Variable-frequency piezoelectric energy capturer based on vibration of stay cable

Abstract

The utility model relates to the technical field of vibration energy capture devices, in particular to a frequency conversion piezoelectric energy capture device based on stay cable vibration, which comprises a vibration absorption device, an energy capture device and a stay cable, the vibration absorption device comprises a first frame body, an optical axis, a vibrator, a first permanent magnet and a first elastic piece, the first frame body sleeves the stay cable and is fixedly connected with the stay cable, the optical axis is fixedly connected with the first frame body, the extension direction of the optical axis is perpendicular to the extension direction of the stay cable, the vibrator sleeves the optical axis, and the first permanent magnet is arranged on the vibrator; the two sides of the vibrator are connected with the first frame body through first elastic pieces, and the other two sides of the vibrator are fixedly provided with first permanent magnets. The energy capturing device comprises a first capturing assembly and a second capturing assembly which are arranged on the stay cable in a sleeving mode and arranged on the two sides of the first frame body respectively, vibration energy is absorbed and converted into electric energy, and meanwhile energy is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of vibration energy capture devices, in particular to a variable frequency piezoelectric energy capturer based on the vibration of a stay cable. Background Art

[0002] The wireless sensor nodes in the cable-stayed cable monitoring equipment need power supply. Currently, they are powered by laying long cables or installing batteries. Laying long cables wastes resources, and using batteries for power supply requires frequent battery replacement, which wastes resources and seriously pollutes the environment. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems in the related art. To this end, the present invention provides a variable frequency piezoelectric energy harvester based on the vibration of a stay cable, which absorbs vibration energy and converts it into electrical energy.

[0004] The utility model provides a variable frequency piezoelectric energy harvester based on the vibration of a cable-stayed cable, comprising: a vibration absorbing device, an energy harvesting device and a cable-stayed cable; the vibration absorbing device comprises a first frame, an optical axis, a vibrator, a first permanent magnet and a first elastic member, the first frame is sleeved on the cable-stayed cable and fixedly connected to the cable-stayed cable, the optical axis is fixedly connected to the first frame, the extension direction of the optical axis is perpendicular to the extension direction of the cable-stayed cable, the vibrator is sleeved on the optical axis, the two sides of the vibrator are connected to the first frame through a first elastic member, and the other two sides of the vibrator are fixedly provided with a first permanent magnet; the energy harvesting device comprises a first capture component and a second capture component which are sleeved on the cable-stayed cable and respectively arranged on both sides of the first frame.

[0005] According to the variable frequency piezoelectric energy capturer based on the vibration of the inclined cable provided by the utility model, the first capture component and the second capture component both include a second frame, a clamping block, a second elastic member and a second permanent magnet, the second frame is sleeved on the inclined cable and fixedly connected to the inclined cable, one end of the second elastic member is clamped by the clamping block and fixed on the second frame, and the other end of the second elastic member is fixedly provided with a second permanent magnet, and the second permanent magnet is arranged opposite to the first permanent magnet.

[0006] According to the variable frequency piezoelectric energy harvester based on stay cable vibration provided by the present invention, there is a gap between the second permanent magnet and the first permanent magnet.

[0007] The variable frequency piezoelectric energy harvester based on the vibration of the oblique cable provided by the present invention also includes a fixing member, one end of which is fixedly connected to the first frame, and the other end of which is fixedly connected to the second frame.

[0008] According to the variable frequency piezoelectric energy capturer based on the vibration of the oblique cable provided by the present invention, the first capture component and the second capture component are both provided with four second elastic members, which are respectively arranged at the upper, lower, left and right positions of the second frame.

[0009] According to the variable frequency piezoelectric energy harvester based on stayed cable vibration provided by the present invention, the second elastic member includes an elastic base layer and piezoelectric ceramic layers adhered to both sides of the elastic base layer, and the piezoelectric ceramic layers are fixedly connected to the clamping block.

[0010] According to the variable frequency piezoelectric energy harvester based on the vibration of the oblique cable provided by the present invention, the length of the elastic base layer is greater than that of the piezoelectric ceramic layer.

[0011] According to the variable frequency piezoelectric energy harvester based on stay cable vibration provided by the utility model, the surface of the piezoelectric ceramic layer is coated with a silver electrode layer, and the silver electrode layer is connected to an external circuit through a wire.

