Vibration measurement and control device and method for multi-layer coupled flexible plate structure based on lifting platform

Abstract

The application discloses a kind of based on lifting platform's multilayer coupling flexible plate structure's vibration measurement and control device and method, including multilayer coupling flexible plate body portion, transmission part, vibration detection part and control part;The multilayer coupling flexible plate body portion is constituted by two horizontal cantilever plate layers and a vertical hinged plate layer, the base of horizontal cantilever plate layer is connected with the base of vertical hinged plate layer by vibration isolation layer respectively, and the flexible plate between horizontal cantilever plate layer and vertical hinged plate layer is coupled by flexible curved beam and magnet block;The transmission part includes lifting mechanism and rotating mechanism, is constituted by servo motor, screw, planetary reducer and synchronous belt transmission mechanism etc.;The vibration detection part mainly uses piezoelectric sensor and the binocular vision principle of industrial camera to detect the vibration signal of flexible plate;The control part mainly utilizes piezoelectric driver, combines active control algorithm, realizes the vibration active control of multilayer coupling flexible plate structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vibration control, in particular to a vibration measurement and control device and method for a multi-layer coupled flexible plate structure based on a lifting platform. BACKGROUND

[0002] With the continuous development of space science and technology, the structure of the spacecraft is developing towards large-scale, lightweight and flexible, and the demand for energy is also increasing. As one of the most typical large flexible components on the spacecraft, the solar sail is a typical deployable space panel array structure, which can be a single panel or multiple panels. The multiple panels are generally connected by hinges. When the spacecraft performs orbit transfer or docking operations, axial translation and rotation around the axis are often required. The vibration of the flexible structure such as the solar sail is excited by the impact of the movement and is difficult to naturally decay in a short time. If not inhibited, it will affect the working state of itself and reduce the precision and service life of the spacecraft. Therefore, it is necessary to study the vibration measurement and control of large flexible structures.

[0003] For vibration measurement of flexible thin plate structures, traditional measurement methods mainly use piezoelectric ceramic sensors, acceleration sensors, strain gauges and other sensor devices. Since the sensor is in direct contact with the measured object, it will inevitably add some physical effects to the measured object, especially for lightweight structures, which will change the inherent characteristics of the system structure and affect the accuracy of the test. As one of the representatives of non-contact measurement, binocular vision measurement generally calculates the three-dimensional world coordinates of the target point through the parallax principle to achieve global measurement characteristics, which is suitable for vibration detection when a large range of motion in the field of view. It is the most commonly used implementation of stereo vision. In addition, binocular vision does not change the frequency, amplitude and other vibration characteristics of the structure during measurement, which can well avoid the load effect, so it has great advantages in the study of large flexible structure vibration measurement and active control.

[0004] In passive vibration control, reasonably designing the vibration isolation buffer layer can effectively absorb vibration energy to achieve the effect of vibration reduction. In recent years, benefiting from the rapid development of 3D printing technology, mechanical metamaterials have attracted widespread attention due to their excellent dynamic and static performance, and related research has also achieved outstanding results. Metamaterials are artificially designed and usually composed of periodic structural units to obtain properties beyond the constituent materials, showing good application prospects in energy absorption and vibration reduction. SUMMARY

[0005] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of the present application is to provide a vibration measurement and control device and method for a multi-layer coupled flexible plate structure based on a lifting platform.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] A vibration measurement and control device based on a multi-layer coupled flexible plate structure of a lifting platform, comprising a multi-layer coupled flexible plate body part, a transmission part, a vibration detection part and a driving control part;

[0008] The multi-layer coupled flexible plate body part comprises an upper horizontal cantilever plate layer, a lower horizontal cantilever plate layer and a vertical hinged plate layer, the upper and lower horizontal cantilever plate layers are coupled by a flexible curved beam, the vertical hinged plate layer is located in the middle of the upper and lower horizontal cantilever plate layers, and the flexible curved beam realizes the coupling between the horizontal cantilever plate layers and the vertical hinged plate layer by magnetic force; the upper and lower horizontal cantilever plate layers are connected with the vertical hinged plate through a second vibration isolation layer;

[0009] The transmission part comprises a lifting mechanism and a rotating mechanism;

[0010] The lifting mechanism drives the multi-layer coupled flexible plate body part connected thereto to move in the vertical direction;

[0011] The rotating mechanism drives the multi-layer coupled flexible plate body part to rotate around the vertical direction;

[0012] The detection part is used for detecting the vibration information of the upper horizontal cantilever plate layer, the lower horizontal cantilever plate layer and the vertical hinged plate layer;

[0013] The control part is used for obtaining a control signal through the vibration information to suppress the vibration of the upper horizontal cantilever plate layer, the lower horizontal cantilever plate layer and the vertical hinged plate layer.

