A design method of ground equivalent test piece for simulating mass characteristics of micro spacecraft

Abstract

The application discloses a ground equivalent test piece design method for simulating mass characteristics of a micro spacecraft, which is used for simulating and researching disturbance conditions of the micro spacecraft under microgravity in a drop tower experiment. The structural design mainly uses the three-dimensional model design and mass characteristic parameter calculation functions of Solidworks software, and mainly adopts an axial mass center symmetry inertia parameter adjustment method. The overall structural design method is as follows: according to known parameters obtained from a real spacecraft, a frame main load-bearing structure is preliminarily determined under the condition of meeting the requirements of the experiment, then mass blocks are adjusted and used for simulating the mass center, rotational inertia, inertia product and overall mass of the ground equivalent test piece, so that the error of the parameters of the ground equivalent test piece and the parameters of the real spacecraft is less than or equal to 3%. The ground equivalent test piece design method of the application accurately simulates the real mass characteristics at low cost and with a simple structure without affecting the spacecraft, and has a good reference function for ground tests of the micro spacecraft and complex equipment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ground test of micro spacecraft, and particularly relates to a design method of a ground equivalent test piece for simulating mass characteristics of a micro spacecraft. BACKGROUND

[0002] With the rapid development of current material science, microelectronic technology, precision manufacturing technology and the like, it is possible to manufacture spacecrafts that are smaller, lighter and more powerful. Compared with traditional large spacecrafts, the development and launch cost of micro spacecrafts is lower, which enables more countries and institutions to participate in space activities, and micro spacecrafts gradually become one of the main directions of spacecraft research. However, due to the complexity and precision of micro spacecrafts, it is difficult to directly carry out ground tests, and many spacecrafts adopt equivalent test pieces corresponding to mass characteristics to carry out ground tests. In terms of launch disturbance of spacecrafts carrying loads, it is particularly important to establish a precise, economical and practical ground equivalent test piece to carry out ground equivalent tests and know the disturbance of micro spacecrafts in microgravity in advance. Through ground tests, the attitude disturbance after the launch of loads can be studied in advance, which can greatly reduce the cost and avoid unnecessary losses, and the technology can be verified.

[0003] The current patent CN202211281718.3 discloses a kind of adjustable moment of inertia simulation device, which changes the moment of inertia parameter by changing the distance between counterweight and rotating shaft. The application field of this device is limited, and the adjustment range is limited. It can only be adjusted in two-dimensional plane, and cannot effectively simulate the inertia parameters in three-dimensional space.

[0004] In the article "Research on Spacecraft Simulation Test Bench" by Chen Tengfei, several mass inertia simulation mechanism configurations are designed according to mass characteristic indicators. The appropriate configuration is selected by programming, and the configuration is installed on the axial slide rod to complete the simulation of the moment of inertia of the test piece. Although the simulation test piece designed by this method can simulate and adjust the moment of inertia in three-dimensional space, it cannot adjust the inertia product. The use of the simulation test piece is greatly limited by the environment, and the simulation device cannot be effectively moved and withstand impact. SUMMARY

[0005] The application provides a design method of a micro spacecraft equivalent test piece with simple structure, high precision and strong practicality, which can effectively simulate the mass characteristic parameters of a micro spacecraft. This method has a simple structure, low cost and easy processing while meeting the requirements of accurate simulation of mass characteristics.

[0006] The technical solution of the application is as follows: a design method of a ground equivalent test piece for simulating mass characteristics of a micro spacecraft, comprising the following steps:

[0007] Step 1: The experimental object includes two sets of separation mechanisms and two loads, the assembly physical object of the two sets of separation mechanisms and the two loads and the size parameters thereof are obtained, and the actual mass characteristic parameters of the micro spacecraft are obtained, and the error of the ground equivalent test piece is ≤3%, the X axis is the load launch direction, the Y axis is parallel to the short side of the top frame, the +Z is determined by the right-hand rule of the +X and the +Y, and the coordinate system of the ground equivalent test piece is consistent with the actual spacecraft.

