Multi-degree-of-freedom vibration testing apparatus in non-equilibrium field environment and testing method thereof

Abstract

Disclosed in the present invention are a multi-degree-of-freedom vibration testing apparatus in a non-equilibrium field environment and a testing method thereof. The apparatus comprises a bottom non-equilibrium field base, multiple axial electric actuators, a decoupling apparatus, and an automatic centering system. In the present invention, by adding an air storage tank between an air source and an air bag, the volume of the air storage tank changes to adjust the stiffness of the air bag, so that the air bag provides a greater preload force. When a swinging table is subjected to a tangential force, the greater the stiffness of the air bag, the smaller the offset generated by the table, thereby realizing the normal operation of a multi-axial vibration testing system in a non-equilibrium field environment, and also ensuring smoother test waveform.

Description

Multi-degree-of-freedom vibration test device and test method in unbalanced field environment TECHNICAL FIELD

[0001] The present application belongs to the field of vibration test, and particularly relates to a multi-degree-of-freedom vibration test device and test method in unbalanced field environment.

[0002] For the test of some aerospace equipment, the vibration-rolling combined environment often needs to be considered. At present, although there are six-degree-of-freedom vibration test systems on the market, the hydraulic six-degree-of-freedom system has a large rolling angle and a low vibration frequency; the electric six-degree-of-freedom vibration system has a high vibration frequency but a small angular displacement. There is no high-frequency two-axis vibration test system in a large-angle rolling environment on the market.

[0003] In the optical equipment of the aviation and aerospace test device, some special optical equipment needs to capture targets in motion, which not only needs a vibration test environment but also needs a rolling test environment. At present, there are few vibration test systems in a rolling field environment on the market.

[0004] A multi-axis vibration test system in an unbalanced field is designed, which has the advantages of hydraulic tables and electric tables and can realize large displacement rolling and high frequency vibration at the same time. The device has an important role in the field of optical testing.

[0005] The multi-axis electric actuator is installed on the rolling table. When the rolling table moves, the multi-axis electric actuator will roll with the rolling table, and at this time, the workbench will generate vertical and tangential centrifugal forces. The vertical centrifugal force is offset by improving the mechanical structure strength, and the tangential force is superimposed with the excitation force generated by the multi-axis electric actuator. Therefore, the multi-axis vibration test table in the unbalanced field needs to be specially designed. SUMMARY

[0006] Technical purpose: In view of the above technical problems, the present application provides a multi-degree-of-freedom vibration test device in an unbalanced field environment, which can realize the normal work of the multi-axis vibration test system in the unbalanced field environment and ensure that the test waveform is smoother.

[0007] In order to achieve the above technical purpose, the present application adopts the following technical means:

[0008] A multi-degree-of-freedom vibration test device in an unbalanced field environment, comprising a bottom unbalanced field foundation and a workbench, an X-direction electric actuator and a Y-direction electric actuator located above the bottom unbalanced field foundation, wherein the X-direction electric actuator and the Y-direction electric actuator are fixed with the table surface of the bottom unbalanced field foundation;

[0009] The bottom unbalanced field foundation can drive the workbench to realize the unbalanced field state;

[0010] The X-direction electric actuator and the Y-direction electric actuator can drive the workbench to vibrate at high frequency; the bottom non-unbalanced field base and the electric actuator are superimposed to generate a non-unbalanced field and high-frequency vibration; a first air bag is arranged between the moving part inside the Y-direction electric actuator and the supporting rigid body, and a third air bag is arranged between the moving part inside the X-direction electric actuator and the supporting rigid body.

[0011] A first counterforce frame is fixedly installed on one side of the bottom non-unbalanced field base relative to the Y-direction electric actuator, and a second air bag coaxially arranged with the first air bag is arranged between the first counterforce frame and the workbench.

[0012] A second counterforce frame is fixedly installed on one side of the bottom non-unbalanced field base relative to the X-direction electric actuator, and a fourth air bag coaxially arranged with the third air bag is arranged between the second counterforce frame and the workbench.

[0013] A two-dimensional decoupling mechanism is arranged to realize the independent movement of the workbench along the X-direction and the Y-direction.

[0014] A position sensor is arranged to collect the real-time position of the workbench.

[0015] The first electromagnetic valve is connected to the first air bag and the second air bag through two gas outlets, respectively.

[0016] The second electromagnetic valve is connected to the third air bag and the fourth air bag through two gas outlets, respectively.

[0017] A control module is connected to the position sensor through a signal input end and connected to the first electromagnetic valve and the second electromagnetic valve through a signal output end.

