Six-degree-of-freedom micro-vibration table in-situ calibration device and method

Abstract

The invention discloses a six-degree-of-freedom micro-vibration table in-situ calibration device and method, and the device comprises a six-degree-of-freedom micro-vibration table top, a mounting platform, a linear vibration calibration unit, an angular vibration calibration unit, a coordinate positioning tool, a coordinate positioning tool fine adjustment mechanism, and a data collection and analysis system upper computer. The linear vibration calibration unit comprises an acceleration measurement unit and a vibration displacement measurement unit, the acceleration measurement unit is used for in-situ calibration of linear vibration parameters of the test system, and the vibration displacement measurement unit is used for in-situ calibration of vibration displacement parameters of the test system; and the angular vibration calibration unit is used for carrying out in-situ calibration on angular vibration parameters of the test system. According to the invention, on-site in-situ calibration of three-axis vibration and three-axis angular vibration of the six-degree-of-freedom micro-vibration table is realized, calibration in a low and medium frequency, micro-amplitude and multi-axis angular compound vibration state is realized through the acceleration sensor and the angular vibration sensor, and the six-degree-of-freedom micro-vibration table has the advantages of low cost, fast response and high reliability.

Description

Technical Field

[0001] The present invention relates to the field of metrology and calibration technology, and in particular to an in-situ calibration device and method for a six-degree-of-freedom micro-vibration table. Background Art

[0002] The degree of micro-vibration in orbit of high-precision spacecraft such as satellites will have a great impact on the pointing accuracy and imaging quality of their payloads. Therefore, it is necessary to conduct six-degree-of-freedom micro-vibration environment simulation tests on satellites and their payloads.

[0003] The six-degree-of-freedom micro-vibration test bench developed for on-orbit micro-vibration tests has a large frequency bandwidth, small vibration amplitude and high resolution, which brings great challenges to in-situ calibration.

[0004] At present, the in-situ calibration of key parameters such as linear vibration parameters and angular vibration parameters of the six-degree-of-freedom micro-vibration table mainly uses accelerometers to calibrate the independent amplitudes in three directions. The test calibration of multi-degree-of-freedom test conditions has not been carried out, and the demand for in-situ calibration of comprehensive parameter system level cannot be met, so the vibration control accuracy of the system cannot be accurately reflected, and the purpose of micro-vibration test cannot be achieved, which brings hidden dangers to the performance test and reliability evaluation of satellite payloads. In order to ensure the smooth development of high-precision satellite components and their payloads, it is urgent to carry out research on the in-situ calibration technology of the six degrees of freedom of the test bench to solve the problem of value traceability.

[0005] Patent 201510441726.3 discloses a diffraction grating heterodyne laser vibrometer for angular vibration measurement, including a diffraction device, a laser interferometer, a signal processing device, and a phase demodulation device. Although the patent involves angular vibration calibration based on a standard angular vibration table, it can only perform single-axis angular vibration calibration and is not suitable for on-site in-situ calibration.

[0006] Patent 201010589368.8 discloses a self-calibrated three-axis vibration monitoring and environmental monitoring acquisition system, which consists of a set of vibration monitoring modules, temperature compensation modules, environmental monitoring modules and signal conditioning modules. The acceleration module provides acceleration measurement in three directions (three-axis acceleration sensor). However, the acceleration measurement range of the patent is -2g to +2g, and the measurement accuracy is 0.66v / g, so the applicable measurement range is different and the measurement accuracy is poor. Summary of the invention

[0007] In order to solve the above problems, the purpose of the present invention is to provide an in-situ calibration device and method for a six-degree-of-freedom micro-vibration table, so as to realize on-site in-situ calibration of the three-axis six-degree-of-freedom linear vibration and angular vibration parameters of a six-degree-of-freedom micro-vibration table with a wide frequency band and a small range.

[0008] The specific technical solutions of the present invention are as follows:

[0009] An in-situ calibration device for a six-degree-of-freedom micro-vibration table includes a table top on the six-degree-of-freedom micro-vibration table, a mounting platform, a linear vibration calibration unit and an angular vibration calibration unit, a coordinate positioning tool, a coordinate positioning tool fine-tuning mechanism, and a data acquisition and analysis system host computer, wherein:

[0010] The mounting platform is mounted on the tabletop of the six-degree-of-freedom micro-vibration table, and the center hole of the mounting platform coincides with the center positioning hole of the tabletop of the six-degree-of-freedom micro-vibration table;

[0011] The coordinate positioning tool is used to obtain the coordinate system origin and the three-axis directions of the coordinate system X-axis, Y-axis and Z-axis corresponding to the six-degree-of-freedom micro-vibration table to ensure accurate coordinate position positioning;

[0012] The linear vibration calibration unit includes an acceleration measurement unit and a vibration displacement measurement unit, wherein: the acceleration measurement unit includes a three-axis acceleration sensor A, a three-axis acceleration sensor B, a three-axis acceleration sensor C, a unidirectional acceleration sensor, a sensor mounting seat, a signal conditioning module, and a high-precision distance measuring instrument, and is used for in-situ calibration of the linear vibration parameters of the test system, wherein the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are respectively mounted on the sensor mounting seat and connected to the signal conditioning module through a data cable, and the unidirectional acceleration sensor is installed at the coordinate origin O position, and is used for obtaining the linear vibration signal;

[0013] The vibration displacement measurement unit includes a vibration displacement measurement tool, a laser head, a laser head installation tool, and a laser vibration measurement system controller, which are used to perform in-situ calibration of the vibration displacement parameters of the test system, wherein the laser head includes a laser head A, a laser head B, and a laser head C, which are incident along the three directions of the coordinate system X-axis, Y-axis, and Z-axis, respectively, and the laser head is fixedly installed on the laser head installation tool, and the laser head installation tool is used to ensure that the laser head does not displace or loosen during in-situ calibration;

[0014] The angular vibration calibration unit includes a three-axis acceleration sensor A, a three-axis acceleration sensor B, a three-axis acceleration sensor C, a sensor mounting seat, an angular vibration sensor, an angular vibration mounting seat, and a signal conditioning module, and is used for performing in-situ calibration of the angular vibration parameters of the test system, wherein the angular vibration sensor is mounted on the angular vibration mounting seat; the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are respectively mounted on the sensor mounting seat; the angular vibration sensor, the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are connected to the signal conditioning module via a data cable;

[0015] The three-axis acceleration sensor 1 is installed on the X-axis, with one sensitive axis installed coincidently with the X-axis, and the other two axes are perpendicular to the coordinate system. The three-axis acceleration sensor 2 is installed on the Y-axis, with one sensitive axis installed coincidently with the Y-axis, and the other two axes are perpendicular to the coordinate system. The three-axis acceleration sensor 3 is installed symmetrically around the Z-axis with the three-axis acceleration sensor 1.

