WO2021160037A1

WO2021160037A1 - Vibration measurement device

Info

Publication number: WO2021160037A1
Application number: PCT/CN2021/075541
Authority: WO
Inventors: 伍康; 郭梅影; 要佳敏; 王力军
Original assignee: 清华大学
Priority date: 2020-02-14
Filing date: 2021-02-05
Publication date: 2021-08-19
Also published as: CN111366231A

Abstract

The present disclosure relates to a vibration measurement device for directly measuring the movement of a sensitive component. A detection circuit can output a displacement signal according to the displacement of a sensing component, and a feedback control circuit outputs a feedback signal according to the displacement signal. A first driving device can drive the sensing component to move according to the feedback signal to make the displacement of the sensing component relative to a displacement reference device be zero or close to zero. The displacement reference device is fixedly arranged relative to a base frame. When the ground vibrates, the sensing component would be displaced relative to the displacement reference device, and the displacement may be a displacement in the vertical direction. In this case, the detection circuit can detect the displacement and output a displacement signal, and the feedback control circuit outputs a feedback signal according to the displacement signal. The feedback signal can directly reflect the vibration of the ground, and because the sensitive component is fixedly arranged relative to the sensing component, the vibration of the sensitive component can be directly reflected. Then, the measurement of the sensing component can be compensated according to the feedback signal, thereby improving the accuracy of a correction result.

Description

Vibration measuring device

Related application

This disclosure claims the priority of the Chinese patent application filed on February 14, 2020 with the application number 202010092551.0 and the title "Vibration Measuring Device", which is hereby incorporated by reference in its entirety.

Technical field

The present disclosure relates to the field of precision measurement, in particular to a vibration measurement device.

Background technique

In the field of precision physics experiments and measurement, ground vibration is the main source of noise in the measurement, which will have a greater impact on the accuracy of the measurement. Vibration compensation technology corrects the measurement results by measuring ground vibration to achieve higher precision measurement, which has a very important role and application prospects. However, in the prior art, the vibration pickup and the measured element (sensitive part) are placed side by side on the substrate through indirect measurement, and the movement of the measured sensitive part is estimated through the output signal of the vibration pickup. This kind of scheme basically adopts a hypothetical transfer function to approach the real transfer function. In theory, there is bound to be an error, which affects the accuracy of the correction result.

Summary of the invention

Based on this, it is necessary to provide a vibration measuring device that directly measures the movement of the sensitive part in response to the above-mentioned problems.

A vibration measuring device, including:

The pedestal frame surrounds and forms an accommodation space;

A sensing element, one end of the sensing element is movably arranged on the base frame for fixing the sensing element;

The displacement reference device is arranged in the accommodating space and is fixedly arranged relative to the base frame;

A detection circuit for outputting a displacement signal according to the displacement of the sensing element relative to the displacement reference device;

A feedback control circuit for outputting a feedback signal according to the displacement signal; and

The first driving device is located in the accommodating space and is arranged between the sensing element and the base frame, and is used to drive the sensing element to move according to the feedback signal so that the displacement of the sensing element is zero or Approaching zero.

In one embodiment, the displacement reference device includes a first fixed electrode plate and a second fixed electrode plate, the first fixed electrode plate and the second fixed electrode plate are fixedly arranged in parallel, and the sensing element is arranged on the Between the first fixed electrode plate and the second fixed electrode plate;

When the sensing element is displaced between the first fixed electrode plate and the second fixed electrode plate, the first capacitance formed by the first fixed electrode plate and the sensing element and the second fixed electrode When the difference between the second capacitance formed by the plate and the sensing element changes, the detection circuit outputs the displacement signal, the feedback control circuit outputs the feedback signal according to the displacement signal, and the first driving device The sensitive element is driven to move according to the feedback signal so that the difference between the first capacitance and the second capacitance is zero or approaches zero.

In one embodiment, the first driving device includes a voice coil motor, the voice coil motor includes a magnet structure and a coil structure, the magnet structure is fixedly arranged relative to the base frame, and the coil structure is relative to the base frame. The sensing element is fixedly arranged.

In one embodiment, the first driving device includes a piezoelectric driver, the piezoelectric driver includes a housing and an output shaft arranged in the housing, the housing is fixedly arranged relative to the base frame, and the The output shaft is fixedly arranged relative to the sensing element.