[0018] The two-dimensional decoupling mechanism includes a Y-direction slide rail pair and a first X-direction slide rail pair arranged between the bottom of the workbench and the bench surface of the bottom non-unbalanced field base, wherein the Y-direction slide rail pair is fixedly connected to the bench surface of the bottom non-unbalanced field base, and the first X-direction slide rail pair is installed on the sliding block of the Y-direction slide rail pair.

[0019] A second X-direction slide rail pair is arranged between the side of the workbench and the actuator head of the Y-direction electric actuator.

[0020] A supporting frame is arranged below the workbench, and the top of the supporting frame is supported and connected to the bottom of the workbench through the Y-direction slide rail pair, the first X-direction slide rail pair, and the workbench.

[0021] Support air bag is arranged between the bottom of the support frame and the mesa of the bottom unbalanced field foundation; the side edge of the support frame is connected with the mesa of the bottom unbalanced field foundation through the installation of a Z-direction sliding rail pair to realize vertical sliding support connection;

[0022] The Z-direction electric actuator is fixedly connected with the mesa of the bottom unbalanced field foundation, and the actuating head of the Z-direction electric actuator can pass through the mesa of the bottom unbalanced field foundation and be connected with the bottom of the support frame;

[0023] The gas source is connected with the fifth gas storage tank through the gas outlet of the third electromagnetic valve, and the fifth gas storage tank is connected with the support air bag;

[0024] The signal output end of the control module is connected with the third electromagnetic valve.

[0025] The Z-direction sliding rail pair comprises:

[0026] The auxiliary support is fixedly connected with the mesa of the unbalanced field foundation;

[0027] The vertical sliding rail is fixedly connected with the auxiliary support;

[0028] The sliding block is in sliding cooperation with the vertical sliding rail.

[0029] The application further discloses a multi-degree-of-freedom vibration test device in an unbalanced field environment, which comprises a bottom unbalanced field foundation and a workbench located above the bottom unbalanced field foundation.

[0030] The workbench, an X-direction electric actuator and a Z-direction electric actuator, wherein the X-direction electric actuator and the Z-direction electric actuator are fixedly connected with the mesa of the bottom unbalanced field foundation; the bottom unbalanced field foundation can drive the workbench to realize an unbalanced field state; the X-direction electric actuator and the Z-direction electric actuator can drive the workbench to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superposed to generate a composite motion of unbalanced field and high-frequency vibration; a third air bag is arranged between the moving component in the X-direction actuator and the supporting rigid body, and the application further comprises:

[0031] The support frame is arranged below the workbench, the top of the support frame is connected with the bottom of the workbench through the installation of an X-direction sliding rail pair; a support air bag is arranged between the bottom of the support frame and the mesa of the bottom unbalanced field foundation; the side edge of the support frame is connected with the mesa of the bottom unbalanced field foundation through the installation of a Z-direction sliding rail pair to realize vertical sliding support connection;

[0032] The Z-direction electric actuator is fixedly connected with the mesa of the bottom unbalanced field foundation, and the actuating head of the Z-direction electric actuator can pass through the mesa of the bottom unbalanced field foundation and be connected with the bottom of the support frame;

[0033] The Z-direction slide rail pair and the X-direction slide rail pair can realize the independent movement of the workbench in the Z-direction and the X-direction;

[0034] The second counterforce frame is fixedly installed on one side of the bottom non-uniform field base relative to the X-direction electric actuator, and a fourth air bag coaxially arranged with the third air bag is arranged between the second counterforce frame and the workbench;

[0035] A position sensor is arranged to collect the real-time position of the workbench;

[0036] The gas source is connected with the fifth gas storage tank through the gas outlet of the third electromagnetic valve, and the fifth gas storage tank is connected with the support air bag;

[0037] The gas source is connected with the fifth gas storage tank through the gas outlet of the third electromagnetic valve, and the fifth gas storage tank is connected with the support air bag;

[0038] A control module is arranged, and a signal input end of the control module is connected with the position sensor, and a signal output end of the control module is connected with the second electromagnetic valve and the third electromagnetic valve.

[0039] The application further discloses a multi-degree-of-freedom vibration test device in a non-uniform field environment, which comprises a bottom non-uniform field base and a workbench located above the bottom non-uniform field base.

