Shape control device

Abstract

To provide a shape control device which can vibrate a film shape body in the direction along a reference axis stably over a comparatively long period.SOLUTION: A shape control device 2 comprises: a holding part 13 which holds a center part when a film shape body 100 is viewed in the thickness direction; an axial line drive part 12 which has a rotary solenoid or piezoelectric element and vibrates the holding part in the direction along a reference axis O1 along the thickness direction; a rotation drive part 35 which rotates the axial line drive part around the reference axis; and a control part 45 which controls the axial line drive part and the rotation drive part. The control part controls the axial line drive part such that the holding part is arranged at the same position in the direction along the reference axis when the holding part is arranged in the prescribed orientation around the reference axis while vibrating the holding part in the direction along the reference axis by the axial line drive part while rotating the axial line drive part around the reference axis by the rotation drive part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a shape control device. [Background technology]

[0002] Conventionally, shape control devices described in Non-Patent Documents 1 and 2 are known for controlling the shape of film-like materials. In the shape control device, the stepper motor and link mechanism are connected to a holding section that holds the film-like material. While the film-like body is held in place by the shape control device's holding section, the central part of the film-like body is vibrated in a direction along the reference axis, and simultaneously rotated around the reference axis, thereby deforming the film-like body into a desired shape. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Bo Fu, Evan Sperber, Fidelis Eke “Solar sail technology-A state of the art review” Progress in Aerospace Sciences, 86(2016), p. 1-19 [Non-Patent Document 2] Yuki Takao, Osamu Mori, Masanori Matsushita, Nobukatsu Okuizumi, Yasutaka Satou, and Junichiro Kawaguchi "Active Shape Control of Membrane Structures Using Spin-Synchronous Vibrations", JOURNAL OF SPACECRAFT AND ROCKETS, Vol. 59, No. 1, January-February 2022 [Overview of the project]

Problems to be Solved by the Invention

[0004] However, in the shape control devices described in Non-Patent Documents 1 and 2, members constituting the link mechanism slide. Therefore, the shape control device may be damaged. In this case, it becomes difficult to use the shape control device for a relatively long period of several years, for example, when used for space applications.

[0005] The present invention has been made in view of such problems, and an object thereof is to provide a shape control device capable of vibrating a film-like body or a linear body stably in a direction along a reference axis over a relatively long period.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention proposes the following means. (1)Aspect 1 of the present invention includes a holding portion that holds the central portion of a film-like body when viewed in the thickness direction, an axial drive portion having a rotary solenoid or a piezoelectric element that vibrates the holding portion in a direction along a reference axis along the thickness direction, a rotation drive portion that rotates the axial drive portion around the reference axis, and a control portion that controls the axial drive portion and the rotation drive portion. The control portion controls the axial drive portion so that, while rotating the axial drive portion around the reference axis by the rotation drive portion and vibrating the holding portion in the direction along the reference axis by the axial drive portion, the holding portion is arranged at the same position in the direction along the reference axis when the holding portion is arranged in a predetermined direction around the reference axis. It is a shape control device.

[0007] In the present invention, with the central portion of the film-like body held by the holding portion, the control portion rotates the axial drive portion that moves the holding portion around the reference axis by the rotation drive portion. Then, the film-like body expands in a direction orthogonal to the reference axis due to centrifugal force. At this time, while the control unit vibrates the holding unit in the direction along the reference axis by the axis drive unit, when the holding unit is arranged in a predetermined direction around the reference axis, the control unit controls the axis drive unit so that the holding unit is arranged at the same position in the direction along the reference axis. Then, in the inertial system, the shape of the entire membranous body rotating around the reference axis becomes a constant shape. The axis drive unit generally has a rotary solenoid or a piezoelectric element with stable operation, and is directly connected to the holding unit without using, for example, a link mechanism. Therefore, the membranous body can be stably vibrated in the direction along the reference axis for a relatively long period.

[0008] (2)Aspect 2 of the present invention may be the shape control device according to (1), wherein the axis drive unit has the rotary solenoid, and by rotating the holding unit by the axis drive unit, a portion of the membranous body held by the holding unit vibrates in the direction along the reference axis. In this invention, the holding unit can be stably rotated by the rotary solenoid over a long period. Thereby, the shape of the membranous body can be stably vibrated in the direction along the reference axis over a relatively long period.

[0009] (3)Aspect 3 of the present invention may be the shape control device according to (1) or (2), which includes a plurality of sets of the holding unit and the axis drive unit, and the plurality of axis drive units are arranged side by side around the reference axis. In this invention, the shape of the membranous body can be controlled to a shape closer to a desired shape by the plurality of axis drive units and the plurality of holding units.

[0010] (4)Aspect 4 of the present invention may be the shape control device according to (3), wherein a plurality of control waveforms used by the control unit to control the vibration of the holding unit by the plurality of axis drive units differ only in phase from each other. In this invention, a plurality of control waveforms necessary for the control unit to control the plurality of axis drive units can be created relatively easily.

[0011] (5) Aspect 5 of the present invention is a shape control device comprising: a holding part that holds the central part of a film-like body when viewed in the thickness direction; an axial drive unit composed of a rotary solenoid or piezoelectric element that vibrates the holding part in a direction along a reference axis along the thickness direction; a rotational drive unit that rotates the axial drive unit around the reference axis; and a control unit that controls the axial drive unit and the rotational drive unit, wherein the control unit rotates the axial drive unit around the reference axis with the rotational drive unit and vibrates the holding part in a direction along the reference axis with the axial drive unit, and controls the axial drive unit such that the position of the holding part in the direction along the reference axis when the holding part is positioned in a predetermined direction around the reference axis and the position of the holding part in the direction along the reference axis when the holding part has rotated further around the reference axis to a position that is one rotation plus a displacement angle shift are equal to each other.

[0012] In this invention, with the central part of the film-like body held by the holding part, the control unit rotates the axial drive unit that moves the holding part around a reference axis using the rotation drive unit. As a result, the film-like body expands in a direction perpendicular to the reference axis due to centrifugal force. At this time, the control unit vibrates the holding part in a direction along the reference axis using the axial drive unit, and controls the axial drive unit as follows: That is, the control unit is controlled so that the position of the holding part in the direction along the reference axis when the holding part is positioned in a predetermined orientation around the reference axis and the position of the holding part in the direction along the reference axis when the holding part has rotated further around the reference axis to a position that is one full rotation plus a displacement angle are equal to each other. As a result, in the inertial frame, the shape of the entire membrane-like body rotating around the reference axis maintains a constant shape while rotating around the reference axis at a predetermined speed. The axial drive unit generally has a rotary solenoid or piezoelectric element that operates stably, and is directly connected to the holding unit without using a link mechanism, for example, so that the membrane can be vibrated stably in a direction along the reference axis over a relatively long period of time.