[0012] According to the variable frequency piezoelectric energy harvester based on the vibration of the oblique cable provided by the present invention, the vibration absorbing device further includes a linear bearing, which is sleeved on the optical axis and fixedly connected to the vibrator.

[0013] According to the variable frequency piezoelectric energy harvester based on the vibration of the oblique cable provided by the present invention, the vibration absorbing device is provided with four optical axes and four vibrators, which are respectively arranged in four directions of up, down, left and right of the first frame.

[0014] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0015] According to an embodiment of the utility model, a variable frequency piezoelectric energy harvester based on the vibration of the inclined cable is provided. By arranging a vibration absorption device and an energy capture device in cooperation, the problem of powering the wireless sensor node is solved, and the vibration absorption device absorbs the energy generated by the vibration of the inclined cable, thereby transmitting it to the energy capture device. The energy capture device converts the vibration energy into electrical energy, thereby improving the utilization rate of energy.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a structural schematic diagram of a variable frequency piezoelectric energy harvester based on the vibration of a stay cable provided by the utility model.

[0019] Figure 2 It is a structural schematic diagram of a vibration absorbing device of a variable frequency piezoelectric energy harvester based on the vibration of a stay cable provided by the utility model.

[0020] Figure 3 It is a structural schematic diagram of the first capture component of the variable frequency piezoelectric energy capturer based on the vibration of the inclined cable provided by the utility model.

[0021] Reference numerals:

[0022] 1. Vibration absorbing device; 11. First frame; 12. Optical axis; 13. Vibrator; 14. First permanent magnet; 15. First elastic member; 16. Linear bearing; 17. Gravity spring; 2. Energy capture device; 21. First capture component; 211. Second frame; 212. Clamp; 213. Second elastic member; 2131. Elastic base layer; 2132. Piezoelectric ceramic layer; 214. Second permanent magnet; 22. Second capture component; 3. Stay cable; 4. Fixing member. DETAILED DESCRIPTION

[0023] To make the purpose, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0026] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0027] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0028] The nonlinear energy well is a passive control technology. Its strong nonlinear stiffness gives it an inconstant natural frequency, allowing it to undergo instantaneous resonance capture with the cable-stayed structure. It has a wide frequency band and can quickly capture the low-frequency vibrations of the cable-stayed structure. The nonlinear energy well device primarily obtains its nonlinear restoring force through the spring. By setting the tension and compression states of the spring, the stiffness of the nonlinear energy well can achieve conditions of approximate cubic stiffness and negative stiffness. Due to the inconsistency of the stiffness, it can undergo instantaneous resonance capture with the cable-stayed structure, thus having the advantage of a wide vibration absorption bandwidth. The nonlinear energy well structure is installed on the cable-stayed structure and can effectively absorb broadband, low-frequency vibrations.

[0029] Usually, a piezoelectric vibration energy harvester is directly connected to the cable to capture energy. However, the energy harvester generates few vibrations under low-frequency forced vibration, the excitation is weak, and the energy capture efficiency is low.

[0030] According to an embodiment of the utility model, a variable frequency piezoelectric energy harvester based on the vibration of the inclined cable is used to capture the broadband, low-frequency vibration of the inclined cable by utilizing the instantaneous resonance of the nonlinear energy well, and then the nonlinear energy well oscillator continuously excites the high-frequency vibration of the elastic base through magnetic coupling, thereby improving the conversion efficiency of vibration energy into electrical energy.

[0031] Figure 1 It is a structural schematic diagram of a variable frequency piezoelectric energy harvester based on the vibration of a stay cable provided by the utility model. Figure 2 It is a structural schematic diagram of a vibration absorbing device of a variable frequency piezoelectric energy harvester based on the vibration of a stay cable provided by the utility model.

[0032] The utility model provides a variable frequency piezoelectric energy harvester based on the vibration of the inclined cable, such as Figure 1 and Figure 2 As shown, it includes: a vibration absorbing device 1, an energy capturing device 2 and an inclined cable 3; the vibration absorbing device 1 includes a first frame 11, an optical axis 12, a vibrator 13, a first permanent magnet 14 and a first elastic member 15, the first frame 11 is sleeved on the inclined cable 3 and fixedly connected to the inclined cable 3, the optical axis 12 is fixedly connected to the first frame 11, the extension direction of the optical axis 12 is perpendicular to the extension direction of the inclined cable 3, the vibrator 13 is sleeved on the optical axis 12, the two sides of the vibrator 13 are connected to the first frame 11 through the first elastic member 15, and the other two sides of the vibrator 13 are fixedly provided with a first permanent magnet 14; the energy capturing device 2 includes a first capturing component 21 and a second capturing component 22 which are sleeved on the inclined cable 3 and are respectively arranged on both sides of the first frame 11.

