Work system and work system control method

Abstract

[Problem] To provide a work system that can better stabilize the attitude of an airframe during work using the airframe. [Solution] The work system according to the present disclosure comprises rotors 3, an airframe 2 that supports the rotors 3, and a tether 5 which is connected to and extends above the airframe 2, and which supports the airframe 2 suspended therefrom, wherein, in a state in which the airframe 2 is suspended from the tether 5, the rotors 3 generate a downward force with respect to the airframe 2 or an upward force that is smaller than the gravitational force acting on the airframe.

Description

[Technical Field]

[0001] The present disclosure relates to a work system and a method for controlling a machine. [Background technology]

[0002] Unmanned aerial vehicles known as drones are sometimes used to efficiently carry out work on structures in a variety of environments, including narrow or bottleneck spaces, indoors or outdoors, etc. For example, Patent Document 1 discloses a system that introduces an unmanned aerial vehicle through a conduit and connects a cable to the unmanned aerial vehicle, thereby suppressing cable flex. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-167044 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the technology disclosed in Patent Document 1, controlling the flexure of the cable makes it difficult to control the attitude of the unmanned aerial vehicle, which makes it difficult to perform work while keeping the vehicle in a stable attitude.

[0005] The present disclosure has been made in consideration of this background, and aims to provide a work system and a method for controlling a machine that can more stabilize the attitude of the machine when working using the machine. [Means for solving the problem]

[0006] In order to solve the above problems, according to the present disclosure, there is provided a work system comprising a thrust generating unit, an aircraft body supporting the thrust generating unit, and a tether connected to the aircraft body, extending upward and suspending and supporting the aircraft, wherein when the aircraft is suspended by the tether, the thrust generating unit generates a downward force on the aircraft body, or an upward force that is smaller than the gravitational force acting on the aircraft body.

[0007] Furthermore, according to the present disclosure, there is provided a method for controlling a machine that performs work, the machine comprising a thrust generating unit supported by the machine, and a tether connected to the machine and extending upward to suspend and support the machine, wherein, while the machine is suspended by the tether, the thrust generating unit generates a downward force on the machine, or generates an upward force on the machine that is smaller than the force of gravity.

[0008] Other problems and solutions disclosed in this application will be made clear in the section on preferred embodiments of the invention and the drawings. [Effects of the Invention]

[0009] According to the present invention, the attitude of the machine can be made more stable during work using the machine. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing the configuration of a working system 1 according to an embodiment of the present invention. [Figure 2] 10A and 10B are diagrams for explaining an example of rotation control around the yaw axis by the rotor 3 according to the embodiment. [Figure 3] FIG. 10 is a perspective view showing the configuration of a modified example of the working system 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant explanations will be omitted.

[0012] In addition, in this specification and drawings, a plurality of components having substantially the same functional configuration may be distinguished by adding different alphabets to the same reference numeral.

[0013] <Details of implementation form> A work system 1 according to one embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the configuration of the work system 1 according to this embodiment. In this specification, the X direction, Y direction, and Z direction shown in FIG. 1 respectively refer to the front-to-rear direction, width direction, and height direction of a machine body 2 in the work system 1. The work system 1 according to this embodiment can be used for work in a variety of applications, such as various inspections and repairs of structures, equipment, piping, etc., or checking instruments in a factory, etc.

[0014] As shown in Figure 1, the work system 1 according to this embodiment includes a body 2, a rotor 3, a tether 5, and a camera 6. Note that the configuration of the work system 1 shown in Figure 1 is one example, and even if a system has a structure, shape, or size different from the body 2 and rotor 3 shown in Figure 1, it can be included in the scope of the present invention as long as it has a configuration corresponding to the body 2 and rotor 3 described below.

