a rope20extending in the horizontal direction ofFIG.4Aby, for example, the winch121, the wheel for travelling on leading edge122, and the wheel for travelling on blade side surface123.

The winch121can be a mechanism connectable to at least one rope20. For example, the rope20enters the winch121from a first end1211of the winch121, is connected to the winch121, and exits from a second end1212of the winch121. The device100moves in the direction of the first end1211(left direction inFIG.4A) by the winch121winding the rope20so that the rope20enters the first end1211(delivering the rope20from the second end1212). The device100moves in the direction of the second end1212(right direction inFIG.4A) by the winch121winding the rope20so that the rope20enters the second end1212(delivering the rope20from the first end1211). The winding action of the winch121is controlled by the processor113. The winch121winds the rope20in accordance with a control signal from the processor113.

Although an example in which the rope20passes through the winch121was explained in the above-described example, the present invention is not limited to this. The scope of the present invention also encompasses a case in which the rope20does not pass through the winch121, that is, a case in which the rope20enters from one end of the winch121but does not exit from the other end. In this case, the rope20does not need to extend between the device100and the ground. For example, the device100moves in the direction toward a nacelle14of a wind turbine by the winch121winding a rope extending between the nacelle14of the wind turbine and the device100. For example, the device100moves in the direction away from the nacelle14of a wind turbine by the winch121delivering a rope extending between the nacelle14of the wind turbine and the device100.

The wheel for travelling on leading edge122and wheel for travelling on blade side surface123are wheels assisting the device100to smoothly move when it moves by the winch121winding the rope20. The wheel for travelling on leading edge122and wheel for travelling on blade side surface123can be non-driving wheels. The wheel for travelling on leading edge122and/or wheel for travelling on blade side surface123may be configured to be able to calculate the distance of the movement on a blade from the number of revolutions.

It should be noted that the moving means120is not limited to the winch121, wheel for travelling on leading edge122, and wheel for travelling on blade side surface123. The device100may comprise another means that enables the device100to move on an object as the moving means120instead of or in addition to the above-described means.

The attaching means130is a means that enables the device100to attach to a leading edge of a blade. The device100can attach to a leading edge of a blade by the attaching means130. The attaching means130is, for example, a pair of frame assemblies, wherein each frame assembly comprises a first frame131, a second frame132, a third frame133, a first hinge134, a second hinge135, and a third hinge136. The first frame131is pivotable with the first hinge134as an axis, the first frame131and the second frame132are pivotable with the second hinge135as an axis, and the second frame132and the third frame133are pivotable with the third hinge136as an axis. Each hinge is independent, and each frame is independently pivotable.

The attaching means130is biased so that a pair of frame assemblies can hold an object therebetween. In this regard, it does not matter how the attaching means130is biased. For example, the attaching means130may be biased by a spring, the attaching means130may be hydraulically biased, or the attaching means130may be biased by magnetic force.

Since the attaching means130is biased so that each frame is pivotably coupled in a pair of frame assemblies and the pair of frame assemblies hold an object therebetween, the attaching means130can deform in accordance with the shape of the object and can fixedly attach to an object even when the shape differs depending on an attachment target or even when the shape of the object changes in association with movement by the moving means120.

In the example shown inFIG.4A, two wheels for travelling on leading edge122are attached to a body. However, the number and attachment position of wheels for travelling on leading edge122do not matter. Any number of wheels for travelling on leading edge122can be attached to any place. For example, one wheel for travelling on leading edge122may be attached to the first frame131, and four wheels for travelling on leading edge122may be attached to the body.

In the example shown inFIG.4A, one wheel for travelling on blade side surface123is attached to each of the second frame132and the third frame133. However, the number and attachment position of wheels for travelling on blade side surface123do not matter. Any number of wheels for travelling on blade side surface123can be attached to any place. For example, a plurality of wheels for travelling on blade side surface123may be attached to each of the first frame131, the second frame132, and the third frame133.

In the example shown inFIG.4A, the device100comprises two attaching means130. However, the number of attaching means130does not matter. The device100can comprise any number of attaching means130. The device100may comprise one attaching means130, or may comprise three or more attaching means130. The device100can comprise an appropriate number of attaching means130in accordance with the total length.

In the example shown inFIG.4A, two attaching means130are not connected to each other, and they independently deform. Since each attaching means130thereby deforms in accordance with change in the shape even when the shape of an attachment target changes in the advancing direction of the device100(horizontal direction inFIG.5), the device100is able to maintain a state of attaching to an object. Furthermore, the frames of the adjacent attaching means130may be connected to each other by a member such as a rod in order to enhance the rigidity of each frame.

In the example shown inFIG.4A, an example in which the device100comprise a maintenance means110, a transmitting and receiving means111, a memory112, a processor113, a moving means120, and an attaching means130was explained. However, the present invention is not limited to the above. The scope of the present invention also encompasses a system in which at least one of the components of the device100is located outside the body of the device100. For example, the nacelle14of a wind turbine may comprise a winch121instead of the device100comprising a winch121. In this case, the device100may be configured to move on the blade11by a rope that extends from the winch121of the nacelle14of the wind turbine being fixed to the device100and the winch121of the nacelle14of the wind turbine winding or delivering the rope. For example, a carrying device (e.g., a device that can fly such as a drone described below) for carrying the device100to a blade may comprise a winch121instead of the device100comprising a winch121. In this case, the device100may be configured to move on a blade by a rope that extends from the winch121of the carrying device being fixed to the device100and the winch121of the carrying device winding or delivering the rope.

FIG.5Ashows a state in which a device100for performing maintenance on a blade of a wind turbine attaches to a thick blade, andFIG.5Bshows a state in which a device100for performing maintenance on a blade of a wind turbine attaches to a thin blade.FIG.5AandFIG.5Bshow a cross section near a leading edge of a blade11along a plane surface perpendicular to the advancing direction of the device100.