[0016] Preferably, the host computer of the data acquisition and analysis system adopts a PXI control system based on PXI bus technology, which is used to collect the voltage signals output by the signal conditioning module and the laser vibration measurement system controller, and obtain the vibration parameters through the solution algorithm. The system software in the host computer of the data acquisition and analysis system includes a self-test module, a calibration test module, and a data management module, wherein:

[0017] The self-check module controls the operation of each module of the hardware system and is used to check the reliability of the system hardware operation;

[0018] The calibration test module is used to control the hardware system to complete the calibration and realize the calibration of three-axis vibration and three-axis angular vibration;

[0019] The data management module displays, saves, and organizes the calibration results, and includes a virtual device driver for implementing the interruption of sampling data.

[0020] Preferably, the center of the installation platform has an assembly interface matching the table top of the six-degree-of-freedom micro-vibration table, a traceability measurement interface matching the table top of the superior traceability mechanism standard device, and mounting holes evenly distributed around the center hole. The mounting holes match the coordinate positioning tooling and the vibration measurement tooling and are used to install the coordinate positioning tooling and the vibration measurement tooling;

[0021] The installation platform table top can be closely fitted on the upper table top and has rigidity and load-bearing capacity.

[0022] Preferably, the coordinate positioning tooling has the functions of fine-tuning translation in three directions, rotation of yaw angle and fine-tuning of two-dimensional yaw, and can realize coordinate positioning and measurement functions, and is used to determine the origin of the coordinate system and the three-axis directions of the coordinate system X-axis, Y-axis and Z-axis during in-situ calibration.

[0023] Preferably, the signal conditioning module is used to condition, amplify and filter the vibration signals acquired by the three-axis acceleration sensor A, the three-axis acceleration sensor B, the three-axis acceleration sensor C and the angular vibration sensor, and convert them into voltage signals.

[0024] Preferably, the high-precision distance measuring instrument is used to obtain the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the coordinate origin.

[0025] Preferably, the vibration displacement measuring tool is connected to the fine-tuning mechanism of the coordinate positioning tool, and is installed at the center hole position of the mounting platform through the positioning mounting hole, and the measuring plane of the vibration displacement measuring tool is perpendicular to the incident direction of the laser head;

[0026] The vibration displacement measuring fixture can provide measuring planes in three directions of the coordinate system, namely, the X-axis, the Y-axis and the Z-axis, and is parallel to the axis corresponding to the coordinate system. At the same time, the vibration displacement measuring fixture does not loosen or deform when the test bench performs linear vibration motion.

[0027] Preferably, the laser vibration measurement system controller controls the laser head to emit laser light onto the measuring surface of the vibration displacement measurement tooling;

[0028] The laser vibration measurement system controller includes a displacement decoding board and a speed decoding board, which are used to collect and analyze analog vibration signals and output vibration simulation signals to a host computer of a data acquisition system.

[0029] Preferably, the laser head installation tooling has a direction adjustment function and a locking function. The direction adjustment function ensures the laser incident direction of the laser probe, and the locking function ensures that the position of the laser probe does not change during the measurement process.

[0030] Preferably, the coordinate positioning tooling fine-tuning mechanism is connected to the installation platform and has a locking function for each degree of freedom, and is used to install a fixed coordinate positioning tooling, a vibration displacement measurement tooling, and a laser head installation tooling to ensure that the fixed coordinate positioning tooling, the vibration displacement measurement tooling, and the laser head installation tooling can coincide with the six-degree-of-freedom micro-vibration table coordinate system.

[0031] A six-degree-of-freedom micro-vibration table in-situ calibration method comprises a six-degree-of-freedom micro-vibration table linear vibration calibration method, a vibration displacement calibration method, and an angular vibration calibration method.

[0032] Preferably, the linear vibration calibration method comprises the following steps:

[0033] S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table;

[0034] Use the coordinate positioning tool to determine the coordinate information corresponding to the six-degree-of-freedom micro-vibration table, and determine the origin of the calibration coordinate system and the three-axis directions of the coordinate system X-axis, Y-axis, and Z-axis;

[0035] Install three-axis acceleration sensor A, three-axis acceleration sensor B, and three-axis acceleration sensor C on the sensor mounting base, and install them to the designated position of the mounting platform through the positioning holes on the surface of the mounting platform;

[0036] The tooling and sensors are kept stable at a constant temperature on site for no less than 4 hours;

[0037] S2. Use a high-precision distance measuring instrument to measure the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the origin of the coordinate system. Measure each distance 10 times in a short period of time, take the average value of the 10 times as the measurement result, and obtain distances l1, l2, and l3 respectively, wherein the three-axis acceleration sensor 1 and the three-axis acceleration sensor 3 are installed symmetrically around the Z axis so that the installation distance l1 is equal to the installation distance l3;

[0038] S3, connecting the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C to the signal conditioning module through a dedicated data cable, and connecting the output end of the signal conditioning module to the calibration test module of the upper computer of the data acquisition system through a cable;

[0039] Special data cables are attached to the installation platform with special anti-static tape to prevent the cables from being pulled and displaced;

[0040] Turn on the signal conditioning module and set it to the specified gear, turn on the data acquisition system host computer, and preheat for 30 minutes;

[0041] S4. Control the six-degree-of-freedom micro-vibration table to vibrate at a specified frequency and amplitude, and obtain the amplitude signals ai (i=1, 2, ..., 9) of each axis direction of the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C through the host computer of the data acquisition system, where a1, a2, ... a9 represent the numbers of the different sensitive axis directions of the sensors.