[0008] Step 2: The ground equivalent test piece is determined to be a cubic structure and the length, width and height dimensions according to the size parameters of the two sets of separation mechanisms and the two load assemblies and the actual mass characteristic parameters of the micro spacecraft, the actual mass characteristic parameters of the micro spacecraft include mass, mass center coordinates, moment of inertia and inertia product, the cubic structure is convenient for installing mass blocks to adjust mass, mass center, moment of inertia and inertia product, and the frame main bearing structure of the ground equivalent test piece is designed according to the experimental requirements.

[0009] The frame main bearing structure of the ground equivalent test piece comprises a top frame, a bottom frame, an upper mass block connecting plate, a lower mass block connecting plate, an electromagnet, an electric control device, an electric control device mounting plate, a baffle, a center mass compensation structure, two separation mechanism mounting plates, two symmetrically arranged front and rear lateral frames, two symmetrically arranged left and right lateral frames, and four columns.

[0010] Step 3: The load and the separation mechanism are assembled in the frame main bearing structure of the ground equivalent test piece, and then the first adjusting mass block and the second adjusting mass block are installed on the frame main bearing structure of the ground equivalent test piece to adjust the mass center thereof, the mass center of the frame main bearing structure of the ground equivalent test piece at this time is adjusted, the mass of the first adjusting mass block and the second adjusting mass block is solved, so that the mass center coordinates of the frame main bearing structure of the ground equivalent test piece at this time meet the ≤3% error requirement.

[0011] Step 4: Based on the frame main bearing structure of the ground equivalent test piece in step 3, two symmetric first mass blocks, second mass blocks, third mass blocks, fourth mass blocks, fifth mass blocks and sixth mass blocks are loaded on the outer surfaces of the X axis, the Y axis, the Z axis and the diagonal directions of the X-Y plane, the Y-Z plane and the Z-X plane respectively, according to the known actual spacecraft moment of inertia and inertia product parameters, the inertia parameter adjustment method along the axial mass center symmetry is adopted, the inertia parameters include the moment of inertia and the inertia product, the mass of the corresponding mass block is solved, so that the moment of inertia and the inertia product of the ground equivalent test piece at this time are within the ≤3% error range.

[0012] Step 5: It is judged whether the total mass of the ground equivalent test piece after the above mass blocks are added meets the ≤3% requirement, if yes, the design is completed, otherwise, a mass block is installed at the center mass compensation structure until the ≤3% requirement is met.

[0013] Compared with the prior art, the present application has the following advantages:

[0014] (1) The present application has the function of simulating and adjusting the mass characteristics in three-dimensional space (including mass, center of mass, moment of inertia, and inertia product).

[0015] (2) The simulation device of the present application can also be used secondarily, and can adjust various parameters of the equivalent test piece mass characteristics within a certain limit according to the test requirements, and the simulation mass characteristic parameter accuracy is high.

[0016] (3) The present application has the advantages of simple structure, high precision, low cost, and strong practicability. When high-precision or complex equipment cannot be used for ground experiments, this method can be used to achieve the purpose of accuracy, efficiency, and low cost.

[0017] (4) The overall ground test piece device is divided into multiple components, and the components can be replaced according to different test components. Since the present application is an independent test device, accurate results can be obtained without affecting the aircraft. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of a mass equivalent test piece simulating a micro-spacecraft.

[0019] Figure 2 It is an assembly drawing of the load and separation mechanism.

[0020] Figure 3 It is a main load-bearing structure diagram of the ground equivalent test piece frame.

[0021] Figure 4 It is a mass block position corresponding diagram for adjusting the inertia parameters of the ground equivalent test piece. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0024] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description and cannot be understood as indicating or implying the relative importance of the technical features indicated or implying the number of technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited.