The device100comprises a pair of frame assemblies as attaching means130, and a washing means160or polishing means170as maintenance means110.

Each frame assembly comprises a first frame131, a second frame132, a third frame133, a first hinge134, a second hinge135, and a third hinge136. A pair of frame assemblies are biased so that each frame is pivotably coupled therein and the pair of frame assemblies hold an object therebetween.

When attaching to a thick blade11as shown inFIG.5A, each frame deforms to be widely enlarged in accordance with the blade11while each frame is biased inwardly in the direction of the blade11. Thus, wheels for travelling on blade surface side123on both sides are pushed against the blade11. The device100thereby attaches to the blade11in a state in which each frame deforms in accordance with the shape of the blade.

When attaching to a thin blade11as shown inFIG.5B, each frame deforms to be slightly enlarged in accordance with the blade11while each frame is biased inwardly in the direction of the blade11. Thus, wheels for travelling on blade surface side123on both sides are pushed against the blade11. The device100thereby attaches to the blade11in a state in which each frame deforms in accordance with the shape of the blade.

The washing means160as maintenance means110may be, for example, a mechanism comprising a sponge161, a rag162stuck to the surface of the sponge161, a holding member163which holds the sponge161, and a supplying device (not shown) that can supply the sponge161with washing liquid. The sponge161, the rag162, and the holding member163are configured to be deformable in accordance with the shape of the cross section of the blade11. When the device100washes the blade11of a wind turbine while moving on the blade11of the wind turbine using such a mechanism, the holding member163collectively holds the sponge161, the rag162, and the blade11. The rag162stuck to the sponge161is pushed against the blade11by the device100attaching to the blade11by the attaching means130. The rag162stuck to the sponge161is also pushed against to the blade11by the gravity which acts to push the device100against the blade11. The washing liquid supplied from the supplying device infiltrates into the rag162via the sponge161. Washing is performed by the device100moving on the blade11while pushing the rag162in which the washing liquid has infiltrated against the blade11.

The polishing means170as maintenance means110may be, for example, a mechanism comprising a sponge171, a sand paper172stuck to the surface of the sponge171, a holding member173which holds the sponge171, and a motor (not shown) which can shake the holding member173. The sponge171, the sand paper172, and the holding member173are configured to be deformable in accordance with the shape of the cross section of the blade11. When the device100polishes the blade11of a wind turbine10while moving on the blade11of the wind turbine10using such a mechanism, the holding member173collectively holds the sponge171, the sand paper172, and the blade11. The sand paper172stuck to the sponge171is pushed against the blade11by the device100attaching to the device11by the attaching means130. The sand paper172stuck to the sponge171is also pushed against the blade11by the gravity which acts to push the device100against the blade11. The motor collectively shakes the holding member173, the sponge171, and the sand paper172. Polishing is performed by the device100moving on the blade11while pushing the shaking sand paper172against the blade11.

In the examples shown inFIG.5AandFIG.5B, frame assemblies comprising three frames and three hinges were explained. However, the number of frames and hinges does not matter. The frame assemblies can comprise any number of frames and hinges. For example, the frame assemblies may comprise two frames and two hinges, or may comprise four or more frames and four or more hinges. Further, the frames were illustrated as elongated members and the hinges were illustrated as circular members in the examples shown inFIG.5AandFIG.5B. However, the frames and hinges are not limited to the illustrated shape. The frames and hinges can have any shape as long as the shape enables them to achieve their function.

FIG.6shows a state in which one embodiment of a device100for performing maintenance on a blade of a wind turbine attaches to a blade11.

InFIG.6, like reference numerals are given to the same components as those shown inFIG.4A. The explanation of the components is omitted here.

The device100comprises a winch121, a wheel for travelling on leading edge122, a wheel for travelling on blade side surface123, a first frame131, a second frame132, a third frame133, a first hinge134, a second hinge135, a third hinge136, a washing means160, and a polishing means170.

The device100is able to move in the vertical direction inFIG.6by the winch121, the wheel for travelling on leading edge122, and the wheel for travelling on blade side surface123.

The wheel for travelling on leading edge122is attached in a position in which the device100, when attaching to the blade11, is in contact with a leading edge LE. The wheel for travelling on blade side surface123is attached to the third frame133so that the device100, when attaching to the blade11, is in contact with the side surface of the blade.

A configuration in which the frames131,132, and133are each biased and coupled by the hinges134,135, and136enables the third frame133to always push the attached wheel for travelling on blade side surface123against the blade11. Even when the shape of the cross section of the blade11changes in association with movement on the blade11, it is possible to always push the wheel for travelling on blade side surface123against the blade by the frames131,132, and133pivoting and deforming in accordance with the shape of the cross section of the blade. Further, even when the shape of the cross section of the blade changes depending on the model of a wind turbine, it is possible to always push the wheel for travelling on blade side surface123against the blade by the frames131,132, and133pivoting and deforming in accordance with the shape of the cross section of the blade. Since the wheels for travelling on blade side surface123on both sides are always pushed against the blade11, the device100can attach to the leading edge LE of the blade11without horizontally deviating.

3. Method for Performing Maintenance on a Blade of a Wind Turbine

FIG.7shows one example of a procedure of a method for using a device100for performing maintenance on a blade of a wind turbine to perform maintenance on a blade of a wind turbine.

Step S801is step of stretching at least one rope over the blade of the wind turbine. For example, while the blade11is positioned so that the blade11extends vertically downward as shown inFIG.1AandFIG.1B, one rope20is fixed to the nacelle14of the wind turbine10, extends from the nacelle14of the wind turbine10to the leading edge at the base of the blade11while going around the hub15, and extends from the leading edge at the base of the blade11to the ground.