[0014] Further, the upper and lower horizontal cantilever plate layers have the same structure, comprising a horizontal layer base, flexible cantilever plates are symmetrically arranged on both sides of the horizontal layer base and horizontally placed, the flexible cantilever plates are four, the fixed ends of the flexible cantilever plates are fixed with the horizontal layer support, and the other ends are free ends, and the free ends of the flexible cantilever plates in the upper horizontal cantilever plate layer and the lower horizontal cantilever plate layer are coupled by a flexible curved beam.

[0015] Further, the vertical hinged plate layer comprises a vertical layer base and two flexible hinged plates, the two flexible hinged plates are arranged on both sides of the vertical layer base and symmetrically distributed, one end of the flexible hinged plate is a fixed end connected with the vertical layer base, and the other end of the flexible hinged plate is a free end, and the flexible hinged plate is arranged in the middle of the upper and lower horizontal cantilever plate layers.

[0016] Further, the flexible curved beam has four, is symmetrically distributed about the flexible hinged plate, the flexible curved beam is provided with a magnet block, the free end of the flexible hinged plate is provided with a magnet block, the flexible curved beam is semicircular, and deformation is generated by force at both ends to change the relative position between the magnet blocks, so as to change the interaction force between the magnet blocks.

[0017] Further, the lifting mechanism comprises a second servo motor, a synchronous belt, a pulley, a screw shaft, a bearing, a guide column and a lifting platform. The top of the lifting platform is fixed with the first vibration isolation layer, and the bottom of the lifting platform is connected with the guide column, thereby forming a moving pair in the vertical direction. The base bottom plate is connected with the base top plate through four guide columns and a screw shaft. The second servo motor drives the screw shaft to rotate through the synchronous belt, thereby driving the lifting platform to move in the vertical direction along the guide column, and driving the multilayer coupled flexible plate body part connected therewith to move in the vertical direction.

[0018] Further, the rotating mechanism comprises a first servo motor, a planetary reducer, a flange and a rotating platform. The first servo motor is connected with the input end of the planetary reducer, and the output end of the planetary reducer is connected with the flange, thereby driving the flange to rotate. The lower end of the rotating platform is connected with the flange, and the upper end of the rotating platform is connected with the lower horizontal cantilever plate layer.

[0019] Further, the detection part comprises a piezoelectric fiber sheet sensor and a binocular vision measurement unit.

[0020] The piezoelectric fiber sheet sensor is arranged on the side close to the fixed end of the flexible cantilever plate and the flexible hinged plate. The piezoelectric fiber sheet sensor detects the vibration signal, which is amplified by a charge amplifier, transmitted to a motion control card through a terminal plate, converted into a digital signal by an A / D conversion module in the motion control card, and then transmitted to a computer.

[0021] The binocular vision measurement unit comprises an industrial camera and a circular marker point. The flexible cantilever plate is attached with the marker point, and the marker point is within the field of view of the industrial camera. The industrial camera captures the marker point image and inputs the image into the computer.

[0022] Further, the control part comprises a piezoelectric fiber driver attached to the fixed end of the flexible cantilever plate and the flexible hinged plate. The vibration feedback signal obtained by the computer is transmitted through the terminal plate after passing through the motion control card, amplified by the piezoelectric amplification circuit, and then output to the piezoelectric fiber sheet driver, thereby suppressing the vibration of the flexible plate.

[0023] Further, the marker point comprises 15 equal-sized marker points arranged in a 5×3 array and symmetric about the center line of the flexible cantilever plate.

[0024] Further, the second vibration isolation layer is composed of a grid structure periodically arranged by nest-like sub-units.