[0025] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixing" and the like should be understood in a broad sense, for example, "fixing" can be fixed connection, or detachable connection, or integral; "connection" can be mechanical connection, or electrical connection. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0026] In addition, the technical solutions of various embodiments of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the protection scope required by the present application.

[0027] The specific embodiments, technical difficulties and points of the present application will be further introduced below in combination with the design examples.

[0028] In combination Figures 1-4 A ground equivalent test piece design method for simulating the mass characteristics of a micro spacecraft, the steps are as follows:

[0029] Step 1: As shown in Figure 2 The experimental object includes two sets of separation mechanisms 20 and two loads 21, the assembly of the two sets of separation mechanisms 20 and the two loads 21 and their size parameters are obtained, and the actual mass characteristic parameters of the micro spacecraft are obtained, the error of the ground equivalent test piece is ≤3%, the X axis is the load launch direction, the Y axis is parallel to the short side direction of the top frame 1, +Z is determined by +X and +Y by the right-hand rule, and the coordinate system of the ground equivalent test piece is consistent with the actual spacecraft, wherein the mass characteristic parameters include mass, mass center coordinates, moment of inertia and inertia product.

[0030] Further, after the separation structure 20 and the load 21 are assembled, the necessary parameters of the designed ground equivalent test piece are measured, including the height h1, the maximum diameter d1, and the installation distance l1 of the two loads, h1 is used to determine the frame height range, d1 is used to design the separation mechanism mounting plate 19 for carrying the assembly, and l1 is used to determine the frame width.

[0031] The mass characteristic parameters of the real spacecraft are known:

[0032] Mass: m0, unit: kg;

[0033] Centroid coordinates: (x0, y0, z0), unit: mm

[0034] Inertia parameters: Unit: kg / mm 2 .

[0035] Step 2: According to the size parameters of the two sets of separation mechanisms 20 and two load assemblies 21 and the actual mass characteristic parameters of the micro-satellite, the ground equivalent test piece is determined as a cubic structure and the length, width and height dimensions, the actual mass characteristic parameters of the micro-satellite include mass, centroid coordinates, moment of inertia and inertia product, the cubic structure is convenient for installing mass blocks to adjust mass, centroid, moment of inertia and inertia product, and the frame main bearing structure of the ground equivalent test piece is designed according to the experimental requirements.

[0036] Further, the basic dimensions of the cubic test piece frame are length l2, width w2 and height h2, wherein: w2>l1+d1, h1<h2<h1+140, unit: mm, the length l2 is determined according to actual requirements, a set of length, width and height dimensions are established according to the existing parameters and the size of the spacecraft, the frame main bearing structure of the ground equivalent test piece is designed in combination with the requirements of the test and the necessary components required to be installed, and the frame main bearing structure of the ground equivalent test piece of the micro-satellite is designed with weight reduction and optimal support strength.

[0037] As shown in Figure 3 , the frame main bearing structure of the ground equivalent test piece comprises: a top frame 1, a bottom frame 2, an upper mass block connecting plate 5, a lower mass block connecting plate 6, an electromagnet 15, an electric control device 16, an electric control device mounting plate 17, a baffle plate 18, a center mass compensation structure 22, two separation mechanism mounting plates 19, two symmetrically arranged front and rear lateral frames 3, two symmetrically arranged left and right lateral frames 4, and four columns 23, the four columns 23 are angle steels, which are used as supports and are connected with the top frame 1, the bottom frame 2, the front and rear lateral frames 3 and the left and right lateral frames 4 in the up-down, front-back and left-right directions respectively, the upper mass block connecting plate 5 is fixed on the top frame 1, the lower mass block connecting plate 6 is fixed on the bottom frame 2, the baffle plate 18 is fixed on the lower mass block connecting plate 6, the electric control device mounting plate 17, the center mass compensation structure 22 and the two separation mechanism mounting plates 19 are all fixed between the two front and rear lateral frames 3, and the two separation mechanism mounting plates 19 are parallel to the top frame 1, the electric control device 16 and the center mass compensation structure 22 are both fixed on the electric control device mounting plate 17, the electromagnet 15 is fixed on the upper mass block connecting plate 5 and located on the X-axis, and all the components are connected by screws and threads.