Step S801may be manually performed by a worker, or may be automatically performed by a robot. When Step S801is automatically performed by a robot, at least one rope may be stretched over the blade of the wind turbine by, for example, a device that can fly such as a drone.

Step S802is a step of attaching the device100to the blade. For example, the device100is raised to the tip of the blade11along the one rope20stretched in Step S801, and the device100is attached to the leading edge at the tip of the blade11via the attaching means130as shown inFIG.2AandFIG.2B. Upon doing so, two ropes21may be connected to the device100and the posture of the device100may be controlled using the two ropes as shown inFIG.2AandFIG.2B. The two ropes21can be used, for example, to assist the device100. The posture of the device100can be controlled using the two ropes21like a sport kite.

Step S802may be manually performed by a worker, or may be automatically performed by a robot. When Step S802is manually performed by a worker, Step S802is performed by at least two workers. One worker, for example, transmits a control signal to the device100by a terminal for operation to cause the device100to wind or deliver the rope20and cause the device100to rise to the tip of the blade11. At least one other worker, for example, uses the two ropes21to control the posture of the device100. Upon doing so, an around view image of the surrounding of the device100may be displayed on the terminal for operation in real time, or 3D image of the blade11of the wind turbine may be displayed on the terminal for operation as described below. Further, the worker using the two ropes21to control the posture of the device100may wear a wearable device such as smart glasses and a head mount display and control the posture of the device100. An around view image of the surrounding of the device100, 3D image of the blade11of the wind turbine, or the like described below can be displayed on the wearable device such as smart glasses and a head mount display in real time.

When Step S802is automatically performed by a robot, step S802is performed by, for example, at least two robots. One robot, for example, transmits a control signal to the device100to cause the device100to wind or deliver the rope20and cause the device100to rise to the tip of the blade11. At least one movable robot, for example, uses the two ropes21to control the posture of the device100. The movable robot can control the posture of the device100as if navigating a sport kite by adjusting the amount and angle of winding or delivering the ropes21as well as tension of the ropes21at the other side of the ropes21connected to the device100. The movable robot can comprise, for example, an encoder, and can thereby detect the amount and angle of winding or delivering the ropes21. The movable robot can comprise, for example, a current sensor, and can thereby detect tension of the ropes21. The movable robot can comprise, for example, a moving means such as a wheel and a continuous track, and can thereby control the posture of the device100while moving on the ground. Upon doing so, the movable robot may grasp its own position by using any position detecting mechanism. For example, the movable robot may grasp its own position by using a position information measuring system such as GPS, may grasp its own position by calculating moving distance from the starting point based on the number of revolutions of a wheel, may grasp its own position based on the relative position of the wind turbine with a tower, or may grasp its own position by using a combination of the foregoing.

In the examples shown inFIG.2AandFIG.2B, it was explained that the two ropes21extend to the ground and the posture of the device100is controlled from the ground. However, the present invention is not limited to the above. For example, the two ropes21may extend to a position higher than the ground and the posture of the device100may be controlled from a position higher than the ground. A position higher than the ground is, for example, the nacelle of the wind turbine. The two ropes21may extend to the nacelle and the posture of the device100may be controlled by using the two ropes21from the nacelle. This is preferable when, for example, maintenance on a wind turbine on the sea is performed. A position higher than the ground is, for example, a device that can fly such as a drone floating in the air. The two ropes21may extend to a device that can fly and the device that can fly may control the posture of the device100by using the two ropes21from the air. For example, the two ropes21may extend on or in water and the posture of the device100may be controlled from on or in water. For example, the two ropes21may extend onto a ship moving near the wind turbine, and a worker or a robot may use the two ropes21from the ship to control the posture of the device100. For example, the two ropes21may extend to a robot that is able to move on or in water, and the robot that is able to move on or in water may use the two ropes21from on or in water to control the posture of the device100. This is preferable when, for example, maintenance on a wind turbine on the sea or along the coast is performed.

Although the device100is raised along the rope stretched over the device100for attachment in the above example, the way of attaching the device100is not limited to the above. For example, the device100may be lifted to the nacelle of the wind turbine in advance and lowered to the base of the blade along the rope from the nacelle of the wind turbine, and the device100may be attached to the leading edge at the base of the blade. For example, the device100may be carried to the blade by utilizing a device that can fly such as a drone, and the device100may be attached to the blade. In this case, the device100and the device that can fly are first connected by a rope. Next, the device that can fly is caused to fly to the blade (e.g., base of the blade) and the device that can fly is attached to the blade. The way of attaching the device that can fly to the blade does not matter. For example, the device that can fly may be attached to the blade by using the same attaching means as the device100, or may be attached by winding an expandable and contractable arm to the blade. The device100is attached to the blade after or concurrently with attachment of the device that can fly to the blade.

Step S803is a step of moving the device100on the blade along the direction in which at least one rope is stretched after the device100is attached to the blade. For example, the device100is moved on the leading edge of the blade11along the direction in which the one rope20is stretched in Step S801as shown inFIG.3AandFIG.3B. Upon doing so, the device100fixedly attaches to the blade11via the attaching means130. This enables the device100to move on the leading edge of the blade11without floating up. Further, since the leading edge of the blade11is inclined by about 5 degrees relative to the vertical direction, the gravity acting on the device100acts so as to push the device100against the leading edge of the blade11and prevents the device100from floating up. For example, Step S803may be performed in response to transmission of a control signal to the device100by a worker using a terminal for operation, or may be performed in response to transmission of a control signal to the device100by a robot.

The step of moving the device100in Step S803may comprise moving the device100on the blade in a first direction along the direction in which at least one rope is stretched, and moving the device100on the blade in a second direction along the direction in which at least one rope is stretched. For example, the first direction is a direction from the tip of the blade toward the root of the blade, and the second direction is a direction from the root of the blade toward the tip of the blade. The device100can move in the first direction or the second direction by controlling the winding or delivering by a winch121.

