A magnetic pendulum device based on liquid crystal elastomer fibers capable of self-sustaining oscillation and a method for calculating its oscillation trajectory.

Abstract

The present invention relates to the technical field of simple pendulum systems, specifically a magnetic pendulum device based on liquid crystal elastomer fibers that can self-sustainingly swing and a swing trajectory calculation method, comprising an experimental platform, a simple pendulum bracket is installed on the top of the experimental platform, an LCE fiber is fixedly connected to one side of the simple pendulum bracket, a metal pendulum is fixedly connected to one end of the LCE fiber away from the simple pendulum bracket, a metal scale is installed on the top of the experimental platform, a magnet is slidably connected to the top of the metal scale, a constant illumination area is applied to the balance of the LCE fiber, the simple pendulum bracket includes a base installed on the top of the experimental platform, a metal rod is fixedly connected to the top of the base, a cross bar is provided on the outside of the metal rod, and a threaded rod is installed on one side of the cross bar. The problem that the existing simple pendulum system relies on external force to drive and it is difficult to provide a new method for realizing continuous swinging is solved, and the low-power continuous swing of the pendulum is realized by using temperature effect.

Description

Technical Field

[0001] The present invention relates to the technical field of simple pendulum systems, and in particular to a magnetic pendulum device capable of self-sustaining swing based on liquid crystal elastic fibers and a swing trajectory calculation method. Background Art

[0002] Some traditional simple pendulums are driven by electromagnetic force, while others are driven by installing a spring like a pendulum. These are external forces, and temperature generates heat, which is a temperature effect. Different from external forces such as magnetic force and the gear force of the spring, it provides a new method to achieve continuous swing of the simple pendulum. The traditional simple pendulum is affected by non-conservative forces such as air resistance and friction. In the absence of external driving force, the motion of the pendulum will gradually decay and eventually stop, resulting in high energy consumption and difficulty in achieving sustained swinging. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a magnetic pendulum device based on liquid crystal elastomer fibers that can swing self-sustainably and a method for calculating the swing trajectory, which solves the problem that the existing simple pendulum system relies on external force to drive and it is difficult to provide a new method for realizing continuous swinging, and utilizes the effect of temperature to achieve low-power continuous swinging of the simple pendulum.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a magnetic pendulum device based on liquid crystal elastomer fiber that can swing self-sustainingly, comprising an experimental platform, a simple pendulum bracket is installed on the top of the experimental platform, an LCE fiber is fixedly connected to one side of the simple pendulum bracket, a metal pendulum is fixedly connected to the end of the LCE fiber away from the simple pendulum bracket, a metal ruler is installed on the top of the experimental platform, a magnet is slidably connected to the top of the metal ruler, a constant illumination area is applied to the balance point of the LCE fiber, and the constant illumination area is achieved by any one of infrared light emitted by an 808nm high-power near-infrared laser and sunlight focused and heated through a magnifying glass.

[0005] Preferably, the LCE fibers are synthesized from anisotropic rod-shaped liquid crystal molecules and stretchable long-chain polymers, and when the temperature rises due to infrared light stimulation, the liquid crystal monomer molecules rotate or phase change to change the configuration, thereby causing the LCE fibers to shrink and deform macroscopically. When there is no infrared light, the LCE fibers will return to their original length.

[0006] Preferably, the simple pendulum includes two stable states, namely a gravity field and a magnetic field, to form a bistable state, and the characteristics of the LCE fiber and the magnetic field are used to achieve remote-controlled self-sustaining motion of the magnetic pendulum device.

[0007] Preferably, the simple pendulum bracket includes a base installed on the top of the experimental platform, the top of the base is fixedly connected to a metal rod, the outside of the metal rod is provided with a cross bar, a threaded rod is installed on one side of the cross bar, the outside of the threaded rod is provided with a nut, one end of the LCE fiber is fixed to the threaded rod, and the distance between the cross bar and the base is greater than the length of the LCE fiber.