[0025] Further, the first vibration isolation layer is composed of a plurality of stable quasi-zero stiffness metamaterial units periodically arranged.

[0026] A method based on the vibration measurement and control device, comprising:

[0027] Step one, the computer-controlled servo motor drives the multi-layer coupled flexible plate structure to lift or rotate to execute the desired trajectory, and excites each flexible plate to generate corresponding vibration;

[0028] Step two, the piezoelectric fiber sensor and binocular vision system are used to measure and detect the vibration of each flexible plate to obtain corresponding measurement signals;

[0029] Step three, the piezoelectric sensor signals collected in step two are amplified by the charge amplifier, transmitted to the motion control card through the terminal board, and then converted into digital signals by the A / D conversion module inside the motion control card, and then transmitted to the computer; the signals detected by the industrial camera are directly input into the computer for processing to obtain corresponding vibration feedback signals;

[0030] Step four, the detection signals obtained in step three are processed by the computer running the corresponding control algorithm, and then the vibration feedback signals are output through the D / A module of the motion control card, transmitted through the terminal board, amplified by the piezoelectric amplifier circuit, and then output to the piezoelectric fiber driver, thereby suppressing the vibration of the multi-layer coupled flexible plate structure;

[0031] Step five, by adjusting the control algorithm and its parameters, repeated tests are carried out to obtain a plurality of experimental data, and the vibration characteristics and control effect of the multi-layer coupled flexible plate structure are analyzed.

[0032] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0033] (1) The present application can study the vibration detection and control method of the multi-layer coupled flexible plate structure during lifting or rotating, simulate the spacecraft with multi-flexible coupled accessories for axial movement and rotation around the shaft, obtain the vibration characteristics in the structure movement through the detected vibration signals, and facilitate subsequent vibration control.

[0034] (2) The present application adopts a binocular vision detection method to measure the vibration displacement of the flexible plate, which has the advantages of non-contact measurement, no additional mass, and multi-point measurement compared with other sensors, and can reflect the global characteristics of the flexible plate vibration.

[0035] (3) The present application uses the stress deformation of the curved beam combined with the magnetic force to couple the horizontal cantilever plate layer and the vertical hinged plate layer, and can study the vibration characteristics of the multi-layer coupled flexible plate structure during lifting or rotating under the action of gravity.

[0036] (4) The present application uses a variety of different mechanical metamaterials to provide buffer and vibration isolation between system structure levels, providing a new solution for passive control of the vibration of the multi-layer coupled flexible plate structure, and has certain reference value and significance.

[0037] (5) The present application is a multi-sensor fusion system, which has both binocular vision sensors and piezoelectric fiber sheet sensors, can identify and study the bending and torsional modes of the hinged plate structure through multi-sensor fusion, and can also collect the vibration information of the marker points through binocular vision and visualize it. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is the overall structure schematic diagram of the vibration measurement and control device of the multi-layer coupled flexible plate structure based on the lifting platform;

[0039] Figure 2 is the front view of Figure 1 ;

[0040] Figure 3 is the top view of Figure 1 ;

[0041] Figure 4 is the left view of Figure 1 ;

[0042] Figure 5 is the lifting mechanism schematic diagram;

[0043] Figure 6 is the synchronous belt transmission mechanism schematic diagram;

[0044] Figure 7 is the sub-unit structure schematic diagram of the first vibration isolation layer;

[0045] Figure 8 is the sub-unit structure schematic diagram of the second vibration isolation layer;

[0046] Figure 9 is the sub-unit structure schematic diagram of the planar array vibration reduction structure;

[0047] Figure 10 is the vibration control flow chart of the experimental device. DETAILED DESCRIPTION

[0048] The present application will be further described in detail below in conjunction with the embodiments, but the embodiments of the present application are not limited thereto.

[0049] As shown in Figures 1-9 , a vibration measurement and control device of a multi-layer coupled flexible plate structure based on a lifting platform, comprising a multi-layer coupled flexible plate body part, a transmission part, a vibration detection part and a driving control part.

