A multi-degree-of-freedom vibration test device and test method under non-equilibrium field environment

Abstract

The present invention discloses a multi-degree-of-freedom vibration test device and a test method thereof in an unbalanced field environment. The device comprises a bottom unbalanced field foundation, a multi-axial electric actuator, a decoupling device and an automatic centering system. The present invention adds an air tank between the air source and the airbag, changes the volume of the air tank to adjust the stiffness of the airbag, and enables the airbag to provide more preload force. When the rocking table is subjected to a tangential force, the greater the stiffness of the airbag, the smaller the offset of the table, and the normal operation of the multi-axial vibration test system in an unbalanced field environment can be achieved, while ensuring that the test waveform is smoother.

Description

Technical Field

[0001] The present invention belongs to the field of vibration testing, and specifically relates to a multi-degree-of-freedom vibration testing device and a testing method thereof in a non-equilibrium field environment.

[0002] For the testing of some aerospace equipment, it is often necessary to consider the vibration-swing compound environment. Although there are six-degree-of-freedom vibration test systems on the market, the hydraulic six-degree-of-freedom system has a large swing angle and 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 swing environment on the market.

[0003] Among the optical devices in aviation and aerospace test equipment, some special optical devices need to capture targets in motion, which requires not only a vibration test environment but also a swing test environment. Currently, there are few vibration test systems in the market under a swing field environment.

[0004] Design a multi-axial vibration test system in an unbalanced field, which combines the advantages of hydraulic table and electric table, and can achieve large displacement swing and high-frequency vibration at the same time. This equipment plays an important role in optical testing and other fields.

[0005] The multi-axial electric actuator is installed on the swing table. When the swing table moves, the multi-axial electric actuator will swing with the swing table, and the worktable will generate vertical and tangential centrifugal forces. The vertical centrifugal force is offset by improving the strength of the mechanical structure, and the tangential force is superimposed on the exciting force generated by the multi-axial electric actuator. Therefore, in the non-balanced field, the multi-axial vibration test bench needs to be specially designed. Summary of the invention

[0006] Technical purpose: In view of the above technical problems, the present invention proposes a multi-degree-of-freedom vibration test device in a non-balanced field environment, which can realize the normal operation of the multi-axial vibration test system in a non-balanced field environment, while ensuring that the test waveform is smoother.

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

[0008] A multi-degree-of-freedom vibration test device in an unbalanced field environment comprises a bottom unbalanced field foundation and a work table, an X-direction electric actuator and a Y-direction electric actuator located on the bottom unbalanced field foundation, wherein the X-direction electric actuator and the Y-direction electric actuator are respectively fixed to the table of the bottom unbalanced field foundation;

[0009] The bottom non-balanced field foundation can drive the work surface to achieve a non-balanced field state;

[0010] The X-axis electric actuator and the Y-axis electric actuator can drive the work surface to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; a first airbag is provided between the moving part inside the Y-axis actuator and the supporting rigid body, and a third airbag is provided between the moving part inside the X-axis actuator and the supporting rigid body, and further includes:

[0011] A first reaction frame is fixedly mounted on the bottom unbalanced field base on one side of the Y-axis electric actuator, and a second airbag coaxially arranged with the first airbag is arranged between the first reaction frame and the work surface;

[0012] A second reaction frame is fixedly mounted on the bottom unbalanced field base on one side of the X-axis electric actuator, and a fourth airbag coaxially arranged with the third airbag is arranged between the second reaction frame and the work surface;

[0013] A two-dimensional decoupling mechanism for realizing independent movement of the worktable in the X and Y directions;

[0014] Position sensor, used to collect the real-time position of the work surface;

[0015] The first gas storage tank and the second gas storage tank are respectively connected through two gas outlets of the first solenoid valve, the first gas storage tank is connected to the first air bag, and the second gas storage tank is connected to the second air bag;

[0016] The third gas tank and the fourth gas tank are connected respectively through the two gas outlets of the second solenoid valve, the third gas tank is connected to the third air bag, and the fourth gas tank is connected to the fourth air bag;

[0017] A control module has a signal input end connected to the position sensor, and a signal output end connected to the first solenoid valve and the second solenoid valve.