In one embodiment, the base frame includes a first supporting column, which is arranged in the containing space, and one end of the sensing element is movably arranged on the first supporting column.

In one embodiment, it further includes a first elastic member, one end of the first elastic member is disposed on the first supporting column, and the other end of the first elastic member is fixed to the sensing member. In a static state, The first elastic member is used to keep the sensing member at an initial position when the displacement relative to the displacement reference device is zero.

In one embodiment, it further includes a second driving device, the second driving device is disposed between the sensing element and the base frame, and the second driving device is disposed far away from the first driving device. At one end of the first support column, in a static state, the second driving device is used to keep the sensing element at an initial position when the displacement relative to the displacement reference device is zero.

In one embodiment, it further includes:

The second supporting column is arranged in the containing space and is arranged at intervals from the first supporting column;

A second elastic element, one end of the second elastic element is connected to one end of the first support column, and the other end of the second elastic element is fixed to the sensing element. In a static state, the second elastic element It is used to keep the sensing element at the initial position when the displacement relative to the displacement reference device is zero.

In one embodiment, it further includes glass beads, which are fixedly arranged on the sensing element, and the displacement reference device includes:

The laser diode is arranged on the second supporting column;

The photodetector is arranged on the first supporting column;

In the static state, when the sensing element is held at the initial position when the displacement is zero relative to the base frame, the laser diode is focused on the center of the photodetector through the glass beads, and the detection circuit is connected to the center of the photodetector. The photodetector is connected, and when the sensing element is displaced, the detection circuit sends out the displacement signal.

In an embodiment, the first support column is provided with a tapered hole, and one end of the sensing element is provided with a matching ball, and the matching ball is tangent to the inner wall of the tapered hole.

In one embodiment, the first support column is provided with a vertical sliding rail, and one end of the sensing element is slidably disposed on the sliding rail.

In one embodiment, the base frame is provided with an observation window.

The vibration detection device provided by the embodiment of the present application. The detection circuit may output a displacement signal according to the displacement of the sensing element, and the feedback control circuit may output a feedback signal according to the displacement signal. The first driving device may drive the sensing element to move according to the feedback signal so that the displacement of the sensing element relative to the displacement reference device is zero or approaches zero. The displacement reference device is fixedly arranged relative to the base frame. When the ground vibrates, the sensing element will be displaced relative to the displacement reference device, that is, relative to the base frame. The displacement may be a displacement in a vertical direction. At this time, the detection circuit can detect the displacement and output a displacement signal, and the feedback control circuit outputs a feedback signal according to the displacement signal. The feedback signal can directly reflect the vibration condition of the ground. Since the sensitive element is fixedly arranged relative to the sensing element, it can directly reflect the vibration condition of the sensitive element. Then, according to the feedback signal, the measurement of the sensing element can be compensated, and the accuracy of the correction result can be improved.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are the embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on the disclosed drawings without creative work.

Fig. 1 is a schematic diagram of a vibration measuring device provided in an embodiment of the application;

Fig. 2 is a schematic diagram of a voice coil motor provided by an embodiment of the application;

FIG. 3 is a schematic diagram of a vibration measurement device provided by an embodiment of the application;

Fig. 4 is a schematic diagram of a vibration measuring device provided by an embodiment of the application;

Fig. 5 is a schematic diagram of a vibration measuring device provided by an embodiment of the application;

Fig. 6 is a schematic diagram of a vibration measurement device provided by an embodiment of the application;

Fig. 7 is a schematic diagram of a vibration measuring device provided by an embodiment of the application;

FIG. 8 is a schematic diagram of a connection method of a sensing element provided by an embodiment of the application;

FIG. 9 is a schematic diagram of a connection method of a sensing element provided by an embodiment of the application.