[0038] Frame main bearing structure installation process and component functions:

[0039] Step1: Y-axis side frame 3 and Z-axis side frame 4 are installed along the four sides between the top frame 1 and the bottom frame 2 as the basic structure of the frame, and the outer surface of the side frame can be used to install the mass block;

[0040] Step2: The column 23 is installed at the four corners of the frame main load-bearing mechanism side for fixing and supporting the overall model;

[0041] Step3: The upper mass block connecting plate 5 is installed on the inner surface of the top frame 1, the upper surface is used to install the electromagnet 15, and the lower surface is used to install the mass block 9. The center of mass of the electromagnet 15 and the mass block 9 is located in the X-axis direction;

[0042] Step4: The lower mass block connecting plate 6 is installed on the inner surface of the bottom frame 2, the upper surface is used to install the mass block 9, and the lower surface is used to install the mass block 8. The center of mass of the mass block 8 and the mass block 9 is located in the X-axis direction;

[0043] Step5: Two separation mechanism installation plates 19 are fixed on the inner side of the front and rear side frames 3 for installing and fixing the separation structure 20;

[0044] Step6: The controller installation plate 17 is installed on the inner side of the front and rear side frames 3, and the controller 16 and the center mass compensation structure 22 are installed on both sides respectively.

[0045] Step 3: The load 21 and the separation mechanism 20 are assembled in the frame main load-bearing structure of the ground equivalent test piece, and then the first adjusting mass block 7 and the second adjusting mass block 8 are installed on the frame main load-bearing structure of the ground equivalent test piece to adjust the center of mass of the frame main load-bearing structure of the ground equivalent test piece at this time. Solve the mass of the first adjusting mass block 7 and the second adjusting mass block 8 to make the center of mass coordinate meet the ≤3% error requirement.

[0046] The calculation method of m2 and m3 corresponding to the first adjusting mass block 7 and the second adjusting mass block 8:

[0047] S31), based on the mass characteristic parameters of the model analyzed by the Solidworks software after the frame main load-bearing mechanism designed in step 2 is assembled with the separation mechanism 20 and the load 21, the total mass is m1, the center of mass coordinate is (x1, y1, z1), and the origin of the reference coordinate system is located at the geometric center point of the ground equivalent test piece.

[0048] S32), solve the mass of the first adjusting mass block 7 and the second adjusting mass block 8 respectively as m2, m3;

[0049]

[0050] Wherein, h2 is the height of the frame main load-bearing structure; l2 is the length of the frame main load-bearing structure; (x0, y0, z0) is the mass center coordinate of the real spacecraft; (x1, y1, z1) is the mass center coordinate of the frame main load-bearing structure after the assembly of the separation mechanism 20 and the load 21 assembly calculated by the Solidworks software.

[0051] In combination Figure 3 And Figure 4 As shown in the figure, the first adjusting mass block 7 is installed on the inner surface of the left lateral frame 4, and the mass center is located in the Z-axis direction; the second adjusting mass block 8 is installed on the outer surface of the lower mass block connecting plate 6, and the mass center is located in the X-axis direction.

[0052] Step 4: Load two symmetrical first mass blocks 9, second mass blocks 10, third mass blocks 11, fourth mass blocks 12, fifth mass blocks 13, and sixth mass blocks 14 on the outer surface of the frame main load-bearing structure in the X-axis, Y-axis, Z-axis, X-Y plane, Y-Z plane, and Z-X plane diagonal directions of the frame main load-bearing structure of the ground equivalent test piece in step 3; according to the known actual spacecraft moment of inertia and inertia product parameters, use the inertia parameter adjustment method along the axial mass center symmetry, the inertia parameters include the moment of inertia and the inertia product, solve the mass of the mass blocks 9-14, so that the moment of inertia and the inertia product of the ground equivalent test piece at this time are within the error range of ≤3%.

