A device and method for calibrating dynamic characteristics of displacement sensor

Abstract

The present invention discloses a device and method for calibrating the dynamic characteristics of a displacement sensor, which relates to the field of automation technology. The device includes a spindle servo motor, a metal disc, four capacitive displacement sensors, a gear disc, a speckle metal disc, a high-speed camera, a high-speed acquisition card, a data processing system, and a plurality of displacement sensors to be measured. The plurality of displacement sensors to be measured may include a Doppler velocimeter, a circular grating, a laser interferometer, and a measuring lens group. The present invention uses the contour features of the metal disc as a measurement reference. By adjusting the rotation speed and size of the metal disc, the dynamic range requirements of the high-speed displacement sensor can be met, and the problem of the difficulty in calibrating the dynamic characteristics of the displacement sensor can be solved. The present invention can also be used to analyze the dynamic characteristics of different types of instruments such as circular gratings, Doppler velocimeters, and high-speed cameras. The present invention has the advantages of high precision, wide speed range, and strong applicability, and can meet the dynamic characteristics calibration requirements of different types of sensors.

Description

Technical Field

[0001] The invention belongs to the field of automation technology, and in particular relates to a device and method for calibrating dynamic characteristics of a displacement sensor. Background Art

[0002] Displacement sensors such as laser interferometers and capacitive displacement sensors are widely used in precision manufacturing, instrument testing and other fields. They can calibrate the static and dynamic characteristics of different types of displacement sensors and are an important link in the length measurement traceability chain.

[0003] With the advancement of my country's scientific research capabilities and the improvement of manufacturing levels, the demand for dynamic displacement measurement in the fields of measurement and manufacturing has increased dramatically, and the required dynamic range has continued to increase, which has put forward higher requirements on the calibration range and accuracy of dynamic displacement calibration devices. However, there is currently a lack of devices and methods that can perform high-precision calibration of the dynamic characteristics of displacement sensors. Traditional dynamic displacement calibration devices provide movement in a straight line, which severely limits the dynamic range of the calibration device and makes it impossible to calibrate the dynamic characteristics of high-speed displacement sensors. In addition, there are more influencing factors in the dynamic calibration process, making it difficult to ensure that the measurement results of the standard device are accurate and reliable, which also leads to the inability to effectively improve the calibration accuracy.

[0004] Therefore, there is an urgent need for a high-precision dynamic displacement calibration device and method that can perform high-precision calibration on the dynamic characteristics of different types of displacement sensors, and then improve the dynamic displacement traceability system to meet the needs of modern precision measurement. Summary of the invention

[0005] The purpose of the present invention is to provide a device and method for calibrating the dynamic characteristics of a displacement sensor, so as to solve the above-mentioned technical problems existing in the prior art.

[0006] To achieve the above object, on the one hand, the present invention provides a device for calibrating dynamic characteristics of a displacement sensor, comprising:

[0007] Spindle servo motor;

[0008] A metal disc is fixedly connected to the spindle of the spindle servo motor, and its outer peripheral surface is a mirror working surface; four capacitive displacement sensors are evenly distributed on the outer peripheral surface of the metal disc;

[0009] A gear plate is fixedly connected to a side of the metal disc away from the spindle servo motor; a speckle metal disc is fixedly connected to a side of the gear plate away from the metal disc, and a plurality of speckle patterns are arranged on a disc surface of the speckle metal disc;

[0010] A high-speed camera is directly facing the speckle metal disk and is used to continuously capture the speckle pattern on the surface of the speckle metal disk;

[0011] A high-speed acquisition card is connected to the capacitive displacement sensor and the displacement sensor to be measured, and is used to collect output values ​​of the capacitive displacement sensor and different types of displacement sensors to be measured. The high-speed acquisition card is communicatively connected to a data processing system.

[0012] Preferably, a laser interferometer and a measuring lens group are provided on one side of the spindle servo motor, the measuring lens group faces the working surface of the metal disk, and the measuring lens group cooperates with the laser interferometer to measure the change in the relative distance between the working surface of the metal disk and the measuring lens group.