Description of reference signs:

Vibration measuring device 10; base frame 100; accommodating space 110; observation window 120; first support column 130; tapered hole 132; second support column 140; first elastic member 150; second elastic member 160; sensing member 170 Matching ball 172; Sensitive element 180; Displacement reference device 190; First fixed pole plate 192; Second fixed pole plate 194; Laser diode 212; Glass beads 214; Photodetector 216; First driving device 220; Magnet structure 214 The coil structure 216; the piezoelectric driver 230; the housing 232; the output shaft 234; the second driving device 240; the fixed post 250; the mounting block 252; the sliding rail 260;

Detailed ways

In order to make the above objectives, features and advantages of the present disclosure more obvious and understandable, the specific implementation manners of the present disclosure will be described in detail below with reference to the accompanying drawings. In the following description, many specific details are explained in order to fully understand the present disclosure. However, the present disclosure can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present disclosure. Therefore, the present disclosure is not limited by the specific implementations disclosed below.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or a central element may also be present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or an intermediate element may be present at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only, and are not meant to be the only embodiments.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the disclosure. The terminology used in the description of the disclosure herein is only for the purpose of describing specific embodiments, and is not intended to limit the disclosure. The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

Please refer to FIG. 1, an embodiment of the present application provides a vibration measuring device 10. The vibration measuring device 10 includes a base frame 100, a sensing element 170, a displacement reference device 190, a detection circuit, a feedback control circuit and a first driving device 220. The base frame 100 surrounds and forms an accommodation space 110. One end of the sensing element 170 is movably disposed on the base frame 100. The sensitive element 180 can be fixedly disposed on the sensitive element 170. The displacement reference device 190 is disposed in the accommodation space 110. The displacement reference device 190 is fixedly arranged relative to the base frame 100. The detection circuit is used to output a displacement signal according to the displacement of the sensing element 170 relative to the base frame 100. The feedback control circuit is used to output a feedback signal according to the displacement signal.

The first driving device 220 is located in the receiving space 110. The first driving device 220 is disposed between the sensing element 170 and the base frame 100. The first driving device 220 is used to drive the sensing element 170 to move according to the feedback signal so that the displacement of the sensing element 170 relative to the displacement reference device (190) is zero or approaches zero.

The base frame 100 may be a hollow closed structure. The accommodating space 110 may be a cubic or cylindrical structure. The sensing element 170 may be horizontally placed in the containing space 110. One end of the sensing element 170 can be movably arranged on the inner wall of the base frame 100 or other structures in the base frame 100, that is, the sensing element 170 can rotate around the movable end, or the sensing element 170 can slide relative to the base frame 100. In an embodiment, the sensing element 170 is movably arranged on the base frame 100 through a flexible hinge.

The sensing element 170 may have a strip-shaped or plate-shaped structure. The sensitive element 180 may be an optical element such as a corner cube or a plane mirror, or other elements that need to be measured for vibration. The sensitive element 180 is also a component that needs to be compensated. The sensitive element 180 can be fixed to the sensitive element 170 via an adapter 182. The adapter may be a bolt. That is, the sensitive element 180 can be fixed to the sensitive element 170 by bolt connection.

The first driving device 220 may be disposed at the bottom of the base frame 100 and may be in contact with the sensing element 170 to drive the sensing element 170. When in a static state, the sensing element 170 can be in a balanced position under the support of the first driving device 220. At this time, the displacement of the sensing element 170 relative to the displacement reference device 190 is zero. That is, the displacement relative to the base frame 100 is zero. When the ground vibrates, the displacement is not zero, the detection circuit outputs the displacement signal, and the feedback control circuit can drive the sensing element 170 according to the displacement signal to restore the sensing element 170 to the original position. In the equilibrium position, even if the displacement of the sensitive component 180 relative to the base frame 100 is zero or close to zero. The feedback signal can directly reflect the vibration of the ground. Since the sensitive element 180 is fixedly arranged relative to the sensitive element 170, that is, the feedback signal can directly reflect the vibration of the sensitive element 180.

The vibration detection device 10 provided by the embodiment of the present application. The detection circuit may output a displacement signal according to the displacement of the sensing element 170, and the feedback control circuit may output a feedback signal according to the displacement signal. The first driving device 220 can drive the sensing element 170 to move according to the feedback signal so that the displacement of the sensing element 170 relative to the displacement reference device 190 is zero or close to zero. The displacement reference device 190 is fixedly arranged relative to the base frame 100. When the ground vibrates, the sensing element 170 will be displaced relative to the displacement reference device 190, that is, relative to the base frame 100. The displacement may be a displacement in a vertical direction. At this time, the detection circuit can detect the displacement and output a displacement signal, and the feedback control circuit outputs a feedback signal according to the displacement signal. The feedback signal can directly reflect the vibration of the ground. Since the sensitive element 180 is fixedly arranged relative to the sensing element 170, it can directly reflect the vibration of the sensitive element 180. Then, the measurement of the sensing element 170 can be compensated according to the feedback signal, and the accuracy of the correction result can be improved.