[0018] 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 working table and the table of the bottom unbalanced field foundation, wherein the Y-direction slide rail pair is fixedly connected to the table of the bottom unbalanced field foundation, the first X-direction slide rail pair is installed on the slider of the Y-direction slide rail pair, and,

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

[0020] It also includes a support frame, which is arranged below the work surface, and the top of the support frame is connected to the bottom support of the work surface by installing the Y-direction slide rail pair and the first X-direction slide rail pair;

[0021] A supporting air bag is arranged between the bottom of the supporting frame and the table top of the bottom unbalanced field foundation; the side of the supporting frame is connected with the table top of the bottom unbalanced field foundation by installing a Z-direction slide rail pair to realize vertical sliding support;

[0022] A Z-direction electric actuator is fixedly connected to the table of the bottom unbalanced field foundation, and its actuator head can pass through the table of the bottom unbalanced field foundation and then be connected to the bottom of the support frame;

[0023] The gas source is connected to a fifth gas storage tank through a gas outlet of a third solenoid valve, and the fifth gas storage tank is connected to the supporting airbag;

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

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

[0026] An auxiliary bracket, fixedly connected to the table top of the non-balanced field foundation;

[0027] A vertical slide rail, fixedly connected to the auxiliary bracket;

[0028] The sliding block is slidably matched with the vertical sliding rail.

[0029] The present invention further discloses a multi-degree-of-freedom vibration test device in an unbalanced field environment, comprising a bottom unbalanced field foundation and a device located on the bottom unbalanced field foundation:

[0030] A work surface, an X-axis electric actuator and a Z-axis electric actuator, wherein the X-axis electric actuator and the Z-axis electric actuator are respectively fixed to the surface of the bottom unbalanced field foundation; the bottom unbalanced field foundation can drive the work surface to achieve an unbalanced field state; the X-axis electric actuator and the Z-axis electric actuator can drive the work surface to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; a third airbag is provided between the moving parts inside the X-axis actuator and the supporting rigid body, and also includes:

[0031] A support frame is arranged below the work surface, the top of the support frame is connected to the bottom support of the work surface by installing an X-direction slide rail pair; a support airbag is arranged between the bottom of the support frame and the table of the bottom unbalanced field foundation; the side of the support frame is connected to the table of the bottom unbalanced field foundation by installing a Z-direction slide rail pair to realize vertical sliding support connection;

[0032] The Z-direction electric actuator is fixedly connected to the table surface of the bottom unbalanced field foundation, and its actuator head can pass through the table surface of the bottom unbalanced field foundation and then be connected to 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 worktable in the Z-direction and the X-direction;

[0034] A second reaction frame is fixedly mounted on the bottom unbalanced field base on one side of the X-axis electric actuator, and a fourth airbag coaxially arranged with the third airbag is arranged between the second reaction frame and the work surface;

[0035] Position sensor, used to collect the real-time position of the work surface;

[0036] The air source is connected to the third air tank and the fourth air tank through the two air outlets of the second solenoid valve, the third air tank is connected to the third air bag, and the fourth air tank is connected to the fourth air bag;

[0037] The gas source is connected to a fifth gas storage tank through a gas outlet of a third solenoid valve, and the fifth gas storage tank is connected to the supporting airbag;

[0038] A control module has a signal input end connected to the position sensor, and a signal output end connected to the second solenoid valve and the third solenoid valve.

[0039] The present invention further discloses a multi-degree-of-freedom vibration test device in an unbalanced field environment, comprising a bottom unbalanced field foundation and a device located on the bottom unbalanced field foundation:

[0040] A work surface, a Y-axis electric actuator and a Z-axis electric actuator, wherein the Y-axis electric actuator and the Z-axis electric actuator are respectively fixed to the surface of the bottom unbalanced field foundation; the bottom unbalanced field foundation can drive the work surface to achieve an unbalanced field state; the Y-axis electric actuator and the Z-axis electric actuator can drive the work surface to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; a first airbag is provided between the moving part inside the Y-axis actuator and the supporting rigid body, and also includes:

[0041] A support frame is arranged below the work surface, the top of the support frame is connected to the bottom support of the work surface by installing a Y-direction slide rail pair; a support airbag is arranged between the bottom of the support frame and the table of the bottom unbalanced field foundation; the side of the support frame is connected to the table of the bottom unbalanced field foundation by installing a Z-direction slide rail pair to realize vertical sliding support connection;