[0013] Preferably, the contour characteristic curve of the metal disc has an inherent roundness error. When the metal disc rotates at high speed, its contour characteristic curve appears continuously and periodically. The radius change corresponding to the contour characteristic curve is used as a standard value to calibrate the dynamic characteristics of the laser interferometer.

[0014] Preferably, the measuring lens assembly comprises a plano-convex lens, a polarization beam splitter and a corner cube prism, and the plano-convex lens is placed between the working surface of the metal disk and the polarization beam splitter so that the working surface of the metal disk is located at the focus of the plano-convex lens.

[0015] Preferably, the outgoing light of the laser interferometer is divided into a reference light and a measuring light whose polarization states are perpendicular to each other at a polarization beam splitter. The reference light is reflected by the polarization beam splitter and enters the corner cube prism. After leaving the corner cube prism, it is reflected by the polarization beam splitter and enters the receiving end of the laser interferometer. The measuring light is transmitted by the polarization beam splitter and enters the plano-convex lens, converges into a light spot on the working surface of the metal disk, and after reflection, enters the receiving end of the laser interferometer again through the plano-convex lens and the polarization beam splitter, thereby realizing the measurement of the change in the relative distance between the working surface of the metal disk and the measuring lens group.

[0016] Preferably, a circular grating is fixedly connected to the working surface of the metal disc, a grating reading head cooperating with the circular grating is provided on the outer peripheral side of the working surface of the metal disc, a Doppler velocimeter is installed on the side of the spindle servo motor, and the Doppler velocimeter and the grating reading head continuously acquire the motion state of the metal disc.

[0017] Preferably, the metal disc is outer-connected with a protective shell, the capacitive displacement sensor extends to the outside of the protective shell, the outer side of the protective shell is connected to an end cover, and a window for image acquisition is opened on the end cover.

[0018] Preferably, a capacitive displacement sensor to be measured is fixedly connected to the peripheral side of the protective housing, and the measuring direction of the capacitive displacement sensor to be measured is perpendicular to the central axis of the working surface of the gear plate.

[0019] Preferably, the gear plates have unequal tooth pitches and a symmetrical geometric structure.

[0020] Preferably, the high-speed acquisition card adopts a synchronous pulse triggering mode.

[0021] On the other hand, the present invention provides a method for calibrating the dynamic characteristics of a displacement sensor, using any of the above-mentioned devices for calibrating the dynamic characteristics of a displacement sensor, comprising the following steps: Step 1, assembling and debugging the device and checking the communication connection between the data processing system and the high-speed acquisition card;

[0022] Step 2, start the spindle servo motor, and after the speed of the metal disk is stable, the high-speed acquisition card sends a synchronous pulse signal to the capacitive displacement sensor and several displacement sensors to be measured, and transmits data back in real time, and the high-speed camera continuously captures the image of the speckle metal disk and transmits it back to the data processing system;

[0023] Step 3, resetting the spindle servo motor speed, repeating step 2, collecting the measurement data of the capacitive displacement sensor and the displacement sensor under test at different speeds, and analyzing the dynamic characteristics of the displacement sensor under test at different speeds;

[0024] Step 4: Process the measured data of the capacitive displacement sensor in the data processing system, record the time when the high-speed acquisition card sends the t-th synchronization pulse as t, obtain the radial runout Δd(t) of the metal disk on the measuring axis of the displacement sensor under test, and subtract the runout from the measured value Y(t) of the displacement sensor under test to obtain the measured value L(t) of the diameter change of the metal disk or the tooth height of the gear plate:

[0025] L(t)=Y(t)-Δd(t)

[0026] Step 5: Compare the measured value L(t) of the displacement sensor at different rotation speeds with the standard value S(t) of the metal disc diameter change or the gear disc tooth height to calibrate the dynamic characteristics of the displacement sensor under test.