[0042] The position coordinate matrix l and the sensitive direction coordinate matrix θ of the nine sensor sensitive axes of the three three-way sensors relative to the origin of the carrier coordinate system are:

[0043]

[0044]

[0045] Get the output of any acceleration sensor's sensitive axis according to the kinematic equation

[0046]

[0047] Where:

[0048] a——Acceleration signal measured on the accelerometer

[0049] K——Coefficient Matrix

[0050] ——Angular acceleration of the carrier coordinate system

[0051] A——Linear acceleration in the three coordinate axes of the carrier coordinate system

[0052] in:

[0053]

[0054] K2=θ=[θ1θ2…θ9], l=[l1 l2…l9], K1=[l1×θ1l2×θ2…l9×θ9]

[0055] The angular velocity, angular acceleration and linear acceleration of the carrier coordinate system are obtained by fully expanding equation (3), and the relationship expression of the relevant parameters characterizing the six-degree-of-freedom midline vibration is obtained by solving equation (4).

[0056]

[0057] The value of the test system line vibration parameter is obtained by formula (4), and the on-site in-situ calibration of the test system line vibration parameter is realized.

[0058] Preferably, the vibration displacement calibration method comprises the following steps:

[0059] S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table;

[0060] Install the coordinate positioning tooling at the coordinate origin of the six-degree-of-freedom micro-vibration table, ensure that the center of the coordinate positioning tooling coincides with the center of the origin of the six-degree-of-freedom micro-vibration table, determine the origin of the calibration coordinate system and the directions of the three axes of the coordinate system, namely, the X-axis, Y-axis, and Z-axis; connect the coordinate positioning tooling to the vibration displacement measurement tooling through the installation interface;

[0061] The laser head installation fixture is installed along the X-axis, Y-axis, and Z-axis directions of the coordinate system, and the laser head is installed on the laser head installation fixture. The direction of the incident laser of the laser head is perpendicular to the measuring surface of the vibration displacement measurement fixture in three directions; ensure that the transmission line of the laser head does not touch the test bench table;

[0062] S2. Install and adjust the fine-tuning mechanism of the coordinate positioning fixture, make the coordinate system axis of the coordinate positioning fixture coincide with the coordinate system axis of the test bench, use a laser interferometer to precisely measure the measuring surface of the linear vibration measurement fixture, and ensure that the three-direction measuring surfaces of the vibration displacement measurement fixture are perpendicular to the coordinate system axis;

[0063] S3, connecting the laser vibration measurement system controller to the calibration test module of the data acquisition system host computer through a dedicated data cable;

[0064] Turn on the laser vibration measurement system controller and set it to the specified gear, turn on the host computer, and preheat for 30 minutes;

[0065] Fine-tune the incident angle of the laser head installed on the laser head installation fixture to maximize the incident laser energy and improve the signal-to-noise ratio of the laser measurement signal;

[0066] S4, control the six-degree-of-freedom micro-vibration table to vibrate at the specified frequency and amplitude, obtain the amplitude signal of each axis direction through the host computer of the data acquisition system, and perform control motion trajectory curve fitting.

[0067] Set the sinusoidal motion function of each axis to

[0068]

[0069] The three axes are measured by the laser vibrometer system, and the measured signals are expressed as but

[0070]

[0071] The vibration displacement signal of the test bench is but

[0072]

[0073] The vibration displacement amplitude indication error is calculated by the following formula

[0074]

[0075] Preferably, the angular vibration calibration method comprises the following steps:

[0076] S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table;

[0077] Install three-axis acceleration sensor A, three-axis acceleration sensor B, and three-axis acceleration sensor C on the sensor mounting base, and install them to the designated position of the mounting platform through the positioning holes on the surface of the mounting platform;

[0078] Use the coordinate positioning tool to determine the coordinate information corresponding to the six-degree-of-freedom micro-vibration table, determine the origin of the calibration coordinate system and the directions of the three axes of the coordinate system, namely, the X-axis, the Y-axis, and the Z-axis; install the angular vibration sensor on the coordinate positioning tool to ensure that the center of the coordinate positioning tool coincides with the center of the six-degree-of-freedom micro-vibration table;

[0079] By adjusting the fine-tuning mechanism of the coordinate positioning fixture, the coordinate system axis of the coordinate positioning fixture is made to coincide with the coordinate system axis of the test bench;

[0080] The tooling and sensors are kept stable at a constant temperature on site for no less than 4 hours;

[0081] S2. Use a high-precision distance measuring instrument to measure the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the origin of the coordinate system. Measure each distance 10 times in a short period of time, take the average value of the 10 times as the measurement result, and obtain distances l1, l2, and l3 respectively, wherein the three-axis acceleration sensor 1 and the three-axis acceleration sensor 3 are installed symmetrically around the Z axis so that the installation distance l1 is equal to the installation distance l3;

[0082] S3, connecting the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C to the signal conditioning module through a dedicated data cable, and connecting the output end of the signal conditioning module to the calibration test module of the upper computer of the data acquisition system through a cable;

[0083] Special data cables are attached to the installation platform with special anti-static tape to prevent the cables from being pulled and displaced;

[0084] Turn on the signal conditioning module and set it to the specified gear, turn on the data acquisition system host computer, and preheat for 30 minutes;

[0085] S4, control the six-degree-of-freedom micro-vibration table to vibrate at a specified frequency and amplitude, and obtain the amplitude signals ai (i=1, 2, ..., 9) of each axis direction of the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C through the host computer of the data acquisition system, where a1, a2, ..., a9 represent the numbers of different sensitive axis directions of the sensors;

[0086] According to the derivation of equations (1) and (2), equation (3) is fully expanded to solve the relevant parameters in the six degrees of freedom: and

[0087]

[0088] The angular vibration sensor is used to collect data through the data acquisition system, and the host computer obtains the angular vibration of the test system around the X-axis. The two linear acceleration sensors on the X-axis are installed symmetrically around the Z-axis, that is, the installation distance l1≈l3, and the three-axis angular vibration parameters of the test bench are expressed as:

[0089]

[0090] Compared with the prior art, the present invention has the following beneficial effects:

[0091] (1) The six-degree-of-freedom micro-vibration table in-situ calibration device provided by the present invention realizes the on-site in-situ calibration of the three-axis vibration and three-axis angular vibration of the six-degree-of-freedom micro-vibration table;

[0092] (2) The present invention adopts a high-precision acceleration sensor and an angular vibration sensor group to solve the problem of performing six-degree-of-freedom parameter testing under medium-low frequency, small amplitude, and multi-axis angular composite vibration conditions, and has the advantages of low cost, fast response, and high reliability;