[0015] More specifically, the airframe 2 is made up of a support frame 21 and an auxiliary frame 22. The auxiliary frame 22 is connected to the support frame 21. Specifically, the auxiliary frame 22 is connected to extend from both the front and rear of the support frame 21. The auxiliary frame 22 includes an arm 23. As shown in FIG. 1 , the rotor 3 is supported by the arm 23. In other words, the rotor 3 is supported by the airframe 2. Note that the arm 23 according to this embodiment is also connected to the support frame 21. The material constituting the airframe 2 is not particularly limited, and may be, for example, carbon fiber resin, glass fiber resin, magnesium, magnesium alloy, aluminum, aluminum alloy, steel, titanium, or other materials.

[0016] The support frame 21 carries and supports components related to the control and power of the rotor 3 of the airframe 2, such as a circuit board, flight controller, sensors, or battery (not shown). For example, a control circuit including a flight controller may be mounted on the support frame 21. Power is supplied from the battery to the motor 4 and sensors, and the rotation speed of the motor 4 is controlled by the flight controller.

[0017] The auxiliary frame 22 constitutes the airframe 2, is connected to the support frame 21, and supports the rotor 3. In the example shown in Fig. 1, the auxiliary frame 22 extends in the front-rear direction from the front-rear end of the support frame 21, and extends laterally in the width direction from the middle. The auxiliary frame 22 can function as a propeller guard for the rotor 3, for example.

[0018] The rotor 3 is provided on the arm 23 between the end of the auxiliary frame 22 and the support frame 21. In the example shown in Figure 1, the arm 23 is provided with a motor mount 231, which is provided with a motor 4 that powers the rotor 3, and the rotor 3 is attached to the motor 4.

[0019] In this embodiment, the arms 23 and the rotors 3 are provided at four locations (front, rear, left, and right), but the present invention is not limited to this example. The number of arms 23 and the number of rotors 3 provided can be changed as appropriate depending on the structure, shape, equipment, size, etc. of the aircraft body 2.

[0020] Furthermore, a camera 6 may be provided on the support frame 21 at the connection between the support frame 21 and the auxiliary frame 22 on the front side of the fuselage 2. The camera 6 may be provided at any location on the support frame 21 in addition to the location shown in Fig. 1. The camera 6 may be, for example, a general imaging device, or any of various imaging devices such as a stereo camera, a night vision camera, an infrared camera, or a thermograph.

[0021] As shown in FIG. 1 , the work system 1 according to this embodiment also includes a tether 5. The tether 5 is connected to the machine body 2, extends upward, and suspends and supports the machine body 2. As shown in FIG. 1 , the tether 5 may be composed of a main portion 50 and branch portions 51. The main portion 50 and the branch portions 51 may be connected at connection portions 52. Note that the tether 5 shown in FIG. 1 is merely an example, and the specific form of the tether 5 is not particularly limited as long as it is connected to the machine body 2, extends upward, and suspends and supports the machine body 2. For example, the main portion 50 and the branch portions 51 may be integrated, or the tether 5 may be composed of only the main portion 50, which is connected to the central portion of the machine body 2.

[0022] The upper part of the main part 50 is supported by a support (not shown). The support may be, for example, a structure such as a hook that secures the main part 50, or a movable structure such as a crane or other flying object. The main part 50 may be configured to be movable in the horizontal direction HZ1. For example, the upper part of the main part 50 may be supported by a guide rail or the like that is movable in the horizontal direction HZ1, thereby allowing the tether 5 to move in the horizontal direction HZ1.

[0023] Furthermore, the main part 50 may be provided so as to be movable in the vertical direction UD1. That is, by moving the main part 50 in the vertical direction UD1, the machine body 2 can also move in the vertical direction UD1. For example, the main part 50 may be movable in the vertical direction UD1 by having the upper part of the main part 50 wound up or fed out by a support such as a crane. Furthermore, the main part 50 may be movable in the vertical direction UD1 by extending and contracting the main part 50 itself.

[0024] A connecting portion 221 is provided at each of the four corners of the auxiliary frame 22 of the airframe 2. Each of these connecting portions 221 is connected to each of the branch portions 51. In this way, the tether 5 suspends and supports the airframe 2.