[0013] (6) Aspect 6 of the present invention is a shape control device comprising: a holding part for holding the end of a linear body; an axial drive unit having a rotary solenoid or piezoelectric element for vibrating the holding part in a direction along a reference axis; a rotational drive unit for rotating the axial drive unit around the reference axis; and a control unit for controlling the axial drive unit and the rotational drive unit, wherein the control unit rotates the axial drive unit around the reference axis with the rotational drive unit and vibrates the holding part in a direction along the reference axis with the axial drive unit, and controls the axial drive unit so that when the holding part is positioned in a predetermined direction around the reference axis, the holding part is positioned in the same position in the direction along the reference axis.

[0014] In this invention, with the end of the linear body held by the holding part, the control unit rotates the axial drive unit that moves the holding part around a reference axis using the rotation drive unit. As a result, the linear body expands in a direction perpendicular to the reference axis due to centrifugal force. At this time, the control unit vibrates the holding part in a direction along the reference axis using the axial drive unit, and controls the axial drive unit so that when the holding part is positioned in a predetermined orientation around the reference axis, the holding part is positioned in the same position in the direction along the reference axis. As a result, in the inertial frame, the trajectory of the linear body rotating around the reference axis takes on a constant shape. The axial drive unit generally has a rotary solenoid or piezoelectric element that operates stably, and is directly connected to the holding unit without using a link mechanism, for example, so that the linear body can be vibrated stably in a direction along the reference axis over a relatively long period of time.

[0015] (7) Aspect 7 of the present invention is a shape control device comprising: a holding part for holding the end of a linear body; an axial drive unit having a rotary solenoid or piezoelectric element for vibrating the holding part in a direction along a reference axis; a rotational drive unit for rotating the axial drive unit around the reference axis; and a control unit for controlling the axial drive unit and the rotational drive unit, wherein the control unit rotates the axial drive unit around the reference axis with the rotational drive unit and vibrates the holding part in a direction along the reference axis with the axial drive unit, and controls the axial drive unit such that the position of the holding part in the direction along the reference axis when the holding part is positioned in a predetermined direction around the reference axis and the position of the holding part in the direction along the reference axis when the holding part has rotated further around the reference axis to a position that is one rotation plus a displacement angle difference are equal to each other.

[0016] In this invention, with the end of the linear body held by the holding part, the control unit rotates the axial drive unit that moves the holding part around a reference axis using the rotation drive unit. As a result, the linear body expands in a direction perpendicular to the reference axis due to centrifugal force. At this time, the control unit vibrates the holding part in a direction along the reference axis using the axial drive unit, and controls the axial drive unit as follows: That is, the control unit is controlled so that the position of the holding part in the direction along the reference axis when the holding part is positioned in a predetermined direction around the reference axis and the position of the holding part in the direction along the reference axis when the holding part has rotated further around the reference axis to a position that is one full rotation plus a displacement angle are equal to each other. As a result, in the inertial frame, the shape of the trajectory of the linear body rotating around the reference axis maintains a constant shape while rotating around the reference axis at a predetermined speed. The axial drive unit is generally configured with a rotary solenoid or piezoelectric element that provides stable operation, and is directly connected to the holding unit without using a link mechanism, for example. This allows the linear body to be vibrated stably in a direction along the reference axis over a relatively long period of time. [Effects of the Invention]

[0017] The shape control device of the present invention can stably vibrate a film-like body or a linear body in a direction along a reference axis over a relatively long period of time. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic perspective view showing a part of a spacecraft in which the shape control device of the first embodiment of the present invention is used. [Figure 2] This is a perspective view of the axis drive unit in the same-shaped control device. [Figure 3] This figure shows an example of a timing chart for the clock signal and control waveform generated by the CPU. [Figure 4] This is a block diagram of multiple drive control units. [Figure 5] This is a photograph from an experiment in which the shape of a membrane was controlled using the same shape control device. [Figure 6] This figure shows an example of the spacecraft's operation. [Figure 7] This figure shows another example of the spacecraft's operation. [Figure 8] This figure shows the main parts of a shape control device in a modified example of the first embodiment of the present invention. [Figure 9] This figure shows the main part of the control device with the same shape, where the flap has been deformed. [Figure 10] This is a schematic perspective view showing a part of a spacecraft in which the shape control device of the second embodiment of the present invention is used. [Figure 11] This diagram illustrates the x and z axes defined for a linear body. [Figure 12] This diagram illustrates the equilibrium conditions for forces acting on a small linear element of a linear body. [Modes for carrying out the invention]

[0019] (First Embodiment) Hereinafter, a spacecraft using the first embodiment of the shape control device according to the present invention will be described with reference to Figures 1 to 9.

[0020] [1.1. Configuration of a spacecraft using the shape control device of the first embodiment] As shown in Figure 1, the shape control device 2 of this embodiment is used by being attached to a structure (main body) 3 for a spacecraft 1, such as a solar sail. The shape control device 2 is a device for controlling the membrane-like body 100 to a desired shape. In Figure 1, the membrane-like body 100 is shown by a dashed line. Here, in a membrane-like body in its natural state (without external forces acting on it, in a flat shape), the direction in which the shortest dimension is obtained is called the shortest direction. The direction perpendicular to the shortest direction is called the orthogonal direction. For example, a membrane-like body as used here means a shape in which the minimum length in the orthogonal direction is 10 times or more the length in the shortest direction.

[0021] For example, the film-like body 100 is made of polyimide resin and is formed in the shape of a ring-shaped film. The shape control device 2 comprises a plurality of axis drive units 10, a rotation drive unit 35, and a control unit 45.

[0022] As shown in Figure 2, the axis drive unit 10 includes a frame 11, an axis drive unit 12, and a flap (holding unit) 13. The frame 11 is C-shaped in side view. The frame 11 has side walls 17, a top wall 18, and a bottom wall 19. The side walls 17, top wall 18, and bottom wall 19 are each plate-shaped. Multiple female threads (not shown) are formed in the side walls 17. For example, the multiple female threads are arranged in a matrix. Through holes (reference numerals omitted) are formed in the side walls 17. The top wall 18 and bottom wall 19 extend in the thickness direction of the side wall 17 from each end in the width direction of the side wall 17. The top wall 18 and bottom wall 19 are arranged to face each other.

[0023] Multiple cylindrical stoppers 20 are attached to the side wall 17a opposite to the side on which the top wall 18 and bottom wall 19 extend. The stoppers 20 are provided with male threads (not shown). These male threads fit into female threads on the side wall 17, thereby allowing the stoppers 20 to be detachably attached to the side wall 17. The position in which the stoppers 20 are attached to the side wall 17 is adjustable. Furthermore, the axial drive unit may be equipped with a motor or the like, allowing the stopper 20 to move automatically relative to the side wall 17.

[0024] In this example, the axis drive unit 12 has a rotary solenoid. In other words, the axis drive unit 12 consists only of a rotary solenoid and does not have a linkage mechanism. The axis drive unit 12 has a known configuration. For example, the axis drive unit 12 has a case 23, a coil (not shown), a shaft 24, and a pair of wires 25. Case 23 is fixed between the top wall 18 and the bottom wall 19 on the side wall 17b opposite to the side wall 17a. The coil is housed in case 23. The first end of the shaft 24 is located inside the coil. The second end of the shaft 24, opposite to the first end, protrudes from the case 23. This second end protrudes from the surface 17a of the side wall 17 through a through-hole in the side wall 17.