[0042] The Z-direction electric actuator is fixedly connected to the table surface of the bottom unbalanced field foundation, and its actuator head can pass through the table surface of the bottom unbalanced field foundation and then be connected to the bottom of the support frame;

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

[0044] A first reaction frame is fixedly mounted on the bottom unbalanced field base on one side of the Y-axis electric actuator, and a second airbag coaxially arranged with the first airbag is arranged between the first reaction frame and the work surface;

[0045] Position sensor, used to collect the real-time position of the work surface;

[0046] An air source, which is connected to a first air tank and a second air tank respectively through two air outlets of a first solenoid valve, the first air tank is connected to the first air bag, and the second air tank is connected to the second air bag;

[0047] The gas source is connected to a fifth gas storage tank through a gas outlet of a third solenoid valve, and the fifth gas storage tank is connected to the supporting airbag;

[0048] A control module, wherein a signal input end thereof is connected to the position sensor, and a signal output end thereof is connected to the first solenoid valve control and the third solenoid valve.

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

[0050] An auxiliary bracket, fixedly connected to the table top of the non-balanced field foundation;

[0051] A vertical slide rail, fixedly connected to the auxiliary bracket;

[0052] The sliding block is slidably matched with the vertical sliding rail.

[0053] The bottom non-balanced field foundation is a rocking table, a centrifugal platform or a turntable rotating at a non-uniform speed.

[0054] The present invention further discloses a test method of the multi-degree-of-freedom vibration test device in a non-equilibrium field environment, comprising the following steps:

[0055] S1. Before the test begins, the work surface is in the original equilibrium position;

[0056] S2. After the test starts, the bottom unbalanced field foundation drives the work surface to realize an unbalanced field state; the X-axis electric actuator and the Y-axis electric actuator drive the work surface to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; when the bottom unbalanced field foundation is in a frequency motion below 2.5 Hz, the work surface is centered only by the first airbag, the second airbag, the third airbag and the fourth airbag, specifically including the following sub-steps:

[0057] S21, in the Y direction, if the position sensor detects that the work surface is eccentric toward the Y-direction electric actuator, the position sensor feeds back a signal to the controller, and the controller controls the first air tank to continuously inflate and the second air tank to continuously deflate through the first solenoid valve, so that the air pressure of the first air bag continuously increases and the air pressure of the second air bag continuously decreases, until the position sensor detects that the work surface returns to the original equilibrium position;

[0058] S22, in the Y direction, if the position sensor detects that the work surface is eccentric toward the second airbag, the position sensor feeds back a signal to the controller, and the controller controls the first air tank to continuously deflate and the second air tank to continuously inflate through the first solenoid valve, so that the air pressure of the first airbag is continuously reduced and the air pressure of the second airbag is continuously increased;

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

[0060] When the bottom unbalanced field foundation moves at a frequency above 2.5Hz, the control speed of the electromagnetic working valve cannot keep up, resulting in the inflation and deflation speed of the airbag failing to keep up with the changes in the work surface. At this time, the moving coil of the X-axis electric actuator or the moving coil of the Y-axis electric actuator generates a force to assist in centering the work surface.

[0061] Beneficial effects:

[0062] First, the multi-degree-of-freedom vibration test device in a non-equilibrium field environment of the present invention includes a rocking table, a multi-axial electric actuator, a decoupling device and an automatic centering system. The multi-axial electric actuator is installed on the rocking table. When the rocking table moves, the multi-axial electric actuator will rock with the rocking table. At this time, the work surface will generate vertical and tangential centrifugal forces. The vertical centrifugal force offsets its influence by improving the strength of the mechanical structure, and the tangential force will be superimposed on the exciting force generated by the multi-axial electric actuator. The present invention adds an air tank between the air source and the airbag, and adjusts the stiffness of the airbag by changing the air pressure in the air tank, so that the airbag provides more or less support force, thereby realizing the centering of the work surface.

[0063] Second, the decoupling device of the present invention adopts a slide rail pair to realize the independent movement of the work surface in the three directions of X, Y and Z, and the slide rail and the slider can provide a strong anti-overturning moment.