[0040] The Y-direction electric actuator and the Z-direction electric actuator are fixedly connected with the table top of the bottom non-uniform field base; the bottom non-uniform field base can drive the workbench to realize the non-uniform field state; the Y-direction electric actuator and the Z-direction electric actuator can drive the workbench to generate high-frequency vibration; the bottom non-uniform field base and the electric actuator are superposed to generate the composite motion of the non-uniform field and the high-frequency vibration; a first air bag is arranged between the moving component in the Y-direction actuator and the support rigid body, and the application further comprises:

[0041] A support frame is arranged below the workbench, the top of the support frame is connected with the bottom of the workbench through the installation of a Y-direction slide rail pair; a support air bag is arranged between the bottom of the support frame and the table top of the bottom non-uniform field base; the side edge of the support frame is connected with the table top of the bottom non-uniform field base through the installation of a Z-direction slide rail pair to realize the vertical sliding support connection;

[0042] The Z-direction electric actuator is fixedly connected with the table top of the bottom non-uniform field base, and the actuating head of the Z-direction electric actuator is connected with the bottom of the support frame after penetrating through the table top of the bottom non-uniform field base;

[0043] The Z-direction slide rail pair and the Y-direction slide rail pair can realize the independent movement of the workbench in the Z-direction and the Y-direction;

[0044] The bottom non-balance field base is fixedly installed with a first counterforce frame on one side of the Y-direction electric actuator, and a second air bag coaxially arranged with the first air bag is arranged between the first counterforce frame and the workbench surface.

[0045] A position sensor is arranged to collect the real-time position of the workbench surface.

[0046] A gas source is connected with the first air tank and the second air tank through two gas outlets of the first electromagnetic valve, the first air tank is connected with the first air bag, and the second air tank is connected with the second air bag.

[0047] The gas source is connected with the fifth air tank through a gas outlet of the third electromagnetic valve, and the fifth air tank is connected with the supporting air bag.

[0048] A control module is connected with the position sensor at a signal input end and connected with the first electromagnetic valve and the third electromagnetic valve at a signal output end.

[0049] The Z-direction slide rail pair comprises:

[0050] An auxiliary support is fixedly connected with the workbench surface of the non-balance field base.

[0051] A vertical slide rail is fixedly connected with the auxiliary support.

[0052] A sliding block is in sliding cooperation with the vertical slide rail.

[0053] The bottom non-balance field base is a swing table, a centrifugal platform or a rotary table.

[0054] The application further discloses a test method of the multi-degree-of-freedom vibration test device in the non-balance field environment, and the test method comprises the following steps:

[0055] S1, before the test starts, the workbench surface is at an original balanced position.

[0056] S2, after the test starts, the bottom non-balance field base drives the workbench surface to realize a non-balance field state; the X-direction electric actuator and the Y-direction electric actuator drive the workbench surface to generate high-frequency vibration; the bottom non-balance field base and the electric actuator are superposed to generate a composite motion of the non-balance field and the high-frequency vibration; when the bottom non-balance field base is at a frequency motion below 2.5 Hz, the workbench surface is centered only by the first air bag, the second air bag, the third air bag and the fourth air bag, and the centering specifically comprises the following sub-steps:

[0057] S21, in Y direction, if the position sensor detects that the workbench is eccentric to the Y direction electro-actuator, the position sensor feeds back the signal to the controller, the controller controls the first electro-magnetic valve to control the first gas tank to continuously charge and the second gas tank to continuously discharge, to realize the first air bag pressure continuously increasing and the second air bag pressure continuously decreasing, until the position sensor detects that the workbench returns to the original balance position;

[0058] S22, in Y direction, if the position sensor detects that the workbench is eccentric to the second air bag, the position sensor feeds back the signal to the controller, the controller controls the first electro-magnetic valve to control the first gas tank to continuously discharge and the second gas tank to continuously charge, to realize the first air bag pressure continuously decreasing and the second air bag pressure continuously increasing;

[0059] The X direction working process is consistent, and different working directions do not interfere with each other.

[0060] When the bottom unbalanced field foundation is in motion above 2.5 Hz frequency, the control speed of the electro-magnetic working valve cannot keep up, resulting in that the charging and discharging speed of the air bag cannot catch up with the change of the workbench, at this time, the moving coil of the X direction electro-actuator or the moving coil of the Y direction electro-actuator generates the acting force to assist the centering of the workbench.

[0061] Beneficial effects:

[0062] First, the multi-degree-of-freedom vibration test device in the unbalanced field environment of the application comprises a swing table, a multi-axial electro-actuator, a decoupling device and an automatic centering system. The multi-axial electro-actuator is installed on the swing table, when the swing table moves, the multi-axial electro-actuator will swing with the swing table, at this time, the workbench will generate vertical and tangential centrifugal forces. The vertical centrifugal force is offset by increasing the mechanical structure strength, and the tangential force is superimposed with the excitation force generated by the multi-axial electro-actuator. The application increases a gas tank between the gas source and the air bag, adjusts the stiffness of the air bag by changing the gas pressure of the gas tank, so that the air bag provides more or less support force, and realizes the centering of the workbench.

[0063] Second, the decoupling device of the application adopts a slide rail pair to realize the independent movement of the workbench in X, Y and Z directions, and the slide rail and the slide block can provide strong anti-overturning moment.