[0008] Preferably, a round hole matching the metal rod is provided at the top of the cross bar, and a bolt with one end movably extending into the round hole is provided on one side of the cross bar.

[0009] Preferably, the metal pendulum is a metal ball, one side of the metal pendulum is provided with a limiting hole penetrating through the center of the circle, and one end of the LCE fiber movably penetrates through the limiting hole.

[0010] Preferably, the size of the metal pendulum is smaller than that of the magnet, and the magnet is placed on a metal scale at a distance from the center point of the pendulum support to attract the metal pendulum.

[0011] Preferably, two bending frames are fixedly connected to the top of the experimental platform, a limit rod is fixedly connected between the bending frame and the experimental platform, and the outer sleeve of the limit rod is provided with a bending plate for pressing the metal scale toward the experimental platform.

[0012] Preferably, a spring is fixedly connected between the bending plate and the experimental platform, and the spring is sleeved on the outside of the limiting rod.

[0013] Preferably, a gasket is fixedly connected to the top of the bending plate, the limiting rod movably penetrates the gasket, and the top of the bending frame is provided with a bolt 2 with one end movably penetrating the bending frame.

[0014] A method for calculating the swing trajectory of a magnetic pendulum device comprises the following steps:

[0015] Step 1: Establish a model of the magnetic pendulum device and measure the model parameters, which include the damping coefficient. , the mass of the metal pendulum , the length of the LCE fiber , the initial length of the LCE fiber , the magnetic force of the magnet on the metal pendulum , the force arm of the magnetic force relative to the LCE fiber , the swing time of the magnetic pendulum , magnetic field strength , lighting area , used to distinguish the different motion states of the magnetic pendulum inside and outside the lighting area, the horizontal distance between the metal pendulum and the magnet , dedimensionalize to get dimensionless , contraction coefficient , after dimensionless transformation, ;

[0016] Step 2, calculating the motion period of the simple pendulum according to the model parameters;

[0017] Step 3, obtaining the first control equation of the magnetic pendulum device according to the momentum theorem;

[0018] Step 4: Import represents the angular velocity of the LCE fiber , the first control equation is optimized to obtain the second control equation of the magnetic pendulum device, is the angle between the LCE fiber and the vertical direction;

[0019] Step 5: Calculate the following dimensionless parameters based on the model parameters:

[0020] ;

[0021] In the formula, is the damping coefficient, is the mass of the metal pendulum, is the length of the LCE fiber, is the initial length of the LCE fiber, is the magnetic force exerted by the magnet on the metal pendulum. is the force arm of the magnetic force relative to the LCE fiber, is the acceleration due to gravity, is the swing time of the magnetic pendulum, is the magnetic field strength, is the horizontal distance between the metal pendulum and the magnet, which is dimensionless after dedimensionalization , is the contraction coefficient, which is dimensionless. , is the thermal duration of the LCE fiber when exposed to light, is the thermal duration of the LCE fiber recovery, T is the optical power;

[0022] Step six, replace the model parameters in the second control equation with dimensionless parameters to obtain the third control equation including both the illuminated interval and the non-illuminated interval.

[0023] Preferably, in step three, the expression of the first control equation of the magnetic pendulum device is:

[0024] ;

[0025] In the formula, is the tangential component of the air damping torque.

[0026] Preferably, in step 4, the expression of the second control equation of the magnetic pendulum device is:

[0027] ;

[0028] In the formula, represents the angular acceleration of the LCE fiber , Indicates the radial velocity of the metal pendulum .

[0029] Preferably, in step six, the expression of the third control equation of the illumination interval is:

[0030] ;

[0031] In the formula, It represents the dimensionless form of the angular velocity of the LCE fiber in the illumination range.

[0032] Preferably, in step six, the expression of the third control equation in the non-illuminated interval is:

[0033] ;

[0034] In the formula, represents the dimensionless form of the angular velocity of the LCE fiber in the non-illuminated range, and n is and ratio.