[0064] Third, the present invention reduces the height of the work surface, increases the anti-overturning moment of the platform, and adds an airbag recovery component to offset the gravity component generated when the swing platform is working. The basic swing platform can use air centering to offset the influence of tangential force when the working frequency is below 2.5Hz. Above 2.5Hz, a variable stiffness support airbag design solution or a variable stiffness airbag control technology of electric centering + air centering is required to solve the influence of tangential centrifugal force generated by the swing environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 The structural layout 1 of the vibration test device of the present invention in which electric actuators are arranged on the X-axis and the Z-axis;

[0066] In the figure, 1. swing table; 2. X-axis electric actuator; 3. wall panel; 4. connector; 5. Z-axis slider; 6. Z-axis guide rail; 7. work surface; 8. X-axis slider, 9. X-axis guide rail, 10. fourth air bag, 11. auxiliary bracket, 12. slider on Z-axis slide rail pair, 13. guide rail on Z-axis slide rail pair, 14. support frame, 15. Z-axis support air bag, 16. Z-axis electric actuator, 17. air duct, 18. air pipe, 19. air storage tank, 20. air source;

[0067] Figure 2 The structural layout of the vibration test device of the present invention in which the electric actuators are arranged on the X-axis and the Z-axis

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

[0069] Figure 3 The structural layout of the vibration test device of the present invention in which electric actuators are arranged on both the X-axis and the Y-axis;

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

[0071] Figure 4 It is a schematic diagram of the forces on the two axial vibration tables in the swing state;

[0072] Among them, 27. first airbag; 28. dynamic coil, 29. second airbag;

[0073] Figure 5 A three-dimensional diagram of a vibration test device of the present invention in which electric actuators are arranged on three axes, namely, the X-axis, the Y-axis and the Z-axis;

[0074] Figure 6 It is a schematic diagram of the internal structure of the electric actuator of the present invention;

[0075] Figure 7 This is a schematic diagram of the gas centering of the present invention;

[0076] Figure 8 It is a schematic diagram of the lateral force of the airbag;

[0077] Fig. 9 A schematic diagram of the structure of an airbag of the present invention with an additional set of slide rail pairs. DETAILED DESCRIPTION

[0078] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0079] Figure 1 The structural layout 1 of the X-axis and Z-axis two-axis vibration test device under the swing field of the present invention;

[0080] Figure 2 The structural layout 2 of the X-axis and Z-axis two-axis vibration test device under the swing field of the present invention;

[0081] The difference between the two layouts is the height of the work surface. Under the same angular acceleration conditions, due to Figure 1 The structure shown has a shorter rotation radius, so the tangential force on the work surface is smaller. Under the condition that the space of the swing table allows, the closer the work surface is to the farthest point of rotation of the swing table, the more conducive it is to the normal operation of the system. Figure 2 The structure shown uses the upper surface of the swing table as the mounting surface, which has the advantage of easy installation.

[0082] Figure 3 The present invention discloses a structural layout of an X-axis and Y-axis two-axis vibration test device under a swing field.

[0083] Example 1

[0084] like Figure 1 As shown, holes for installing electric actuators are opened on the swing table 1, and the X-axis electric actuator 2 and the Z-axis electric actuator 16 are respectively installed on the table body mounting plate through the wall panel 3 and the vertical table cylinder cover. The table body mounting plate is installed in conjunction with the holes reserved on the swing table 1 and fixed by screws.

[0085] In order to achieve the synchronous vibration of the X-axis electric actuator and the Z-axis electric actuator, the work table 7 adopts a decoupling device composed of a Z-axis slider 5, a Z-axis guide rail 6, an X-axis slider 8 and an X-axis guide rail 9, which can realize the independent movement of the work table 7 along the X-axis and Z-axis. At the same time, the slide rail and the slider can provide a strong anti-overturning torque.

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

[0087] In the vertical direction, i.e., the Z direction, the support frame 14 is connected to the Z direction support airbag 15, and the other end of the Z direction support airbag 15 is installed on the table mounting plate to provide additional support force for the support frame 14, which is equivalent to providing additional support force for the work surface 7 to increase the load-bearing capacity of the work surface 7.

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

[0089] The air duct is fixed along the work surface 7 by a clamp or a corresponding clamp, or is directly fixed to the ground from below the swing platform.

[0090] A key technology is how to achieve the centering of the work surface 7. Figure 4 As shown in the figure, one way is to use electric centering + air centering to achieve the centering of the table in an unbalanced field. A key technology is how to achieve stable centering of the work table. If the air source directly inflates the airbag, and the airbag directly deflates to the outside, it is easy to cause the airbag to be over-inflated or over-discharged, resulting in repeated execution of the air centering procedure, but the table cannot be centered.