[0053] Further, based on the frame main load-bearing structure in step 3, the same and symmetrical mass blocks are installed on each surface, and the mass centers are located in the axial direction, based on the mass of the mass blocks 9-14, the inertia parameters of the ground equivalent test piece are adjusted by using the inertia parameter adjustment method along the axial mass center symmetry, and the error of the inertia parameters of the real micro spacecraft is ≤3%, the mass calculation method and installation position of the mass blocks 9-14 are as follows:

[0054] S41), the mass characteristics parameters of the frame main load-bearing structure of the ground equivalent test piece in step 3 after adjusting the mass center are accurately obtained by software analysis as follows:

[0055] Mass: m'0=m1+m2+m3

[0056] Mass center coordinates: (x2, y2, z2)

[0057] Inertia parameters:

[0058] S42), set along the coordinate X axis, Y axis, Z axis rotation inertia adjustment first mass 9, second mass 10 and third mass 11 mass respectively: m4, m5, m6, X-Y plane, Y-Z plane and Z-X plane diagonal inertia product adjustment fourth mass 12, fifth mass 13 and sixth mass 14 mass respectively: m7, m8, m9, wherein mass 9~14 are regular body can be equivalent to the centroid point, corresponding centroid point coordinates for (x i ,y i ,z i ), subscript i = 4~9.

[0059] Solve the mass of mass 9~14 m i , mass block serial number n = 9:

[0060]

[0061]

[0062] This kind of calculation method can effectively calculate the mass of regular geometric mass block (can be equivalent to the centroid point).

[0063] Wherein, Indicate the inertia parameters of the frame main bearing structure after installing the separation mechanism 20, the load 21 and the mass blocks 7~14, and (x2, y2, z2) is the centroid coordinates of the frame main bearing structure analyzed by Solidworks software after installing the separation mechanism 20, the load 21, the first adjustment mass block 8 and the second adjustment mass block 9.

[0064] S43), mass 9~14 are installed at the corresponding positions of the frame main bearing structure of the ground equivalent test piece as shown in Figure 4 And Figure 3 The first mass 9 is symmetrically installed on the inner surfaces of the upper mass block mounting plate 5 and the lower mass block mounting plate 6 along the X axis, the second mass 10 is symmetrically installed on the outer surfaces of the front and rear lateral frames 3 along the Y axis, the third mass 11 is symmetrically installed on the outer surfaces of the left and right lateral frames 4 along the Z axis, the fourth mass 12 is installed on the outer surfaces of the front and rear lateral frames 3 along the X-Y plane diagonal line, the fifth mass 13 is installed on the outer surfaces of the column 23 along the Y-Z plane diagonal line, and the sixth mass 14 is installed on the outer surfaces of the column 23 along the Z-X plane diagonal line.

[0065] Step 5: judge whether the total mass of the ground equivalent test piece after adding the mass blocks 7~14 meets the requirement of ≤3%, if it meets, the design is completed, otherwise, add mass blocks at the center mass compensation structure 22 until it meets the requirement of ≤3%.

[0066] The judgment method is as follows:

[0067] |m'0+2(m4+m5+m6+m7+m8+m9)-m0|≤3%

[0068] The last expansion function of the present application can add the required mass on the surface of the mass block according to the required accuracy of the test, and the mass calculation method is the same as the above steps, so as to achieve higher accuracy; the mass can be added at the center mass compensation structure 22 without affecting the moment of inertia and inertia product of the model; at the same time, the two symmetrically arranged front and rear lateral frames 3 and the two symmetrically arranged left and right lateral frames 4 can also be translated within a limited range; these expansion functions not only can meet more test requirements, but also can further improve the accuracy.