Step S804is a step of causing the device100to perform maintenance on the blade during movement of the device100along the direction in which at least one rope is stretched. For example, the device100is caused to perform maintenance on the blade11during movement of the device100on the leading edge of the blade11as shown inFIG.3AandFIG.3B. Upon doing so, the device100is fixedly attached to the blade11via the attaching means130. This enables the device100to push a maintenance means such as a washing means160and polishing means170against the leading edge of the blade11without floating up. Further, since the leading edge of the blade11is inclined by about 5 degrees relative to the vertical direction, the gravity acting on the device100acts so as to push the device100against the leading edge of the blade11and prevents the device100from floating up. For example, Step S804may be performed in response to transmission of a control signal to the device100by a worker using a terminal for operation, or may be performed in response to transmission of a control signal to the device100by a robot.

As described above, each step of the method for performing maintenance on a blade of a wind turbine may be initiatively performed by a worker, or may be automatically performed by a robot. When each step is performed by a robot, a worker does not need to be in a work site, which enables maintenance on an object to be safely performed.

As used herein, “during movement” refers to a period of moving from one position to another position. It is not necessarily required to keep moving. For example, a period during which a device100moves from the tip of a blade to the base of the blade while repeating advancing and stopping is also encompassed in “during movement”.

FIG.8shows one example of a procedure of actions performed in Step S804when Step S803comprises moving the device100in the first direction and moving the device100in the second direction.

In Step S901, the device100is caused to perform first maintenance during movement of the device100in the first direction along the direction in which at least one rope is stretched. For example, the device100is caused to image the surface of the blade by using an imaging means140during movement of the device100in the direction from the tip of the blade toward the base of the blade.

In Step S902, the device100is caused to perform second maintenance different from the first maintenance during movement of the device100on the blade in the second direction different from the first direction. For example, the device100is caused to wash the surface of the blade by using a washing means160during movement of the device100in the direction from the base of the blade toward the tip of the blade after the device100reaches the base of the blade while performing the first maintenance in Step S901.

The timing for switching Step S901and Step S902does not matter. For example, the step may be switched to Step S902to cause the device100to move in the second direction and perform the second maintenance after the device100reaches the end of the first direction (base of the blade in the above-described example) in Step S901, or the step may be switched to Step S902to cause the device100to move in the second direction and perform the second maintenance before the device100reaches the end of the first direction in Step S901.

A plurality of additional steps may follow Step S902. For example, the device100may be caused to perform third maintenance different from the first maintenance or second maintenance during movement of the device100on the blade in the first direction in Step S903. For example, the device100may be caused to perform fourth maintenance different from the first to third maintenance during movement of the device100on the blade in the second direction in Step S904after Step S903. This procedure enables the device100to change the working content of maintenance for each movement on the blade.

4. Alternative Embodiment of a Device for Performing Maintenance on a Blade of a Wind Turbine

FIG.9A,FIG.9B, andFIG.9Cshow one example of the appearance of a device1000, which is an alternative example of a device100for performing maintenance on a blade of a wind turbine.FIG.9Ais a top side perspective view of the device1000,FIG.9Bis a bottom side perspective view of the device1000, andFIG.9Cis a front view of the device1000. For explanation below, the longitudinal direction of the device1000is deemed as an x-axis, the transverse direction of the device1000is deemed as a y-axis, and the direction perpendicular to the x-axis and y-axis is deemed as a z-axis inFIG.9A.

InFIG.9A,FIG.9B, andFIG.9C, like reference numerals are given to the same components as those shown inFIG.4A. The explanation of the components is omitted here. It should be noted that although the device1000has a different configuration from that of the device100, maintenance on a blade of a wind turbine can be performed in the same method as the method described above with reference toFIG.7andFIG.8.

The device1000can comprise two winches121on both sides of the device1000. The example shown inFIG.9AandFIG.9Bshows the two winches121in a state in which one winch is encased in a housing and the other winch is not encased in the housing. Although the presence or absence of a housing of a winch does not matter in the present invention, it is preferable to have a housing. The reason is as follows: when there is space around a rope wound around a winch, the rope may be loosened, which causes a defect such as entanglement of the rope; thus, generation of looseness of the rope can be suppressed by filling the space around the rope using a housing. It is preferable that the housing has a shape to fill the space around the winch. It is further preferable that the housing has a shape to push the rope against the winch.

The two winches121are each connected to two ropes20stretched over a blade of a wind turbine and can support the device1000from both sides. This makes the posture of the device1000more stable.

The two winches121have a first mode in which the winches are independently controlled and a second mode in which the winches are controlled in synchronization. When the two winches121are each connected to the two ropes20, the two winches121are actuated in the first mode in which the winches are independently controlled. For example, when the two winches121are each connected to the two ropes20, the posture may be inclined due to deviation generated in the winding of the ropes between the two winches121. In this case, it is possible to eliminate the deviation in the winding of the ropes and maintain a stable posture by independently controlling only one winch121. After the two winches121are each connected to the two ropes20, the two winches121are controlled in the second mode in which the winches are controlled in synchronization. This makes it possible to equally wind or deliver the ropes by the two winches121and to maintain a stable posture. For example, the device1000can move on the blade while maintaining a stable posture by being actuated in the second mode when moving the device1000on the blade.

FIG.10toFIG.12are figures showing a state in which a device1000comprising two winches121performs maintenance on a blade11of a wind turbine10.FIG.10AandFIG.10Bshow the state of a preparation stage before attaching the device1000to the blade11of the wind turbine10,FIG.11AandFIG.11Bshow the state of a stage for attaching the device1000to the blade11of the wind turbine10, andFIG.12AandFIG.12Bshow a state in which the device1000moves on the leading edge of the blade11along ropes20.FIG.10toFIG.12explain the same examples as those inFIG.1toFIG.3except for the point that the device1000comprises two winches121.