[0050] The multi-layer coupled flexible plate part comprises:

[0051] The multilayer coupling flexible plate body part includes an upper horizontal cantilever plate layer, a lower horizontal cantilever plate layer and a vertical hinged plate layer, the upper and lower horizontal cantilever plate layers are coupled through flexible curved beams 17, the vertical hinged plate layer is located in the middle of the upper and lower horizontal cantilever plate layers, and the flexible curved beams 17 realize the coupling between the horizontal cantilever plate layers and the vertical hinged plate layer through magnetic force; the upper and lower horizontal cantilever plate layers are connected with the vertical hinged plate through a second vibration isolation layer;

[0052] Further description:

[0053] The upper horizontal cantilever plate layer 21 and the lower horizontal cantilever plate layer 7 have basically the same structure, the lower horizontal cantilever plate layer includes a lower horizontal layer base 11 and four identical flexible cantilever plates, the flexible cantilever plates are symmetrically arranged at the front end and the rear end of the lower horizontal layer base and are horizontally arranged, the flexible cantilever plates are fixed by a mechanical clamping device 8 and are connected to the lower horizontal layer base through dovetail supports 13, one end connected with the mechanical clamping device is a fixed end, and the other end is a free end.

[0054] The upper horizontal cantilever plate layer 21 includes an upper horizontal layer base 20 and four identical flexible cantilever plates, and the flexible cantilever plates are arranged in the same manner as the lower horizontal cantilever plate layer. The difference lies in that two flexible cantilever plates of the upper horizontal cantilever plate layer are attached with marker points 23. The flexible cantilever plates are provided with piezoelectric fiber sheet sensors 9 and piezoelectric fiber sheet drivers 10 on the side close to the fixed end. The midpoints of the free ends of the flexible cantilever plates of the upper and lower horizontal cantilever layers are coupled through flexible curved beams, and there are four flexible curved beams for connecting the flexible cantilever plates of the upper and lower horizontal cantilever plate layers.

[0055] The upper and lower horizontal layer bases are internally processed into dovetail guide rail shapes, the flexible cantilever plates on both sides are connected to the dovetail supports 13 through the planar array vibration reduction structure 12, and the lower horizontal cantilever plate layer is connected with the rotating platform through a flange 33. The planar array vibration reduction structure is a 6x6 planar array.

[0056] In the embodiment, the two flexible cantilever plates attached with the marker points are located at the front end of the upper horizontal layer base and the rear end of the upper horizontal layer base, and the two flexible cantilever plates are symmetrically arranged about the upper horizontal layer base.

[0057] The marker points specifically refer to 15 circular marker points 23, which are equal in size, form a 5x3 dot matrix, are symmetric about the center line of the cantilever plate, and have a total size of 200mmx160mm.

[0058] The vertical hinged plate layer includes a vertical layer base 15 and two identical flexible hinged plates 16, which are placed vertically and symmetrically distributed on both sides. The flexible hinged plates are composed of two flexible plates of the same material connected by hinges. The flexible hinged plates are fixedly connected to the vertical layer base by a mechanical clamping device. A piezoelectric fiber sensor and a piezoelectric fiber driver are provided on the side of the flexible hinged plate near the fixed end. The flexible hinged plate is located in the middle of the upper and lower horizontal cantilever plate layers, and a magnet block 19 is embedded on the side near the free end. The coupling between the horizontal cantilever plate layer and the vertical hinged plate layer is achieved by magnetic force and the magnet block 18 on the flexible curved beam.

[0059] The flexible curved beam is semi-circular, and its deformation caused by forces at both ends changes the relative positions of the magnets, thereby altering the interaction force between them. This device can be used to study the effects of the curved beam, magnetic coupling, gravity, and other factors on the vibration characteristics of multilayer flexible plates under translational and rotational conditions.

[0060] This embodiment also includes metamaterial vibration isolation layers, specifically a first vibration isolation layer 3 and a second vibration isolation layer 14. The first vibration isolation layer 3 is composed of an array structure of mechanical metamaterial sub-units, with horizontal cantilever plates and vertical hinged plates connected by bolts. It is composed of periodically arranged multi-stable quasi-zero stiffness metamaterial units in a 9×6×2 array structure. The second vibration isolation layer 14 is also composed of an array structure of mechanical metamaterial sub-units, with lifting mechanism and rotating mechanism parts connected by bolts. It is composed of a periodically arranged grid structure of nested sub-units in a 3×3×2 array structure.