[0025] The pair of wires 25 are connected to each end of the coil. The pair of wires 25 protrude from the surface 17a of the side wall 17 through through holes in the side wall 17.

[0026] As shown in Figure 2, the flap 13 has a main body 28 and a pair of arm portions 29. The main body 28 is rod-shaped. The main body 28 is positioned along the surface 17a of the side wall 17. The first end (not shown in the reference numerals) of the main body 28 is directly fixed to the second end of the shaft 24. The second end 28b of the main body 28 (the part that holds the membrane-like body 100 in the flap 13), opposite to the first end, protrudes from the side wall 17. A pair of arms 29 are fixed to the first end of the main body 28. For example, the pair of arms 29 are at an obtuse angle. Multiple stoppers 20 are positioned between the obtuse-angled sides of the pair of arms 29. The rotational range of the flap 13 around the shaft 24 is restricted by the locking of the pair of arms 29 with the multiple stoppers 20. As the shaft 24 rotates, the second end 28b of the flap 13 vibrates in a direction along the reference axis O1, which will be described later. The angle formed by the pair of arms 29 is not limited to an obtuse angle. The angle formed by the pair of arms 29 is set appropriately depending on the arrangement of the multiple stoppers 20, etc.

[0027] The rotary drive unit 35 rotates a plurality of axial drive units 10 (axial drive units 12) around a reference axis O1, which will be described later. As shown in Figure 1, for example, the rotary drive unit 35 has a mounting member 36, a shaft portion 37, and a plurality of thrusters 38A, 38B. The mounting member 36 is disc-shaped, and the shaft portion 37 is rod-shaped. The central axes of the mounting member 36 and the shaft portion 37 are arranged coaxially with the common axis. Hereinafter, the common axis will be referred to as the reference axis O1. When viewing the shape control device 2 from a direction along the reference axis O1, the direction perpendicular to the reference axis O1 is called the radial direction, and the direction that circles around the reference axis O1 is called the circumferential direction.

[0028] Multiple axial drive units 10 frames 11 are fixed to the outer periphery of the mounting member 36. The multiple axial drive units 10 (axial drive section 12) are arranged in a line around the reference axis O1. The second end 28b of the flaps 13 of the multiple axial drive units 10 are positioned to protrude radially outward from the mounting member 36. It is preferable that the multiple axis drive units 10 are arranged at equal angles around the reference axis O1. In the following, when referring to multiple axis drive units 10 in a distinguished manner, they may be referred to as axis drive units 10A, 10B, 10C, etc., around the reference axis O1.

[0029] The inner periphery of the membrane-like body 100 is fixed to the second end 28b of the flap 13. The flap 13 holds the central part of the membrane-like body 100 when viewed in the direction along the reference axis O1. The reference axis O1 is aligned with the thickness direction of the film-like material 100 when it is in a flat state. The thickness direction of the film-like material 100 when it is in a flat state is aligned with the reference axis O1. When the axial drive unit 12 rotates the flap 13 around the shaft 24, the second end portion 28b of the flap 13 vibrates in a direction along the reference axis O1.

[0030] As shown in Figure 1, the shaft portion 37 has a small diameter portion 37a and a large diameter portion 37b. The first end of the small diameter portion 37a is fixed to the mounting member 36. The outer diameter of the large diameter portion 37b is larger than the outer diameter of the small diameter portion 37a. The large diameter portion 37b is fixed to the first end of the small diameter portion 37a coaxially with the small diameter portion 37a. For example, multiple thrusters 38A and 38B forcefully push and mix hydrazine fuel and dinitrogen tetroxide oxidizer using helium gas. Then, by burning these mixtures and injecting the combustion gases, thrust is generated. Multiple thrusters 38A and 38B are fixed to a frame 60, which will be described later, of the structure 3 to which the shape control device 2 is attached. Multiple thrusters 38A rotate multiple axial drive units 10 (axial drive sections 12) via the structure 3 to the first side D1 around the reference axis O1 by injecting combustion gases. On the other hand, multiple thrusters 38B rotate multiple axial drive units 10 via the structure 3 to the second side D2, which is opposite to the first side D1 around the reference axis O1 by injecting combustion gases.

[0031] The control unit 45 comprises a main control unit 45a and a plurality of drive control units 45b. The main control unit 45a comprises a CPU (Central Processing Unit) 46, a memory 47, a communication unit 48, and a power supply unit 49. The CPU 46, memory 47, communication unit 48, and power supply unit 49 are connected to each other by a bus 50. CPU46 receives the clock signal S shown in Figure 3. CLK, and a control waveform (D signal) S D_A is generated. In FIG. 3, the horizontal axis represents time t, and the vertical axis represents the clock signal S CLK , and the control waveform S D_A , S D_B , S D_C indicates the timing at which, S D_A , S D_B [[ID=1"]] D_C changes. When not distinguishing between the control waveforms S D , it is also referred to as the control waveform S D and the clock signal S CLK are digital signals, respectively. The clock signal S CLK The rising time difference Δt in corresponds to the phase difference of the control waveform S D input to the coils of the axis drive units 12 adjacent in the circumferential direction.

[0032] The CPU 46 (control unit 45) controls the plurality of drive control units 45b based on the observation results of the observation unit 61 described later. The memory 47 is a RAM (Random Access Memory), a ROM (Read Only Memory), or the like. The memory 47 stores a control program or the like for controlling the CPU 46. The communication unit 48 communicates with the mechanism control unit of the structure 3 described later by wired communication or the like. The power supply unit 49 supplies power to the CPU 46, the memory 47, the communication unit 48, and the plurality of drive control units 45b, respectively.

[0033] As shown in FIG. 1, each drive control unit 45b is fixed to the frame ll of the axis drive unit 10. Hereinafter, the drive control unit 45b fixed to the frame 11 of the axis drive units 10A, 10B, 10C,... is also referred to as drive control units 45bA, 45bB, 45bC,.... The configurations of the plurality of drive control units 45b are equal to each other. Hereinafter, among the plurality of drive control units 45b, the drive control unit 45bA will be described.

[0034] As shown in Figures 2 and 4, the drive control unit 45bA includes a circuit board 52, a logic circuit 53, a full bridge 54, a first connector 55a, a second connector 55b, and a third connector 55c. The circuit board 52 is equipped with a logic circuit 53, a full bridge 54, and connectors 55a, 55b, and 55c. For example, logic circuit 53 is a known D flip-flop. Logic circuit 53 has a D terminal, a CLK terminal, and a Q terminal. Connector 55a is connected to the D terminal and CLK terminal of logic circuit 53. Connector 55b is connected to the CLK terminal and Q terminal of logic circuit 53.