[0093] (3) The present invention adopts a three-axis acceleration sensor combination, which avoids the multiple installation errors introduced by the traditional use of 6 or 9 single-axis acceleration sensors installed orthogonally to each other, and also avoids the hidden danger of interference between the installation positions caused by each single-axis sensor occupying a certain volume. At the same time, the spatial volume and the cumulative error of the solution of the entire system are small, thereby improving the overall measurement accuracy of the system;

[0094] (4) The present invention adopts an installation and positioning tool developed after precise measurement and structural design, and a vibration displacement measurement tool based on precision machining and high-precision fine-tuning mechanism, which are applied to the in-situ calibration of the three-axis vibration and three-axis angular vibration of the test bench, so as to achieve the coincidence of the motion coordinate system of the six-degree-of-freedom micro-vibration table and the measurement coordinate system of the installation and positioning tool at the measured point position during the in-situ calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] In order to more clearly illustrate the technical solutions disclosed in the present invention, the following briefly introduces the drawings required to be used in some embodiments disclosed in the present invention. Obviously, the drawings described below are only drawings of some embodiments disclosed in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual size of the products involved in the embodiments disclosed in the present invention, the actual process of the method, etc.

[0096] Figure 1 A schematic diagram of the overall structure of an in-situ calibration device for a six-degree-of-freedom micro-vibration table provided by the present invention;

[0097] Figure 2 A schematic structural diagram of a linear vibration calibration unit provided by the present invention;

[0098] Figure 3 A schematic structural diagram of an angular vibration calibration unit provided by the present invention;

[0099] Figure 4 A schematic diagram of the installation position of a three-way sensor provided by the present invention;

[0100] Figure 5 A schematic diagram of the installation position of an acceleration measurement unit provided by the present invention;

[0101] Figure 6 A schematic diagram of the installation position of a vibration displacement measurement unit provided by the present invention;

[0102] Figure 7 A schematic diagram of the installation position of an angular vibration calibration unit provided by the present invention;

[0103] Figure 8 A schematic diagram of an installation platform provided by the present invention;

[0104] Fig. 9 A schematic diagram of a coordinate positioning tool provided by the present invention;

[0105] Fig.10 A schematic diagram of a vibration displacement measurement tool provided by the present invention installed on a coordinate positioning tool. DETAILED DESCRIPTION

[0106] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings 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. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0107] like Figure 1 , Figure 2 and Figure 3 As shown, a six-degree-of-freedom micro-vibration table in-situ calibration device includes a six-degree-of-freedom micro-vibration table top, a mounting platform, a linear vibration calibration unit and an angular vibration calibration unit, a coordinate positioning tool, a coordinate positioning tool fine-tuning mechanism, and a data acquisition and analysis system host computer, wherein:

[0108] The mounting platform is mounted on the tabletop of the six-degree-of-freedom micro-vibration table, and the center hole of the mounting platform coincides with the center positioning hole of the tabletop of the six-degree-of-freedom micro-vibration table;

[0109] The coordinate positioning tool is used to obtain the coordinate system origin and the three-axis directions of the coordinate system X-axis, Y-axis and Z-axis corresponding to the six-degree-of-freedom micro-vibration table to ensure accurate coordinate position positioning;

[0110] like Figure 2 As shown, the linear vibration calibration unit includes an acceleration measurement unit and a vibration displacement measurement unit, wherein: the acceleration measurement unit includes a three-axis acceleration sensor A, a three-axis acceleration sensor B, a three-axis acceleration sensor C, a unidirectional acceleration sensor, a sensor mounting seat, a signal conditioning module, and a high-precision distance measuring instrument, which are used to perform in-situ calibration of the linear vibration parameters of the test system, such as Figure 5As shown, the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are respectively installed on the sensor mounting seat and connected to the signal conditioning module through a data cable, and the unidirectional acceleration sensor is installed at the coordinate origin O position for obtaining the line vibration signal;

[0111] The vibration displacement measurement unit includes a vibration displacement measurement tool, a laser head, a laser head installation tool, and a laser vibration measurement system controller, which is used to perform in-situ calibration of the vibration displacement parameters of the test system, such as Figure 6 As shown, the laser head includes laser head A, laser head B, and laser head B, which are incident along the three directions of the coordinate system X axis, Y axis, and Z axis respectively, and the laser head is fixedly installed on the laser head installation tooling, and the laser head installation tooling is used to ensure that the laser head does not move or loosen during in-situ calibration;

[0112] like Figure 3 As shown, the angular vibration calibration unit includes a three-axis acceleration sensor A, a three-axis acceleration sensor B, a three-axis acceleration sensor C, a sensor mounting seat, an angular vibration sensor, an angular vibration mounting seat, and a signal conditioning module, which is used to perform in-situ calibration of the angular vibration parameters of the test system, such as Figure 7 As shown, the angular vibration sensor is mounted on an angular vibration mounting seat; the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are respectively mounted on the sensor mounting seat; the angular vibration sensor, the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are connected to the signal conditioning module through a data cable;

[0113] like Figure 4 As shown, the three-axis acceleration sensor 1 is installed on the X-axis, one sensitive axis is installed coincidently with the X-axis, and the other two axes are perpendicular to the coordinate system. The three-axis acceleration sensor B is installed on the Y-axis, one sensitive axis is installed coincidently with the Y-axis, and the other two axes are perpendicular to the coordinate system. The three-axis acceleration sensor C is installed symmetrically around the Z-axis with the three-axis acceleration sensor A.

[0114] The host computer of the data acquisition and analysis system adopts a PXI control system based on PXI bus technology, which is used to collect the voltage signals output by the signal conditioning module and the laser vibration measurement system controller, and obtain the vibration parameters through the solution algorithm. The system software in the host computer of the data acquisition and analysis system includes a self-test module, a calibration test module, and a data management module, wherein:

[0115] The self-check module controls the operation of each module of the hardware system and is used to check the reliability of the system hardware operation;

[0116] The calibration test module is used to control the hardware system to complete the calibration and realize the calibration of three-axis vibration and three-axis angular vibration;

[0117] The data management module displays, saves, and organizes the calibration results, and includes a virtual device driver for implementing the interruption of sampling data.