[0091] In this example, a second gas tank 19 is added between the gas source 20 and the fourth gas bag 10, and the stiffness of the fourth gas bag 10 can be adjusted by changing the volume of the second gas tank 19. By adding a gas tank, under the same gas pressure, since the gas bag is connected to the gas tank, the volume of the compressible gas increases, and when the gas bag is compressed, the stiffness of the gas bag changes more slowly, and the deformation of the gas bag tends to change more linearly.

[0092] A second reaction frame is fixedly mounted on the swing table 1 on one side opposite to the X-axis electric actuator, and a fourth air bag 10 is provided between the second reaction frame and the work 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 to the air outlet of the fourth air storage tank through a second air pipe, and the air inlet of the fourth air storage tank is connected to the air source;

[0094] The air inlet of the third gas tank and the air inlet of the fourth gas tank use a solenoid valve, and the other ports of the second air bag and the third air bag are directly blocked. When the solenoid valve is working, one air inlet of the solenoid valve inflates the connected gas tank, and the other air inlet deflates the connected gas tank.

[0095] When the rocking platform 1 is in a high-frequency motion state, the inflation and deflation speed of the fourth airbag cannot keep up with the changes of the work surface 7. At this time, the centering is achieved through electrical centering. The method for achieving this is that the position of the work surface 7 is fed back through a position sensor. When the position sensor measures that the position of the work surface 7 is biased toward the actuator direction, a positive bias current is applied to the moving coil of the electric actuator. Otherwise, a negative bias current is applied to the moving coil of the electric actuator.

[0096] Example 2

[0097] Figure 3 The overall structure of the vibration test system composed of the double water platforms shown in the figure is Figure 1 Similarly, two horizontal electric actuators are embedded on the swing table 1 by making a low wall plate, and the decoupling device adopts a combination of a Y-direction slide rail pair and a first X-direction slide rail pair to achieve separate movements in the X and Y directions;

[0098] Figure 2 and Figure 3 The structure of the airbag plus air chamber is essentially the same as the airbag plus air tank, which can change the stiffness of the airbag and make the change of the stiffness of the airbag more gradual.

[0099] like Figure 6 As shown, it is a schematic diagram of the internal structure of the electric actuator of the present invention. The electric centering is to use the stable magnetic field formed by the excitation coil to apply bias direct current to the moving coil to make the moving coil move upward or downward.

[0100] The present invention further discloses a test method for the multi-degree-of-freedom vibration test device under the non-equilibrium field environment, taking the structural layout of the vibration test device in which electric actuators are arranged on the X-axis and the Y-axis as an example, the method comprises the following steps:

[0101] S1, Selection of the second and fourth airbags:

[0102] Calculate the maximum centrifugal force, maximum tangential force and maximum gravitational force component generated by the movement of the rocking table 1;

[0103] like Figure 4 As shown, when the swing table 1 is working, the two axial electric actuators are equivalent to making circular motion around a certain point.

[0104] Angular velocity ;

[0105] Angular acceleration ;

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

[0107] Maximum normal force ;

[0108] Maximum tangential force ;

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

[0110] Calculate with 1Hz / 10° and 5Hz / 1° of the swing table, assuming that the radius of the circular motion of the swing table 1 is 2m, and calculate with sinusoidal motion, where , , then at 5Hz / 3°, 5Hz / 1° and 1Hz / 10°, the angular velocity and angular acceleration are:

[0111] 5Hz / 1°: , ;

[0112] 1Hz / 10°: , ;

[0113] The vertical acceleration at this time is , the tangential acceleration is , and then the force on the system can be calculated based on the mass. The maximum inclination angle generated during the working process is , then the maximum gravity component The maximum resultant force is equal to .

[0114] Then, according to the test conditions, the maximum centrifugal force, maximum tangential force and maximum gravity component force generated by the swing table movement are calculated, and then the second and fourth airbags that meet the stiffness requirements are selected; specifically, according to the resultant force of the maximum tangential force and the maximum gravity component force, according to the airbag selection manual, the second and fourth airbags whose maximum support force is greater than 2 times the resultant force of the maximum tangential force and the maximum gravity component force under the air pressure of 0.5Mpa are selected, and according to the volume of the second and fourth airbags, the corresponding air tank volume is selected to be 2~3 times that of the airbag;

[0115] For example: For an airbag with a volume of 22L, the throttling area The damping is maximum. Ensure that the air source pressure is between 0.6Mpa and 0.8Mpa, or other high-pressure air sources that are 0.5Mpa higher than the required air pressure;

[0116] The acceleration of the vibration test is calculated according to Newton's second law: Since the airbag has a large tangential force, the thrust generated by the electric actuator needs to be reduced by the lateral force of the airbag.