[0027] Preferably, obtaining the radial runout Δd(t) of the metal disk on the measuring axis of the displacement sensor to be measured comprises:

[0028] At time t, the radial runout Δd(t) on the measuring axis of the displacement sensor under test is:

[0029]

[0030] Among them, Δd(t) is the radial runout component on the measuring axis of the displacement sensor being measured, d1(t) is the value measured by the first capacitive displacement sensor, d2(t) is the value measured by the second capacitive displacement sensor, d3(t) is the value measured by the third capacitive displacement sensor, d4(t) is the value measured by the fourth capacitive displacement sensor, and R is the radius of the metal disk.

[0031] Compared with the prior art, the present invention at least discloses the following beneficial effects:

[0032] The present invention uses the profile features of the metal disc as a measurement reference, and by adjusting the rotation speed and size of the metal disc, can meet the dynamic range requirements of the high-speed displacement sensor, solve the problem of difficult calibration of the dynamic characteristics of the displacement sensor, and can also be used to analyze the dynamic characteristics of different types of instruments such as circular gratings, Doppler velocimeters and high-speed cameras. The present invention has the advantages of high precision, wide speed range, and strong applicability, and can meet the dynamic characteristics calibration requirements of different types of sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a structural schematic diagram of a device for calibrating dynamic characteristics of a displacement sensor according to the present invention;

[0035] Figure 2 An exploded view of a device for calibrating dynamic characteristics of a displacement sensor according to the present invention;

[0036] Figure 3 This is a main structure diagram of the device for calibrating the dynamic characteristics of a displacement sensor of the present invention after removing the end cover and the protective shell;

[0037] Figure 4 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0038] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0039] Figure 6 This is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0040] In the figure: 1. spindle servo motor; 2. metal disk; 3. end cover; 4. protective shell; 5. capacitive displacement sensor; 501. capacitive displacement sensor one; 502. capacitive displacement sensor two; 503. capacitive displacement sensor three; 504. capacitive displacement sensor four; 6. Doppler velocimeter; 7. measuring mirror group; 701. plano-convex lens; 702. polarization beam splitter; 703. corner cone prism; 8. laser interferometer; 9. high-speed camera; 10. pad; 11. gear plate; 12. circular grating; 13. capacitive displacement sensor to be measured; 14. speckle metal disk; 15. grating reading head; 16. high-speed acquisition card; 17. data processing system. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Reference Figures 1 to 3 As shown, the present invention provides a device for calibrating the dynamic characteristics of a displacement sensor, comprising a spindle servo motor 1 fixed above two cushion blocks 10, a metal disc 2 being mounted on the spindle of the spindle servo motor 1, the outer peripheral surface of the metal disc 2 being used as a working surface, and the working surface being processed into a mirror surface, the metal disc 2 being connected to the spindle servo motor 1 through a spindle transmission, and converting the rotational motion generated by the spindle servo motor 1 into a linear motion in the tangential direction of the working surface of the metal disc 2; four capacitive displacement sensors 5 are evenly distributed on the outer peripheral surface of the metal disc 2, the metal disc 2 is covered with a protective shell 4, the protective shell 4 is connected to the body of the spindle servo motor 1 and rotates with the rotation of the metal disc 2 , four capacitive displacement sensors 5 penetrate the protective shell 4 and extend out of the protective shell 4, the four capacitive displacement sensors 5 are evenly distributed on the outer circumference of the metal disk 2, and an angle of 90° is formed between two adjacent capacitive displacement sensors 5. The outer side of the protective shell 4 is connected to the end cover 3, and a window for image acquisition is opened on the end cover 3; a gear disk 11 is connected to the side of the metal disk 2 away from the spindle servo motor 1, the outer circumferential surface of the gear disk 11 and the working surface of the metal disk 2 are on the same circumferential surface, the gear disk 11 has different tooth pitches, and the geometric structure is symmetrical, and a speckle metal disk 14 is connected to the side of the gear disk 11 away from the metal disk 2, and a plurality of speckle patterns are arranged on the disk surface of the speckle metal disk 14.