As shown inFIG.10toFIG.12, the two ropes20used by the two winches121do not need to extend from a nacelle14of the wind turbine10to the leading edge at the base of the blade11while going around a hub15, different from the case of using one rope20as shown inFIG.1toFIG.3. The two ropes20used by the two winches121are able to directly extend from the nacelle14of the wind turbine10to the ground without going around the hub15. That is because the two ropes20do not need to be stretched over the leading edge of the blade. Since such rope arrangement is the same as the rope arrangement in a conventional method in which a worker moves on a blade along a rope stretched over the blade to perform maintenance, there is an advantage that existing ropes in a work site can be utilized as they are without requiring special rope arrangement for using the device1000. Furthermore, since such rope arrangement does not interfere with the hub15of the wind turbine, it is possible to rotate the blade11of the wind turbine10while keeping the ropes20attached to the nacelle14in the same manner as a conventional method in which a worker moves on a blade along a rope stretched over the blade to perform maintenance. As a result, it is not necessary to stretch a rope for each blade when performing maintenance on a plurality of blades of a wind turbine, and thus maintenance can be efficiently performed.

The device1000may comprise a posture controlling device. The posture controlling device can be a device that is able to generate a moment around any axis in order to control the posture of the device1000. The posture controlling device may be used concomitantly with adjusting the tension of two ropes21by a worker from the ground to control the posture of the device1000, or may be used without adjusting the tension of the two ropes21by the worker from the ground to control the posture of the device1000. This makes it possible to assist adjusting the tension of the two ropes21by the worker from the ground to control the posture of the device1000, or to eliminate need for adjusting the tension of the two ropes21by the worker from the ground to control the posture of the device1000.

For example, the posture controlling device can be propellers attached to both sides of the device1000. The propellers can be attached to, for example, a frame115extending to both sides of the device1000. The propellers can adjust generated propulsive force by control of the rotational speed. The propellers also can make the direction for generating propulsive force variable by being configured to have a changeable attachment angle to the device1000. For example, when the attachment angle is changed so that the propellers generate propulsive force in the z-axis direction, a moment around the x-axis is generated in the device1000by controlling the propellers on both sides to have a different rotational speed. This makes it possible to control the posture around the x-axis. For example, when the attachment angle is changed so that the propellers generate propulsive force in the x-axis direction, a moment around the z-axis is generated in the device1000by controlling the propellers on both sides to have a different rotational speed. This makes it possible to control the posture around the z-axis. It should be noted that the propellers can be attached to not only left and right both sides but also upper and lower both sides or front and rear both sides in order to generate a moment around a desired axis.

For example, the posture controlling device can be a device that can fly such as a drone attached to the both sides of the device1000. The device that can fly can be attached, for example, to the frame115extending to both sides of the device1000. It should be noted that the device that can fly can be attached to not only left and right both sides but also upper and lower both sides or front and rear both sides in order to generate a moment around a desired axis.

It is possible to readily control the posture of the device1000by using such a posture controlling device concomitantly with operation of the two ropes21by a worker even when it is difficult to control the posture due to, for example, a strong wind.

As shown inFIG.9C, the frame in attaching means130is attached to the body of the device1000via first hinges134in the device1000. Further, the device1000comprises wide wheels for travelling on leading edge122. The wheels for travelling on leading edge122are configured to have an outer wheel with a larger diameter than that of an inner wheel. In this case, the frame in attaching means130and the wheels for travelling on leading edge122form a convex shape in the front view by narrowing the gap between the first right and left hinges134and widening the width of the wheels for travelling on leading edge122. For example, the convex shape is indicated as a double broken line inFIG.9C. The frame in attaching means130and the wheels for travelling on leading edge122forming a convex shape in the front view is helpful for properly positioning a blade of a wind turbine in central position of the device1000when attaching the device1000to the blade. Specifically, the blade is guided by the frame in attaching means130and the wheels for travelling on leading edge122and positioned in the central position of the device1000to be stable even if the blade is deviated from the central position of the device1000when the device1000is attached to the blade of the wind turbine. It is preferable that there is no gap in the front view between the frame in attaching means130and the wheels for travelling on leading edge122. That is because, when there is a gap in the front view between the frame in attaching means130and the wheels for travelling on leading edge122, the blade may fit in the gap when the blade is guided to the central position.

The device1000may comprise two manipulators114. The two manipulators114are configured to be foldable. At least one of maintenance means can be provided to the tip of the two manipulators114. For example, an imaging means140is provided to the tip of the two manipulators114. The device1000is able to image a place away from the device1000by extending the manipulators114to which the imaging means140is attached. The device1000can, for example, image the surface near the trailing edge (rear edge) of a blade of a wind turbine while being attached to the leading edge of the blade. For example, a conduction examining means150is provided to the tip of the two manipulators114. The device1000is able to examine a lightning receiving portion located away from the device1000by extending the manipulators114to which the conduction examining means150is attached. For example, an applying means180is provided to the tip of the two manipulators114. The device1000is able to apply a material to a place away from the device1000by extending the manipulators114to which the applying means180is attached. Furthermore, the number and attachment position of the manipulators114do not matter. Any number of manipulators114can be attached to any place of the device1000.