[0035] As shown in Figure 1, the connector 55a of the drive control unit 45bA is connected to the output port of the CPU 46 via wiring 56. The control waveform S sent from the CPU 46 is connected to the D terminal and CLK terminal of the logic circuit 53 via connector 55a. D_A , clock signal S CLK The input is received. Power is supplied to connector 55a from the power supply unit 49. The logic circuit 53 controls the waveform S D_A , clock signal S CLK Based on this, the control waveform S is output from the Q terminal. D_B Outputs. The full bridge 54 is connected to the Q terminal of the logic circuit 53. The full bridge 54 receives the input control waveform S D_B Based on this, an analog signal is output. Connector 55c is connected to the output port of the full bridge 54. Connector 55c is connected to a pair of wires 25 of the axis drive unit 10A via wire 57. The analog signal output by the full bridge 54 of the drive control unit 45bA is applied to the coil of the axis drive unit 10A via the connector 55c and wiring 57.

[0036] The connector 55b of the drive control unit 45bA and the connector 55a of the drive control unit 45bB are connected to each other by wiring 58. Power is output from the connector 55b of the drive control unit 45bA, and this power is input to the connector 55a of the drive control unit 45bB via wiring 58. The drive control units 45bB and 45bC, 45bC and 45bD, etc., are connected in the same way as the drive control units 45bA and 45bB. The logic circuit 53 of the drive control unit 45bB controls the control waveform S D_B , clock signal S CLK Based on this, the control waveform S is output from the Q terminal. D_C The full bridge 54 of the drive control unit 45bB outputs the input control waveform S. D_C Based on this, an analog signal is output to the coil of the axis drive unit 10B.

[0037] As explained above, of the multiple axis drive units 10, only axis drive unit 10A is connected to the CPU 46 of the control unit 45. Furthermore, even if the number of axis drive units 10 equipped in the shape control device 2 changes, there is no need to change the number of output ports of the CPU 46, making it easy to adapt. As described above, the control unit 45 uses multiple control waveforms S to control the vibration of the flap 13 by the multiple axis drive units 12. D These may differ only in phase (hereinafter, this type of control will be referred to as phase control).

[0038] In the axis drive unit 10, the axis drive section 12 enters a first applied state in which a positive potential is applied to the first end of the coil and a negative potential is applied to the second end of the coil opposite to the first end. In the second applied state, the axis drive section 12 enters a second applied state in which a negative potential is applied to the first end of the coil and a positive potential is applied to the second end of the coil. Thus, in this embodiment, the axis drive unit 12 of the axis drive unit 10 is controlled by switching between a first applied state and a second applied state.

[0039] As described above, the shape control device 2 comprises a plurality of axial drive units 10, each having a flap 13 and an axial drive unit 12. The shape control device 2 comprises a plurality of sets of flaps 13 and axial drive units 12. Furthermore, it is preferable that the shape control device 2 has three or more axial drive units 10. The flaps 13 of the three axial drive units 10 uniquely define the plane on which the film-like body 100 is held.

[0040] As shown in Figure 1, for example, the structure 3 includes a frame 60, an observation unit 61, a wireless communication unit (not shown), a mechanism control unit, and a power generation unit. Frame 60 constitutes the external shape of the structure 3. The wireless communication unit and the mechanism control unit are built into frame 60. The observation unit 61 has a camera and the like. The observation unit 61 observes the conditions around the spacecraft 1. The wireless communication unit exchanges signals wirelessly with a command device installed on Earth. The mechanism control unit controls the observation unit and the wireless communication unit, and also exchanges signals with the control unit 45 of the shape control device 2 via wired communication. The power generation unit has solar cells and the like, and is fixed to the frame 60 while being located outside the frame 60. The power generation unit supplies power to the observation unit 61, the wireless communication unit, the mechanism control unit, and the power supply unit 49 of the shape control device 2.

[0041] [1.2. Control method for shape control device when a film-like body is maintained] This control method is a known method, and is disclosed, for example, in reference 1 below. Reference 1: Yuki Takao, Osamu Mori, Masanori Matsushita, Nobukatsu Okuizumi, Yasutaka Sato, Junichiro Kawaguchi, "Shape control system for deployable thin-film structures by active excitation and its ground demonstration experiment," Proceedings of the Japan Aerospace Science and Technology Conference, 2020, 64th. Below, we will explain by applying only the outline of this document 1 to the shape control device 2.

[0042] By rotating the film-like body 100 around a reference axis O1 while vibrating it in a direction along the reference axis O1, the entire film-like body 100 can be shaped into a desired form. By canceling out the propagation of the wave excited in the film-like body 100 by the vibration along the reference axis O1 with the rotation around the reference axis O1, the waveform of the film-like body 100 in the inertial frame can be made to appear stationary. Hereinafter, the waveform of the film-like body 100 that is stationary in the inertial frame will be referred to as a standing wave. On the other hand, in an inertial frame, the waveform of the film-like body 100, in which the overall shape of the film-like body 100 changes around the reference axis O1 over time, is called a quasi-standing wave.

[0043] Furthermore, for units of length and other properties described below, SI units such as "m" are preferably used for length. The rotational speed (spin rate) of the film-like body 100 around the reference axis O1 is defined as Ω. A cylindrical coordinate system r-θ-z that rotates with the film-like body 100 is defined. The displacement of a small amount dμ of the film-like body 100 in the z direction at time t is defined as w(r,θ,t). The input per unit area to the film-like body 100 is defined as f(r,θ,t). In this case, the condition for exciting only backward waves propagating in the antispin direction to form a standing wave is given by equation (1).

[0044]

number

[0045] At this point, the waveform appearing in the inertial frame is obtained by equation (2) through a coordinate transformation φ=θ+Ωt to a cylindrical coordinate system r-φ-z fixed to the inertial frame. However, r^ (the symbol "r" with a "^" symbol above it) is replaced with (r / r b ) is stipulated. However, r b φ is the radius of the outer diameter of the membrane-like body 100. φ is the azimuth angle in inertial space. In this case, the displacement w can be expressed as shown in equation (2) using equation (3).

[0046]

number

[0047] The rotational speed v0 represents the wave propagation speed in the +φ direction, i.e., the phase change rate of the standing wave. Therefore, for an input of frequency ω0, the phase shifts at rotational speed v0, and the membrane 100 becomes a quasi-standing wave in the inertial frame. On the other hand, when ω0 = m0Ω, that is, when the frequency ω0 is an integer m0 times the rotational speed Ω, the membrane 100 becomes a standing wave in the inertial frame.

[0048] Furthermore, in order to switch between the first and second application states of the multiple axis drive units 12 based on the input f(r,θ,t) represented by equation (1), the following process is performed. In other words, for example, when the input f(r,θ,t) is positive (greater than or equal to 0), the axis drive unit 12 is set to a first applied state, and when the input f(r,θ,t) is negative, the axis drive unit 12 is set to a second applied state.