[0061] —The transmission system includes:

[0062] It consists of two parts: a lifting mechanism and a rotating mechanism.

[0063] like Figure 5 As shown, the lifting mechanism includes components such as a second servo motor 28, a synchronous belt 36, a pulley 37, a lead screw 30, a bearing 27, a guide column 31, and a lifting platform 2. The top of the lifting platform 2 is fixed to the first vibration isolation layer 3, and the bottom of the lifting platform is connected to the guide column 31 via the bearing 27, forming a vertical sliding pair. The top and bottom are connected by a support column 29. The base plate 26 is placed on the ground by a foot bracket, and the base top plate 32 is fixed to the experimental table 1 by bolts. The base bottom plate and the base top plate are connected by four guide columns 31 and one lead screw 30. The second servo motor 28 is fixed on the base and drives the lead screw 30 to rotate via the synchronous belt 36, causing the lifting platform to move vertically along the guide column 31, thereby driving the multi-layer coupled flexible plate connected to it to perform a translational motion in the vertical direction.

[0064] Furthermore, the synchronous belt is provided with a synchronous belt protective cover 35.

[0065] As shown in Figure 6 The rotating mechanism part includes a first servo motor 5, a planetary reducer 6, a flange 33, a rotating platform 34, etc., wherein the computer sends control signals to the first servo motor through a motion control card, a terminal board and a servo motor driver, the first servo motor 5 is decelerated by the planetary reducer 6 and fixed to the first vibration isolation layer 3 through the rotating table support 4; the input end of the planetary reducer 6 is connected with the first servo motor 5, and the output end is connected with the flange 33 to drive the flange to rotate; the lower end of the rotating platform 34 is connected with the flange 33 through bolts, and the upper end is fixedly connected with the lower horizontal cantilever plate layer through bolts; the first servo motor 5 drives the flange 33 to rotate through the planetary reducer 6, and further drives the multi-layer coupled flexible plate part to rotate around the vertical direction.

[0066] The vibration detection part includes:

[0067] A piezoelectric fiber sheet sensor 9 is used to detect the vibration signal of the flexible cantilever plate and the flexible hinged plate, and convert the vibration signal into a corresponding electrical signal output by the sensing characteristics of the piezoelectric fiber sheet sensor 9. After being amplified by a charge amplifier 40, the electrical signal is transmitted to a motion control card 42 through a terminal board 41, and then converted into a digital signal by an A / D conversion module in the motion control card, and finally transmitted to a computer 43.

[0068] A binocular vision measurement unit composed of four identical industrial cameras 24 and marker points 23; the industrial cameras 24 are fixed on a guide rail 25 and connected with the fixed end of the upper horizontal cantilever plate 21 through a camera support 22; the image information is input to the computer for processing through a USB interface, the marker points on the image are extracted, and the vibration information of the marker points is obtained through a certain algorithm, so as to reflect the vibration condition of the flexible cantilever plate.

[0069] Specifically, the piezoelectric fiber sheet sensor is composed of two piezoelectric fiber sheets, which are symmetrically pasted on the front and back surfaces of the flexible cantilever plate and the flexible hinged plate, one on each surface and connected in parallel, and specifically pasted on the center line of the wide edge of the flexible plate close to the fixed end.

[0070] The four industrial cameras 24 are opposite to the flexible cantilever plate on one side of the upper horizontal cantilever plate layer, and the distance from the flexible plate is about 250mm; the industrial cameras are installed on the guide rail 25 and connected to the fixed end of the cantilever plate through the camera support 22; the relative positions of the two industrial cameras 24 on the same side on the guide rail 25 can be adjusted, and the distance from the flexible plate can also be adjusted as needed, and the circular marker points should be located within the field of view of the cameras during measurement.

[0071] The control part includes:

[0072] The piezoelectric fiber sheet driver 10 transmits the measured vibration signal to the computer 43, and through running the active control algorithm produces the corresponding control signal, which is input to the motion control card 42, output by the D / A output module, transmitted through the terminal board 41, amplified by the piezoelectric amplification circuit 39, and output to the piezoelectric fiber sheet driver 10, thereby the vibration of the flexible plate can be suppressed.