[0064] Third, the application reduces the height of the workbench, improves the anti-overturning moment of the table body, and increases the air bag recovery assembly to offset the gravity component generated when the swing table works. The foundation swing table can use gas centering to offset the influence of the tangential force below 2.5 Hz working frequency. Above 2.5 Hz, the variable stiffness support air bag design scheme or the electric centering + variable stiffness air bag control technology of gas centering is adopted to solve the influence of the tangential centrifugal force generated in the swing environment. BRIEF DESCRIPTION OF DRAWINGS

[0065] Fig. 1 is a structural layout of the vibration test device of the present application with two-axis arrangement of electric actuators in X and Z axes;

[0066] In the figure, 1. rocking table; 2. X-direction electric actuator; 3. wall plate; 4. connecting head; 5. Z-direction slider; 6. Z-direction guide rail; 7. workbench surface; 8. X-direction slider; 9. X-direction guide rail; 10. fourth air bag; 11. auxiliary support; 12. slider on Z-direction guide rail pair; 13. guide rail on Z-direction guide rail pair; 14. support frame; 15. Z-direction support air bag; 16. Z-direction electric actuator; 17. air pipe; 18. gas pipe; 19. gas storage tank; 20. gas source;

[0067] Fig. 2 is a structural layout of the vibration test device of the present application with two-axis arrangement of electric actuators in X and Z axes

[0068] In the figure, 21. second counterforce frame; 22. air chamber;

[0069] Fig. 3 is a structural layout of the vibration test device of the present application with two-axis arrangement of electric actuators in X and Y axes;

[0070] In the figure, 23. rocking table; 24. Y-direction electric actuator; 25. low wall plate; 26. Y-direction guide rail pair, first X-direction guide rail pair;

[0071] Fig. 4 is a force schematic diagram of the two-axis vibration table in rocking state;

[0072] In the figure, 27. first air bag; 28. moving coil; 29. second air bag;

[0073] Fig. 5 is a perspective view of the vibration test device of the present application with three-axis arrangement of electric actuators in X, Y and Z axes;

[0074] Fig. 6 is a schematic diagram of the internal structure of the electric actuator of the present application;

[0075] Fig. 7 is a schematic diagram of the air pair of the present application;

[0076] Fig. 8 is a schematic diagram of the lateral force of the air bag;

[0077] Fig. 9 is a schematic diagram of the structure of the air bag of the present application with an additional set of guide rail pairs. DETAILED DESCRIPTION

[0078] The technical solutions of the present application will be further described in detail below in combination with the drawings in the specification and specific embodiments.

[0079] Fig. 1 is a structural layout of the vibration test device of the present application with two-axis arrangement of electric actuators in X and Z axes;

[0080] Fig. 2 is a structural layout of the vibration test device of the present application with two-axis arrangement of electric actuators in X and Z axes

[0081] The difference between the two layouts is the height of the workbench surface. Under the same angular acceleration, the structure shown in Fig. 1 has a shorter rotation radius, so the tangential force acting on the workbench surface is smaller. Under the condition that the space of the swing table allows, the closer the workbench surface is to the far point of the swing table rotation, the more conducive to the normal work of the system. The structure shown in Fig. 2 has the advantage of easy installation, with the upper surface of the swing table as the installation surface.

[0082] Fig. 3 is a structural layout of the two-axis vibration test device of the present application under the swing field.

[0083] Example 1

[0084] As shown in Fig. 1, the swing table 1 has a hole for installing the electric actuator. The X-direction electric actuator 2 and the Z-direction electric actuator 16 are installed on the table body mounting plate through the wall plate 3 and the vertical table cylinder cover, respectively, and are mounted in cooperation with the reserved hole on the swing table 1 and fixed by screws.

[0085] To achieve the same vibration of the X-direction electric actuator and the Z-direction electric actuator, the workbench surface 7 uses a decoupling device composed of a Z-direction slider 5, a Z-direction guide rail 6, an X-direction slider 8, and an X-direction guide rail 9, which can realize the independent movement of the workbench surface 7 along the X-direction and the Z-direction, and the slide rail and the slider can provide strong anti-overturning moment.

[0086] The force generated by the electric actuator is transmitted to the X-direction and Y-direction decoupling devices through the connecting head 4 and the support frame 14, and then to the workbench surface 7.

[0087] In the vertical direction, i.e. the Z-direction, the support frame 14 is connected with the Z-direction support air bag 15, and the other end of the Z-direction support air bag 15 is installed on the top of the table body mounting plate, providing additional support force for the support frame 14, which is equivalent to providing additional support force for the workbench surface 7, to improve the carrying capacity of the workbench surface 7.

[0088] The Z-direction slider 12 on the Z-direction slide rail pair is installed around the support frame 14, and the guide rail 13 on the Z-direction slide rail pair is installed on the auxiliary support 11 through screws, preventing the lateral force generated by the workbench surface 7 and the test piece from being too large and damaging the Z-direction electric actuator.