[0033] In this embodiment, the problem of powering the wireless sensor node is solved by arranging a vibration absorbing device 1 and an energy capturing device 2 in cooperation. The vibration absorbing device 1 absorbs the energy generated by the vibration of the inclined cable 3, and transmits it to the energy capturing device 2. The energy capturing device 2 converts the vibration energy into electrical energy, thereby improving the utilization rate of energy.

[0034] According to some embodiments of the present invention, by arranging a vibration absorbing device 1 and an energy capturing device 2 on the cable-stayed cable 3, the broadband, low-frequency vibration instantaneous resonance of the cable-stayed cable 3 can be captured by utilizing the broadband, low-frequency vibration absorbing characteristics of the nonlinear energy sink.

[0035] According to some embodiments of the present invention, the inclined cable 3 is fixedly connected to the first frame 11. The vibration of the inclined cable 3 drives the first frame 11 to vibrate, and the vibrator 13 is displaced along the optical axis 12. Since the vibrator 13 is connected to the first elastic member 15, the vibration of the vibrator 13 is received by the nonlinear restoring force of the first elastic member 15, thereby realizing the reciprocating vibration of the vibrator 13. The broadband and low-frequency vibration energy of the inclined cable 3 structure can be absorbed into the vibrator 13. The vibrator 13 uses magnetic force through the first permanent magnet 14 to excite the first capture component 21 and the second capture component 22, thereby generating a voltage, which is transmitted to the wireless sensor node through an external circuit.

[0036] According to some preferred embodiments of the present invention, the first elastic member 15 includes a spring and an elastic wire to provide a non-linear restoring force.

[0037] According to some preferred embodiments of the present invention, the first frame 11 is fixed to the stay cable 3 by bolts, and the optical axis 12 is fixedly connected to the first frame 11 by bolts.

[0038] According to some preferred embodiments of the present invention, the optical axis 12 is arranged in the four directions of up, down, left and right of the first frame 11. The optical axis 12 located at the top of the first frame 11 is sleeved with a gravity spring 17 to prevent the vibrator 13 from being affected by gravity and the force of the first elastic member 15 cannot support the vibrator 13 to perform reciprocating motion.

[0039] Figure 3 It is a structural schematic diagram of the first capture component of the variable frequency piezoelectric energy capturer based on the vibration of the inclined cable provided by the utility model.

[0040] According to the variable frequency piezoelectric energy harvester based on the vibration of the cable, Figures 1 to 3 As shown, the first capture component 21 and the second capture component 22 both include a second frame 211, a clamping block 212, a second elastic member 213 and a second permanent magnet 214. The second frame 211 is sleeved on the inclined cable 3 and fixedly connected to the inclined cable 3. One end of the second elastic member 213 is clamped and fixed on the second frame 211 by the clamping block 212. The other end of the second elastic member 213 is fixedly provided with a second permanent magnet 214. The second permanent magnet 214 is arranged opposite to the first permanent magnet 14.

[0041] In this embodiment, by arranging the second permanent magnet 214 opposite to the first permanent magnet 14 , the second permanent magnet 214 drives the second elastic member 213 to vibrate, and the vibration energy is converted into electrical energy through the second elastic member 213 .

[0042] According to some embodiments of the present invention, a magnetic repulsion occurs between the first permanent magnet 14 and the second permanent magnet 214 within a certain distance range, and the vibrator 13 excites the second elastic member 213 to vibrate through the magnetic force.

[0043] According to some embodiments of the present invention, the second frame 211 is fixed to the stay cable 3 by bolts.

[0044] According to the variable frequency piezoelectric energy harvester based on the vibration of the cable, Figures 1 to 3 As shown, there is a gap between the second permanent magnet 214 and the first permanent magnet 14 .