[0035] Compared with the prior art, the present invention provides a magnetic pendulum device based on liquid crystal elastomer fibers that can self-sustainably swing and a swing trajectory calculation method, which has the following beneficial effects:

[0036] 1. By setting up LCE fibers, metal pendulums, magnets and constant illumination areas, the heat from the illumination in the constant area is used to continuously drive the pendulum system to swing continuously with low power consumption. It does not need to rely on external forces such as electromagnetic force and springs to drive the pendulum. Instead, it uses the temperature provided by the illumination area to achieve low-power continuous swing of the pendulum, providing a new method for achieving continuous swing.

[0037] 2. Through the set single pendulum bracket, the height of the single pendulum system can be adjusted as needed to meet the needs of adapting to the single pendulum composed of LCE fibers of different lengths.

[0038] 3. By setting the bending plate and bolt 2, the metal ruler is squeezed and fixed on the experimental platform, which can increase the firmness of the connection between the metal ruler and the experimental platform, prevent the magnet from dragging the metal ruler to move along the experimental platform, and at the same time use the gravity of the magnet itself and the magnetic attraction between the magnet and the metal ruler to increase the friction between them. The scale on the surface of the metal ruler also increases the friction between them by increasing the roughness, reducing the possibility of the magnet being moved after being driven by the metal pendulum, and increasing the stability of the simple pendulum system.

[0039] 4. Through the swing trajectory calculation method of the magnetic pendulum device and according to the control equation of the magnetic pendulum, the relationship between the magnetic pendulum angle and the light intensity and the magnetic field intensity can be obtained. Taking the light intensity as an example, the greater the light intensity, the greater the swing amplitude of the magnetic pendulum and the smaller the frequency. Therefore, by controlling the light intensity and the magnetic field intensity, the swing amplitude and frequency of the magnetic pendulum can be controlled to meet the needs of different swing amplitudes and frequencies of the magnetic pendulum, making it convenient to apply the magnetic pendulum to different scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0041] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0042] Figure 2 It is a structural schematic diagram of a simple pendulum and a metal scale of the present invention;

[0043] Figure 3 is a cross-sectional view of a simple pendulum and a metal scale of the present invention;

[0044] Figure 4 It is a schematic diagram of the structure of the crossbar, LCE fiber and metal pendulum of the present invention;

[0045] Figure 5 It is a schematic structural diagram of the metal scale and bending frame of the present invention;

[0046] Figure 6 It is a structural schematic diagram of the bending frame of the present invention;

[0047] Figure 7 It is a wave line diagram of a single-period self-excited oscillation of the magnetic pendulum of the present invention;

[0048] Figure 8 It is the force diagram of the magnetic pendulum of the present invention;

[0049] Fig. 9 It is a model diagram of the magnetic pendulum of the present invention.

[0050] In the figure: 1. Experimental platform; 2. LCE fiber; 3. Metal pendulum; 4. Magnet; 5. Metal ruler; 6. Simple pendulum bracket; 61. Base; 62. Metal rod; 63. Cross bar; 64. Threaded rod; 65. Nut; 7. Constant illumination area; 8. Bolt 1; 9. Bending frame; 10. Limit rod; 11. Bending plate; 12. Spring; 13. Gasket; 14. Bolt 2. DETAILED DESCRIPTION

[0051] The following will describe the implementation methods of the present application in detail with the help of accompanying drawings and examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0052] Embodiment 1