[0117] According to the Mechanical Design Manual: The calculation formula for the lateral stiffness of a multi-curved airbag is:

[0118] ,

[0119] Where, h is the height of a curved rubber bag; is the height of the middle ring waist of the airbag, P is the vertical load on the air spring. F is the axial load, n is the number of air spring bends, Bending stiffness, Shear stiffness.

[0120] Due to the deformation of the airbag, the maximum displacement of the electric actuator is X, and the maximum tangential force of the airbag is , then the effective force of the electric actuator is ;

[0121] S1. Before the test begins, the work surface is in its original position;

[0122] S2. After the test starts, the rocking table 1 can drive the work surface 7 to achieve an unbalanced field state; the X-axis electric actuator and the Y-axis electric actuator can drive the work surface 7 to generate high-frequency vibration; the rocking table 1 and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; when the rocking table 1 is in motion at a frequency below 2.5 Hz, the work surface 7 is centered only by the first airbag 27, the second airbag 29, the third airbag and the fourth airbag 10, which specifically includes the following sub-steps:

[0123] S21, in the Y direction, if the position sensor detects that the work surface is eccentric toward the Y-direction electric actuator, the position sensor feeds back a signal to the controller, and the controller controls the first air tank to continuously inflate and the second air tank to continuously deflate through the first solenoid valve, so that the air pressure of the first air bag continuously increases and the air pressure of the second air bag continuously decreases, until the position sensor detects that the work surface returns to the original equilibrium position;

[0124] S22, in the Y direction, if the position sensor detects that the work surface is eccentric toward the second airbag, the position sensor feeds back a signal to the controller, and the controller controls the first air tank to continuously deflate and the second air tank to continuously inflate through the first solenoid valve, so that the air pressure of the first airbag is continuously reduced and the air pressure of the second airbag is continuously increased;

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

[0126] When the rocking table 1 moves at a frequency above 2.5 Hz, the control speed of the electromagnetic working valve cannot keep up, resulting in the inflation and deflation speeds of the airbag failing to keep up with the changes in the work surface 7. At this time, the moving coil of the X-axis electric actuator or the moving coil of the Y-axis electric actuator generates a force to assist in centering the work surface 7.

Claims

1. A multi-degree-of-freedom vibration test device in an unbalanced field environment, comprising a bottom unbalanced field foundation and located on the bottom unbalanced field foundation: a work table (7), an X-direction electric actuator and a Y-direction electric actuator, wherein: The X-axis electric actuator and the Y-axis electric actuator are respectively fixed to the table surface of the bottom non-balanced field foundation; The bottom non-balanced field foundation can drive the work surface (7) to achieve a non-balanced field state; The X-axis electric actuator and the Y-axis electric actuator can drive the work surface (7) to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; A first airbag is provided between the internal moving part of the Y-axis actuator and the supporting rigid body, and a third airbag is provided between the internal moving part of the X-axis actuator and the supporting rigid body, characterized in that it also includes: A first reaction frame is fixedly mounted on the bottom unbalanced field base on one side of the Y-axis electric actuator, and a second airbag coaxially arranged with the first airbag is arranged between the first reaction frame and the work surface (7); A second reaction frame is fixedly mounted on the bottom unbalanced field base on one side of the X-axis electric actuator, and a fourth airbag coaxially arranged with the third airbag is provided between the second reaction frame and the work surface (7); A two-dimensional decoupling mechanism, used to realize the independent movement of the worktable (7) along the X direction and the Y direction; A position sensor for collecting the real-time position of the work surface (7); An air source, which is connected to a first air tank and a second air tank respectively through two air outlets of a first solenoid valve, the first air tank is connected to the first air bag, and the second air tank is connected to the second air bag; The air source is connected to the third air tank and the fourth air tank respectively through the two air outlets of the second solenoid valve, the third air tank is connected to the third air bag, and the fourth air tank is connected to the fourth air bag; A control module has a signal input end connected to the position sensor, and a signal output end connected to the first solenoid valve and the second solenoid valve.