[0118] like Figure 8 As shown, the center of the installation platform has an assembly interface that matches the table top of the six-degree-of-freedom micro-vibration table, a traceability measurement interface that matches the table top of the superior traceability mechanism standard device, and mounting holes that are evenly distributed around the center hole. The mounting holes match the coordinate positioning tooling and the vibration measurement tooling and are used to install the coordinate positioning tooling and the vibration measurement tooling;

[0119] The installation platform table top can be closely fitted on the upper table top and has rigidity and load-bearing capacity.

[0120] like Fig. 9 As shown, the coordinate positioning tooling has the functions of fine-tuning translation in three directions, rotation of yaw angle and fine-tuning of two-dimensional runout, and can realize coordinate positioning and measurement functions, and is used to determine the origin of the coordinate system and the three-axis directions of the coordinate system X-axis, Y-axis and Z-axis during in-situ calibration.

[0121] The signal conditioning module is used to condition, amplify and filter the vibration signals acquired by the three-axis acceleration sensor A, the three-axis acceleration sensor B, the three-axis acceleration sensor C and the angular vibration sensor, and convert them into voltage signals.

[0122] The high-precision distance measuring instrument is used to obtain the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the coordinate origin.

[0123] like Fig.10 As shown, the vibration displacement measuring tool is connected to the fine-tuning mechanism of the coordinate positioning tool, and is installed at the center hole position of the mounting platform through the positioning mounting hole. The measuring plane of the vibration displacement measuring tool is perpendicular to the incident direction of the laser head;

[0124] The vibration displacement measuring fixture can provide measuring planes in three directions of the coordinate system, namely, the X-axis, the Y-axis and the Z-axis, and is parallel to the axis corresponding to the coordinate system. Meanwhile, the vibration displacement measuring fixture does not loosen or deform when the test bench performs linear vibration motion.

[0125] The laser vibration measurement system controller controls the laser head to emit laser light onto the measuring surface of the vibration displacement measurement tooling;

[0126] The laser vibration measurement system controller includes a displacement decoding board and a speed decoding board, which are used to collect and analyze analog vibration signals and output vibration simulation signals to a host computer of a data acquisition system.

[0127] The laser head installation tool has a direction adjustment function and a locking function. The direction adjustment function ensures the laser incident direction of the laser probe, and the locking function ensures that the position of the laser probe does not change during the measurement process.

[0128] The coordinate positioning tooling fine-tuning mechanism is connected to the installation platform and has a locking function for each degree of freedom. It is used to install a fixed coordinate positioning tooling, a vibration displacement measurement tooling, and a laser head installation tooling to ensure that the fixed coordinate positioning tooling, the vibration displacement measurement tooling, and the laser head installation tooling can coincide with the six-degree-of-freedom micro-vibration table coordinate system.

[0129] A six-degree-of-freedom micro-vibration table in-situ calibration method comprises a six-degree-of-freedom micro-vibration table linear vibration calibration method, a vibration displacement calibration method, and an angular vibration calibration method.

[0130] The line vibration calibration method comprises the following steps:

[0131] S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table;

[0132] Use the coordinate positioning tool to determine the coordinate information corresponding to the six-degree-of-freedom micro-vibration table, and determine the origin of the calibration coordinate system and the three-axis directions of the coordinate system X-axis, Y-axis, and Z-axis;

[0133] Install three-axis acceleration sensor A, three-axis acceleration sensor B, and three-axis acceleration sensor C on the sensor mounting base, and install them to the designated position of the mounting platform through the positioning holes on the surface of the mounting platform;

[0134] The tooling and sensors are kept stable at a constant temperature on site for no less than 4 hours;

[0135] S2. Use a high-precision distance measuring instrument to measure the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the origin of the coordinate system. Measure each distance 10 times in a short period of time, take the average value of the 10 times as the measurement result, and obtain distances l1, l2, and l3 respectively, wherein the three-axis acceleration sensor 1 and the three-axis acceleration sensor 3 are installed symmetrically around the Z axis so that the installation distance l1 is equal to the installation distance l3;

[0136] S3, connecting the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C to the signal conditioning module through a dedicated data cable, and connecting the output end of the signal conditioning module to the calibration test module of the upper computer of the data acquisition system through a cable;

[0137] Special data cables are attached to the installation platform with special anti-static tape to prevent the cables from being pulled and displaced;

[0138] Turn on the signal conditioning module and set it to the specified gear, turn on the data acquisition system host computer, and preheat for 30 minutes;

[0139] S4. Control the six-degree-of-freedom micro-vibration table to vibrate at a specified frequency and amplitude, and obtain the amplitude signals ai (i=1, 2, ..., 9) of each axis direction of the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C through the host computer of the data acquisition system, where a1, a2, ... a9 represent the numbers of the different sensitive axis directions of the sensors.

[0140] The position coordinate matrix l and the sensitive direction coordinate matrix θ of the 9 sensor sensitive axes of the 3 three-way sensors relative to the origin of the carrier coordinate system are:

[0141]

[0142] Get the output of any acceleration sensor's sensitive axis according to the kinematic equation

[0143]

[0144] Where:

[0145] a——Acceleration signal measured on the accelerometer

[0146] K——Coefficient Matrix

[0147] ——Angular acceleration of the carrier coordinate system

[0148] A——Linear acceleration in the three coordinate axes of the carrier coordinate system

[0149] in:

[0150]

[0151] K2=θ=[θ1 θ2 … θ9], r=[r1 r2 … r9], K1=[r1×θ1 r2×θ2 … r9×θ9]

[0152] The angular velocity, angular acceleration and linear acceleration of the carrier coordinate system are obtained by fully expanding equation (3), and the relationship expression of the relevant parameters characterizing the six-degree-of-freedom midline vibration is obtained by solving equation (4).

[0153]

[0154] The value of the test system line vibration parameter is obtained by formula (4), and the on-site in-situ calibration of the test system line vibration parameter is realized.