[0053] In order to provide a new low-power continuous motion method for the pendulum and reduce the pendulum's dependence on external forces such as electromagnetic force and spring, Figure 1-Figure 4 As one embodiment of the present invention, a magnetic pendulum device based on a liquid crystal elastomer fiber that can swing continuously is proposed. The liquid crystal elastomer fiber has certain flexibility and shape variability, and can produce shape changes through temperature changes. The constant illumination area is achieved by infrared light emitted by an 808nm high-power near-infrared laser, or sunlight is focused and heated by a magnifying glass. A pendulum bracket 6 is installed on the top of the experimental platform 1, and an LCE fiber 2 is fixedly connected to one side of the pendulum bracket 6. A metal pendulum 3 is fixedly connected to the end of the LCE fiber 2 away from the pendulum bracket 6. The top of the experimental platform 1 A metal scale 5 is installed on the top, and a magnet 4 is slidably connected to the top of the metal scale 5. After the LCE fiber 2 reaches equilibrium, a constant light area 7 is applied at the equilibrium position. When in use, a single-domain LCE fiber 2 is first made, and then a simple pendulum bracket 6 is built. The metal pendulum 3 moves to the vertical direction under the action of gravity, and then the magnet 4 is moved along the metal scale 5 until the magnet 4 moves to a certain distance from the center point of the simple pendulum bracket 6. At this time, the metal pendulum 3 moves toward the direction close to the magnet 4 under the influence of the magnetic field of the magnet 4 until the metal pendulum 3 tilts at a certain angle and maintains balance under the action of gravity and the magnetic force of the magnet 4.

[0054] A near-infrared linear laser is used to irradiate the balance point of the LCE fiber 2, forming a constant illumination area 7 at the balance point of the LCE fiber. The LCE fiber 2 contracts under the illumination, driving the metal pendulum 3 to swing downward. At the same time, the LCE fiber 2 moves to the outside of the constant illumination area 7 and gradually recovers its initial length. The metal pendulum 3 returns to the balance point under the action of its own gravity and the magnetic force of the magnet 4, and the above process is repeated. The heat from the illumination in the constant area is used to continuously drive the simple pendulum system to perform low-power continuous swinging. It does not need to rely on external forces such as electromagnetic force and springs to drive it, but instead uses the temperature provided by the illumination area to achieve low-power continuous swinging of the simple pendulum, providing a new method for achieving continuous swinging.

[0055] In order to facilitate the adjustment of the height of the single pendulum system, refer to Figure 1-Figure 4The single pendulum bracket 6 includes a base 61 installed on the top of the experimental platform 1, a metal rod 62 is fixedly connected to the top of the base 61, a swing rod crossbar 63 is sleeved on the outside of the metal rod 62, a threaded rod 64 is installed on one side of the swing rod crossbar 63, a nut 65 is sleeved on the outside of the threaded rod 64, one end of the LCE fiber 2 is fixed to the threaded rod 64, the distance between the crossbar 63 and the base 61 is greater than the length of the LCE fiber 2, a round hole matching the metal rod 62 is provided on the top of the crossbar 63, a bolt 8 with one end movably extending into the inside of the round hole is provided on one side of the crossbar 63, the metal pendulum 3 is a metal ball, a limiting hole penetrating the center of the circle is provided on one side of the metal pendulum 3, one end of the LCE fiber 2 movably penetrates the limiting hole, when in use, the crossbar 63 is moved along the metal rod 62 until the distance between the crossbar 63 and the base 61 exceeds the length of the LCE fiber 2, the bolt 8 is rotated to enter the inside of the round hole, the bolt 8 is pressed against the metal rod 62 and then the crossbar 63 is fixed on the metal rod 62.

[0056] At this time, one end of the LCE fiber 2 is wound around and fixed on the threaded rod 64, and the other end of the LCE fiber 2 is passed through the metal pendulum 3 and tied to prevent the metal pendulum 3 from falling off the LCE fiber 2. The spherical metal pendulum 3 is convenient for measuring its center of gravity position and the length of the simple pendulum system. At this time, the assembly of the simple pendulum system is completed, and then the magnet 4 is moved along the metal scale 5 to keep a distance between the magnet 4 and the metal rod 62. The metal pendulum 3 swings a certain angle under the combined action of its own gravity and the magnetic force of the magnet 4 to maintain balance, driving the LCE fiber 2 to swing at the same time, and finally a near-infrared linear laser is used to irradiate the balance point of the LCE fiber 2. The LCE fiber 2 shrinks under light and stretches under non-light. The continuous swing of the simple pendulum system is achieved by using light in a fixed area. The height of the simple pendulum system can be adjusted as needed to meet the needs of adapting to the simple pendulum composed of LCE fibers 2 of different lengths.