[0073] Further, the piezoelectric fiber sheet driver 10 is composed of 8 piezoelectric fiber sheets, which are pasted on the front and back surfaces of the flexible plate near the fixed end, and are symmetric about the vertical median plane of the flexible plate, 4 on each surface and connected in parallel, the center distance from the fixed end edge is 60mm, the attitude is 90°, the center distance of the adjacent two is 50mm, and is used for suppressing the low-order modal vibration of the flexible plate.

[0074] The method of the vibration measurement and control device based on the multi-layer coupled flexible plate structure in motion of the lifting platform comprises the following steps:

[0075] Step one uses the computer 43 to control the servo motor to drive the multi-layer coupled flexible plate structure to lift or rotate to execute the input desired trajectory, excite the corresponding vibration of each flexible plate;

[0076] Step two uses the piezoelectric fiber sheet sensor 9 and the binocular vision system to measure and detect the vibration of each flexible plate, and obtains the corresponding measurement signal;

[0077] Step three transmits the piezoelectric sensor signal collected in step two to the motion control card 42 through the terminal board 41 after being amplified by the charge amplifier 40, and then converts the analog signal into a digital signal through the A / D conversion module inside the motion control card 42, and then transmits it to the computer 43; the signal detected by the industrial camera 24 is directly input to the computer 43 for processing, and the corresponding vibration feedback signal is obtained;

[0078] Step four obtains the detection signal in step three, runs the corresponding control algorithm through the computer 43, and then obtains the vibration feedback signal, which is output by the D / A module of the motion control card 42, transmitted through the terminal board 41, amplified after passing through the piezoelectric amplification circuit 39, and output to the piezoelectric fiber sheet driver 10, thereby suppressing the vibration of the multi-layer coupled flexible plate structure;

[0079] Step five adjusts the control algorithm and its parameters, repeatedly tests, obtains a plurality of experimental data, and analyzes the vibration characteristics and control effect of the multi-layer coupled flexible plate structure.

[0080] Figure 1 The dashed line in the figure indicates the connection relationship between each device, and the direction arrow indicates the transmission direction of the detection and control signal flow.

[0081] In this embodiment, the materials of the flexible plates are completely the same, and are all thin plates of epoxy resin material. The horizontal flexible cantilever plate has a geometric size of 430 mm x 250 mm x 2 mm, and the two flexible plates in the vertical flexible hinged plate 16 have geometric sizes of 125 mm x 250 mm x 2 mm and 250 mm x 250 mm x 2 mm respectively. The elastic modulus of the epoxy resin is Ep = 34.64 Gpa, and the density is p = 1840 kg / m 3 .

[0082] The piezoelectric drivers 10 are all made of piezoelectric ceramic material, and have a geometric size of 40 mm x 12 mm x 1 mm. They are pasted on the flexible plates in a sheet shape, 60 mm away from the fixed end and 19 mm away from the left and right edges of the flexible plate in the width direction. The piezoelectric ceramic material has an elastic modulus of Ep = 63 Gpa and d31 = -166 pm / V.

[0083] The piezoelectric fiber sheet sensor 9 is made of piezoelectric ceramic material, and has a geometric size of 40 mm x 12 mm x 1 mm. It is pasted on the center line of the flexible beam in a sheet shape, 60 mm away from the fixed end.

[0084] The experimental bench 1 is assembled from aluminum profiles with lengths of 480 mm and 300 mm. The bench top is a stainless steel plate with a size of 600 mm x 600 mm x 10 mm, which is connected to the profiles by screws. Each connection of the profiles is fixed by an angle iron.

[0085] The first vibration isolation layer 3, the second vibration isolation layer 14 and the planar array vibration reduction structure 12 are all manufactured by 3D printing technology. The first vibration isolation layer 3 and the second vibration isolation layer 14 are made of nylon with a Young's modulus of 770 MPa, and the planar array vibration reduction structure 12 is made of photosensitive resin with a Young's modulus of 2050 MPa.