[0025] There are no particular limitations on the material that constitutes the tether 5. However, as will be described later, it is preferable that the tether 5 be made of a material with little elasticity in order to ensure the stability of the attitude of the airframe 2. The tether 5 may be, for example, a rod, plate, cable, or rope made of fiber, metal, hard plastic, or the like.

[0026] The rotor 3 according to this embodiment is an example of a thrust generating unit. Unlike unmanned aerial vehicles such as general multicopters that are composed of an airframe and rotors, the rotor 3 according to this embodiment generates a downward thrust DF1. Therefore, a mechanism for generating lift in an airframe such as an unmanned aerial vehicle is not used in the system according to this embodiment. In other words, the configuration of the system according to this embodiment is different from a conventional configuration in which a cable or the like is connected to an unmanned aerial vehicle.

[0027] The rotor 3 according to this embodiment generates an airflow from below to above by rotation, generating a downward thrust. Note that a downward thrust means that the directional component of the thrust includes a vertically downward component. When the rotor 3 generates a downward thrust, a downward force is exerted on the airframe 2. This generates tension on the tether 5, and when the movement of the tether 5 in the vertical direction UD1 is restricted, the airframe 2 is fixed in a state where it receives the downward thrust. In this situation, assume that the tether 5 moves in the vertical direction UD1. For example, if the tether 5 moves downward, the tether 5 relaxes, causing the airframe 2 to move downward. In this case, not only gravity but also a downward thrust acts on the airframe 2, so the downward acceleration of the airframe 2 is greater than that of a free fall, allowing it to quickly move to the desired position. Furthermore, even after moving to the desired position, a downward force is exerted on the airframe 2 by the rotor 3, making it less likely to flap due to impact after the movement, and the airframe 2 can be quickly controlled to a stable attitude.

[0028] In particular, compared to the configuration described above in which a cable is connected to a typical unmanned aerial vehicle, the unmanned aerial vehicle attempts to maintain its attitude by using lift, and the cable does not act on the body of the unmanned aerial vehicle. As a result, the attitude may become unstable depending on the performance of the vehicle and the flight environment. On the other hand, in the system according to this embodiment, a balance of forces in the opposite direction (pulling direction) is generated on the airframe 2 due to the tension of the tether 5 and the downward thrust of the rotor 3 of the airframe 2. Therefore, it is possible to stably maintain the airframe 2 even when it is floating in the air.

[0029] The airframe 2 according to this embodiment may be controlled based on input from a control terminal such as a remote control, similar to an unmanned aerial vehicle (e.g., a drone), or may move autonomously according to a program. The attitude of the airframe 2 may be controlled by a flight controller based on input from appropriate sensors. Furthermore, the attitude of the airframe 2 may be controlled by adjusting the thrust generated by the lift generating unit, by moving the tether 5 vertically or horizontally, or both. Specifically, when a target value is set so that the attitude of the airframe 2 relative to the horizontal direction is 0 degrees, the attitude feedback control may be performed by controlling the rotation speed of each rotor 3, or by controlling the horizontal or vertical movement of the tether 5. This makes it possible to suppress the horizontal movement of the airframe 2 and more reliably maintain its attitude, even if the attitude of the airframe 2 tilts due to wind or drift.

[0030] The number of rotors 3 that generate downward thrust is not particularly limited, but it is preferable that the number of rotors 3 be four or more in order to further stabilize the attitude of the aircraft 2. Furthermore, the thrust generating unit may be realized by a mechanism other than rotors.