[0057] In order to maintain the balance of the pendulum system at a certain angle, refer to Figure 2 The size of the metal pendulum 3 is smaller than that of the magnet 4. The magnet 4 is placed on a metal scale 5 at a distance from the center point of the pendulum bracket 6 to attract the metal pendulum 3. The purpose of placing the magnet 4 is to establish a second steady state other than the gravitational field through the magnet 4: the magnetic field. One end of the LCE fiber 2 is connected to the metal pendulum 3, and maintains balance under the gravity and the attraction of the magnet to the metal pendulum 3.

[0058] Embodiment 2

[0059] Since the magnet 4 has a tendency to move upward due to the reaction force of the metal pendulum 3, in order to maintain the stability of the position of the magnet 4 and prevent the magnet 4 from moving along the metal scale 5 after being driven by the metal pendulum 3, refer to Figure 1-Figure 6On the basis of the first embodiment, two bending frames 9 are fixedly connected to the top of the experimental platform 1, and a limit rod 10 is fixedly connected between the bending frame 9 and the experimental platform 1. The outer sleeve of the limit rod 10 is provided with a bending plate 11 for squeezing the metal scale 5 toward the experimental platform 1, and a spring 12 is fixedly connected between the bending plate 11 and the experimental platform 1. The spring 12 is sleeved on the outside of the limit rod 10, and a gasket 13 is fixedly connected to the top of the bending plate 11. The limit rod 10 movably penetrates the gasket 13, and a bolt 14 with one end movably penetrates the bending frame 9 is provided on the top of the bending frame 9. When in use, in order to reduce the possibility of the magnet 4 being attracted by the metal pendulum 3 and moving upward, the metal scale 5 of the present invention is made of magnetic metal material, and the magnetic attraction between the magnet 4 and the metal scale 5 is utilized, and the gravity of the magnet 4 itself is cooperated to prevent the magnet 4 from being attracted by the metal pendulum 3 and moving upward.

[0060] Since the metal pendulum 3 exerts a pulling force on the magnet 4 in the upward and left directions, the squeezing force between the magnet 4 and the metal scale 5 is reduced, thereby reducing the static friction between the magnet 4 and the metal scale 5, making it easier to drive the magnet 4 to move along the metal scale 5. The bending plate 11 is manually moved to above the two ends of the metal scale 5, and then the bolt 2 14 is turned. The bolt 2 14 gradually descends along the bending frame 9, pushing the gasket 13 and the bending plate 11 to gradually descend until the bending plate 11 is pressed against the top of the metal scale 5, and the metal scale 5 is squeezed and fixed on the experimental platform 1, which can increase the firmness of the connection between the metal scale 5 and the experimental platform 1, prevent the magnet 4 from dragging the metal scale 5 to move along the experimental platform 1, and at the same time use the gravity of the magnet 4 itself and the magnetic attraction between the magnet 4 and the metal scale 5 to increase the friction between them. The scale on the surface of the metal scale 5 also increases the friction between them by increasing the roughness, reducing the possibility of the magnet 4 being moved after being driven by the metal pendulum 3, and increasing the stability of the simple pendulum system.