[0049] In order to make the waveform of the film-like body 100 a standing wave, the control unit 45 controls it as follows, for example, based on equations (1) and (2). In other words, in the inertial frame, the control unit 45 rotates the axial drive unit 12 in a predetermined direction around the reference axis O1 using the rotation drive unit 35, while simultaneously vibrating the flap 13 in a direction along the reference axis O1 using the multiple axial drive units 12 (hereinafter, this control is referred to as basic rotation and vibration control). While performing basic rotation and vibration control, the control unit 45 controls the axial drive unit 12 so that when the second end 28b of the flap 13 is positioned in a predetermined direction around the reference axis O1 in the inertial frame, the second end 28b of the flap 13 is positioned in the same position in the direction along the reference axis O1, regardless of the rotational speed of the membrane-like body 100 around the reference axis O1 (hereinafter, this control is referred to as same-position control for a predetermined direction). Preferably, the control unit 45 controls each of the multiple axial drive units 12 such that, when the second end 28b of the flap 13 is positioned in a predetermined orientation around the reference axis O1 in the inertial frame, the second end 28b of the flap 13 is positioned in the same location in the direction along the reference axis O1, regardless of the rotational speed of the membrane-like body 100 around the reference axis O1.

[0050] For example, the control unit 45 performs phase control, etc., based on equation (1) for an axis drive unit 10 whose circumferential position is different from that of the axis drive unit 10A (shifted by position θ in the cylindrical coordinate system).

[0051] On the other hand, in order to make the waveform of the film-like body 100 a quasi-standing wave, the control unit 45 controls it as follows, for example. In other words, while performing the basic rotation and vibration control, the control unit 45 controls the axial drive unit 12 so that the position of the second end 28b of the flap 13 in the direction along the reference axis O1 when the flap 13 is positioned in a predetermined direction around the reference axis O1 in the inertial frame, and the position of the second end 28b of the flap 13 in the direction along the reference axis O1 when the flap 13 has rotated further around the reference axis O1 to a position shifted by a displacement angle in addition to one full rotation, are equal to each other (hereinafter, this control is referred to as same-position control for shifted positions). Here, the displacement angle is, for example, a predetermined angle of -180° or more and less than 180°. It is preferable that the control unit 45 performs the same position control for each of the multiple axis drive units 12 relative to the offset positions. For example, it is preferable that the control unit 45 performs the phase control.

[0052] [1.3. Experimental Results] The results of experiments conducted under Earth's atmospheric pressure using the shape control device 2 described above will now be explained. In this case, it is preferable that the film-like body 100 is formed of polyethylene resin. As shown in Figure 5, the film-like body 100, whose shape is controlled by the shape control device 2, has two peaks 101 and two valleys 102 (one of the valleys 102 is not shown) in its inertial frame. At the peaks 101, the film-like body 100 protrudes toward the first side in the direction along the reference axis O1. At the valleys 102, the film-like body 100 protrudes toward the second side, which is opposite to the first side in the direction along the reference axis O1.

[0053] [1.4. Spacecraft Operation] Next, the operation of the spacecraft 1 configured as described above will be explained. As shown in Figure 6, it is assumed that the spacecraft 1 is orbiting the sun 110 in the direction of arrow A1 in an orbit 111. The power generation unit of the structure 3 generates electricity from sunlight L1 emitted from the sun 110. The power generation unit supplies power to the observation unit 61, the wireless communication unit, the mechanism control unit, and the power supply unit 49 of the shape control device 2, respectively. The observation unit 61 observes the conditions around the spacecraft 1. This allows it to measure the rotational speed of the spacecraft 1 around the reference axis O1.

[0054] Let's assume that at this point, the operator on Earth wanted to move spacecraft 1 outside of orbit 111. Sunlight L1 acts on the membrane 100 of spacecraft 1. In this case, the operator operates the command device to send a signal to spacecraft 1 via wireless communication. When the wireless communication unit of spacecraft 1 receives this signal, the signal is sent to the control unit 45 of the shape control device 2 via the mechanism control unit.

[0055] The control unit 45 rotates the multiple axial drive units 12 around the reference axis O1 using the rotation drive unit 35, and vibrates the multiple flaps 13 in a direction along the reference axis O1 using the multiple axial drive units 12. This deforms the shape of the membrane-like body 100 into a predetermined non-flat shape. As a result, the force acting on the membrane-like body 100 by sunlight L1 changes depending on its position around the reference axis O1 (circumferential direction), and the orientation of the spacecraft 1 changes. The control unit 45 causes the reference axis O1, which points outward from the sun 110, to tilt in the direction of arrow A1. As a result, the membrane 100 receives a force in the direction of arrow A2 from the sunlight L1, and the spacecraft 1 moves to the position shown by the dashed line L5, outside of orbit 111.

[0056] On the other hand, suppose an operator on Earth wants to move spacecraft 1 inside orbit 111. In this case as well, upon receiving a signal from the operator, the control unit 45 changes the orientation of spacecraft 1. Then, as shown in Figure 7, the control unit 45 tilts the reference axis O1, which points outward from the sun 110, in the opposite direction to arrow A1. As a result, the membrane 100 receives a force in the direction of arrow A3 from sunlight L1, and spacecraft 1 moves inside orbit 111 to the position shown by the dashed line L6.

[0057] As described above, by controlling the orientation of the membrane-like body 100 relative to the sun 110, the direction in which the spacecraft 1 moves can be changed. For example, when adjusting the rotational speed of the spacecraft 1 around the reference axis O1, the control unit 45 generates thrust as appropriate using the multiple thrusters 38A and 38B of the rotational drive unit 35. For example, Spacecraft 1 can capture space debris and collect samples from small celestial bodies. Furthermore, the spacecraft 1 may be configured to autonomously change the direction in which it moves. Specifically, the observation unit of the structure 3 detects the position of the spacecraft 1 in outer space. The memory 47 of the control unit 45 of the shape control device 2 stores the target orbit of the spacecraft 1 in advance. The control unit 45 uses functions such as AI (Artificial Intelligence) to calculate the deviation of the actual orbit from the target orbit, which is determined from the detected position of the spacecraft 1. Based on the calculated deviation, it may autonomously control the shape of the membrane 100 so that the spacecraft 1 is positioned on the target orbit.

[0058] [1.5. Effects of this embodiment] As described above, in the shape control device 2 of this embodiment, the control unit 45, for example, makes the waveform of the film-like body 100 a standing wave. That is, with the center of the film-like body 100 held by a plurality of flaps 13, the control unit 45 uses the rotation drive unit 35 to rotate a plurality of axial drive units 12 that move the plurality of flaps 13 around the reference axis O1. As a result, the film-like body 100 expands in a direction perpendicular to the reference axis O1 due to centrifugal force. At this time, the control unit 45 vibrates the multiple flaps 13 in a direction along the reference axis O1 using the multiple axial drive units 12, and controls the axial drive units 12 so that when the flaps 13 are positioned in a predetermined orientation around the reference axis O1, the flaps 13 are positioned in the same position in the direction along the reference axis O1. As a result, in the inertial frame, the overall shape of the membrane-like body 100 rotating around the reference axis O1 becomes a constant shape. The multiple axial drive units 12 generally have rotary solenoids that operate stably and are directly connected to the flap 13 without using a link mechanism, for example, so that the membrane body 100 can be vibrated stably in the direction along the reference axis O1 for a relatively long period of time.