In one embodiment, the displacement reference device 190 is disposed in the accommodation space 110. The displacement reference device 190 includes a first fixed electrode plate 192 and a second fixed electrode plate 194. The first fixed electrode plate 192 and the second fixed electrode plate 194 are fixedly arranged in parallel. The sensing element 170 is disposed between the first locating plate 192 and the second locating plate 194. When the sensing element 170 is displaced between the first fixed electrode plate 192 and the second fixed electrode plate 194, the first capacitance formed by the first fixed electrode plate 192 and the sensing element 170 and the When the difference of the second capacitance formed by the second fixed electrode plate 194 and the sensing element 170 changes, the detection circuit outputs the displacement signal, and the feedback control circuit outputs a feedback signal according to the displacement signal. The first driving device 220 drives the sensitive element 180 to move according to the feedback signal to make the difference between the first capacitor and the second capacitor zero or close to zero. The first locating plate 192, the second locating plate 194, and the sensing element 170 may be conductive materials. The sensing element 170 may constitute a moving electrode plate. The first locating plate 192, the second locating plate 194, and the sensing element 170 may constitute a differential parallel plate capacitor. The first locating plate 192 and the second locating plate 194 may be fixed to the base frame 100 through a fixing post 250.

According to the capacitance formula

Among them, ε is the dielectric constant of the inter-electrode medium, S is the effective area of the two pole plates covering each other, and D is the distance between the two pole plates. All the plates are in the same working environment, and the effective area of the sensing element 170 is equal to the effective area of the first locating plate 192 and the second locating plate 194. When there is no vibration, the sensing element 170 is in the middle position of the first fixed electrode plate 192 and the second fixed electrode plate 194. At this time, the sensing element 170 is connected to the first fixed electrode plate 192 and the The distance D between the second fixed electrode plates 194 is equal, and the capacitance values formed are equal. In the vibration state, the position of the sensing element 170 between the first fixed electrode plate 192 and the second fixed electrode plate 194 changes. The distance D between the sensing element 170 and the first locating plate 192 and the second locating plate 194 is not equal, that is, the first capacitor and the second capacitor are not equal. At this time, the difference between the first capacitor and the second capacitor changes. The detection circuit can detect the difference between the first capacitance and the second capacitance, which reflects the displacement of the sensing element 170 relative to the movement of the first fixed electrode plate 192 and the second fixed electrode plate 194. The feedback control circuit applies a corresponding driving force to the sensing element 170 through the first driving device 220 according to the size of the differential capacitance, so that the sensing element 170 is positioned between the first fixed plate 192 and the second fixed plate 192 and the second fixed plate. The middle position of the electrode plate 194 allows the sensing element 170 to track the movement of the first electrode plate 192 and the second electrode plate 194. At this time, the feedback control voltage, that is, the feedback signal can reflect the movement of the ground. That is, the movement of the sensitive element fixed on the sensing element 170. The sensing element 170 tracks the first locating plate 192 and the second locating plate 194 so that the positions of the three remain relatively unchanged. That is, the sensitive element 180 can directly track the ground motion. At this time, direct measurement of the movement of the sensitive element 180 can be realized.

When the first capacitance and the second capacitance are not equal to produce a differential capacitance, the differential capacitance enters the capacitance detection circuit, and after amplifying, filtering, etc., the voltage signal, that is, the displacement signal, is obtained, which represents that the sensing element is in place. The positions of the first fixed electrode plate and the second fixed electrode plate.

In one embodiment, the first driving device 220 includes a voice coil motor. The voice coil motor includes a magnet structure 214 and a coil structure 216. The magnet structure 214 is fixedly arranged relative to the base frame 100. The coil structure 216 is fixedly arranged relative to the induction element 170. The magnet structure 214 may have an installation slot, and the coil structure 216 may be installed in the installation slot. By changing the current in the coil structure 216, the coil structure 216 can be moved in the vertical direction, thereby driving the inductive element 170 to the equilibrium position in the vertical direction. It can be understood that the displacement signal is amplified and processed by the feedback control circuit to generate a corresponding current to the coil structure 216. The voice coil motor has the advantages of fast response speed and precise control.