[0031] Furthermore, when rotating the airframe 2 along a horizontal plane (so-called rotation around a yaw axis perpendicular to the horizontal plane), this may be achieved by twisting the tether 5 or by controlling the rotation of the rotors 3. FIG. 2 is a diagram illustrating an example of control of rotation around the yaw axis by the rotors 3 according to this embodiment. As shown in FIG. 2, the airframe 2 can be rotated around the yaw axis by varying the rotation directions of the four rotors 3a, 3b, 3c, and 3d. Specifically, the rotation directions of the rotors 3a and 3d (second rotors) are set counterclockwise (CCW1, CCW2) and the rotation directions of the rotors 3b and 3c (first rotors) are set clockwise (CW1, CW2), and the rotation speeds of the first rotor and the second rotor are controlled to be different, thereby rotating the airframe 2 around the yaw axis. 2, the rotors 3b and 3c rotate clockwise and the rotors 3a and 3d rotate counterclockwise, but these rotation directions may be opposite. That is, the rotors 3b and 3c may rotate counterclockwise and the rotors 3a and 3d may rotate clockwise.

[0032] With this configuration, it is possible to determine the orientation of the airframe 2 with greater precision than simply twisting the tether 5 to rotate the airframe 2.

[0033] As described above, in the work system 1 according to an embodiment of the present disclosure, the aircraft 2 is suspended and supported by the tether 5, while the rotors 3 of the aircraft 2 generate downward thrust, thereby applying a vertical pulling force to the aircraft 2. This allows the aircraft 2 to be momentarily maintained in a stable attitude even when moving in the vertical direction, etc. Furthermore, by enabling the aircraft 2 itself to rotate around the yaw axis, the attitude of the aircraft 2 relative to the work target can be maintained with high precision. The configuration according to this embodiment is particularly effective in controlling a small aircraft 2 used for photography, inspection, etc. in closed or narrow spaces.

[0034] Although the present embodiment has been described above, the above embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and equivalents thereof are also included in the present invention.

[0035] In the above embodiment, the thrust generating unit is configured to generate a downward force (thrust force DF1) on the airframe when the airframe is suspended by the tether, but this is not limited thereto. The thrust generating unit may also be configured to generate an upward force (thrust force DF2) that is smaller than the force of gravity G acting on the airframe (see FIG. 3). In this case, the burden on the tether 5 can be reduced. Even in this case, the force that the thrust generating unit generates upward on the airframe is smaller than the force of gravity G acting on the airframe, so the tether 5 does not relax and can stably hold the airframe 2, as in the above embodiment.

[0036] The tether 5 may also include a cable connected to an electric winch. In this case, the length of the cable can be adjusted by winding and unwinding the electric winch. In this case, the cable moves up and down, allowing the height of the aircraft to be changed. The installation location of the electric winch is not particularly limited and may be inside or outside the flight environment. Alternatively, one or more pulleys may be installed above the aircraft, and the cable may be connected via the pulleys. In this case, the electric winch may be installed below the aircraft. The electric winch may be controlled to wind and unwind based on input from a control terminal such as a radio control, or may be controlled autonomously according to a program or the like. It is preferable that a single control device can simultaneously control the aircraft and the electric winch, thereby enabling more efficient control of the aircraft's position.

[0037] As shown in Figure 3, a rotary joint 7 may be provided on the tethering body 5. The rotary joint 7 is configured to be freely rotatable, and rotation (torsion) of the tethering body 5 connected to one side of the rotary joint 7 (for example, the lower side in Figure 3) is not transmitted to the tethering body 5 connected to the other side of the rotary joint 7 (for example, the upper side in Figure 3). With this configuration, even if the aircraft rotates around the yaw axis, the tethering body 5 does not twist, so it is not affected by reaction forces in the torsional direction, making it easier to control the aircraft. The position of the rotary joint 7 is not particularly limited and can be provided at any position, but it is preferably provided on the main section 50 near the connection section 52.

[0038] Furthermore, as shown in FIG. 3, a weight 8 may be attached to the tether 5. By providing the weight 8, the airframe and tether 5 are less susceptible to the effects of air currents, improving stability. Furthermore, even if a weight 8 is provided, the airframe is supported by the tether 5, so there is almost no effect on the battery consumption when controlling the airframe. The weight 8 may be located above or below the rotary joint 7, or may be integral with the rotary joint 7. The location of the weight 8 is not particularly limited, and it may be located at one or more positions on the main portion 50, each branch portion 51, or connecting portion 52 of the tether 5, or on the airframe.