[0089] The air pipe is fixed along the workbench surface 7 by a hoop or a single pipe clamp, or directly fixed to the ground from below the swing table.

[0090] A key technology is how to realize the centering of the workbench surface 7. As shown in Fig. 4, one way is to use electric centering + air centering, which can realize the centering of the table under unbalanced field. A key technology is how to realize the stable centering of the workbench surface. If the air source directly inflates the air bag and the air bag directly releases air, it is easy to cause the air bag to be over-inflated or over-deflated, resulting in repeated execution of the air centering program, but the table surface cannot be centered.

[0091] In this example, by adding a second gas tank 19 between the gas source 20 and the fourth air bag 10, the rigidity of the fourth air bag 10 can be adjusted by changing the volume of the second gas tank 19. By increasing the gas tank, the volume of the compressible gas increases when the air bag is connected to the gas tank at the same gas pressure. When the air bag is compressed, the rigidity of the air bag changes more gently, and the deformation of the air bag tends to be linear.

[0092] A second counterforce frame is fixedly installed on one side of the swing table 1 relative to the X-direction electric actuator, and a fourth air bag 10 is arranged between the second counterforce frame and the worktable surface 7.

[0093] The fourth air bag 10 is provided with a second exhaust port and a second air inlet, the second air inlet is connected with the fourth gas tank exhaust port through a second air pipe, and the air inlet of the fourth gas tank is connected with the gas source.

[0094] The air inlets of the third gas tank and the fourth gas tank use an electromagnetic valve, and the other port of the second air bag and the third air bag is directly plugged. When the electromagnetic valve is working, one air inlet of the electromagnetic valve charges the connected gas tank, and the other air inlet realizes the exhaust of the connected gas tank.

[0095] When the swing table 1 is in a high-frequency motion state, the charging and discharging speed of the fourth air bag cannot catch up with the change of the worktable surface 7. At this time, the centering is realized by electric centering. The realization method is that the position of the worktable surface 7 is fed back through the position sensor. When the position sensor detects that the worktable surface 7 is deviated to the actuator direction, a positive bias current is applied to the moving coil of the electric actuator, and vice versa.

[0096] Embodiment 2

[0097] The overall structure of the vibration test system composed of the double water platform shown in FIG. 3 is similar to that of FIG. 1. Two horizontal electric actuators are embedded on the swing table 1 by making low wall plates, and the decoupling device adopts the combination of Y-direction slide rail pair and first X-direction slide rail pair to realize independent movement in X and Y directions.

[0098] The structure of the air bag gas chamber adopted in FIG. 2 and FIG. 3 is essentially consistent with the air bag gas tank mode. Both the rigidity of the air bag can be changed, and the rigidity change of the air bag can be more gentle.

[0099] As shown in FIG. 6, it is a schematic diagram of the internal structure of the electric actuator of the application. The electric centering is to use the stable magnetic field formed by the excitation coil to apply a bias direct current to the moving coil, so that the moving coil moves upward or downward.

[0100] The application further discloses a test method of the multi-degree-of-freedom vibration test device in the unbalanced field environment, taking the structural layout of the vibration test device with the electric actuators arranged in the X axis and the Y axis as an example, and comprising the following steps:

[0101] S1, selection of the second air bag and the fourth air bag:

[0102] The maximum centrifugal force, the maximum tangential force and the maximum gravity component generated by the swing table 1 are calculated;

[0103] As shown in FIG. 4, when the swing table 1 is working, the two-axis electric actuators are equivalent to circular motion around a point,

[0104] Angular velocity

[0105] Angular acceleration

[0106] Wherein A is the maximum rotation angle, and f is the rotation frequency;

[0107] Maximum normal force F = Mω 2 r;

[0108] Maximum tangential force F = Mαr;

[0109] Wherein M is the mass of the moving part, r is the rotation radius,

[0110] Taking the swing table 1 Hz / 10° and 5 Hz / 1° as an example, the radius of the circular motion of the swing table 1 is assumed to be 2 m, and the sine motion is calculated, wherein ω = A·2πf, and a = A·(2πf) 2 Therefore, under the conditions of 5 Hz / 3°, 5 Hz / 1° and 1 Hz / 10°, the angular velocity and the angular acceleration are respectively:

[0111] 5 Hz / 1°:

[0112] 1 Hz / 10°:

[0113] At this time, the vertical acceleration is a n = ω 2 r, the tangential acceleration is a τ = ra, and the acting force of the system can be calculated according to the mass. The maximum inclination angle generated in the working process is θ, the maximum gravity component is F = Mg sin θ, and the maximum resultant force is equal to F 合 = Mar + Mg sin θ.