[0069] Compared with the real model, the mass characteristics of theoretical calculation and software analysis all have errors, in order to avoid error accumulation, the above steps need to be adjusted once, and the mass characteristic parameters need to be re-analyzed by software, so as to obtain more accurate mass characteristic parameters, and then the next step analysis and design are carried out, so that the error can be greatly reduced, and the influence of error accumulation on the accuracy of the ground test piece can be reduced.

[0070] As shown in Figure 1 The electromagnet 15 in the simulation device is installed at the topmost position and the center of mass is along the X-axis direction, this design is used to keep the device in a stable horizontal state to the greatest extent when suspended, and the electrical unlocking is faster and the disturbance is smaller; the separation mechanism mounting plate 19 is offset from the center of mass of the whole device by a certain distance, which can also move along the inner surface of the two symmetrically arranged front and rear lateral frames 3 in the Y-axis direction, which is limited by the screw connection and can only move horizontally within a limited range; the baffle 18 is installed on the lower mass block connecting plate 6, and is located between the two loads 21, which is used to simulate the real situation of shielding when the spacecraft door is opened.

Claims

1. A method for designing a ground-based equivalent test specimen to simulate the mass characteristics of a micro spacecraft, characterized in that, The design steps are as follows: Step 1: the experimental objects include two sets of separation mechanisms (20) and two loads (21), the assembly physical objects and size parameters of the two sets of separation mechanisms (20) and the two loads (21) are obtained, and the actual mass characteristic parameters of the micro-satellite are obtained, the error of the ground equivalent test piece is ≤3%, the X axis is the load launch direction, the Y axis is parallel to the short side of the top frame (1), the +Z is determined by the right-hand rule of +X and +Y, and the coordinate system of the ground equivalent test piece is consistent with the actual satellite; Step 2: according to the size parameters of the two sets of separation mechanisms (20) and the two loads (21) and the actual mass characteristic parameters of the micro-satellite, the ground equivalent test piece is determined as a cubic structure and the length, width and height dimensions, the actual mass characteristic parameters of the micro-satellite include mass, mass center coordinates, moment of inertia and inertia product, the cubic structure is convenient for installing mass blocks to adjust mass, mass center, moment of inertia and inertia product, and the frame main bearing structure of the ground equivalent test piece is designed according to the experimental requirements; The frame main bearing structure of the ground equivalent test piece comprises a top frame (1), a bottom frame (2), an upper mass block connecting plate (5), a lower mass block connecting plate (6), an electromagnet (15), an electric control device (16), an electric control device mounting plate (17), a baffle (18), a center mass compensation structure (22), two separation mechanism mounting plates (19), two symmetrically arranged front and rear lateral frames (3), two symmetrically arranged left and right lateral frames (4) and four columns (23); Step 3: the load (21) and the separation mechanism (20) are assembled in the frame main bearing structure of the ground equivalent test piece, and then the first adjusting mass block (7) and the second adjusting mass block (8) are additionally installed on the frame main bearing structure of the ground equivalent test piece to adjust the mass center of the frame main bearing structure of the ground equivalent test piece at this time, the mass of the first adjusting mass block (7) and the second adjusting mass block (8) is solved, so that the mass center coordinates of the frame main bearing structure of the ground equivalent test piece at this time meet the ≤3% error requirement; Step 4: based on the frame main bearing structure of the ground equivalent test piece in step 3, two symmetric first mass blocks (9), second mass blocks (10), third mass blocks (11), fourth mass blocks (12), fifth mass blocks (13) and sixth mass blocks (14) are respectively installed on the outer surfaces of the frame main bearing structure of the ground equivalent test piece in the diagonal directions of the X axis, the Y axis, the Z axis and the X-Y plane, the Y-Z plane and the Z-X plane, according to the known actual satellite moment of inertia and inertia product parameters, the inertia parameter adjustment method along the axial mass center symmetry is adopted, the inertia parameters include the moment of inertia and the inertia product, the mass of the mass blocks (9-14) is solved, so that the moment of inertia and the inertia product of the ground equivalent test piece at this time are within the ≤3% error range; Step 5: whether the total mass error of the ground equivalent test piece after adding the mass blocks (7-14) meets the ≤3% requirement is judged, if yes, the design is completed, otherwise, a mass block is additionally installed at the center mass compensation structure (22) until the ≤3% requirement is met.