2. The multi-degree-of-freedom vibration test device under non-equilibrium field environment according to claim 1, characterized in that: 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 a working table (7) and the table of a bottom unbalanced field foundation, wherein the Y-direction slide rail pair is fixedly connected to the table of the bottom unbalanced field foundation, the first X-direction slide rail pair is installed on a slider of the Y-direction slide rail pair, and a second X-direction slide rail pair is arranged between a side of the working table (7) and an actuating head of a Y-direction electric actuator.

3. The multi-degree-of-freedom vibration test device under non-equilibrium field environment according to claim 2, characterized in that: It also includes a support frame, which is arranged below the work surface (7), and the top of the support frame is connected to the bottom support of the work surface (7) by installing the Y-direction slide rail pair and the first X-direction slide rail pair; A supporting air bag is arranged between the bottom of the supporting frame and the table top of the bottom unbalanced field foundation; the side of the supporting frame is connected with the table top of the bottom unbalanced field foundation by installing a Z-direction slide rail pair to realize vertical sliding support; A Z-direction electric actuator is fixedly connected to the table of the bottom unbalanced field foundation, and its actuator head can pass through the table of the bottom unbalanced field foundation and then be connected to the bottom of the support frame; The gas source is connected to a fifth gas storage tank through a gas outlet of a third solenoid valve, and the fifth gas storage tank is connected to the supporting airbag; The signal output end of the control module is connected to the third solenoid valve.

4. The multi-degree-of-freedom vibration test device under non-equilibrium field environment according to claim 3, characterized in that: The Z-direction slide rail pair comprises: An auxiliary bracket, fixedly connected to the table top of the non-balanced field foundation; A vertical slide rail, fixedly connected to the auxiliary bracket; The sliding block is slidably matched with the vertical sliding rail.

5. The test method of the multi-degree-of-freedom vibration test device under the non-equilibrium field environment according to claim 1, characterized in that: The following steps are involved: S1. Before the test begins, the work surface (7) is in its original equilibrium position; S2. After the test starts, the bottom unbalanced field foundation drives the work surface (7) to achieve an unbalanced field state; the X-axis electric actuator and the Y-axis electric actuator drive the work surface (7) to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; when the bottom unbalanced field foundation is in motion at a frequency below 2.5 Hz, the work surface is centered only by the first airbag, the second airbag, the third airbag and the fourth airbag, specifically including the following sub-steps: S21, in the Y direction, if the position sensor detects that the work surface is eccentric toward the Y-direction electric actuator, the position sensor feeds back a signal to the controller, and the controller controls the first air tank to continuously inflate and the second air tank to continuously deflate through the first solenoid valve, so that the air pressure of the first air bag continuously increases and the air pressure of the second air bag continuously decreases, until the position sensor detects that the work surface returns to the original equilibrium position; S22, in the Y direction, if the position sensor detects that the work surface is eccentric toward the second airbag, the position sensor feeds back a signal to the controller, and the controller controls the first air tank to continuously deflate and the second air tank to continuously inflate through the first solenoid valve, so that the air pressure of the first airbag is continuously reduced and the air pressure of the second airbag is continuously increased; The working process in the X direction is consistent, and different working directions do not interfere with each other.

6. The test method of the multi-degree-of-freedom vibration test device under the non-equilibrium field environment according to claim 5, characterized in that: When the bottom unbalanced field foundation moves at a frequency above 2.5Hz, the control speed of the electromagnetic working valve cannot keep up, resulting in the inflation and deflation speed of the airbag failing to keep up with the changes in the work surface. At this time, the moving coil of the X-axis electric actuator or the moving coil of the Y-axis electric actuator generates a force to assist in centering the work surface.