[0086] As shown in Figs. Figure 7 , Figure 8 and Figure 9 , each unit of the first vibration isolation layer 3 is composed of intersecting curved beams, elastic rings and frames. The units are connected by vertical rods, and the overall size of the unit is 36 mm x 36 mm x 24 mm. Each sub-unit of the second vibration isolation layer 14 is composed of three semicircular curved beams with different radii and support frames. The units are connected by support frames, and the radii of the semicircular curved beams are 8 mm, 12 mm and 16 mm respectively. Each sub-unit of the planar array vibration reduction structure 12 is composed of a support frame, a positive stiffness element, a negative stiffness element and a central mass, which are connected by the positive stiffness element. The overall size of the unit is 60 mm x 40 mm x 25 mm.

[0087] The first servo motor 5 is a product of Mitsubishi, model HC-KFS13, power 100W, maximum speed 3000r / min, resolution 40000 pulses / turn; the second servo motor 28 is a product of Delta, model ECMA-F21845, power 400W, maximum speed 3000r / min, resolution 40000 pulses / turn; the synchronous pulley is a product of MITSUMI, model HTPA32S3M100; the planetary reducer 6 is a product of Neugart, model PLFN-64, reduction ratio 64:1.

[0088] The industrial camera 24 is a COMS camera of Basler, model Basler acA1600-60gc, image size 1600*1200 pixels, about 200 million pixels, frame rate 60 frames / s, lens interface C, camera interface GigE, transmission speed better than USB.

[0089] The lens of the industrial camera 24 is an industrial lens of Computar, model computar M1214-MP2, focal length 12mm, size Φ33.5mm*28.2mm, maximum image size 8.8mm*6.6mm, interface C.

[0090] The charge amplifier 40 is a YE5850 type charge amplifier of Jiangsu Lian Neng Electronics Co., Ltd.; the servo motor driver 38 is a servo unit of Σ-II series, model SGDM-04ADAR; the motion control card 42 is a DMC-2x00 digital motion controller of GALIL, providing a standard PCI bus interface; the selected computer 43 has a CPU model core76650U2.2GHz, memory 4G, and a PCI-e slot in the mainboard, which can install the motion control card.

[0091] The piezoelectric amplifier circuit 39 can be composed of parts such as APEX-PA241DW or APEX-PA240CX piezoelectric amplifiers, and its research unit is South China University of Technology. It is introduced in detail in the patent of the applicant, entitled "Space sailboard bending and torsional modal vibration simulation active control device and method", application number 200810027186.4. The amplification factor can reach 52 times, i.e. -5V~+5V is amplified to -260~+260V.

[0092] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application shall be equivalent replacement manners and shall be included in the protection scope of the present application.