[0114] Then, according to the test conditions, the maximum centrifugal force, the maximum tangential force and the maximum gravity component generated by the swing table motion are calculated, and then the second air bag and the fourth air bag meeting the stiffness requirement are selected; Specifically: according to the maximum tangential force and the maximum gravity component, according to the air bag selection manual, the second air bag and the fourth air bag are selected under the condition of 0.5Mpa air pressure, the maximum supporting force is greater than 2 times the maximum tangential force and the maximum gravity component, and the corresponding gas tank volume is 2-3 times the volume of the air bag according to the volume of the second air bag and the fourth air bag.

[0115] For example: the volume of the air bag is 22L, the throttle area is 57mm 2 The damping is maximum. Ensure that the air pressure is between 0.6Mpa and 0.8Mpa, or other high-pressure gas source greater than the required air pressure by 0.5Mpa;

[0116] The acceleration of the vibration test is calculated according to Newton's second law a=F 有效 / m, because the air bag has a large lateral force, the thrust generated by the electric actuator needs to be subtracted from the lateral force of the air bag.

[0117] According to the mechanical design manual: the lateral stiffness calculation formula of multi-curved air bag is:

[0118]

[0119] Where h is the height of the curved rubber bag; h' is the height of the middle waist of the air bag, P is the vertical load of the air spring. F is the axial load, n is the number of air spring curves, T' is the bending stiffness, P' 1r Shear stiffness.

[0120] Because the air bag deforms, the maximum displacement of the electric actuator is X, and the maximum tangential force of the air bag is Then the effective force of the electric actuator is

[0121] S1, before the test starts, the workbench is in the original position;

[0122] S2, after the test starts, the swing table 1 can drive the workbench 7 to realize the non-equilibrium field state; the X-direction electric actuator and the Y-direction electric actuator can drive the workbench 7 to generate high-frequency vibration; the swing table 1 and the electric actuator superimpose to generate the composite motion of non-equilibrium field and high-frequency vibration; when the swing table 1 is in motion below 2.5Hz, only the first air bag 27, the second air bag 29, the third air bag and the fourth air bag 10 are used to center the workbench 7, which includes the following sub-steps:

[0123] S21, in Y direction, if the position sensor detects that the worktable is eccentric to the Y direction electro-actuator, the position sensor feeds back the signal to the controller, the controller controls the first electromagnetic valve to make the first gas tank continuously charge and the second gas tank continuously discharge, to realize the first air bag pressure continuously increasing and the second air bag pressure continuously decreasing, until the position sensor detects that the worktable returns to the original balance position;

[0124] S22, in Y direction, if the position sensor detects that the worktable is eccentric to the second air bag direction, the position sensor feeds back the signal to the controller, the controller controls the first electromagnetic valve to make the first gas tank continuously discharge and the second gas tank continuously charge, to realize the first air bag pressure continuously decreasing and the second air bag pressure continuously increasing;

[0125] The X direction working process is consistent, and different working directions do not interfere with each other.

[0126] When the swing table 1 is in motion above 2.5 Hz frequency, the control speed of the electromagnetic working valve cannot keep up, resulting in that the charging and discharging speed of the air bag cannot catch up with the change of the worktable 7, at this time, the moving coil of the X direction electro-actuator or the moving coil of the Y direction electro-actuator generates the acting force to assist the centering of the worktable 7.

Claims

1. A multi-degree-of-freedom vibration testing device in a non-uniform field environment, comprising a bottom non-uniform field base and, on the bottom non-uniform field base: a worktable (7), an X-direction electric actuator, and a Y-direction electric actuator, wherein, The X-direction electric actuator and the Y-direction electric actuator are fixed to the bottom non-uniform field base table respectively; The bottom non-uniform field base can drive the worktable (7) to realize the non-uniform field state; The X-direction electric actuator and the Y-direction electric actuator can drive the worktable (7) to generate high-frequency vibration; the bottom non-uniform field base and the electric actuator are superimposed to generate the non-uniform field and high-frequency vibration compound motion; A first air bag is arranged between the internal moving part of the Y-direction actuator and the supporting rigid body, and a third air bag is arranged between the internal moving part of the X-direction actuator and the supporting rigid body, characterized in that further comprising: A first counterforce frame is fixedly installed on one side of the bottom non-uniform field base relative to the Y-direction electric actuator, and a second air bag coaxially arranged with the first air bag is arranged between the first counterforce frame and the worktable (7); A second counterforce frame is fixedly installed on one side of the bottom non-uniform field base relative to the X-direction electric actuator, and a fourth air bag coaxially arranged with the third air bag is arranged between the second counterforce frame and the worktable (7); A two-dimensional decoupling mechanism is arranged to realize the independent movement of the worktable (7) along the X-direction and the Y-direction; A position sensor is arranged to collect the real-time position of the worktable (7); A gas source is connected with a first storage tank and a second storage tank through two gas outlets of a first electromagnetic valve, the first storage tank is connected with the first air bag, and the second storage tank is connected with the second air bag; The gas source is connected with a third storage tank and a fourth storage tank through two gas outlets of a second electromagnetic valve, the third storage tank is connected with the third air bag, and the fourth storage tank is connected with the fourth air bag; A control module is connected with the position sensor at a signal input end and connected with the first electromagnetic valve and the second electromagnetic valve at a signal output end.