[0059] The axial drive unit 12 has a rotary solenoid, and when the axial drive unit 12 rotates the flap 13, the second end portion 28b of the flap 13 vibrates in a direction along the reference axis O1. Therefore, the rotary solenoid can rotate the flap 13 stably over a long period of time. As a result, the shape of the membrane body 100 can be stably vibrated in a direction along the reference axis O1 over a relatively long period of time. The shape control device 2 comprises multiple sets of flaps 13 and axial drive units 12, with the multiple axial drive units 12 arranged in a line around a reference axis O1. Therefore, the multiple axial drive units 12 and multiple flaps 13 allow the shape of the film-like body 100 to be controlled to a shape closer to the desired shape.

[0060] Multiple control waveforms S used by the control unit 45 to control the vibration of the flap 13 by multiple axis drive units 12 D These may differ only in phase. In this case, the control unit 45 needs to control multiple control waveforms S to control the multiple axis drive units 12. D It can be made relatively easily.

[0061] The control unit 45 may make the waveform of the film-like body 100 a quasi-standing wave. That is, while performing the basic rotation and vibration control, the control unit 45 may control the axial drive unit 12 such that the position of the second end 28b of the flap 13 in the direction along the reference axis O1 when the flap 13 is positioned in a predetermined direction around the reference axis O1 in the inertial frame is equal to the position of the second end 28b of the flap 13 in the direction along the reference axis O1 when the flap 13 has rotated further around the reference axis O1 to a position that is one full rotation plus a displacement angle difference. In this case, in the inertial frame, the overall shape of the membrane-like body 100 rotating around the reference axis O1 remains constant while rotating at a predetermined speed around the reference axis O1. The axial drive unit 12 has a rotary solenoid, which generally operates stably, and is directly connected to the flap 13 without using a link mechanism, for example. Therefore, the shape of the membrane body 100 can be stably vibrated in a direction along the reference axis O1 over a relatively long period of time.

[0062] As shown in Figure 8, the axial drive unit 62 of the shape control device 2A may be composed of a plurality (in this embodiment, a pair) of piezoelectric elements 62a, 62b. In this case, for example, piezoelectric element 62a is fixed to the first side of the flap 13 in the direction along the reference axis O1. Piezoelectric element 62b is fixed to the second side of the flap 13, opposite to the first side in the direction along the reference axis O1. For example, when the control unit applies power to the piezoelectric elements 62a and 62b, the piezoelectric elements 62a and 62b retract in the longitudinal direction of the flap 13. When the control unit applies power only to the piezoelectric element 62a, the second end 28b of the flap 13 moves to the first side in the direction along the reference axis O1. On the other hand, when the control unit applies power only to the piezoelectric element 62b, as shown in Figure 9, the second end 28b of the flap 13 moves to the second side in the direction along the reference axis O1. By alternately applying power to the piezoelectric elements 62a and 62b, the second end 28b of the flap 13 vibrates in the direction along the reference axis O1. Furthermore, there is no limit to the number of piezoelectric elements used in the axial drive unit.

[0063] The flap 13 may be directly held by a piezo bender, which is constructed by directly attaching a pair of piezoelectric elements to each other.

[0064] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figures 10 to 12. The same reference numerals are used for parts identical to those in the previous embodiment, and their descriptions will be omitted. Only the differences will be described.

[0065] [2.1. Configuration of a spacecraft using the shape control device of the second embodiment] As shown in Figure 10, the shape control device 4 of this embodiment is used by being attached to a structure 3 for a spacecraft 5, such as a solar sail. The shape control device 4 is a device for controlling a plurality of linear bodies 115 to a desired shape. In Figure 10, the plurality of linear bodies 115 are shown by dashed lines. Here, in a linear body in its natural state (without external forces acting on it, in a flat shape), the direction in which the longest dimension is obtained is called the longest direction, and the direction in which the shortest dimension is obtained is called the shortest direction. The directions perpendicular to the longest and shortest directions are called orthogonal directions. For example, a linear body as used here means a shape in which the length in the orthogonal direction is between 1 and 10 times the length in the shortest direction, and the length in the longest direction is at least 2 times the length in the orthogonal direction. A linear body also includes so-called strip-shaped objects (strip-shaped bodies).

[0066] For example, the linear body 115 is formed in a linear shape from polyimide resin. For example, the linear body 115 is a rope (tether). Preferably, a conductive member is embedded in the linear body 115. In this case, the spacecraft can be used as an electric sail. When the width of the linear body is relatively wide, it is preferable to provide a coating or the like with relatively high reflectivity on the outer surface of the linear body. In this case, the spacecraft can be used as a heliogyro (a space version of a helicopter) by reflecting sunlight with the linear body for propulsion.

[0067] The shape control device 4 includes a control unit 45A in place of the control unit 45 of the shape control device 2 in the second embodiment. In the main control unit 45a1 of the control unit 45A, the control program for controlling the CPU 46 stored in memory 47A is different from that of memory 47 in the first embodiment. The end of the linear body 115 is fixed to the second end 28b of the flap 13. The flap 13 holds the end of the linear body 115. The shape control device 4 may have only one axis drive unit 10. In this case, the shape control device will have one flap 13 and one axis drive unit 12.

[0068] [2.2. Control method for shape control device when a linear body is held] [2.2.1. Equation of motion for a linear body] As shown in Figure 11, for a single linear body 115, the x-axis is defined along the longitudinal direction of the linear body 115. The first end of the linear body 115 is taken as the origin of the x-axis, and the direction from the first end to the second end of the linear body 115 is taken as the positive direction of the x-axis. That is, x is the coordinate in the direction perpendicular to the (defined) reference axis O1 in the linear body 115. The z-axis is defined in a direction perpendicular to the x-axis and parallel to the reference axis O1. The length of the linear body 115 is defined as L. The rotational speed of the linear body 115 around the z-axis is defined as Ω. The linear density of the linear body 115 is defined as ρ. The tension of the linear body 115 at position x is defined as T(x), and the displacement of the linear body 115 in the z direction is defined as w(x,t), where t is time (time). First, we determine the tension T(x) acting on the linear body 115 when there is no displacement (w=0).

[0069] As shown in Figure 12, the force equilibrium condition acting on a small linear element 116 of the linear body 115 with a length of Δx in the x-axis direction is expressed as shown in equation (11).

[0070]

number

[0071] Considering the limit as △x→0 in equation (11), we obtain equation (12).

[0072]

number

[0073] By adding boundary conditions to equation (12) such that the tension T(x)=0 at the second end (x=L) of the linear body 115, we obtain equation (13).

[0074]

number

[0075] Next, assuming that there is no displacement, we assume that the tension T(x) remains unchanged because the displacement w is small. In this case, the force F in the z direction acting on the small line element 116 is z This is obtained by equation (14).