Claims

1. A vibration monitoring and control device for a multi-layer coupled flexible plate structure based on a lifting platform, characterized in that, It includes a multi-layer coupled flexible plate body, a transmission part, a vibration detection part, and a control part; The multi-layer coupled flexible plate body includes an upper horizontal cantilever plate layer, a lower horizontal cantilever plate layer, and a vertical hinged plate layer. The upper and lower horizontal cantilever plate layers are coupled by a flexible curved beam. The vertical hinged plate layer is located between the upper and lower horizontal cantilever plate layers. The flexible curved beam achieves coupling between the horizontal cantilever plate layer and the vertical hinged plate layer through magnetic force. The upper and lower horizontal cantilever plate layers are connected to the vertical hinged plate layer through a second vibration isolation layer. The transmission component includes a lifting mechanism and a rotating mechanism; The lifting mechanism drives the multi-layer coupled flexible plate body to move in a vertical direction. The rotating mechanism drives the multi-layer coupled flexible plate body to rotate in the vertical direction. The vibration detection section is used to detect the vibration information of the upper horizontal cantilever plate layer, the lower horizontal cantilever plate layer and the vertical hinged plate layer; The control section is used to obtain control signals through vibration information to suppress the vibration of the upper horizontal cantilever plate layer, the lower horizontal cantilever plate layer and the vertical hinged plate layer. The upper and lower horizontal cantilever slabs have the same structure, including a horizontal slab base. Flexible cantilever slabs are symmetrically arranged on both sides of the horizontal slab base. There are four flexible cantilever slabs, which are placed horizontally. The fixed end of each flexible cantilever slab is fixed to the horizontal slab base, and the other end is a free end. The free ends of the flexible cantilever slabs in the upper horizontal cantilever slab are coupled to the free ends of the flexible cantilever slabs in the lower horizontal cantilever slab through flexible curved beams. The vertical hinged plate layer includes a vertical layer base and two flexible hinged plates. The two flexible hinged plates are arranged on both sides of the vertical layer base and are symmetrically distributed. One end of the flexible hinged plate is a fixed end connected to the vertical layer base, and the other end of the flexible hinged plate is a free end. The flexible hinged plate is located in the middle of the upper and lower horizontal cantilever plate layers. There are four flexible curved beams, symmetrically distributed about the flexible hinge plate. Each flexible curved beam is equipped with a magnet block, and the free end of the flexible hinge plate is also equipped with a magnet block. The flexible curved beam is semi-circular. By applying force to both ends, the relative positions of the magnet blocks are changed, thereby changing the interaction force between the magnet blocks. The lifting mechanism includes a second servo motor, a synchronous belt, pulleys, a lead screw, bearings, guide columns, and a lifting platform. The top of the lifting platform is fixed to the first vibration isolation layer, and the bottom of the lifting platform is connected to the guide columns, forming a vertical sliding pair. The base plate is connected to the base top plate through four guide columns and one lead screw. The second servo motor drives the lead screw to rotate through the synchronous belt, driving the lifting platform to move vertically along the guide columns, and driving the multi-layer coupled flexible plate body connected to it to perform translational motion in the vertical direction. The rotating mechanism includes a first servo motor, a planetary reducer, a flange, and a rotating platform. The first servo motor is decelerated by the planetary reducer. The input end of the planetary reducer is connected to the first servo motor, and its output end is connected to the flange, driving the flange to rotate. The lower end of the rotating platform is connected to the flange, and the upper end of the rotating platform is connected to the lower horizontal cantilever plate. The vibration detection section includes a piezoelectric fiber sensor and a binocular vision measurement unit. A piezoelectric fiber sensor is installed on the side of the flexible cantilever plate and flexible hinge plate near the fixed end; the piezoelectric fiber sensor detects vibration signals, which are amplified by a charge amplifier and transmitted to the motion control card through the terminal board. The analog signal is then converted into a digital signal by the A / D conversion module inside the motion control card and transmitted to the computer. The binocular vision measurement unit includes an industrial camera and marker points. The flexible cantilever plate is attached with marker points, which are within the field of view of the industrial camera. The industrial camera captures images of the marker points and inputs them into a computer. The control unit includes a piezoelectric fiber sheet driver, which is attached to the fixed end of the flexible cantilever plate and the flexible hinge plate. The computer receives the vibration feedback signal, which is transmitted through the motion control card and the terminal board. After being amplified by the piezoelectric amplifier circuit, it is output to the piezoelectric fiber sheet driver to suppress the vibration of the flexible plate.

2. The vibration measurement and control device according to claim 1, characterized in that, The markers are circular, consisting of 15 equal-sized markers arranged in a 5×3 array, symmetrical about the centerline of the flexible cantilever plate.

3. A method based on the vibration measurement and control device according to any one of claims 1-2, characterized in that, include: Step 1 uses a computer-controlled servo motor to drive the multi-layer coupled flexible plate structure to rise or rotate, in order to execute the input desired trajectory and excite each flexible plate to generate corresponding vibrations. Step 2 uses piezoelectric fiber sheet sensors and binocular vision measurement units to detect the vibration of each flexible plate and obtain the corresponding measurement signals; Step 3: The piezoelectric fiber sensor signal acquired in Step 2 is amplified by a charge amplifier and then transmitted to the motion control card through the terminal board. The analog signal is then converted into a digital signal by the A / D conversion module inside the motion control card and transmitted to the computer. The signal detected by the industrial camera is directly input into the computer for processing to obtain the corresponding vibration detection signal. Step four involves running the vibration detection signal obtained in step three through a computer to generate a corresponding vibration feedback signal. This signal is then output through the D / A module of the motion control card, transmitted through the terminal board, amplified by the piezoelectric amplifier circuit, and finally output to the piezoelectric fiber sheet driver, thereby suppressing the vibration of the multilayer coupled flexible plate structure. Step 5 involves adjusting the control algorithm and its parameters, conducting repeated experiments to obtain multiple sets of experimental data, and analyzing the vibration characteristics and control effect of the multi-layer coupled flexible plate structure.

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