[0044] In this embodiment, a high-speed acquisition card 16, a data processing system 17 and a plurality of different types of displacement sensors to be measured are also included. The high-speed acquisition card 16, the data processing system 17 and the displacement sensors to be measured are connected to each other by signals.

[0045] In some embodiments, a circular grating 12 is also provided on the working surface of the metal disc 2, and a Doppler velocimeter 6 cooperating with the circular grating 12 is installed on the side of the spindle servo motor 1. The light spots of the laser emitted by the Doppler velocimeter 6 converge on the working surface of the metal disc 2, and the Doppler velocimeter 6 and the circular grating 12 cooperate to obtain the motion state of the metal disc 2 in real time.

[0046] In some embodiments, a measuring lens group 7 and a laser interferometer 8 are disposed on the side of the spindle servo motor 1. The measuring lens group 7 faces the working surface of the metal disk 2. The measuring lens group 7 is composed of a plano-convex lens 701, a polarization beam splitter 702, and a corner cube prism 703. The plano-convex lens 701 is placed between the working surface of the metal disk 2 and the polarization beam splitter 702, so that the working surface of the metal disk 2 is located at the focus of the plano-convex lens 701. The measuring lens group 7 cooperates with the laser interferometer 8 to measure the change in the relative distance between the working surface of the metal disk 2 and the measuring lens group 7.

[0047] In some embodiments, the high-speed camera 9 is installed in front of the spindle servo motor 1 and directly facing the speckle metal disk 14 , so as to continuously capture the speckle pattern on the surface of the speckle metal disk 14 .

[0048] To further optimize the solution, the input and output ports of the high-speed acquisition card 16 are respectively connected to the output and input ports of the capacitive displacement sensor 5, the laser interferometer 8, the grating reading head 15 and the Doppler velocimeter 6, and are connected to the data processing system 17 to check the communication connection between the data processing system 17 and the high-speed acquisition card 16; the high-speed acquisition card 16 adopts a synchronous pulse triggering method, by collecting the output values ​​of the capacitive displacement sensor 5 and different types of displacement sensors to be measured, and after transmitting the collected data to the data processing system 17, the diameter change of the metal disk 2 and the tooth height of the gear disk 11 are respectively used as measurement references, so that the dynamic characteristics of different types of displacement sensors to be measured, such as the laser interferometer 8 and the capacitive displacement sensor 13 to be measured, can be calibrated with high precision, and the dynamic characteristics of the high-speed camera 9, the Doppler velocimeter 6 and the circular grating 12 can also be analyzed and evaluated.

[0049] Embodiment 1:

[0050] like Figure 4As shown, embodiment 1 of the present invention provides a device for calibrating the dynamic characteristics of a displacement sensor, which can be used for calibrating the dynamic characteristics of a laser interferometer 8. The device includes: a spindle servo motor 1, a metal disk 2, a cushion block 10, a protective shell 4, a capacitive displacement sensor 1 501, a capacitive displacement sensor 2 502, a capacitive displacement sensor 3 503, a capacitive displacement sensor 4 504, a measuring mirror group 7, a plano-convex lens 701, a polarization beam splitter 702, a reference mirror 703, a high-speed acquisition card 16, a data processing system 17, and a laser interferometer 8.

[0051] The cylindrical surface of the metal disk 2 is used as a working surface, and the working surface is processed into a mirror surface.

[0052] The metal disc 2 is mounted on the spindle to convert the rotational motion generated by the spindle servo motor 1 into a linear motion in the tangential direction of the working surface of the metal disc 2 .

[0053] The capacitive displacement sensors 5 are fixed on the protective housing 4 and are arranged around the working surface of the metal disk 2 at an angle of 90° with equal spacing.

[0054] The measuring lens assembly 7 is composed of the plano-convex lens 701 , the polarization beam splitter 702 and the corner cube prism 703 .

[0055] The plano-convex lens 701 is placed between the working surface of the metal disk 2 and the polarization beam splitter 702 , so that the working surface of the metal disk 2 is located at the focus of the plano-convex lens 701 .