[0045] In this embodiment, a gap is provided to achieve the first permanent magnet 14 and the second permanent magnet 214 being arranged opposite to each other in the stationary state.

[0046] According to the variable frequency piezoelectric energy harvester based on the vibration of the cable, Figure 1 As shown, the variable frequency piezoelectric energy harvester based on the vibration of the oblique cable further includes a fixing member 4 , one end of which is fixedly connected to the first frame 11 , and the other end of which is fixedly connected to the second frame 211 .

[0047] In this embodiment, the fixing member 4 is provided to fix the first frame 11 and the second frame 211 , thereby ensuring the magnet spacing between the first permanent magnet 14 and the second permanent magnet 214 .

[0048] According to the variable frequency piezoelectric energy harvester based on the vibration of the cable, Figure 1 and Figure 3 As shown, the first capture assembly 21 and the second capture assembly 22 are both provided with four second elastic members 213 , which are respectively provided at four positions of the upper, lower, left and right of the second frame 211 .

[0049] According to the variable frequency piezoelectric energy harvester based on the vibration of the cable, Figure 3 As shown, the second elastic member 213 includes an elastic base layer 2131 and piezoelectric ceramic layers 2132 adhered to both sides of the elastic base layer 2131 , and the piezoelectric ceramic layers 2132 are fixedly connected to the clamping block 212 .

[0050] According to the variable frequency piezoelectric energy harvester based on the vibration of the cable, Figure 3 As shown, the length of the elastic base layer 2131 is greater than that of the piezoelectric ceramic layer 2132 .

[0051] In this embodiment, by arranging the elastic base layer 2131 in the middle of the piezoelectric ceramic layer 2132, and the length of the elastic base layer 2131 is greater than the piezoelectric ceramic layer 2132, the vibration of the second permanent magnet 214 drives the elastic base layer 2131 to bend and vibrate, and the piezoelectric ceramic layer 2132 is subjected to tension and pressure, thereby converting vibration energy into electrical energy.

[0052] According to some embodiments of the present invention, after capturing the vibration of the inclined cable 3, the low-frequency vibration of the vibrator 13 is forced to vibrate through the electromagnetic force elastic base layer 2131 and the high-frequency self-vibration, thereby improving the vibration efficiency of the second elastic member 213 and improving the conversion efficiency of vibration energy into electrical energy in combination with the collection circuit.

[0053] According to some embodiments of the present invention, a single period of reciprocating vibration of the vibrator 13 will excite the elastic base layer 2131 structure to vibrate multiple times, increasing the number of times the piezoelectric ceramic layer 2132 is subjected to tension and compression, thereby improving the efficiency of capturing vibration energy.

[0054] According to some embodiments of the present invention, the elastic base layer 2131 bends, generating a tensile or compressive force on the piezoelectric ceramic layer 2132 , so that the piezoelectric ceramic layer 2132 generates a voltage.

[0055] According to the variable frequency piezoelectric energy harvester based on the vibration of the oblique cable provided by the present invention, the surface of the piezoelectric ceramic layer 2132 is coated with a silver electrode layer, and the silver electrode layer is connected to the external circuit through a wire.

[0056] According to the variable frequency piezoelectric energy harvester based on the vibration of the cable, Figures 1 to 2 As shown, the vibration absorbing device 1 further includes a linear bearing 16 , which is sleeved on the optical axis 12 and fixedly connected to the vibrator 13 .

[0057] In this embodiment, the linear bearing 16 is provided to reduce the wear of the vibrator 13 during the vibration process.

[0058] According to the variable frequency piezoelectric energy harvester based on the vibration of the cable, Figure 1 and Figure 2 As shown, the vibration absorbing device 1 is provided with four optical axes 12 and four vibrators 13, which are respectively arranged at four positions of the first frame 11, namely, up, down, left and right.

[0059] In this embodiment, the device is provided with vibrators 13 in the upper, lower, left, and right directions of the stay cable 3, which can collect vibrations in all directions of the stay cable 3 and convert the vibration energy into electrical energy.

[0060] The technical solution of the present invention is further explained below in conjunction with a specific embodiment. It should be noted that this specific embodiment is only for those skilled in the art to better understand the technical solution of the present invention, and should not be regarded as an unreasonable limitation on the protection scope of the present invention.