2. The method of claim 1, wherein the method is characterized by: In step 1, the necessary parameters of the designed ground equivalent test piece are measured after the separation structure (20) and the load (21) are assembled, including the height h1, the maximum diameter d1, and the two load installation distances l1, h1 is used to determine the height range of the frame, d1 is used to design the installation plate (19) of the separation mechanism that bears the assembled body, and l1 is used to determine the width of the frame; The mass characteristic parameters of the actual spacecraft are known: Mass: m0, unit: kg; The center of mass coordinates are: (x0, y0, z0), unit: mm; Inertial parameters: Units: kg / mm 2 ; The various parameters of the mass characteristics of the designed ground equivalent test piece are required to be ≤3% error compared with the actual spacecraft parameters, the X axis is the load launch direction, the Y axis is parallel to the short side of the top frame (1), +Z is determined by the right-hand rule of +X and +Y, and the coordinate system of the ground equivalent test piece is consistent with that of the actual spacecraft.

3. The method of claim 2, wherein the method further comprises: In step 2, the basic dimensions of the cubic test piece frame are length l2, width w2, and height h2, wherein: w2>l1+d1, h1<h2<h1+140, unit: mm, the length l2 is determined according to actual requirements, and the frame main bearing structure of the ground equivalent test piece is designed according to experimental requirements.

4. The method of claim 3, wherein the method further comprises: In step 2, the frame main bearing structure of the ground equivalent test piece includes a top frame (1), a bottom frame (2), an upper mass block connecting plate (5), a lower mass block connecting plate (6), an electromagnet (15), an electric control device (16), an electric control device mounting plate (17), a baffle (18), a center mass compensation structure (22), two separation mechanism mounting plates (19), two symmetrically arranged front and rear lateral frames (3), two symmetrically arranged left and right lateral frames (4), and four columns (23), the four columns (23) are used as supports, and the top frame (1), the bottom frame (2), the front and rear lateral frames (3), and the left and right lateral frames (4) are connected to the upper and lower, front and rear, and left and right of the four columns (23) respectively, the upper mass block connecting plate (5) is fixed on the top frame (1), the lower mass block connecting plate (6) is fixed on the bottom frame (2), the baffle (18) is fixed on the lower mass block connecting plate (6), the electric control device mounting plate (17), the center mass compensation structure (22), and the two separation mechanism mounting plates (19) are all fixed between the two front and rear lateral frames (3), and the two separation mechanism mounting plates (19) are parallel to the top frame (1), the electric control device (16) and the center mass compensation structure (22) are both fixed on the electric control device mounting plate (17), and the electromagnet (15) is fixed on the upper mass block connecting plate (5) and located on the X axis.