[0056] The method for calibrating the dynamic characteristics of the laser interferometer 8 using the above device comprises the following steps:

[0057] Step 101, fix the metal disc 2 on the spindle of the spindle servo motor 1, fix the protective housing 4 to the body of the spindle servo motor 1, install four capacitive displacement sensors 5 on the protective housing 4, and arrange them around the metal disc 2 at an angle of 90° at equal intervals, and fix the measuring lens group 7 in front of the working surface of the metal disc 2;

[0058] Step 102, the input and output ports of the high-speed acquisition card 16 are connected to the output and input ports of the capacitive displacement sensor 5 and the laser interferometer 8 respectively, and connected to the data processing system 17, and the communication connection between the data processing system 17 and the high-speed acquisition card 16 is checked;

[0059] Step 103, start the spindle servo motor 1, and after the rotation speed of the metal disc 2 is stabilized, the high-speed acquisition card 16 sends a synchronous pulse signal to the capacitive displacement sensor 5 and the laser interferometer 8, and transmits data back in real time;

[0060] Step 104, adjusting the rotation speed of the spindle servo motor 1, repeating step 3, collecting measurement data of the capacitive displacement sensor 5 and the laser interferometer 8 at different rotation speeds;

[0061] Step 105: Process the measurement data of the capacitive displacement sensor 5 in the data processing system 17, record the time when the data acquisition card sends the tth synchronization pulse as t, and obtain the radial runout Δd of the metal disk 2 on the measurement axis of the laser interferometer 8. x (t), and compare the runout with the measured value Y of the laser interferometer 8 x (t) After subtracting, the measured value L of the diameter change of the metal disk 2 is obtained. x (t):

[0062] L x (t) = Y x (t)-Δd x (t)

[0063] Step 106: Taking the diameter change of the metal disk 2 as the measurement reference, respectively calculate the measured values ​​L of the diameter change of the metal disk 2 at different rotation speeds. x (t) and the standard value S of the diameter change of the metal disk 2 x (t) Compare and calibrate the dynamic characteristics of the laser interferometer 8.

[0064] The method of measuring the radial runout by the capacitive displacement sensor 5 is as follows: at time t, the radial runout Δd on the measuring axis of the laser interferometer 8 x (t) is:

[0065]

[0066] Where, Δd x (t) is the radial runout component on the measurement axis of the laser interferometer 8, d1(t) is the measured value of the capacitive displacement sensor 1 501, d2(t) is the measured value of the capacitive displacement sensor 2 502, d3(t) is the measured value of the capacitive displacement sensor 3 503, d4(t) is the measured value of the capacitive displacement sensor 4 504, and R is the radius of the metal disk 2.

[0067] Embodiment 2:

[0068] like Figure 5As shown, embodiment 2 of the present invention provides a device for calibrating the dynamic characteristics of a displacement sensor, which can be used to calibrate the dynamic characteristics of a capacitive displacement sensor 5. The device includes: a spindle servo motor 1, a metal disc 2, a cushion block 10, a protective shell 4, a capacitive displacement sensor 1 501, a capacitive displacement sensor 2 502, a capacitive displacement sensor 3 503, a capacitive displacement sensor 4 504, a high-speed acquisition card 16, a data processing system 17, a gear disc 11 and a capacitive displacement sensor 13 to be measured.

[0069] The metal disc 2 is mounted on the spindle to convert the rotational motion generated by the spindle servo motor 1 into a linear motion in the tangential direction of the working surface of the metal disc 2 .

[0070] The gear plate 11 is installed on the outside of the metal disc 2 .

[0071] The capacitive displacement sensors 5 are fixed on the protective housing 4 and are arranged around the working surface of the metal disk 2 at an angle of 90° with equal spacing.

[0072] The capacitive displacement sensor 13 to be measured is fixed on the protective housing 4 , and the measuring direction is perpendicular to the central axis of the working surface of the gear plate 11 .