7. A multi-degree-of-freedom vibration test device in an unbalanced field environment, comprising a bottom unbalanced field foundation and located on the bottom unbalanced field foundation: A worktable (7), an X-axis electric actuator and a Z-axis electric actuator, wherein: The X-direction electric actuator and the Z-direction electric actuator are respectively fixed to the table top of the bottom unbalanced field foundation; the bottom unbalanced field foundation can drive the working table top (7) to achieve an unbalanced field state; the X-direction electric actuator and the Z-direction electric actuator can drive the working table top (7) to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; a third air bag is provided between the internal moving part of the X-direction actuator and the supporting rigid body, characterized in that it also includes: A support frame is arranged below the work surface (7); the top of the support frame is connected to the bottom support of the work surface (7) by installing an X-direction slide rail pair; a support airbag is arranged between the bottom of the support frame and the surface of the bottom unbalanced field foundation; and the side of the support frame is connected to the surface of the bottom unbalanced field foundation in a vertical sliding support manner by installing a Z-direction slide rail pair; The Z-direction electric actuator is fixedly connected to the table surface of the bottom unbalanced field foundation, and its actuator head can pass through the table surface of the bottom unbalanced field foundation and then be connected to the bottom of the support frame; The Z-direction slide rail pair and the X-direction slide rail pair are capable of realizing independent movement of the work surface (7) in the Z-direction and the X-direction; A second reaction frame is fixedly mounted on the bottom unbalanced field base on one side of the X-axis electric actuator, and a fourth airbag coaxially arranged with the third airbag is provided between the second reaction frame and the work surface (7); A position sensor for collecting the real-time position of the work surface (7); The air source is connected to the third air tank and the fourth air tank through the two air outlets of the second solenoid valve, the third air tank is connected to the third air bag, and the fourth air tank is connected to the fourth air bag; The air source is connected to the fifth air storage tank through the air outlet of the third solenoid valve, and the fifth air storage tank is connected to the supporting airbag; A control module has a signal input end connected to the position sensor, and a signal output end connected to the second solenoid valve and the third solenoid valve.

8. A multi-degree-of-freedom vibration test device in an unbalanced field environment, comprising a bottom unbalanced field foundation and a device located on the bottom unbalanced field foundation: A worktable (7), a Y-axis electric actuator and a Z-axis electric actuator, wherein: The Y-direction electric actuator and the Z-direction electric actuator are respectively fixed to the table top of the bottom unbalanced field foundation; the bottom unbalanced field foundation can drive the working table top (7) to achieve an unbalanced field state; the Y-direction electric actuator and the Z-direction electric actuator can drive the working table top (7) to generate high-frequency vibration; the bottom unbalanced field foundation and the electric actuator are superimposed to generate a composite motion of unbalanced field and high-frequency vibration; a first air bag is provided between the internal moving part of the Y-direction actuator and the supporting rigid body, characterized in that it also includes: A support frame is arranged below the work surface (7); the top of the support frame is connected to the bottom support of the work surface (7) by installing a Y-direction slide rail pair; a support airbag is arranged between the bottom of the support frame and the surface of the bottom unbalanced field foundation; and the side of the support frame is connected to the surface of the bottom unbalanced field foundation in a vertical sliding support manner by installing a Z-direction slide rail pair; The Z-direction electric actuator is fixedly connected to the table surface of the bottom unbalanced field foundation, and its actuator head can pass through the table surface of the bottom unbalanced field foundation and then be connected to the bottom of the support frame; The Z-direction slide rail pair and the Y-direction slide rail pair are capable of realizing independent movement of the work surface (7) in the Z-direction and the Y-direction; A first reaction frame is fixedly mounted on the bottom unbalanced field base on one side of the Y-axis electric actuator, and a second airbag coaxially arranged with the first airbag is arranged between the first reaction frame and the work surface (7); A position sensor for collecting the real-time position of the work surface (7); An air source, which is connected to a first air tank and a second air tank respectively through two air outlets of a first solenoid valve, the first air tank is connected to the first air bag, and the second air tank is connected to the second air bag; The air source is connected to the fifth air storage tank through the air outlet of the third solenoid valve, and the fifth air storage tank is connected to the supporting airbag; A control module, wherein a signal input end thereof is connected to the position sensor, and a signal output end thereof is connected to the first solenoid valve control and the third solenoid valve.

9. The multi-degree-of-freedom vibration test device in a non-equilibrium field environment according to claim 7 or 8, characterized in that: The Z-direction slide rail pair comprises: An auxiliary bracket, fixedly connected to the table top of the non-balanced field foundation; A vertical slide rail, fixedly connected to the auxiliary bracket; The sliding block is slidably matched with the vertical sliding rail.

10. The multi-degree-of-freedom vibration test device under a non-equilibrium field environment according to any one of claims 1 to 8, characterized in that: The bottom non-balanced field foundation is a rocking table, a centrifugal platform or a turntable rotating at a non-uniform speed.

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