[0039] 3, the aircraft may be provided with a light 9 that emits light. The position and orientation of the light 9 are not particularly limited, but it is preferable that the light 9 be disposed so as to illuminate the shooting direction and shooting range of the camera 6. In the illustrated example, the light 9 is disposed so as to illuminate the front of the aircraft in correspondence with the camera 6 that shoots the view ahead of the aircraft. In the illustrated example, the light 9 is located above the camera 6, but it may be located below, on the left, or on the right side of the camera 6.

[0040] The system 1 may also include a communication cable for data communication between the aircraft and an external device (e.g., a control terminal, a control terminal, etc.). This allows a wired connection between the aircraft and the external device, allowing data to be exchanged via the communication cable. This data may include, for example, control signals transmitted from the control device to the aircraft to control the aircraft, images (still images, video) captured by the aircraft's camera 6, data acquired by various sensors, etc. The communication cable may be provided integrally with the tether 5. Specifically, for example, as shown in FIG. 3, a communication cable 53 provided integrally with the main portion 50 of the tether 5 may branch off at a connection portion 52 and be connected to a control board of the aircraft.

[0041] Similarly, the present system 1 may include a power cable that supplies power to the aircraft from an external power source. In this case, there is no need to provide a battery in the aircraft, which allows for weight reduction and prevents battery shortages during flight. The power cable may be provided integrally with the tether 5, similar to the communication cable 53 described above. The power cable may be provided integrally with the communication cable 53, or may be provided separately. Note that it is preferable to position the power cable and communication cable 53 so that they are not subjected to tension when the tether 5 supports the aircraft.

[0042] The following configurations also fall within the technical scope of the present disclosure. (Item 1) a thrust generating unit; an airframe supporting the thrust generating unit; A tether connected to the airframe, extending upward, and suspending and supporting the airframe; Equipped with When the airframe is suspended by a tether, the thrust generating unit generates a downward force on the airframe, or generates an upward force that is smaller than gravity acting on the airframe. Working system. (Item 2) The tether is movable horizontally; The airframe is moved horizontally by moving the tether in a horizontal direction while a downward or upward force is generated by the thrust generating unit. Item 1. The working system according to item 1. (Item 3) the thrust generating unit is a rotor, The rotors have at least one first rotor that rotates clockwise and at least one second rotor that rotates counterclockwise when the rotation is controlled; By controlling the rotation speed of the first rotor and the rotation speed of the second rotor to be different, the airframe is rotated around an axis perpendicular to a horizontal plane. Item 1 or 2. A working system according to item 1 or 2. (Item 4) The airframe moves up and down in response to the vertical movement of the tether. The operation system according to any one of items 1 to 3. (Item 5) 5. The working system according to any one of items 1 to 4, wherein the tether is provided with a rotary joint that is rotatable around the yaw axis of the aircraft. (Item 6) 6. The working system according to any one of items 1 to 5, wherein the tether is provided with a weight. (Item 7) The work system described in any one of items 1 to 6, wherein at least one of a communication cable for data communication between an external device and the aircraft and a power cable for supplying power to the aircraft is integrally provided with the tether. (Item 8) A method for controlling a machine that performs work, comprising: The airframe is a thrust generating unit supported by the airframe; A tether connected to the airframe, extending upward, and suspending and supporting the airframe; Equipped with When the airframe is suspended by a tether, the thrust generating unit generates a downward force on the airframe, or generates an upward force on the airframe that is smaller than the force of gravity. How to control the aircraft. [Explanation of symbols]