[0073] The method for calibrating the dynamic characteristics of the capacitive displacement sensor 13 under test using the above device comprises the following steps:

[0074] Step 201, fix the metal disc 2 on the spindle of the spindle servo motor 1, fix the protective housing 4 to the body of the spindle servo motor 1, install four capacitive displacement sensors 5 on the protective housing 4, and arrange them around the metal disc 2 at an angle of 90° with equal spacing, and install the gear disc 11 on the side of the metal disc 2;

[0075] Step 202: The input and output ports of the high-speed acquisition card 16 are respectively connected to the output and input ports of the capacitive displacement sensor 5 and the capacitive displacement sensor 13 to be measured, and are connected to the data processing system 17 to check the communication connection between the data processing system 17 and the high-speed acquisition card 16;

[0076] Step 203, start the spindle servo motor 1, and after the rotation speed of the metal disk 2 is stabilized, the high-speed acquisition card 16 sends a synchronous pulse signal to the capacitive displacement sensor 5 and the capacitive displacement sensor 13 to be measured, and transmits data back in real time;

[0077] Step 204, adjusting the rotation speed of the spindle servo motor 1, repeating step 3, collecting measurement data of the capacitive displacement sensor 5 and the measured capacitive displacement sensor 13 at different rotation speeds;

[0078] Step 205: Process the measurement data of the capacitive displacement sensor 5 in the data processing system 17 to obtain the radial runout Δd in the measurement direction of the capacitive displacement sensor 13 under test. y (t):

[0079]

[0080] Where, Δd y (t) is the radial runout component on the measuring axis of the capacitive displacement sensor 13 under test, d1(t) is the measured value of the capacitive displacement sensor 1 501, d2(t) is the measured value of the capacitive displacement sensor 2 502, d3(t) is the measured value of the capacitive displacement sensor 3 503, d4(t) is the measured value of the capacitive displacement sensor 4 504, and R is the radius of the metal disk 2.

[0081] Step 206: compare the jump value with the measured value Y of the capacitive displacement sensor 13. y (t) After subtraction, the tooth height measurement value L of the gear plate 11 is obtained y (t):

[0082] L y (t) = Y y (t)-Δd y (t)

[0083] The measured value L of the tooth height of the gear plate 11 at different speeds y (t) and the standard value S of the tooth height of the gear plate 11 y The difference between the values ​​of (t) and (t) is compared to calibrate the dynamic characteristics of the capacitive displacement sensor 13 under test.

[0084] Embodiment 3:

[0085] like Figure 6 As shown, embodiment 3 of the present invention provides a device for calibrating the dynamic characteristics of a displacement sensor, which can be used to analyze the dynamic characteristics of a high-speed camera 9, a circular grating 12 and a Doppler velocimeter 6. The device includes: a spindle servo motor 1, a metal disc 2, a cushion block 10, a protective housing 4, a Doppler velocimeter 6, a measuring lens group 7, a data processing system 17, a circular grating 12, a speckle metal disc 14, a high-speed camera 9 and a grating reading head 15.

[0086] The cylindrical surface of the metal disk 2 is used as a working surface, and the working surface is processed into a mirror surface.

[0087] The metal disc 2 is mounted on the spindle to convert the rotational motion generated by the spindle servo motor 1 into a linear motion in the tangential direction of the working surface of the metal disc 2 .

[0088] The circular grating 12 is installed on the inner side of the metal disk 2 .

[0089] The grating reading head 15 is fixed on the protective housing 4 , and the measuring area is aligned with the working surface of the circular grating 12 .

[0090] The Doppler velocimeter 6 and the circular grating 12 acquire the rotation speed and position of the metal disk 2 in real time.

[0091] The speckle metal disc 14 is mounted on the side of the gear disc 11 and rotates together with the metal disc 2 .

[0092] The grating reading head 15 is fixed on the protective housing 4 , and its reading area is aligned with the working surface of the circular grating 12 .

[0093] The high-speed camera 9 is installed on the front side of the working surface of the spindle servo motor 1 to continuously acquire the speckle pattern on the surface of the speckle metal disk 14 .