Referring to FIG. 2, in one embodiment, the first driving device 220 includes a piezoelectric driver 230. The piezoelectric driver 230 includes a housing 232 and an output shaft 234 disposed in the housing 232. The housing 232 is fixedly arranged relative to the base frame 100. The output shaft 234 is fixedly arranged relative to the sensing element 170. The length of the output shaft 234 can be controlled by the displacement signal, and thus the position of the sensing element 170 in the vertical direction can be controlled. The piezoelectric driver 230 can be based on the inverse piezoelectric effect of the piezoelectric ceramic material to generate linear motion by controlling its mechanical deformation, and the response is fast and accurate.

In an embodiment, the base frame 100 includes a first support column 130. The first supporting column 130 is disposed in the receiving space 110. One end of the sensing element 170 is movably disposed on the first supporting column 130. One end of the first supporting column 130 may be fixed to the bottom of the base frame 100. The first supporting column 130 may be perpendicular to the bottom surface of the base frame 100. The first supporting column 130 may be a column or a cubic column. One end of the sensing element 170 can be rotated or slidably disposed on the first supporting column 130.

Referring to FIG. 3, in one embodiment, the vibration measuring device 10 further includes a first elastic member 150. One end of the first elastic member 150 is disposed on the first supporting column 130. The other end of the first elastic element 150 is fixed to the sensing element 170. In a static state, the first elastic member 150 is used to keep the sensing member 170 at an initial position relative to the base frame 100, that is, when the displacement of the displacement reference device 190 is zero. The first elastic member 150 may be a spring. One end of the spring may be fixed to the bottom of the first support column 130 away from the base frame 100. The other end of the spring may be fixed to an end of the sensing element 170 away from the first support column 130. Therefore, the sensing element 170 can be stretched to a balanced state by the first elastic element 150. The first driving device 220 can also support the sensing element 170. Through the joint action of the first sensing element 170 and the first driving device 220, the sensing element 170 can reach a state where the displacement is zero.

Referring to FIG. 4, in one embodiment, the vibration measuring device 10 further includes a second driving device 240. The second driving device 240 is disposed between the sensing element 170 and the base frame 100. The second driving device 240 is disposed at an end of the first driving device 220 away from the first supporting column 130. In a static state, the second driving device 240 is used to keep the sensing element 170 at the initial position when the displacement relative to the base frame 100 is zero. The second driving device 240 may have the same structure as the first driving device 220. The second driving device 240 may also be a voice coil motor. The coil structure of the voice coil motor can be fixed to the induction member 170 by a fixing adapter 242.

The second driving device 240 can balance the gravity of the sensing element 170. When starting to work, the force applied to the sensing element 170 by the second driving device 240 is constant. When the second driving device 240 is a voice coil motor, the current of the voice coil motor is also constant. Therefore, the supporting force of the first driving device 220 to the sensing element 170 can be reduced. At the same time, the position of the first driving device 220 can also be flexibly changed to avoid the inclination of the sensing element 170 due to the improper position of the first driving device 220. The farther the second driving device 240 is from the first support column 130, the smaller the force that the second driving device 240 needs to provide to keep the sensing element 170 in the equilibrium position, which can save power.

Referring to FIGS. 5-6, in one embodiment, the vibration measuring device 10 further includes a second supporting column 140 and a second elastic member 160. The second supporting column 140 is disposed in the receiving space 110. The second supporting column 140 is spaced apart from the first supporting column 130. One end of the second elastic element 160 is connected to an end of the sensing element 170 away from the first supporting column 130. The other end of the second elastic member 160 is fixed to the second supporting column 140. In a static state, the second elastic member 160 is used to keep the sensing member 170 at the initial position when the displacement relative to the displacement reference device 190 is zero. The structure of the second support column 140 and the first support column 130 may be the same. The second supporting column 140 and the first supporting column 130 may be arranged in parallel. The sensing element 170 may be located between the first supporting column 130 and the second supporting column 140. The first support column 130 and the second support column 140 can be respectively connected to the two ends of the sensing element 170, and at the same time, under the action of the first driving device 220, the sensing element 170 can be kept in balance Location. It can be understood that the first driving device 220 may be located directly below the displacement reference device 190 or may be located on one side of the displacement reference device 190. The displacement reference device 190 may be the differential parallel plate capacitor.