5. The method of claim 4, wherein the method further comprises: In step 3, the center of mass of the frame main bearing structure of the ground equivalent test piece at this time is adjusted, and the masses of the first adjustment mass block (7) and the second adjustment mass block (8) are solved to make the center of mass coordinates of the frame main bearing structure of the ground equivalent test piece at this time satisfy the ≤3% error requirement, which is as follows: The calculation method of the first adjustment mass block (7) and the second adjustment mass block (8) corresponding to the masses m2 and m3 is as follows: S31), the overall mass of the quality characteristic parameter of the model of the frame main load-bearing structure designed based on step 2 after the assembly of the separation mechanism (20) and the load (21) assembly body is calculated by the Solidworks software, and the mass center coordinates are (x1, y1, z1), and the origin of the reference coordinate system is located at the geometric center point of the ground equivalent test piece; S32), the masses of the first adjusting mass block (7) and the second adjusting mass block (8) are m2 and m3 respectively; Wherein, h2 is the height of the frame main load-bearing structure; l2 is the length of the frame main load-bearing structure; (x0, y0, z0) is the mass center coordinates of the real spacecraft, and (x1, y1, z1) is the mass center coordinates of the frame main load-bearing structure after the assembly of the separation mechanism (20) and the load (21) assembly body analyzed by the Solidworks software; The first adjusting mass block (7) is installed on the inner surface of the left lateral frame (4), and the mass center is located in the Z-axis direction; the second adjusting mass block (8) is installed on the outer surface of the lower mass block connecting plate (6), and the mass center is located in the X-axis direction.

6. The method of claim 5, wherein the method further comprises: In step 4, two symmetrical first mass blocks (9), second mass blocks (10), third mass blocks (11), fourth mass blocks (12), fifth mass blocks (13) and sixth mass blocks (14) are loaded on the outer surface of the X-axis, Y-axis, Z-axis and X-Y plane, Y-Z plane and Z-X plane of the frame main load-bearing structure of the ground equivalent test piece in step 3 in the diagonal direction, according to the known actual spacecraft moment of inertia and inertia product parameters, using the inertia parameter adjusting method along the axial mass center symmetry, the inertia parameters include the moment of inertia and the inertia product, the mass of the mass block (9-14) is solved, so that the moment of inertia and the inertia product of the ground equivalent test piece are within the error range of ≤3%, and the specific method is as follows: Based on the frame main load-bearing structure of step 3, the same and symmetrical mass blocks are installed on each surface, and the mass centers are located in the axial direction, based on the mass of the mass block (9-14), the inertia parameters of the ground equivalent test piece are adjusted by using the inertia parameter adjusting method along the axial mass center symmetry, and the error of the inertia parameters of the real micro spacecraft is ≤3%, the mass calculation method and installation position of the mass block (9-14) are as follows: S41), the mass parameters of the ground equivalent test piece frame main load-bearing structure after adjusting the mass center in step 3 are accurately calculated by software analysis as follows: Mass: m'0 = m1 + m2 + m3 Mass center coordinates: (x2, y2, z2) Inertial parameters: S42), set along the coordinate X axis, Y axis and Z axis symmetry of the moment of inertia adjustment first mass (9), the second mass (10), the third mass (11) quality is: m4, m5, m6, X-Y plane, Y-Z plane and Z-X plane diagonal inertia product adjustment fourth mass (12), the fifth mass (13), the sixth mass (14) quality is: m7, m8, m9, wherein the mass (9~14) are regular body can be equivalent to the centroid point, the corresponding centroid point coordinates for (x i ,y i ,z i ), subscript i = 4~9; Solving the mass m corresponding to the mass block (9-14) i , mass block number n = 9 This calculation method can effectively calculate the mass of the regular geometric mass block; wherein, (x2, y2, z2) is the center of mass coordinate of the frame main load-bearing structure after the installation of the separation mechanism (20), the load (21), the first adjusting mass block (8), and the second adjusting mass block (9); S43), the first mass block (9) is symmetrically installed on the inner surfaces of the upper mass block mounting plate (5) and the lower mass block mounting plate (6) along the X-axis, the second mass block (10) is symmetrically installed on the outer surface of the front-rear lateral frame (3) along the Y-axis, the third mass block (11) is symmetrically installed on the outer surface of the left-right lateral frame (4) along the Z-axis, the fourth mass block (12) is installed on the outer surface of the front-rear lateral frame (3) along the diagonal of the X-Y plane, the fifth mass block (13) is installed on the outer surface of the column (23) along the diagonal of the Y-Z plane, and the sixth mass block (14) is installed on the outer surface of the column (23) along the diagonal of the Z-X plane.

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