2. The multi-degree-of-freedom vibration testing apparatus under non- balanced field environment according to claim 1, wherein, The two-dimensional decoupling mechanism comprises a Y-direction slide rail pair and a first X-direction slide rail pair arranged between the bottom of the worktable (7) and the table of the bottom non-uniform field base, wherein the Y-direction slide rail pair is fixedly connected with the table of the bottom non-uniform field base, the first X-direction slide rail pair is installed on a sliding block of the Y-direction slide rail pair, and a second X-direction slide rail pair is arranged between the side of the worktable (7) and the actuator head of the Y-direction electric actuator.

3. The multi-degree-of-freedom vibration testing apparatus under non- balanced field environment according to claim 2, wherein, A supporting frame is arranged below the worktable (7), the top of the supporting frame is supported and connected with the bottom of the worktable (7) by installing the Y-direction slide rail pair, the first X-direction slide rail pair and the worktable (7); A supporting air bag is arranged between the bottom of the supporting frame and the table of the bottom non-uniform field base; the side of the supporting frame is vertically slidably supported and connected with the table of the bottom non-uniform field base by installing a Z-direction slide rail pair; A Z-direction electric actuator is fixedly connected with the table of the bottom non-uniform field base, and the actuator head of the Z-direction electric actuator can pass through the table of the bottom non-uniform field base and be connected with the bottom of the supporting frame; The gas source is connected with a fifth storage tank through a gas outlet of a third electromagnetic valve, and the fifth storage tank is connected with the supporting air bag; The signal output end of the control module is connected with the third electromagnetic valve.

4. The multi-degree-of-freedom vibration testing apparatus under non- balanced field environment according to claim 3, wherein, The Z-direction slide rail pair comprises: An auxiliary supporting frame is fixedly connected with the table of the non-uniform field base; A vertical slide rail is fixedly connected with the auxiliary supporting frame; a slider, in sliding fit with the vertical slide rail.

5. The test method of the multi-degree-of-freedom vibration test apparatus in the non- balanced field environment according to claim 1, characterized by, The method comprises the following steps: S1, before the test starts, the workbench (7) is in the original balanced position; S2, after the test starts, the bottom unbalanced field foundation drives the workbench (7) to realize the unbalanced field state; the X-direction electric actuator and the Y-direction electric actuator drive the workbench (7) to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator superimpose to generate the composite motion of the unbalanced field and high-frequency vibration; when the bottom unbalanced field foundation is in the motion below 2.5 Hz, only the first air bag, the second air bag, the third air bag and the fourth air bag are used to center the workbench, and the centering specifically comprises the following sub-steps: S21, in the Y-direction, if the position sensor detects that the workbench is eccentric to the Y-direction electric actuator, the position sensor feeds back a signal to the controller, the controller controls the first electromagnetic valve to control the first air tank to continuously inflate and the second air tank to continuously deflate, so as to continuously increase the air pressure of the first air bag and continuously reduce the air pressure of the second air bag, until the position sensor detects that the workbench returns to the original balanced position; S22, in the Y-direction, if the position sensor detects that the workbench is eccentric to the second air bag, the position sensor feeds back a signal to the controller, the controller controls the first electromagnetic valve to control the first air tank to continuously deflate and the second air tank to continuously inflate, so as to continuously reduce the air pressure of the first air bag and continuously increase the air pressure of the second air bag; The X-direction working process is consistent, and different working directions do not interfere with each other.

6. The test method of the multi-degree-of-freedom vibration test apparatus in the non- balanced field environment according to claim 5, wherein When the bottom unbalanced field foundation is in the motion above 2.5 Hz, the control speed of the electromagnetic working valve cannot keep up with the change of the workbench, so the inflation and deflation speed of the air bag cannot keep up with the change of the workbench. At this time, the moving coil of the X-direction electric actuator or the moving coil of the Y-direction electric actuator generates a force to assist in centering the workbench.