Referring to FIG. 7, in one embodiment, the displacement reference device 190 includes a laser diode 212 and a photodetector 216. The vibration measuring device 10 further includes glass beads 214. The laser diode 212 is disposed on the second supporting column 140. The glass beads 214 are fixedly disposed on the sensing element 170. The photodetector 216 is disposed on the first supporting column 130. The detection circuit is connected to the photodetector 216. In the static state, when the sensing element 170 is maintained at the initial position when the displacement is zero relative to the base frame 100, the laser diode 212 passes through the glass beads 214 and is focused on the center of the photodetector 216. When the sensing element 170 is displaced, the photodetector 216 sends out the displacement signal through the detection circuit. It can be understood that the laser diode 212 can emit a laser beam. The glass beads 214 can be used to condense the laser beam, and then irradiate the photodetector 216. In the static state, the position of the sensing element 170 can be adjusted so that the laser beam emitted by the laser diode 212 is condensed to the initial position of the photodetector 216 through the glass beads 214. When the ground vibrates, the sensing element 170 is displaced relative to the base frame 100. At this time, the position of the glass beads 214 relative to the laser diode 212 changes. The detection circuit may output the displacement signal according to the position change, and the feedback control circuit may output a feedback signal to control the first driving device 220 to drive the sensing element 170 to track the movement of the base frame 100, thereby making the sensitive Piece 180 tracks ground movement. At this time, the feedback signal can reflect the movement of the sensitive element 180.

Referring to FIG. 8, in one embodiment, the first support column 130 is provided with a tapered hole 132. A matching ball 172 is provided at one end of the sensing element 170. The matching ball 172 is tangent to the inner wall of the tapered hole 132. The first supporting bead may include a mounting block 252. The tapered hole 132 may be opened in the mounting block 252. The diameter of the mating ball 172 may be smaller than the diameter of the opening of the tapered hole 132, so the mating ball 172 may enter the tapered hole 132 and make the mating ball 172 and the tapered hole 132 separate The inner wall is tangent. Therefore, the mating ball 172 can rotate in the tapered hole 132, and the sensing element 170 can rotate around the mating ball 172.

Referring to FIG. 9, in one embodiment, the first support column 130 is provided with a vertical sliding rail 260. One end of the sensing element 170 is slidably disposed on the sliding rail 260. In a static state, the sensing element 170 can be located at an equilibrium position under the support of the first driving device 220, that is, a position where the displacement is zero. When the ground vibrates, the sensing element 170 can slide in the vertical direction in the sliding rail 260. The detection circuit outputs the displacement signal, and the feedback control circuit outputs a feedback signal according to the displacement signal. After receiving the feedback signal, the first driving device 220 can drive the sensing element 170 to move closer to Zero position. In an embodiment, a sliding block 262 may be fixedly arranged at one end of the sensing element 170. The sliding block 262 can slide in the sliding rail. The upper end and the lower end of the sliding rail may be respectively provided with a limiting portion 260 to prevent the sliding block 262 from sliding out.

In an embodiment, the base frame 100 is provided with an observation window 120. The observation window 120 may be provided on the top of the base frame 100. Through the observation window 120, the working status of the internal components of the base frame 100 can be observed.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express several implementation manners of the present disclosure, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several modifications and improvements can be made, and these all fall within the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent should be subject to the appended claims.