[0076]

number

[0077] Therefore, the equation of motion for the infinitesimal line element 116 is equation (15), which is equation (16) obtained by rearranging equation (15).

[0078]

number

[0079] [2.2.2. General solution for free vibration of a linear body] Assume that the displacement w(x,t) of the linear body 115 is the product of Φ(x), which is a function of position x, and q(t), which is a function of time t, and that by separating x and t, it can be expressed as w(x,t)=Φ(x)q(t). Φ(x) is an eigenfunction, a function that represents the shape of the natural vibration mode. Then, equation (19) and equation (20), which is a transformation of equation (19), are obtained.

[0080]

number

[0081] The tension T(x) depends on x. Therefore, the left side of equation (20) depends only on time t, and the right side of equation (20) depends only on x. Therefore, based on the method of separation of variables, both sides of equation (20) can be treated as constants. This constant is -ω 2 Then, equations (21) and (22) are obtained.

[0082]

number

[0083] Here, we define (x / L) as the dimensionless position x^ and (ω / Ω) as the dimensionless angular frequency ω^. Substituting equation (13), position x^, and angular frequency ω^ into equation (22), we obtain equations (23) and (24).

[0084]

number

[0085] Here, 2(ω^) 2 If we set =n(n+1), equation (24) coincides with Legendre's differential equation. Therefore, the eigenfunction Φ(x) can be written as a Legendre polynomial. Legendre polynomials are 2(ω^) 2 It takes on various values ​​depending on the value of x. For the Legendre polynomial to have a finite value at x^=1 (the second end of the linear field 115), n must be a non-negative integer. From this condition, the natural frequency ω^ n The nth eigenfunction Φ is determined discretely. n (x^) is obtained by equation (27).

[0086]

number

[0087] From the above, the general solution for the displacement w(x,t) of the linear body 115 rotating around the z axis is given by equation (28). However, A n ,B n This is an integral constant determined by the initial conditions.

[0088]

number

[0089] An important property is that the eigenfunctions (Legendre polynomials) have the property of orthogonality, as expressed in equation (29). However, δ mn This is a Kronecker Delta.

[0090]

number

[0091] [2.2.3. Shape control of linear bodies: External input response] Assume that an external force F(x,t) is applied to the linear body 115 at position x and time t. The external force F(x,t) is the external force in the z-axis direction per unit length in the x-axis direction. At this time, the equation of motion for the linear body 115 is given by equation (32).

[0092]

number

[0093] The eigenfunction Φ(x) remains the same as that of the free vibration of the linear body 115 in [7.2], and we assume that the mode coordinate q(t) is an unknown. Then we obtain equation (33). Substituting equation (33) into equation (32), we obtain equation (34).

[0094]

number

[0095] (34) Add Φ to both sides of equation m Multiply by (x^) and integrate over the interval [0,1] with respect to position x^. Then, due to the orthogonality of the eigenfunctions, only one mode is extracted, and equation (35) is obtained. However, M ~ n F ~ n These are the nth-order generalized mass and generalized force, respectively, and are expressed by equations (36) and (37).

[0096]

number

[0097] Therefore, given an external force F(x,t), equation (35) is expressed in mode coordinate q. n By solving for (t) and superimposing the results using eigenfunctions, the displacement w(x,t) of the linear body 115 as the response can be obtained. The displacement w(x,t) will be explained below.

[0098] [2.2.4. Shape control of linear bodies: control side] Assume that a periodic input F0(t) represented by equation (40) is applied to the first end (x=0) of the linear body 115 rotating around the z axis. However, A0 and α0 are constants. ω0 is the angular frequency that causes the end of the linear body 115 to vibrate in a direction along the reference axis O1.

[0099]

number

[0100] Let us assume that the generalized force F(x,t) can be expressed as F(x,t)=δ(x)F0(t) using Dirac's delta function. ~ n This is expressed by equation (42).

[0101]

number

[0102] Here, the frequency response function of equation (35) for a single-degree-of-freedom system is H n Let (ω) be defined as such. In this case, the response of the mode coordinates is expressed by equation (43). However, H n (ω0) is the frequency response function corresponding to the angular frequency ω0.

[0103]

number

[0104] Therefore, the displacement w(x,t) of the linear body 115 is expressed by equation (44).

[0105]

number

[0106] Here, the amplification factor G relative to the input. ω0 Let (x) be defined as being expressed by equation (45). Then the displacement w(x,t) is expressed by equation (46).

[0107]

number

[0108] Here, we define the cylindrical coordinate system r-θ-z in inertial space. r is the coordinate in the direction perpendicular to the (defined) reference axis O1 in the linear body 115, with the z-axis as the origin. θ is the coordinate of each linear body 115 around the reference axis O1. The linear body 115 is rotating around the z-axis at a rotational speed Ω. Assume that the linear body 115 passes through position θ=0 at time t=0. The first end (base) of the linear body 115 is excited at a certain angular rotation speed ω0 = mΩ. The deformation response of the linear body 115 is expressed by equation (49).

[0109]

number

[0110] Here, since θ = Ωt, the displacement w(r,θ,t) of the linear body 115 when passing through position θ is expressed by equation (50).

[0111]

number

[0112] Therefore, if m is a natural number, the sin(mθ+α0) term on the right-hand side of equation (50) is a waveform (standing wave) that closes in one rotation around the z-axis with respect to position θ. In other words, the displacement w(r,θ,t) of the linear body 115 in inertial space (inertial frame) is constant regardless of time t. To put it another way, the linear body 115 is G ω0 It undergoes vibrational deformation while traversing a wavefront that is stationary in inertial space, represented by (r)A0sin(mθ+α0).

[0113] [2.2.5. Control of linear bodies by the control unit] In order to make the waveforms of the multiple linear bodies 115 into standing waves, the control unit 45A controls them in the same way as the control unit 45, based on equation (50). On the other hand, in order to make the waveforms of the multiple linear bodies 115 into quasi-standing waves, the control unit 45A controls them in the same way as the control unit 45, based on equation (50).

[0114] [2.3. Effects of this embodiment] As described above, in the shape control device 4 of this embodiment, the control unit 45A makes the waveforms of the multiple linear bodies 115 into standing waves. That is, while performing the basic rotation and vibration control, it performs position control for the same position in the predetermined direction. At this time, with the ends of the multiple linear bodies 115 held by the multiple flaps 13, the control unit 45A uses the rotation drive unit 35 to rotate the multiple axial drive units 12 that move the multiple flaps 13 around the reference axis O1. As a result, the multiple linear bodies 115 spread out in a direction perpendicular to the reference axis O1 due to centrifugal force. At this time, the control unit 45A vibrates the multiple flaps 13 in a direction along the reference axis O1 using the multiple axial drive units 12, and controls the axial drive units 12 so that when the flaps 13 are positioned in a predetermined direction around the reference axis O1, the flaps 13 are positioned in the same position in the direction along the reference axis O1. As a result, in the inertial frame, the trajectory of the multiple linear bodies 115 as a whole rotating around the reference axis O1 takes on a constant shape. The multiple axial drive units 12 generally have rotary solenoids that operate stably and are directly connected to the flap 13 without using a link mechanism, for example, so that the multiple linear bodies 115 can be vibrated stably in a direction along the reference axis O1 over a relatively long period of time.