At least one of maintenance means may be detachably attached to the tip of the manipulators114. This enables the manipulators114to perform a plurality of maintenances. For example, in a first step, the surface of a blade of a wind turbine is observed by attaching an imaging means140to the tip of the manipulators114and making movement on the blade of the wind turbine. In a second step, a part requiring repair discovered in the first step is polished by exchanging the imaging means140at the tip of the manipulators114with a polishing means170and making movement on the blade of the wind turbine. In a third step, putty is applied to the part requiring repair polished in the second step by exchanging the polishing means170at the tip of the manipulators114with an applying means180and making movement on the blade of the wind turbine. In a fourth step, the part requiring repair to which putty was applied in the third step is polished to be smooth by exchanging the applying means180at the tip of the manipulators114with the polishing means170and making movement on the blade of the wind turbine. In a fifth step, the part requiring repair polished to be smooth in the fourth step is washed by exchanging the polishing means170at the tip of the manipulators114with a washing means160and making movement on the blade of the wind turbine. In a sixth step, the part requiring repair washed in the fifth step is painted by exchanging the washing step160at the tip of the manipulators114with the applying means180and making movement on the blade of the wind turbine. The part requiring repair may be repaired by these steps.

The manipulators114may comprise a mechanism (e.g., robot hand) (not shown) which operates while imitating the actions of an operator's arms, hands, fingers or the like. This enables the device1000to perform maintenance by using the manipulators114that operate according to the operator's actions. Upon doing so, the manipulators114may comprise a sensor detecting the state of the surface of an object to be in contact (e.g., a sensor detecting the elasticity of the surface, a sensor detecting the roughness on the surface, or the like) and thereby deliver the detected state of the surface of the object to the operator as tactile feedback. This enables the operator to operate the manipulators114with a sense as if he/she actually touches the surface of the object. For example, when putty is applied to the surface of a leading edge of a blade, a skilled sense is required in order to apply a proper amount of putty in a proper thickness. The operator can apply putty to the surface of the leading edge of the blade while utilizing his/her skilled sense by operating the manipulators114based on the provided tactile feedback. For example, the manipulators114may be configured to perform an action of holding an object. This enables performing an action of holding an object by using the manipulators114and sticking the held object to a blade of a wind turbine. This enables the manipulators114to stick, for example, a device such as a vortex generator that modifies an aerodynamic characteristic to the blade of the wind turbine.

The tip of the manipulators114can be controlled to be always perpendicular to the surface of a blade. This is useful when, for example, the conduction examining means150is provided to the tip of the manipulators114. The lightning receiving portion on a blade of a wind turbine is formed as a recessed portion having a wall surface perpendicular to the surface of the blade of the wind turbine. It is necessary to insert a probe straight in the recessed portion when examining the conduction of the light receiving portion. That is because the probe cannot be properly inserted in the recessed portion when the probe is inclined. Thus, it is preferable to control the probe for examining conduction at the tip of the manipulators114to be always perpendicular to the surface of the blade.

Controlling the tip of the manipulators114to be always perpendicular to the surface of the blade can be achieved by, for example, using a technique for controlling a relative posture. The technique for controlling a relative posture is, for example, a technique using at least two separated lasers provided to the tip of the manipulators114. This is to calculate the inclination of the probe by detecting a path difference between the at least two separated lasers. For example, the path difference between the at least two separated lasers is zero when the tip of the manipulators114is perpendicular to the surface of the blade, whereas the path difference between the at least two separated lasers is non-zero when the tip of the manipulators114is inclined relative to the surface of the blade. This is utilized to control the inclination of the tip of the manipulators114so that the path difference between the at least two separated lasers is zero.

FIG.13shows the state of two manipulators114before and after folding. InFIG.13, the manipulator114on the left side is shown in the folded state, while the manipulator114on the right side is shown in the extended state. The two manipulators114can transition between the folded state and the extended state in accordance with the situation. For example, the manipulators114are maintained in the folded state when a device1000does not perform maintenance using the manipulators114. This enables avoiding collision of the manipulators114with a blade of a wind turbine when the device1000is attached to the blade. It is also possible to avoid collision of the manipulators114with the blade even when the blade becomes thicker as the device1000moves on the blade.

The device1000may comprise a plurality of imaging means140in a plurality of positions on the device1000. The device1000can comprise, for example, seven imaging means140. The positions of the seven imaging means140may be, for example, (1) the tip of the manipulator114on the right side, (2) the tip of the manipulator114on the left side, (3) the intermediate position between the manipulators114on the right and left sides, (4) the outermost portion of a frame115on the right side, (5) the outermost portion of a frame115on the left side, (6) the intermediate position between the frames115on the right and left sides, or (7) the most rear portion of the device1000. The device1000can create an around view image from outputs of the plurality of imaging means140in the plurality of positions. The around view image is an image by which a wide area (e.g., 180°, 270°, 360°, or the like) around the device1000can be visually recognized. The around view image can be created by, for example, applying a known image synthesis technique to the outputs of the plurality of imaging means140in the plurality of positions. Displaying the created around view image to an interface for operation of a terminal for operation of an operator enables the operator to intuitively operate the device1000by, which leads to improvement of the operability of the device1000by operation.

The interface for operation displayed to the terminal for operation of the operator may display current position information and/or dimension information (e.g., a ruler) of the device1000on the blade in addition to or instead of the around view image. This enables detecting and recording the position and/or size of damage on the blade. For example, the current position information of the device1000on the blade may be displayed as a distance from the tip of the blade. This is achieved by, for example, calculating the distance of the movement of the device1000on the blade from the number of revolutions of a wheel for travelling on leading edge122and/or a wheel for travelling on blade side surface123. For example, the dimension information can be obtained by imaging an object with a known size on the blade and calculating the relative size based on the known size and the magnification of the image.

It is possible to create a damage map of the blade by detecting and recording the position and/or size of damage on the blade. The operator can move the device1000to a position with the damage based on the created damage map and perform maintenance in accordance with the damage. For example, it is possible to create a damage map by utilizing the image imaged during movement of the device1000in the direction from the tip of the blade toward the base of the blade in the above-described Step S901. Subsequently, it is possible to cause the device1000to perform maintenance such as washing, polishing, and applying based on the created damage map during movement of the device1000in the direction from the base of the blade toward the tip of the blade in Step S902.