[0061] Embodiment 3

[0062] Reference Figure 1-Figure 9 , Figure 7 is the angle between the LCE fiber and the vertical direction in the magnetic pendulum device Waveline diagram changing with time. Based on Example 1, a method for calculating the swing trajectory of a magnetic pendulum device based on self-sustaining swing of liquid crystal elastomer fibers is proposed. For simplicity, we ignore the air damping of the LCE fiber and only consider the air damping of the metal pendulum. Compared with the mass of the metal pendulum, the mass of the LCE fiber is negligible. In the absence of light, the LCE fiber reaches a balance state at a certain angle under the action of the magnetic force of the magnet. The applied range at this angle is In the illumination interval, the LCE fiber shrinks under the illumination conditions, the balance is broken, and it swings downward under the action of gravity into the non-illumination interval. The LCE fiber slowly stretches and performs a simple pendulum-like motion in the non-illumination interval. After the LCE fiber recovers its original length, it returns to its initial position under the action of magnetic force, that is, in the illumination interval, and then performs the above-mentioned periodic motion.

[0063] During exercise, according to Figure 8 The force analysis of the magnetic pendulum can be obtained by the momentum theorem:

[0064]

[0065] here is the tangential component of the air damping torque, is the damping coefficient, is the mass of the ball, is the length of the LCE fiber, is the initial length of the LCE fiber, is the magnetic force exerted by the magnet on the metal pendulum. is the force arm of the magnetic force relative to the LCE fiber, Indicates the lighting area, is the acceleration due to gravity, and is the angle between the LCE fiber and the vertical direction, represent , that is, the angular velocity of the LCE fiber, is the swing time of the magnetic pendulum, is the magnetic field intensity. Equation (6) can be further transformed into

[0066]

[0067] represents the angular acceleration of the LCE fiber , Indicates the radial velocity of the metal pendulum .

[0068] Then the dimensionless parameter is introduced: , , , , , , , is the damping coefficient, is the mass of the metal pendulum, is the length of the LCE fiber, is the initial length of the LCE fiber, is the magnetic force exerted by the magnet on the metal pendulum. is the force arm of the magnetic force relative to the LCE fiber, is the acceleration due to gravity, is the swing time of the magnetic pendulum, is the magnetic field strength.

[0069] After defining the dimensionless parameters, equation (7) can be transformed into the following dimensionless equation:

[0070] Light range:

[0071]

[0072] Non-lighting area:

[0073]

[0074] According to the control equation of the magnetic pendulum, we can obtain the relationship between the magnetic pendulum angle and the light intensity and magnetic field intensity. Taking the light intensity as an example, the greater the light intensity, the greater the swing amplitude of the magnetic pendulum and the smaller the frequency. Therefore, by controlling the light intensity and magnetic field intensity, the swing amplitude and frequency of the magnetic pendulum can be controlled to meet the needs of different swing amplitudes and frequencies of the magnetic pendulum, making it convenient to apply the magnetic pendulum to different scenarios.

[0075] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-sustaining magnetic pendulum device based on liquid crystal elastomer fibers, comprising an experimental platform (1), characterized in that: A pendulum bracket (6) is installed on the top of the experimental platform (1), an LCE fiber (2) is fixedly connected to one side of the pendulum bracket (6), and a metal pendulum (3) is fixedly connected to one end of the LCE fiber (2) away from the pendulum bracket (6). A metal scale (5) is installed on the top of the experimental platform (1), and a magnet (4) is slidably connected to the top of the metal scale (5). A constant illumination area (7) is applied to the balance of the LCE fiber (2). The constant illumination area (7) is achieved by using infrared light emitted by an 808nm high-power near-infrared laser and sunlight through a magnifying glass for focusing and heating. After the metal pendulum (3) is tilted at a certain angle, it maintains balance under the action of gravity and the magnetic force of the magnet (4).

2. The magnetic pendulum device according to claim 1, characterized in that: The pendulum bracket (6) comprises a base (61) mounted on the top of the experimental platform (1); a metal rod (62) is fixedly connected to the top of the base (61); a cross rod (63) is sleeved on the outside of the metal rod (62); a threaded rod (64) is mounted on one side of the cross rod (63); a nut (65) is sleeved on the outside of the threaded rod (64); one end of the LCE fiber (2) is fixed to the threaded rod (64); and the distance between the cross rod (63) and the base (61) is greater than the length of the LCE fiber (2).