7. A multi-degree-of-freedom vibration test device in an unbalanced field environment, comprising a bottom unbalanced field foundation and a workbench (7) located above the bottom unbalanced field foundation, wherein the X-direction electric actuator and the Z-direction electric actuator are respectively fixed to the table of the bottom unbalanced field foundation; the bottom unbalanced field foundation can drive the workbench (7) to realize an unbalanced field state; the X-direction electric actuator and the Z-direction electric actuator can drive the workbench (7) to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator superimpose to generate the composite motion of the unbalanced field and high-frequency vibration; a third air bag is arranged between the internal moving part of the X-direction actuator and the supporting rigid body, and the device further comprises: a worktable (7), an X-direction electric actuator, and a Z-direction electric actuator, wherein a support frame arranged below the workbench (7), wherein the top of the support frame is connected to the bottom of the workbench (7) through the installation of an X-direction slide rail pair; a support air bag is arranged between the bottom of the support frame and the table of the bottom unbalanced field foundation; the side edge of the support frame is connected to the table of the bottom unbalanced field foundation through the installation of a Z-direction slide rail pair to realize vertical sliding support connection; the Z-direction electric actuator is fixedly connected to the table of the bottom unbalanced field foundation, and the actuator head can pass through the table of the bottom unbalanced field foundation and be connected to the bottom of the support frame; ​ The Z-direction slide rail pair and the X-direction slide rail pair can realize the independent movement of the workbench surface (7) in the Z-direction and the X-direction; A second counterforce frame is fixedly installed on one side of the bottom non-uniform field base relative to the X-direction electric actuator, and a fourth air bag coaxially arranged with the third air bag is arranged between the second counterforce frame and the workbench surface (7); A position sensor is arranged to collect the real-time position of the workbench surface (7); An air source is connected with a third air tank and a fourth air tank through two air outlets of a second electromagnetic valve, the third air tank is connected with the third air bag, and the fourth air tank is connected with the fourth air bag; The air source is connected with a fifth air tank through an air outlet of a third electromagnetic valve, and the fifth air tank is connected with the support air bag; A control module is connected with the position sensor at a signal input end and connected with the second electromagnetic valve and the third electromagnetic valve at a signal output end.

8. A multi-degree-of-freedom vibration test device in a non-uniform field environment, comprising a bottom non-uniform field base and a workbench surface (7) located above the bottom non-uniform field base: a worktop (7), a Y-direction electric actuator, and a Z-direction electric actuator, wherein A Y-direction electric actuator and a Z-direction electric actuator are fixedly connected with the table surface of the bottom non-uniform field base; the bottom non-uniform field base can drive the workbench surface (7) to realize a non-uniform field state; the Y-direction electric actuator and the Z-direction electric actuator can drive the workbench surface (7) to generate high-frequency vibration; the bottom non-uniform field base and the electric actuator are superimposed to generate a composite motion of non-uniform field and high-frequency vibration; a first air bag is arranged between the internal moving part of the Y-direction actuator and the support rigid body, characterized in that it further comprises: A support frame is arranged below the workbench surface (7), the top of the support frame is supported and connected with the bottom of the workbench surface (7) through a Y-direction slide rail pair, and a support air bag is arranged between the bottom of the support frame and the table surface of the bottom non-uniform field base; the side edge of the support frame is vertically slidably connected with the table surface of the bottom non-uniform field base through a Z-direction slide rail pair; The Z-direction electric actuator is fixedly connected with the table surface of the bottom non-uniform field base, and the actuator head can be connected with the bottom of the support frame after penetrating through the table surface of the bottom non-uniform field base; The Z-direction slide rail pair and the Y-direction slide rail pair can realize the independent movement of the workbench surface (7) in the Z-direction and the Y-direction; A first counterforce frame is fixedly installed on one side of the bottom non-uniform field base relative to the Y-direction electric actuator, and a second air bag coaxially arranged with the first air bag is arranged between the first counterforce frame and the workbench surface (7); A position sensor is arranged to collect the real-time position of the workbench surface (7); An air source is connected with a first air tank and a second air tank through two air outlets of a first electromagnetic valve, the first air tank is connected with the first air bag, and the second air tank is connected with the second air bag; The air source is connected with a fifth air tank through an air outlet of a third electromagnetic valve, and the fifth air tank is connected with the support air bag; A control module is connected with the position sensor at a signal input end and connected with the first electromagnetic valve and the third electromagnetic valve at a signal output end.

9. The multi-degree-of-freedom vibration testing apparatus under non- balanced field environment according to claim 7 or 8, wherein, The Z-direction slide rail pair comprises: An auxiliary support frame is fixedly connected with the table surface of the non-uniform field base; A vertical slide rail is fixedly connected with the auxiliary support frame; A slider in sliding engagement with the vertical slide rail.

10. The multi-degree-of-freedom vibration testing apparatus under non- balanced field environment according to any one of claims 1 to 8, characterized by, The bottom non-uniform field base is a swing table, a non-uniform speed rotating centrifugal platform or a rotary table.

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