The interface for operation displayed to the terminal for operation of the operator may display 3D image of the blade of the wind turbine in addition to or instead of the above-described image and/or information. The 3D image can be constructed, for example, based on outputs or the like of the plurality of imaging means140. The 3D image can be displayed, for example, to the terminal for operation such as a head mount display. The operator can freely observe the blade of the wind turbine via the 3D image by operation such as scaling or changing the viewpoint of the 3D image of the blade of the wind turbine. The 3D image of the blade of the wind turbine and the manipulators114comprising a mechanism that operates while imitating the operator's actions enable the operator to operate the device1000on the ground as if he/she is working on the blade of the wind turbine.

FIG.14shows one example of the appearance of a device2000, which is an alternative embodiment of a device100for performing maintenance on a blade of a wind turbine.FIG.14is a bottom side perspective view of the device2000.

InFIG.14, like reference numerals are given to the same components as those shown inFIG.4AandFIG.9AtoFIG.9C. The explanation of the components is omitted here. It should be noted that although the device2000has a different configuration from that of the device100or1000, maintenance on a blade of a wind turbine can be performed in the same manner as the method described above with reference toFIG.7andFIG.8.

The device2000can comprise a rope guide124for guiding a rope delivered from a winch121. This enables the rope delivered from the winch121to extend without interfering with the device2000. It is preferable to provided a bearing to the tip of the rope guide124. The largest frictional resistance to the rope is generated at the tip of the rope guide124. It is possible to decrease the frictional resistance to be generated by providing a bearing.

The device2000can comprise a wheel for travelling125on the opposite side to an attaching means130. The wheel for travelling125is different from a wheel for travelling on leading edge122and a wheel for travelling on leading edge122provided in a different position from a wheel for travelling on blade side surface123, or the wheel for travelling on blade side surface123. The wheel for travelling125is a wheel for travelling in a place other than the blade of the wind turbine. The wheel for travelling125is used, for example, to move the device2000while inclining it like a carry bag when carrying the device2000. The wheel for travelling125is used, for example, for the device2000to travel on the tower of the wind turbine. It may be necessary to image not only the surface on the leading edge side but also the surface on the trailing edge side when performing maintenance on the blade of the wind turbine. In this case, if the trailing edge side is imaged from the ground, the imaging location is so far from the trailing edge that it is difficult to obtain a clear image. As shown inFIG.15, the device2000can image the trailing edge side from a position closer to the trailing edge by vertically moving on the tower of the wind turbine by the wheel for travelling125along a rope20extending from the nacelle of the wind turbine, and can thereby obtain a clearer image.

Although it was explained that the wheel for travelling125is provided on the opposite side to the attaching means130in the example shown inFIG.14, the wheel for travelling125can be provided in any position as long as it can travel in contact with the tower of the wind turbine. For example, the wheel for travelling125may be provided on the side of the device2000(the side with the winch121inFIG.14).

It is preferable that the rope20extends from the front side of the nacelle14of the wind turbine10, that is, from near the hub15, to the ground as in the example shown inFIG.10toFIG.12. That is because, when the rope20extends from the rear side of the nacelle14to the ground, the rope20may hang on the lateral side of the wind turbine10and the device1000may come into contact with the tower when the device1000is moved along the rope20. For example, when hatches16of the nacelle14(seeFIG.16) are disposed on the rear side of the nacelle14, the rope hangs on the lateral side of the wind turbine10like the rope20′ inFIG.16when the rope is merely fixed to the hatches16. In this case, a rope position adjusting device500shown inFIG.16can be utilized so that the rope20extends from the front side of the nacelle14to the ground.

FIG.16is a perspective view of a nacelle14of a wind turbine10viewed from behind. Like reference numerals are given to the same components as those shown inFIG.1toFIG.3andFIG.10toFIG.12. The explanation of the components is omitted here.

A rope position adjusting device500comprises two slings510, two carabiners520, and a mat530. One end of the slings510is fixed to hatches16, and the other end of the slings is connected to the carabiners520. The two carabiners520are connected to each other. This results in that the two slings510and the two carabiners520form a loop shape on the nacelle14. The mat530is disposed between the carabiners520and the slings510, and the nacelle14, so as to prevent the nacelle14from being damaged by the carabiners520and the slings510. Further, the mat530also plays a role as a seat for holding the loop shape formed by the carabiners520and the slings510.

Ropes20extending from the hatches16extend in the direction in which the slings510extend, that is, the forward direction of the nacelle14, and the ropes are turned by passing through the carabiners520to extend in the direction to the ground. The ropes20fixed to the hatches16can extend from the front side of the nacelle14to the ground by the rope position adjusting device500.

For example, it is possible to adjust the position in which the ropes20extend from the nacelle14to the ground by configuring the length of the slings510adjustable.

Although the two ropes20extending from the hatches16extend in parallel to the direction in which the slings510extend in the example shown inFIG.16, the present invention is not limited to the above. The two ropes20may be crossed. For example, the rope20extending from the hatch16on the left side of the nacelle may extend to the carabiner520disposed on the right side of the nacelle and the rope may be turned by passing through the carabiner520to extend in the direction to the ground, whereas the rope20extending from the hatch16on the right side of the nacelle may extend to the carabiner520disposed on the left side of the nacelle and the rope may be turned by passing through the carabiner520to extend in the direction to the ground. Crossing the two ropes20enables decreasing the distance of the swing of a device100even when one of the two ropes20breaks during working.

Maintenance on a blade of a wind turbine is performed about once a year at most. Although the present invention can inexpensively provide a device for performing maintenance on an object, it is less cost-effective to purchase a device for performing maintenance for such maintenance performed once a year. In this regard, if an owner of a wind turbine can rent a device100for performing maintenance on the wind turbine, the cost can be further reduced and the cost-effectiveness can be improved.