[0155] The vibration displacement calibration method comprises the following steps:

[0156] S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table;

[0157] Install the coordinate positioning tooling at the coordinate origin of the six-degree-of-freedom micro-vibration table, ensure that the center of the coordinate positioning tooling coincides with the center of the origin of the six-degree-of-freedom micro-vibration table, determine the origin of the calibration coordinate system and the directions of the three axes of the coordinate system, namely, the X-axis, Y-axis, and Z-axis; connect the coordinate positioning tooling to the vibration displacement measurement tooling through the installation interface;

[0158] The laser head installation fixture is installed along the X-axis, Y-axis, and Z-axis directions of the coordinate system, and the laser head is installed on the laser head installation fixture. The direction of the incident laser of the laser head is perpendicular to the measuring surface of the vibration displacement measurement fixture in three directions; ensure that the transmission line of the laser head does not touch the test bench table;

[0159] S2. Install and adjust the fine-tuning mechanism of the coordinate positioning fixture, make the coordinate system axis of the coordinate positioning fixture coincide with the coordinate system axis of the test bench, use a laser interferometer to precisely measure the measuring surface of the linear vibration measurement fixture, and ensure that the three-direction measuring surfaces of the vibration displacement measurement fixture are perpendicular to the coordinate system axis;

[0160] S3, connecting the laser vibration measurement system controller to the calibration test module of the data acquisition system host computer through a dedicated data cable;

[0161] Turn on the laser vibration measurement system controller and set it to the specified gear, turn on the host computer, and preheat for 30 minutes;

[0162] Fine-tune the incident angle of the laser head installed on the laser head installation fixture to maximize the incident laser energy and improve the signal-to-noise ratio of the laser measurement signal;

[0163] S4, control the six-degree-of-freedom micro-vibration table to vibrate at the specified frequency and amplitude, obtain the amplitude signal of each axis direction through the host computer of the data acquisition system, and perform control motion trajectory curve fitting.

[0164] Set the sinusoidal motion function of each axis to

[0165]

[0166] The three axes are measured by the laser vibrometer system, and the measured signals are expressed as but

[0167]

[0168] The vibration displacement signal of the test bench is but

[0169]

[0170] The vibration displacement amplitude indication error is calculated by the following formula

[0171]

[0172] The angular vibration calibration method comprises the following steps:

[0173] S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table;

[0174] Install three-axis acceleration sensor A, three-axis acceleration sensor B, and three-axis acceleration sensor C on the sensor mounting base, and install them to the designated position of the mounting platform through the positioning holes on the surface of the mounting platform;

[0175] Use the coordinate positioning tool to determine the coordinate information corresponding to the six-degree-of-freedom micro-vibration table, determine the origin of the calibration coordinate system and the directions of the three axes of the coordinate system, namely, the X-axis, the Y-axis, and the Z-axis; install the angular vibration sensor on the coordinate positioning tool to ensure that the center of the coordinate positioning tool coincides with the center of the six-degree-of-freedom micro-vibration table;

[0176] By adjusting the fine-tuning mechanism of the coordinate positioning fixture, the coordinate system axis of the coordinate positioning fixture is made to coincide with the coordinate system axis of the test bench;

[0177] The tooling and sensors are kept stable at a constant temperature on site for no less than 4 hours;

[0178] S2. Use a high-precision distance measuring instrument to measure the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the origin of the coordinate system. Measure each distance 10 times in a short period of time, take the average value of the 10 times as the measurement result, and obtain distances l1, l2, and l3 respectively, wherein the three-axis acceleration sensor 1 and the three-axis acceleration sensor 3 are installed symmetrically around the Z axis so that the installation distance l1 is equal to the installation distance l3;

[0179] S3, connecting the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C to the signal conditioning module through a dedicated data cable, and connecting the output end of the signal conditioning module to the calibration test module of the upper computer of the data acquisition system through a cable;

[0180] Special data cables are attached to the installation platform with special anti-static tape to prevent the cables from being pulled and displaced;

[0181] Turn on the signal conditioning module and set it to the specified gear, turn on the data acquisition system host computer, and preheat for 30 minutes;

[0182] S4, control the six-degree-of-freedom micro-vibration table to vibrate at a specified frequency and amplitude, and obtain the amplitude signals ai (i=1, 2, ..., 9) of each axis direction of the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C through the host computer of the data acquisition system, where a1, a2, ..., a9 represent the numbers of different sensitive axis directions of the sensors;

[0183] According to the derivation of equations (1) and (2), equation (3) is fully expanded to solve the relevant parameters in the six degrees of freedom: and

[0184]

[0185] The angular vibration sensor is used to collect data through the data acquisition system, and the host computer obtains the angular vibration of the test system around the X-axis. The two linear acceleration sensors on the X-axis are installed symmetrically around the Z-axis, that is, the installation distance l1≈l3, and the three-axis angular vibration parameters of the test bench are expressed as:

[0186]

[0187] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention using the above disclosed contents without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the contents of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A six-degree-of-freedom micro-vibration table in-situ calibration device, characterized in that: The calibration device includes a six-degree-of-freedom micro-vibration table top, a mounting platform, a linear vibration calibration unit and an angular vibration calibration unit, a coordinate positioning tool, a coordinate positioning tool fine-tuning mechanism, and a data acquisition and analysis system host computer, wherein: The table top of the six-degree-of-freedom micro-vibration table is provided with a central positioning hole and a mounting hole matching the shape and position dimensions of the test product; The mounting platform is mounted on the tabletop of the six-degree-of-freedom micro-vibration table, and the mounting platform is provided with a center hole that coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table; The coordinate positioning tool is used to obtain the coordinate system origin and the three-axis directions of the coordinate system X-axis, Y-axis and Z-axis corresponding to the six-degree-of-freedom micro-vibration table to ensure accurate coordinate position positioning; The linear vibration calibration unit includes an acceleration measurement unit and a vibration displacement measurement unit, wherein: the acceleration measurement unit includes a three-axis acceleration sensor A, a three-axis acceleration sensor B, a three-axis acceleration sensor C, a unidirectional acceleration sensor, a sensor mounting seat, a signal conditioning module, and a high-precision distance measuring instrument, and is used for in-situ calibration of the linear vibration parameters of the test system, wherein the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are respectively mounted on the sensor mounting seat and connected to the signal conditioning module through a data cable, and the unidirectional acceleration sensor is installed at the coordinate origin O position, and is used for obtaining the linear vibration signal; The vibration displacement measurement unit includes a vibration displacement measurement tool, a laser head, a laser head installation tool, and a laser vibration measurement system controller, which are used to perform in-situ calibration of the vibration displacement parameters of the test system, wherein the laser head includes a laser head A, a laser head B, and a laser head C, which are incident along the three directions of the coordinate system X-axis, Y-axis, and Z-axis, respectively, and the laser head is fixedly installed on the laser head installation tool, and the laser head installation tool is used to ensure that the laser head does not displace or loosen during in-situ calibration; The angular vibration calibration unit includes a three-axis acceleration sensor A, a three-axis acceleration sensor B, a three-axis acceleration sensor C, a sensor mounting seat, an angular vibration sensor, an angular vibration mounting seat, and a signal conditioning module, and is used for performing in-situ calibration of the angular vibration parameters of the test system, wherein the angular vibration sensor is mounted on the angular vibration mounting seat; the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are respectively mounted on the sensor mounting seat; the angular vibration sensor, the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C are connected to the signal conditioning module via a data cable; The three-axis acceleration sensor 1 is installed on the X-axis, with one sensitive axis installed coincidently with the X-axis, and the other two axes are perpendicular to the coordinate system. The three-axis acceleration sensor B is installed on the Y-axis, with one sensitive axis installed coincidently with the Y-axis, and the other two axes are perpendicular to the coordinate system. The three-axis acceleration sensor C is installed symmetrically around the Z-axis with the three-axis acceleration sensor A.

2. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The host computer of the data acquisition and analysis system adopts a PXI control system based on PXI bus technology, which is used to collect the voltage signals output by the signal conditioning module and the laser vibration measurement system controller, and obtain the vibration parameters through the solution algorithm. The system software in the host computer of the data acquisition and analysis system includes a self-test module, a calibration test module, and a data management module, wherein: The self-check module controls the operation of each module of the hardware system and is used to check the reliability of the system hardware operation; The calibration test module is used to control the hardware system to complete the calibration and realize the calibration of three-axis vibration and three-axis angular vibration; The data management module displays, saves, and organizes the calibration results, and includes a virtual device driver for implementing the interruption of sampling data.

3. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The center of the installation platform has an assembly interface that matches the table top of the six-degree-of-freedom micro-vibration table, a traceability measurement interface that matches the table top of the superior traceability mechanism standard device, and mounting holes that are evenly distributed around the center hole. The mounting holes match the coordinate positioning tooling and the vibration measurement tooling and are used to install the coordinate positioning tooling and the vibration measurement tooling; The installation platform table top can be closely fitted on the upper table top and has rigidity and load-bearing capacity.

4. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The coordinate positioning tool is used to determine the origin of the coordinate system and the directions of the three axes of the coordinate system, namely, the X-axis, the Y-axis and the Z-axis, during in-situ calibration.

5. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The signal conditioning module is used to condition, amplify and filter the vibration signals acquired by the three-axis acceleration sensor A, the three-axis acceleration sensor B, the three-axis acceleration sensor C and the angular vibration sensor, and convert them into voltage signals.

6. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The high-precision distance measuring instrument is used to obtain the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the coordinate origin.

7. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The vibration displacement measuring tool is connected to the fine-tuning mechanism of the coordinate positioning tool and is installed at the center hole position of the mounting platform through the positioning mounting hole. The measuring plane of the vibration displacement measuring tool is perpendicular to the incident direction of the laser head. The vibration displacement measuring fixture can provide measuring planes in three directions of the coordinate system, namely, the X-axis, the Y-axis and the Z-axis, and is parallel to the axis corresponding to the coordinate system. Meanwhile, the vibration displacement measuring fixture does not loosen or deform when the test bench performs linear vibration motion.

8. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The laser vibration measurement system controller controls the laser head to emit laser light onto the measuring surface of the vibration displacement measurement tooling; The laser vibration measurement system controller includes a displacement decoding board and a speed decoding board, which are used to collect and analyze analog vibration signals and output vibration simulation signals to a host computer of a data acquisition system.

9. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The laser head installation tool has a direction adjustment function and a locking function. The direction adjustment function ensures the laser incident direction of the laser probe, and the locking function ensures that the position of the laser probe does not change during the measurement process.

10. The six-degree-of-freedom micro-vibration table in-situ calibration device according to claim 1, characterized in that: The coordinate positioning tooling fine-tuning mechanism is connected to the installation platform and has a locking function of the degrees of freedom. It is used to install the fixed coordinate positioning tooling, the vibration displacement measurement tooling, and the laser head installation tooling to ensure that the fixed coordinate positioning tooling, the vibration displacement measurement tooling, and the laser head installation tooling can coincide with the six-degree-of-freedom micro-vibration table coordinate system.

11. A six-degree-of-freedom micro-vibration table in-situ calibration method, characterized in that: An in-situ calibration device for a six-degree-of-freedom micro-vibration table as described in any one of claims 1 to 9 is used, and the in-situ calibration method includes a linear vibration calibration method, a vibration displacement calibration method, and an angular vibration calibration method.

12. The in-situ calibration method of a six-degree-of-freedom micro-vibration table according to claim 11, characterized in that: The line vibration calibration method comprises the following steps: S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table; Use the coordinate positioning tool to determine the coordinate information corresponding to the six-degree-of-freedom micro-vibration table, and determine the origin of the calibration coordinate system and the three-axis directions of the coordinate system X-axis, Y-axis, and Z-axis; Install three-axis acceleration sensor A, three-axis acceleration sensor B, and three-axis acceleration sensor C on the sensor mounting base, and install them to the designated position of the mounting platform through the positioning holes on the surface of the mounting platform; The tooling and sensor are stable at a constant temperature on site for more than or equal to 4 hours; S2. Use a high-precision distance measuring instrument to measure the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the origin of the coordinate system. Measure each distance 10 times in a short period of time, take the average value of the 10 times as the measurement result, and obtain distances Q, W, and E respectively. The three-axis acceleration sensor A and the three-axis acceleration sensor C are installed symmetrically around the Z axis so that the installation distance Q is equal to the installation distance E. S3, connecting the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C to the signal conditioning module through a dedicated data cable, and connecting the output end of the signal conditioning module to the calibration test module of the upper computer of the data acquisition system through a cable; Special data cables are attached to the installation platform with special anti-static tape to prevent the cables from being pulled and displaced; Turn on the signal conditioning module and set it to the specified gear, turn on the data acquisition system host computer, and preheat for 30 minutes; S4, control the six-degree-of-freedom micro-vibration table to vibrate at a specified frequency and amplitude, and obtain the amplitude signals ai (i=1, 2, ..., 9) of each axis direction of the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C through the host computer of the data acquisition system, where a1, a2, ..., a9 represent the numbers of different sensitive axis directions of the sensors; The position coordinate matrix l and the sensitive direction coordinate matrix θ of the nine sensor sensitive axes of the three three-way sensors relative to the origin of the carrier coordinate system are: Get the output of any acceleration sensor's sensitive axis according to the kinematic equation Where: a——Acceleration signal measured on the accelerometer K——Coefficient Matrix ——Angular acceleration of the carrier coordinate system A——Linear acceleration in the three coordinate axes of the carrier coordinate system in: K2=θ=[θ1θ2…θ9], l=[l1 l2…l9], K1=[l1×θ1l2×θ2…l9×θ9] The angular velocity, angular acceleration and linear acceleration of the carrier coordinate system are fully expanded by formula (3), and the relationship expression of the relevant parameters characterizing the linear vibration of the six degrees of freedom is solved as formula (4); The value of the test system line vibration parameter is obtained by formula (4), and the on-site in-situ calibration of the test system line vibration parameter is realized.