[0115] The control unit 45A may make the multiple linear bodies 115 into quasi-standing waves. That is, while performing the basic rotation and vibration control, it performs same-position control for the shifted positions. At this time, in the inertial frame, the overall shape of the multiple linear bodies 115 rotating around the reference axis O1 rotates at a predetermined speed around the reference axis O1 while maintaining a constant shape. The axial drive unit 12 has a rotary solenoid, which generally operates stably, and is directly connected to the flap 13 without using a link mechanism, for example. Therefore, multiple linear bodies 115 can be vibrated stably in a direction along the reference axis O1 over a relatively long period of time.

[0116] In the spacecraft 5, an electric current is passed through conductive members embedded in multiple linear bodies 115, causing the multiple linear bodies 115 to deform into a desired shape. Then, when the spacecraft 5 is affected by a magnetic field such as that of the sun 110, the multiple linear bodies 115 are subjected to the Lorentz force, which can change the direction in which the spacecraft 5 moves.

[0117] [3. Modified examples of shape control devices] Although the first and second embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications, combinations, deletions, etc., of the configuration are also included without departing from the spirit of the present invention. Furthermore, it goes without saying that each of the configurations shown in each embodiment can be used in appropriate combinations.

[0118] [3.1. When using shape control devices in outer space] For example, in the shape control devices of the first and second embodiments, a film-like body or a plurality of linear bodies (hereinafter referred to as "film-like body, etc.") may be formed from a material that reflects radio waves, and the film-like body, etc. may be used as an antenna with a variable focal length.

[0119] [3.2. When using the shape control device on the ground] Instead of a thruster, a motor is used as the rotational drive unit to rotate multiple axial drive units 10 (axial drive units 12) around a reference axis O1. A stepping motor is preferred as the motor. An encoder may be used in the motor to detect the rotational speed of the drive shaft relative to the main body. In this case, the encoder sends the detection result to the control unit 45. The control unit 45 controls the motor based on the received detection result.

[0120] On the ground, or indoors, a membrane-like material may be attached to cover the wall surface, and the membrane-like material may be deformed. The acoustic effect may then be actively altered by the membrane-like material. This effect is equivalent to the wall surface being able to be deformed three-dimensionally. The waveform of a film-like material formed from a prism or other material that reflects or refracts light may be made into a standing wave. By shining light on the film-like material, various lighting conditions can be actively and continuously changed. In this way, the film-like material may be used as a lighting device in place of a mirror ball.

[0121] A film-like body to which light-emitting elements such as LEDs (Light Emitting Diodes) are attached may be deformed. Furthermore, by deforming the film-like body and changing the color and brightness of the light-emitting elements, i.e., the pattern, the film-like body may be used as a three-dimensional monitor. Alternatively, three-dimensional projection mapping using an external light source may be performed on a film-like body deformed into a desired shape. Wind power generation may be performed using multiple linear bodies. Furthermore, the flight path of the UAV (Unmanned Aerial Vehicle) using a shape control device may be made more three-dimensional, and the power generation efficiency in UAV control may be improved. [Explanation of Symbols]

[0122] 2,2A,4 Shape control device 12,62 Axle drive unit 13. Flap (holding part) 35 Rotary drive unit 45,45A Control Unit 62a, 62b Piezoelectric element 100 Membrane 115 Linear body O1 Reference axis S D Control waveform

Claims

1. A holding part that holds the center of the film-like material when viewed in the thickness direction, An axial drive unit having a rotary solenoid or piezoelectric element, which vibrates the holding portion in a direction along a reference axis along the thickness direction, A rotational drive unit that rotates the axial drive unit around the reference axis, A control unit that controls the axial drive unit and the rotation drive unit, Equipped with, The control unit, While the rotational drive unit rotates the axial drive unit around the reference axis, the axial drive unit vibrates the holding unit in a direction along the reference axis, A shape control device that controls the axis drive unit so that when the holding unit is positioned in a predetermined orientation around the reference axis, the holding unit is positioned in the same position in the direction along the reference axis.

2. The axial drive unit has the rotary solenoid, The shape control device according to claim 1, wherein the axial drive unit rotates the holding unit, causing the portion of the holding unit that holds the membrane to vibrate in a direction along the reference axis.

3. The system comprises multiple sets of the holding part and the axial drive part. The shape control device according to claim 1 or 2, wherein the plurality of axis drive units are arranged in a line around the reference axis.

4. The shape control device according to claim 3, wherein the control unit uses a plurality of control waveforms to control the vibration of the holding portion by the plurality of axis drive units, the control waveforms differ from each other only in phase.

5. A holding part that holds the center of the film-like material when viewed in the thickness direction, An axial drive unit having a rotary solenoid or piezoelectric element, which vibrates the holding portion in a direction along a reference axis along the thickness direction, A rotational drive unit that rotates the axial drive unit around the reference axis, A control unit that controls the axial drive unit and the rotation drive unit, Equipped with, The control unit, While the rotational drive unit rotates the axial drive unit around the reference axis, the axial drive unit vibrates the holding unit in a direction along the reference axis, A shape control device that controls the axis drive unit such that the position of the holding part in the direction along the reference axis when the holding part is positioned in a predetermined direction around the reference axis and the position of the holding part in the direction along the reference axis when the holding part is further rotated around the reference axis to a position that is one full rotation plus a displacement angle are equal to each other.

6. A retaining part that holds the end of the linear body, An axial drive unit having a rotary solenoid or piezoelectric element that vibrates the holding part in a direction along the reference axis, A rotational drive unit that rotates the axial drive unit around the reference axis, A control unit that controls the axial drive unit and the rotation drive unit, Equipped with, The control unit, While the rotational drive unit rotates the axial drive unit around the reference axis, the axial drive unit vibrates the holding unit in a direction along the reference axis, A shape control device that controls the axis drive unit so that when the holding unit is positioned in a predetermined orientation around the reference axis, the holding unit is positioned in the same position in the direction along the reference axis.

7. A retaining part that holds the end of the linear body, An axial drive unit having a rotary solenoid or piezoelectric element that vibrates the holding part in a direction along the reference axis, A rotational drive unit that rotates the axial drive unit around the reference axis, A control unit that controls the axial drive unit and the rotation drive unit, Equipped with, The control unit, While the rotational drive unit rotates the axial drive unit around the reference axis, the axial drive unit vibrates the holding unit in a direction along the reference axis, A shape control device that controls the axis drive unit such that the position of the holding part in the direction along the reference axis when the holding part is positioned in a predetermined direction around the reference axis and the position of the holding part in the direction along the reference axis when the holding part is further rotated around the reference axis to a position that is one full rotation plus a displacement angle are equal to each other.

Images