Claims

A vibration measuring device, characterized in that it comprises:

The base frame (100) surrounds and forms an accommodation space (110);

A sensing element (170), one end of the sensing element (170) is movably arranged on the base frame (100) for fixing the sensing element (180);

The displacement reference device (190) is arranged in the accommodating space (110) and is fixedly arranged relative to the base frame (100);

A detection circuit for outputting a displacement signal according to the displacement of the sensing element (170) relative to the displacement reference device (190);

A feedback control circuit for outputting a feedback signal according to the displacement signal; and

The first driving device (220) is located in the accommodating space (110) and is arranged between the sensing element (170) and the base frame (100), and is used for driving the sensing element (170) and the base frame (100) according to the feedback signal. The movement of the element (170) makes the displacement of the sensing element (170) relative to the displacement reference device (190) zero or close to zero.
The vibration measuring device according to claim 1, wherein the displacement reference device (190) comprises a first fixed electrode plate (192) and a second fixed electrode plate (194), and the first fixed electrode plate ( 192) and the second fixed electrode plate (194) are fixedly arranged in parallel, and the sensing element (170) is arranged between the first fixed electrode plate (192) and the second fixed electrode plate (194);

When the sensing element (170) is displaced between the first fixed electrode plate (192) and the second fixed electrode plate (194), the first fixed electrode plate (192) and the sensing element (170) When the difference between the first capacitor formed by the (170) and the second capacitor formed by the second fixed electrode plate (194) and the sensing element (170) changes, the detection circuit outputs the displacement signal, so The feedback control circuit outputs the feedback signal according to the displacement signal, and the first driving device (220) drives the sensitive element (180) to move according to the feedback signal to make the first capacitor and the second The difference in capacitance is zero or close to zero.
The vibration measuring device according to claim 2, wherein the first driving device (220) includes a voice coil motor, the voice coil motor includes a magnet structure (214) and a coil structure (216), and the magnet The structure (214) is fixedly arranged with respect to the base frame (100), and the coil structure (216) is fixedly arranged with respect to the induction element (170).
The vibration measuring device according to claim 2, wherein the first driving device (220) includes a piezoelectric driver (230), and the piezoelectric driver (230) includes a housing (232) and is disposed on the The output shaft (234) in the housing (232), the housing (232) is fixedly arranged relative to the base frame (100), and the output shaft (234) is fixedly arranged relative to the sensing element (170).
The vibration measuring device according to claim 1, wherein the base frame (100) comprises a first supporting column (130), which is arranged in the containing space (110), and the sensing element (170) One end is movably arranged on the first support column (130).
The vibration measuring device according to claim 5, further comprising a first elastic member (150), one end of the first elastic member (150) is arranged on the first supporting column (130), and the The other end of the first elastic element (150) is fixed to the sensing element (170). In a static state, the first elastic element (150) is used to keep the sensing element (170) at a position relative to the displacement reference. The initial position of the device (190) when the displacement is zero.
The vibration measuring device according to claim 5, further comprising a second driving device (240), and the second driving device (240) is disposed on the sensing element (170) and the base frame ( 100), the second driving device (240) is arranged at an end of the first driving device (220) away from the first support column (130), and in a static state, the second driving device (240) ) Is used to keep the sensing element (170) at the initial position when the displacement relative to the displacement reference device (190) is zero.
8. The vibration measuring device of claim 5, further comprising:

The second supporting column (140) is arranged in the containing space (110) and is arranged at intervals from the first supporting column (130);

The second elastic member (160), one end of the second elastic member (160) is connected to one end of the second supporting column (140), and the other end of the second elastic member (160) is fixed to the sensor In the static state, the second elastic member (160) is used to keep the sensing member (170) at the initial position when the displacement relative to the displacement reference device (190) is zero.
The vibration measuring device according to claim 8, characterized in that it further comprises glass beads (214) fixedly arranged on the sensing element (170), and the displacement reference device (190) comprises:

The laser diode (212) is arranged on the second supporting column (140);

The photodetector (216) is arranged on the first supporting column (130);

In the static state, when the sensing element (170) is kept at the initial position when the displacement is zero relative to the base frame (100), the laser diode (212) passes through the glass beads (214) and is focused at the place At the center of the photodetector (216), the detection circuit is connected to the photodetector (216), and when the sensing element (170) is displaced, the detection circuit sends out the displacement signal.
The vibration measuring device according to claim 5, wherein the first support column (130) is provided with a tapered hole (132), and one end of the sensing element (170) is provided with a matching ball (172), so The matching ball (172) is tangent to the inner wall of the tapered hole (132).
The vibration measuring device according to claim 5, wherein the first support column (130) is provided with a vertical slide rail, and one end of the sensing element (170) is slidably provided on the slide rail.
The vibration measuring device according to claim 1, wherein the base frame (100) is provided with an observation window (120).