[0061] Example 1

[0062] The device's vibration absorber and energy capture device are both mounted on the cable and secured by fasteners to maintain a certain distance between the magnets. The vibration absorber consists of four sections: upper, lower, left, and right. These sections include an optical axis, an oscillator, a linear bearing, a first elastic member, and a first permanent magnet. The first frame is bolted to the cable. The optical axis is bolted to the first frame, which is fitted with a linear bearing that is fixedly connected to the oscillator. A tension spring capable of providing a nonlinear restoring force is positioned between the oscillator and the first frame. The energy capture device also consists of four sections: upper, lower, left, and right. These sections include a clamping block, a second elastic member, and a second permanent magnet. The second frame is bolted to the cable. The central elastic base is bolted to the second frame via the clamping block. A second permanent magnet is positioned at the free end of the elastic base. The piezoelectric ceramic layer is coated with a silver electrode layer, which is connected to the collection circuit via wires. The first permanent magnet and the second permanent magnet arranged at the free end of the elastic base layer generate magnetic repulsion interaction within a certain distance range, and the vibrator excites the elastic base layer to vibrate through the magnetic force.

[0063] When the cable-stayed structure experiences in-plane or out-of-plane vibration, the vibration-absorbing device and the cable generate instantaneous resonance and capture. This causes the vibrator to experience the nonlinear restoring force of the tension spring, reciprocating along the optical axis. This absorbs the broadband, low-frequency vibration energy of the cable into the vibrator. The vibrator magnetically excites the energy capture device, causing the elastic base layer to bend, stretching or compressing the piezoelectric ceramic layer. This generates a voltage, which is then harvested by the energy collection circuit. Each reciprocating vibration cycle of the vibrator excites multiple frequency-varying self-oscillations in the elastic base layer, increasing the number of times the piezoelectric ceramic layer is subjected to tension or compression, thereby improving the efficiency of vibration energy capture.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A variable frequency piezoelectric energy harvester based on cable vibration, characterized in that: include: vibration absorbers, energy capture devices, and stay cables; The vibration absorbing device includes a first frame, an optical axis, a vibrator, a first permanent magnet, and a first elastic member. The first frame is sleeved on the inclined cable and fixedly connected to the inclined cable. The optical axis is fixedly connected to the first frame. The extension direction of the optical axis is perpendicular to the extension direction of the inclined cable. The vibrator is sleeved on the optical axis. Two sides of the vibrator are connected to the first frame via the first elastic member. The other two sides of the vibrator are fixedly provided with the first permanent magnet. The energy capture device includes a first capture component and a second capture component which are sleeved on the inclined cable and respectively arranged on two sides of the first frame.

2. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 1 is characterized in that: The first capture assembly and the second capture assembly both include a second frame, a clamping block, a second elastic member and a second permanent magnet. The second frame is sleeved on the inclined cable and fixedly connected to the inclined cable. One end of the second elastic member is clamped by the clamping block and fixed on the second frame. The other end of the second elastic member is fixedly provided with a second permanent magnet, and the second permanent magnet is arranged opposite to the first permanent magnet.

3. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 2 is characterized in that: There is a gap between the second permanent magnet and the first permanent magnet.

4. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 2 is characterized in that: It also includes a fixing member, one end of which is fixedly connected to the first frame, and the other end of which is fixedly connected to the second frame.

5. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 2 is characterized in that: The first capture assembly and the second capture assembly are both provided with four second elastic members, which are respectively arranged at four positions of the upper, lower, left and right of the second frame.

6. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 5 is characterized in that: The second elastic member includes an elastic base layer and piezoelectric ceramic layers adhered to both sides of the elastic base layer, and the piezoelectric ceramic layers are fixedly connected to the clamping block.

7. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 6 is characterized in that: The length of the elastic base layer is greater than that of the piezoelectric ceramic layer.

8. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 6 is characterized in that: The surface of the piezoelectric ceramic layer is coated with a silver electrode layer, and the silver electrode layer is connected to an external circuit through a wire.

9. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 1, characterized in that: The vibration absorbing device further comprises a linear bearing, which is sleeved on the optical axis and fixedly connected to the vibrator.

10. The variable frequency piezoelectric energy harvester based on cable vibration according to claim 1, characterized in that: The vibration absorbing device is provided with four optical axes and four vibrators, which are respectively arranged at four directions of up, down, left and right of the first frame.

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