[0094] The method for analyzing the dynamic characteristics of the high-speed camera 9 using the above device comprises the following steps:

[0095] Step 301, fix the metal disc 2 on the spindle of the spindle servo motor 1, the protective housing 4 is fixed to the body of the spindle servo motor 1, the Doppler velocimeter 6 is installed on the side of the spindle servo motor 1, the light spots of the emitted laser converge on the working surface of the metal disc 2, the gear disc 11 and the circular grating 12 are respectively installed on both sides of the metal disc 2, the grating reading head 15 is fixed on the protective housing 4, and its working area is aligned with the working surface of the circular grating 12, the speckle metal disc 14 is installed on the gear disc 11, and the high-speed camera 9 is installed in front of the speckle metal disc 14;

[0096] Step 302, the input and output ports of the high-speed acquisition card 16 are respectively connected to the output and input ports of the Doppler velocimeter 6 and the grating reading head 15, and connected to the data processing system 17, and the communication connection between the data processing system 17 and the high-speed acquisition card 16 and the high-speed camera 9 is checked;

[0097] Step 303, start the spindle servo motor 1, and after the speed of the metal disk 2 is stabilized, the high-speed acquisition card 16 sends a synchronous pulse signal to the capacitive displacement sensor 5, the laser interferometer 8, the grating reading head 15 and the Doppler velocimeter 6, and transmits data back in real time, and the high-speed camera 9 continuously captures the image of the speckle metal disk 14 and transmits it back to the data processing system 17;

[0098] Step 304, adjust the rotation speed of the spindle servo motor 1, repeat step 303, collect the measurement data of the grating reading head 15 and the Doppler velocimeter 6 at different rotation speeds, and the image data of the high-speed camera 9 at different rotation speeds, and analyze the dynamic characteristics of the Doppler velocimeter 6, the high-speed camera 9 and the grating reading head 15.

[0099] The details not described in detail in the present invention are all conventional technical means well known to those skilled in the art.

[0100] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0101] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A device for calibrating the dynamic characteristics of a displacement sensor, characterized in that: include: A spindle servo motor (1), wherein a laser interferometer (8) and a measuring mirror assembly (7) are provided on one side of the spindle servo motor (1); A metal disc (2) is fixedly connected to the spindle of the spindle servo motor (1), and its outer peripheral surface is a mirror-like working surface; four capacitive displacement sensors (5) are evenly distributed on the outer peripheral surface of the metal disc (2); A gear plate (11) is fixedly connected to a side of the metal disc (2) away from the spindle servo motor (1); a speckle metal disc (14) is fixedly connected to a side of the gear plate (11) away from the metal disc (2), and a plurality of speckle patterns are provided on a disc surface of the speckle metal disc (14); A high-speed camera (9) facing the speckle metal disk (14) and used for continuously photographing speckle patterns on the surface of the speckle metal disk (14); A high-speed acquisition card (16), the high-speed acquisition card (16) being connected to the capacitive displacement sensor (5) and the displacement sensor to be measured, and being used to acquire output values ​​of the capacitive displacement sensor (5) and different types of displacement sensors to be measured, the high-speed acquisition card (16) being communicatively connected to a data processing system (17); The measuring lens assembly (7) comprises a plano-convex lens (701), a polarization beam splitter (702) and a corner cube prism (703); the plano-convex lens (701) is placed between the working surface of the metal disk (2) and the polarization beam splitter (702), so that the working surface of the metal disk (2) is located at the focus of the plano-convex lens (701); The measuring mirror group (7) faces the working surface of the metal disk (2), and the measuring mirror group (7) cooperates with the laser interferometer (8) to measure the change in the relative distance between the working surface of the metal disk (2) and the measuring mirror group (7); The profile characteristic curve of the metal disc (2) has an inherent roundness error. When the metal disc (2) rotates at a high speed, its profile characteristic curve appears continuously and periodically. The radius variation corresponding to the profile characteristic curve is used as a standard value to calibrate the dynamic characteristics of the laser interferometer (8).