13. The in-situ calibration method of a six-degree-of-freedom micro-vibration table according to claim 11, characterized in that: The vibration displacement calibration method comprises the following steps: S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table; Install the coordinate positioning tooling at the coordinate origin of the six-degree-of-freedom micro-vibration table, ensure that the center of the coordinate positioning tooling coincides with the center of the origin of the six-degree-of-freedom micro-vibration table, determine the origin of the calibration coordinate system and the directions of the three axes of the coordinate system, namely, the X-axis, Y-axis, and Z-axis; connect the coordinate positioning tooling to the vibration displacement measurement tooling through the installation interface; The laser head installation fixture is installed along the X-axis, Y-axis, and Z-axis directions of the coordinate system, and the laser head is installed on the laser head installation fixture. The direction of the incident laser of the laser head is perpendicular to the measuring surface of the vibration displacement measurement fixture in three directions; ensure that the transmission line of the laser head does not touch the test bench table; S2. Install and adjust the fine-tuning mechanism of the coordinate positioning fixture, make the coordinate system axis of the coordinate positioning fixture coincide with the coordinate system axis of the test bench, use a laser interferometer to precisely measure the measuring surface of the linear vibration measurement fixture, and ensure that the three-direction measuring surfaces of the vibration displacement measurement fixture are perpendicular to the coordinate system axis; S3, connecting the laser vibration measurement system controller to the calibration test module of the data acquisition system host computer through a dedicated data cable; Turn on the laser vibration measurement system controller and set it to the specified gear, turn on the host computer, and preheat for 30 minutes; Fine-tune the incident angle of the laser head installed on the laser head installation fixture to maximize the incident laser energy and improve the signal-to-noise ratio of the laser measurement signal; S4, control the six-degree-of-freedom micro-vibration table to vibrate at the specified frequency and amplitude, obtain the amplitude signal of each axis direction through the host computer of the data acquisition system, and perform control motion trajectory curve fitting. Set the sinusoidal motion function of each axis to The three axes are measured by the laser vibrometer system, and the measured signals are expressed as but The vibration displacement signal of the test bench is but The vibration displacement amplitude indication error is calculated by the following formula 14. The in-situ calibration method of a six-degree-of-freedom micro-vibration table according to claim 11, characterized in that: The angular vibration calibration method comprises the following steps: S1. Install the mounting platform at the designated position on the tabletop of the six-degree-of-freedom micro-vibration table, so that the center hole of the mounting platform coincides with the center positioning hole on the tabletop of the six-degree-of-freedom micro-vibration table; Install three-axis acceleration sensor A, three-axis acceleration sensor B, and three-axis acceleration sensor C on the sensor mounting base, and install them to the designated position of the mounting platform through the positioning holes on the surface of the mounting platform; Use the coordinate positioning tool to determine the coordinate information corresponding to the six-degree-of-freedom micro-vibration table, determine the origin of the calibration coordinate system and the directions of the three axes of the coordinate system, namely, the X-axis, the Y-axis, and the Z-axis; install the angular vibration sensor on the coordinate positioning tool to ensure that the center of the coordinate positioning tool coincides with the center of the six-degree-of-freedom micro-vibration table; By adjusting the fine-tuning mechanism of the coordinate positioning fixture, the coordinate system axis of the coordinate positioning fixture is made to coincide with the coordinate system axis of the test bench; The tooling and sensor are stable at a constant temperature on site for more than or equal to 4 hours; S2. Use a high-precision distance measuring instrument to measure the distances between the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C and the origin of the coordinate system. Measure each distance 10 times in a short period of time, take the average value of the 10 times as the measurement result, and obtain distances Q, W, and E respectively. The three-axis acceleration sensor A and the three-axis acceleration sensor C are installed symmetrically around the Z axis so that the installation distance Q is equal to the installation distance E. S3, connecting the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C to the signal conditioning module through a dedicated data cable, and connecting the output end of the signal conditioning module to the calibration test module of the upper computer of the data acquisition system through a cable; Special data cables are attached to the installation platform with special anti-static tape to prevent the cables from being pulled and displaced; Turn on the signal conditioning module and set it to the specified gear, turn on the data acquisition system host computer, and preheat for 30 minutes; S4, control the six-degree-of-freedom micro-vibration table to vibrate at a specified frequency and amplitude, and obtain the amplitude signals ai (i=1, 2, ..., 9) of each axis direction of the three-axis acceleration sensor A, the three-axis acceleration sensor B, and the three-axis acceleration sensor C through the host computer of the data acquisition system, where a1, a2, ..., a9 represent the numbers of different sensitive axis directions of the sensors; According to the derivation of equations (1) and (2), equation (3) is fully expanded to solve the relevant parameters in the six degrees of freedom: and The angular vibration sensor is used to collect data through the data acquisition system, and the host computer obtains the angular vibration of the test system around the X-axis. Value α(x); the two linear acceleration sensors on the X-axis are installed symmetrically around the Z-axis, that is, the installation distance l1≈l3, then the three-axis angular vibration parameters of the test bench are expressed as:

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