3. The magnetic swing device according to claim 2, characterized in that: A round hole matching the metal rod (62) is provided at the top of the cross bar (63), and a bolt (8) having one end movably extending into the round hole is provided on one side of the cross bar (63).

4. The magnetic swing device according to claim 1, characterized in that: The metal pendulum (3) is a metal ball. A limiting hole pendulum-penetrating the center of the metal pendulum (3) is provided on one side thereof. One end of the LCE fiber (2) movably penetrates the limiting hole. The size of the metal pendulum (3) is smaller than the size of the magnet (4). The magnet (4) is placed on a metal scale (5) at a distance from the center point of the pendulum bracket (6) to attract the metal pendulum (3).

5. The magnetic pendulum device according to claim 1, characterized in that: The top of the experimental platform (1) is fixedly connected to two bending frames (9), a limit rod (10) is fixedly connected between the bending frame (9) and the experimental platform (1), the outer sleeve of the limit rod (10) is provided with a bending plate (11) for pressing the metal scale (5) toward the experimental platform (1), a spring (12) is fixedly connected between the bending plate (11) and the experimental platform (1), the spring (12) is sleeved on the outside of the limit rod (10), a gasket (13) is fixedly connected to the top of the bending plate (11), the limit rod (10) movably penetrates the gasket (13), and a bolt (14) is provided at one end of the bending frame (9) that movably penetrates the bending frame (9).

6. A method for calculating the swing trajectory of a magnetic swing device according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1, establishing a model of the magnetic pendulum device and measuring model parameters; Step 2, calculating the motion period of the simple pendulum according to the model parameters; Step 3, obtaining the first control equation of the magnetic pendulum device according to the momentum theorem; Step 4: Import represents the angular velocity of the LCE fiber , the first control equation is optimized to obtain the second control equation of the magnetic pendulum device, is the angle between the LCE fiber and the vertical direction; Step 5: Calculate the following dimensionless parameters based on the model parameters: ； In the formula, is the damping coefficient, is the mass of the metal pendulum, is the length of the LCE fiber, is the initial length of the LCE fiber, is the magnetic force exerted by the magnet on the metal pendulum. is the force arm of the magnetic force relative to the LCE fiber, is the acceleration due to gravity, is the swing time of the magnetic pendulum, is the magnetic field strength, is the horizontal distance between the metal pendulum and the magnet, which is dimensionless after dedimensionalization , is the contraction coefficient, which is dimensionless. , is the thermal duration of the LCE fiber when exposed to light, is the thermal duration of the LCE fiber recovery, T is the optical power; Step six, replace the model parameters in the second control equation with dimensionless parameters to obtain the third control equation including both the illuminated interval and the non-illuminated interval.

7. The swing trajectory calculation method according to claim 6, characterized in that: In step three, the expression of the first control equation of the magnetic pendulum device is: ； In the formula, is the tangential component of the air damping torque.

8. The swing trajectory calculation method according to claim 6, characterized in that: In step 4, the expression of the second control equation of the magnetic pendulum device is: ； In the formula, represents the angular acceleration of the LCE fiber , Indicates the radial velocity of the metal pendulum .

9. The swing trajectory calculation method according to claim 6, characterized in that: In step six, the expression of the third control equation in the illumination interval is: ； In the formula, It represents the dimensionless form of the angular velocity of the LCE fiber in the illumination range.

10. The swing trajectory calculation method according to claim 6, characterized in that: In step six, the expression of the third control equation in the non-illuminated interval is: ； In the formula, represents the dimensionless form of the angular velocity of the LCE fiber in the non-illuminated range, and n is and ratio.

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