2. The device for calibrating the dynamic characteristics of a displacement sensor according to claim 1, characterized in that: The output light of the laser interferometer (8) is divided into reference light and measurement light with mutually perpendicular polarization states at the polarization beam splitter (702); the reference light is reflected by the polarization beam splitter (702) and enters the corner cube prism (703); after leaving the corner cube prism, it is reflected by the polarization beam splitter (702) and enters the receiving end of the laser interferometer; the measurement light is transmitted by the polarization beam splitter (702) and enters the plano-convex lens (701), converges into a light spot on the working surface of the metal disk (2), and after reflection, enters the receiving end of the laser interferometer again through the plano-convex lens (701) and the polarization beam splitter (702), thereby realizing the measurement of the relative distance change between the working surface of the metal disk (2) and the measurement lens group (7).

3. The device for calibrating dynamic characteristics of a displacement sensor according to claim 1, characterized in that: A circular grating (12) is fixedly connected to the working surface of the metal disc (2); a grating reading head (15) cooperating with the circular grating (12) is provided on the outer peripheral side of the working surface of the metal disc (2); a Doppler velocimeter (6) is installed on the side of the spindle servo motor (1); the Doppler velocimeter (6) and the grating reading head (15) continuously acquire the motion state of the metal disc (2).

4. The device for calibrating the dynamic characteristics of a displacement sensor according to claim 1, characterized in that: The outer shell of the metal disc (2) is connected to a protective shell (4), the capacitive displacement sensor (5) extends to the outside of the protective shell (4), the outer side of the protective shell (4) is connected to an end cover (3), and a window for image acquisition is provided on the end cover (3).

5. The device for calibrating the dynamic characteristics of a displacement sensor according to claim 4, characterized in that: A capacitive displacement sensor (13) to be measured is fixedly connected to the peripheral side of the protective housing (4), and the measuring direction of the capacitive displacement sensor (13) to be measured is perpendicular to the central axis of the working surface of the gear plate (11).

6. A method for calibrating the dynamic characteristics of a displacement sensor, using the device for calibrating the dynamic characteristics of a displacement sensor according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1, assembling and debugging the device and checking the communication connection between the data processing system (17) and the high-speed acquisition card (16); Step 2, start the spindle servo motor (1), and after the rotation speed of the metal disk (2) is stabilized, the high-speed acquisition card (16) sends a synchronous pulse signal to the capacitive displacement sensor (5) and a plurality of displacement sensors to be measured, and transmits data back in real time, and the high-speed camera (9) continuously captures images of the speckle metal disk (14) and transmits them back to the data processing system (17); Step 3, resetting the speed of the spindle servo motor (1), repeating step 2, collecting measurement data of the capacitive displacement sensor (5) and the displacement sensor under test at different speeds, and analyzing the dynamic characteristics of the displacement sensor under test at different speeds; Step 4: Process the measurement data of the capacitive displacement sensor (5) in the data processing system (17), record the time when the high-speed acquisition card (16) sends the t-th synchronization pulse as t, and obtain the radial runout of the metal disk (2) on the measuring axis of the displacement sensor to be measured. and compare the runout with the measured value of the displacement sensor After the difference is made, the measured value of the diameter change of the metal disc (2) or the tooth height of the gear disc (11) is obtained. : Step 5: The measured values ​​of the displacement sensor at different speeds The change in diameter of the metal disc (2) or the standard value of the tooth height of the gear disc (11) By comparison, the dynamic characteristics of the displacement sensor under test are calibrated; The radial runout of the metal disk (2) on the measuring axis of the displacement sensor to be measured is obtained include: At time t, the radial runout of the measured displacement sensor on the measuring axis is for: in, The radial runout component of the displacement sensor on the measured axis is is the value measured by the first capacitive displacement sensor (5), is the value measured by the second capacitive displacement sensor (5), is the value measured by the third capacitive displacement sensor (5), is the value measured by the fourth capacitive displacement sensor (5), and R is the radius of the metal disk (2).

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