A supplier of the device100can do rental business of the device100using, for example, the device100constructed in a size that can be conveyed by home delivery service (e.g., the full length of 80 cm or less, the weight of 40 kg or less). For example, the size that can be conveyed by home delivery service may be achieved by configuring the device100in such a manner that a winch121can be separated and separating the winch121from the device100. For example, the size that can be conveyed by home delivery service and/or can be carried may be achieved by configuring the device100in such a manner that the device100can be separated into four parts and disassembling the device100into four parts. Upon doing so, the subsequent assembling work will be easy if, for example, attaching means130are configured to be separatable from the device100with the attaching means130put together.

The owner of the wind turbine can always use the device100of the latest model to perform maintenance by renting the device100. Further, when the supplier of the device100exchanges consumables such as a rag162for a washing means160, a sand paper172for a polishing means170, and paint for an applying means180and supplies the device100, the owner of the wind turbine can perform maintenance on the wind turbine without being troubled. When the labor and cost for maintenance on the wind turbine are reduced, the maintenance on the wind turbine can be performed more frequently, which leads to more efficient operation of the wind turbine. One of the factors which enable increasing the frequency of maintenance on the wind turbine is that use of the device100of the present invention can eliminate the need for a worker to work at a high place and thereby maintenance can be safely performed.

Although a device and method for performing maintenance on a blade of a wind turbine were explained in the examples explained with reference toFIG.1toFIG.16, the present invention is not limited to the above. The target for which maintenance is performed by the device and method of the present invention can be any object requiring maintenance to which the device100can attach. For example, any object may be a wall surface of a building, or may be a main wing of a plane. For example, in the case of a wall surface of a building, it is necessary to wash dirt due to rain. For example, in the case of a main wing of a plane, it is necessary to inspect and wash the wing in order to keep the surface of the wing smooth. The device100can attach to the object by an attaching means130. For example, the device100attaches to a wall surface of a building by holding a projected portion of the wall surface of the building with the attaching means130. For example, the device100attaches to a main wing of a plane by holding the main wing of the plane with the attaching means130.

For example, any object can be a part of any structure. For example, any structure may be a wind turbine. In this case, any object can be a blade of the wind turbine. Any structure may be a building. In this case, any object can be a wall surface of the building. Any structure may be a plane. In this case, any object can be a main wing of the plane. For example, a device2000is able to travel on a portion other than a blade of a wind turbine, for example, on a tower, by a wheel for travelling125. For example, the device2000is able to travel on a portion other than a wall surface of a building, for example, on a rooftop by the wheel for travelling125. For example, the device2000is able to travel on a portion other than a main wing of a plane, for example, on a body, by the wheel for travelling125.

Any object is preferably an object at a high place. A high place herein refers to a place in a height that a worker on the ground cannot reach. A high place may be, for example, a place 3 m or more high from the ground, a place 5 m or more high from the ground, a place 10 m or more high from the ground, or a place 100 m or more high from the ground. A high place may be, for example, a place 3 m to 100 m high from the ground, a place 5 m to 100 m high from the ground, or a place 10 m to 100 m high from the ground. It should be noted that the ground may be an outdoor place, or may be an indoor place.

Any object is preferably an object having a non-uniform cross section. Since it is possible to deal with the change in the shape of an object by deformation of the attaching means130of the device100, the device100can maintain the attached state even when the shape of the object changes in association with movement when the device100moves on the object having a non-uniform cross section. An object having a non-uniform is preferably a wing body, and is more preferably a blade of a wind turbine.

Further, although the surface on which the device100attaches to any object has any angle, it is preferable that the surface on which the device100attaches to any object is inclined relative to the vertical direction. That is because, in addition to the holding force by the attaching means130, the gravity acting on the device100acts so as to push the device100against the object due to attachment of the device100to the inclined surface, and the device100is thereby more stable on the object.

Further, although it was explained that the posture of a device100is controlled using two ropes21connected to the device100in the examples explained with reference toFIG.2A,FIG.2B, andFIG.7, the present invention is not limited to the above. Operating the device100by at least two ropes remains within the scope of the present invention. For example, an operator can deliver a specific instruction to the device100via the tension of the ropes by operating at least two ropes. For example, simultaneously pulling a first rope and a second rope may be an instruction to stop. For example, pulling the second rope once after pulling the first rope twice may be an instruction to advance. Upon doing so, the device100may comprise a converter converting the tension applied to the ropes to a predetermined electrical signal to read out an instruction represented by the tension. In this manner, by operating the device100using at least two ropes, it is possible to operate the device100using tension without depending on electronics such as a controller.

Further, although a device for performing maintenance on an object was explained in the examples explained with reference toFIG.1toFIG.16, the present invention is not limited to the above. The device of the present invention may be a robot having a function to achieve any objective comprising performing maintenance. For example, any objective may be an objective to carry goods to a high place. It is possible to make it easy to carry goods to a high place by attaching a device mounted with goods to an object at a high place (e.g., an outer wall of a balcony of an apartment). For example, any objective may be an objective to decorate an object. It is possible to easily decorate an object at a high place by attaching a device with decoration to the object at a high place.

The present invention is not limited to the above-described embodiments. It is understood that the scope of the present invention should be interpreted only by the Claims. It is understood that those skilled in the art can practice an equivalent scope based on the descriptions in the present invention and common general knowledge from the descriptions of specific and preferable embodiments of the present invention.

INDUSTRIAL APPLICABILITY

The present invention is useful for providing a device, system, and method for inexpensively and safely performing maintenance on an object.

Further, the present invention is also useful for enabling performing maintenance on an object in accordance with the change in the shape of the object.

Furthermore, the present invention is also useful for providing a method for operating a robot located away from an operator by tension.

REFERENCE SIGNS LIST

10wind turbine11,12,13blade14nacelle15hub20,21rope100device110maintenance means121winch122wheel for travelling on leading edge123wheel for travelling on blade side surface130attaching means