[0043] 1. Work System 2 aircraft 3 rotor blades 4 motors 5 Tethered body

Claims

1. a thrust generating unit; an airframe supporting the thrust generating unit; A tether connected to the airframe, extending upward, and suspending and supporting the airframe; an electric winch capable of winding and unwinding the tether; one control terminal capable of inputting both an instruction to control the movement of the airframe by the thrust generating unit and an instruction to control the winding and unwinding of the electric winch; Equipped with the tether is supported by a non-flying support; When the airframe is suspended by a tether and the airframe is not moving in the vertical direction, the thrust generating unit generates a downward force on the airframe, or generates an upward force that is smaller than the force of gravity acting on the airframe, The airframe is suspended and supported by a single tether extending downward from the support; The tether has a main portion extending below the support and a branch portion branching from a lower end of the main portion, The branch portions are connected to connection portions located at four corners outside the thrust generating portion when viewed from the center of the aircraft in a plan view.

2. The tether is movable horizontally; The airframe is moved horizontally by moving the tether in a horizontal direction while a downward or upward force is generated by the thrust generating unit. The work system according to claim 1 .

3. the thrust generating unit is a rotor, The rotors have at least one first rotor that rotates clockwise and at least one second rotor that rotates counterclockwise when the rotation is controlled; rotating the airframe about an axis perpendicular to a horizontal plane by controlling the rotation speed of the first rotor and the rotation speed of the second rotor to be different from each other; The work system according to claim 1 or 2.

4. The airframe moves up and down in response to the vertical movement of the tether. The work system according to any one of claims 1 to 3.

5. The work system according to any one of claims 1 to 4, wherein the tether is provided with a rotary joint that is rotatable around the yaw axis of the aircraft.

6. The work system according to any one of claims 1 to 5, wherein the tether is provided with a weight located above the aircraft body to reduce the effect of airflow on the tether.

7. A work system described in any one of claims 1 to 6, wherein at least one of a communication cable for data communication between an external device and the aircraft and a power cable for supplying power to the aircraft is integrally provided with the tether.

8. the aircraft is equipped with a camera or a sensor; The work system according to any one of claims 1 to 7, which inspects and repairs structures or facilities.

9. The work system according to claim 8 , wherein the vehicle is supported by being suspended inside the structure or facility.

10. A thrust generating unit; an airframe supporting the thrust generating unit; A tether connected to the airframe, extending upward, and suspending and supporting the airframe; an electric winch capable of winding and unwinding the tether; one control terminal capable of inputting both an instruction to control the movement of the airframe by the thrust generating unit and an instruction to control the winding and unwinding of the electric winch; Equipped with the tether is supported by a non-flying support; When the airframe is suspended by a tether and the airframe is not moving in the vertical direction, the thrust generating unit generates a downward force on the airframe, or generates an upward force that is smaller than the force of gravity acting on the airframe, The airframe is suspended and supported by a single tether extending downward from the support; An operating system in which the aircraft is suspended by a tether and the aircraft is not moving in the vertical direction, and the thrust generating unit is capable of generating a downward force on the aircraft.

11. 2. The work system according to claim 1, wherein the airframe can be rotated about a yaw axis by twisting the tether, and the airframe can be rotated about the yaw axis by controlling rotors that constitute the thrust generating unit.

12. A control method for a work system including a machine that performs work, The working system comprises: a thrust generating unit supported by the airframe; A tether connected to the airframe, extending upward, and suspending and supporting the airframe; an electric winch capable of winding and unwinding the tether; one control terminal capable of inputting both an instruction to control the movement of the airframe by the thrust generating unit and an instruction to control the winding and unwinding of the electric winch; Equipped with the tether is supported by a non-flying support; When the airframe is suspended by a tether and is not moving in the vertical direction, the thrust generating unit generates a downward force on the airframe, or generates an upward force that is smaller than the gravity acting on the airframe, The airframe is suspended and supported by a single tether extending downward from the support; The tether has a main portion extending below the support and a branch portion branching from a lower end of the main portion, the branch portions are connected to connection portions located at four corners that are outer than the thrust generating portion when viewed from the center of the airframe in a plan view. How to control the work system.

Images