A microgravity simulation device and method

Abstract

The application discloses a microgravity simulation device and method, and belongs to the field of microgravity simulation technology.The device comprises a mounting base, a vertical mounting support, a universal ring group and an experiment platform.The mounting base is used for providing a stable mounting and running base for microgravity simulation.The vertical mounting support is provided at two ends of the mounting base and is used for mounting the universal ring group.The universal ring group comprises an outer universal ring, a middle universal ring and an inner universal ring, and is used for providing a three-dimensional rotating environment for a to-be-tested article.The experiment platform is mounted on the inner universal ring and is used for providing a mounting space for the to-be-tested article.

Description

Technical Field

[0001] This invention relates to the fields of space technology and control simulation, specifically to a microgravity simulation device and method. Background Technology

[0002] When preparing for long-duration space missions lasting 3 to 6 months or more, the medical and psychological aspects of the mission personnel become a crucial concern. The spatial constraints and psychological isolation experienced by personnel, especially the potential dangers of missions from Low Earth Orbit (LEO) to the Moon and Mars, present enormous challenges and risks to human performance. These risks can stem from a variety of factors, including boredom, apathy, anxiety, crew self-management and increasing interdependence, interpersonal tensions, confined spaces, long flight times, mechanical failures, and unexpected physical health issues. A vast array of technologies across various fields of space science required for all these aspects need to be acquired through human space simulators. These technologies are vital for the future development of scientific knowledge and the advancement of space exploration.

[0003] Currently, simulations of the space environment include free-fall simulators and parabolic flight of aircraft. Free-fall simulators (FFMs) operate on the principle of free fall. In FFM, the maximum free-fall period is approximately 900 milliseconds (ms), interrupted by an acceleration of 20g for about 20–80 ms. FFM is a good weightlessness simulator for many biological samples. However, this technology also has some drawbacks, such as the short duration of microgravity, making it impossible to study the effects of microgravity on the system, and preventing experimenters from conducting passenger-carrying experiments. Parabolic flight of an aircraft can achieve a microgravity state of 25 seconds. A typical flight lasts 2–3 hours, with passengers and experimental subjects starting at an altitude of approximately 7 kilometers. The aircraft rapidly climbs at a 45-degree angle (ascent phase), then transitions to parabolic flight (level flight phase), and finally descends rapidly at a 45-degree angle (descent phase). The occupants and test subjects will experience hypergravity on the order of 2-2.5g during ascent and descent, while during the parabolic level flight phase, at an altitude of 7.3 km to 10.4 km, they will experience 10 -2 Microgravity on the order of grams, lasting for more than 15 seconds. While aircraft cannot achieve the same high-quality microgravity conditions as a drop tower, it can be used to study the effects of microgravity on the cardiovascular systems of animals and humans. Performing parabolic flight by aircraft is costly and complex to maintain.

[0004] The current problem to be solved is how to develop and manufacture devices that can simulate microgravity conditions for a long time based on the ground environment. Summary of the Invention

[0005] This invention primarily addresses the problem of how to develop and manufacture devices capable of simulating microgravity conditions for extended periods based on terrestrial environments. This invention discloses a microgravity simulation device and method.

[0006] In a first aspect, the present invention discloses a microgravity simulation device, comprising: a mounting base, a vertical mounting bracket, a universal joint assembly, and an experimental platform;

[0007] The mounting base is used to provide a stable mounting and operating base for microgravity simulation;

[0008] The vertical mounting brackets, numbered two, are located at both ends of the mounting base and are used to mount the universal joint assembly;

[0009] The gimbal assembly, including an outer gimbal, a middle gimbal, and an inner gimbal, is used to provide a three-dimensional rotational environment for the object to be tested.

[0010] An experimental platform is installed on the internal gimbal.

[0011] The experimental platform is used to provide installation space for the items to be tested.

[0012] The first and second connection points on the external universal ring are respectively connected to the upper ends of the two vertical mounting brackets through the first bearing. The line connecting the first and second connection points is the diameter of the external universal ring.

[0013] The third and fourth connection points on the central universal joint are respectively connected to the first and second connection points on the outer universal joint via the second bearing.

[0014] The fifth and sixth connection points on the central universal joint are respectively connected to the seventh and eighth connection points on the inner universal joint via the third bearing.

[0015] The lines connecting the third and fourth connection points on the central universal joint, as well as the lines connecting the fifth and sixth connection points on the central universal joint, are both the diameter of the central universal joint.

[0016] The ninth and tenth connection points on the internal universal joint are respectively connected to the experimental platform via the fourth bearing.

[0017] The line connecting the seventh and eighth connection points on the inner gimbal, and the line connecting the ninth and tenth connection points on the inner gimbal, constitute the diameter of the inner gimbal.

[0018] Each bearing is equipped with a drive motor inside; the drive motor is used to drive the bearing to rotate.

[0019] The microgravity simulation device also includes a microgravity triaxial accelerometer, a drive module, and a control module;

[0020] The microgravity triaxial accelerometer is mounted on the experimental platform and is used to measure the set of motion value sequences of the experimental platform; the set of motion value sequences includes a gravity value sequence, an X-axis acceleration sequence, a Y-axis acceleration sequence, and a Z-axis acceleration sequence.

[0021] The drive module is used to output the corresponding motor drive value to the drive motor of each bearing according to the set of motor drive values;

[0022] The control module is used to perform feedback calculation processing on the received set of motion value sequences and the set of motor drive values ​​for the current time period to obtain the set of motor drive values ​​for the next time period.

[0023] The control module performs feedback calculations on the received set of motion value sequences and the set of motor drive values ​​for the current time period to obtain the set of motor drive values ​​for the next time moment, including:

[0024] The control module performs microgravity evaluation processing on the received set of motion value sequences to obtain an evaluation value sequence.

[0025] The evaluation value sequence, motion value sequence set, and motor drive value set for the current time period are fused and fed back to obtain the motor drive value set for the next time period.

[0026] A second aspect of this invention discloses a microgravity simulation method, implemented using the aforementioned microgravity simulation device, comprising:

[0027] S1, the motors on each bearing of the universal ring assembly are used to drive each universal ring to rotate, so that the test item on the experimental platform is in a microgravity environment.

[0028] S2, using the microgravity triaxial accelerometer, the set of motion value sequences of the experimental platform is measured;

[0029] S3, using the drive module, output the corresponding motor drive value to each bearing according to the set of motor drive values;

[0030] S4. Using the control module, perform feedback calculation processing on the received motion value sequence set and the motor drive value set of the current time period to obtain the motor drive value set of the next time moment.

[0031] The step of performing feedback calculations on the received set of motion value sequences and the set of motor drive values ​​for the current time period to obtain the set of motor drive values ​​for the next time period includes:

[0032] S41, perform microgravity evaluation processing on the received set of motion value sequences to obtain an evaluation value sequence;

[0033] S42, perform fusion feedback calculation processing on the evaluation value sequence, motion value sequence set and motor drive value set of the current time period to obtain the motor drive value set of the next time moment.

[0034] The process of performing microgravity evaluation on the received set of motion value sequences to obtain an evaluation value sequence includes:

[0035] S411, obtains the standard gravity value and the standard acceleration values ​​of the X-axis, Y-axis and Z-axis under standard gravity;

[0036] S412, for each sequence in the received motion value sequence set, subtract the standard value of the corresponding type to obtain the corresponding difference sequence;

[0037] S413, using all the difference sequences, construct the difference matrix; the row vectors in the difference matrix are the difference sequences;

[0038] S414, Perform cross-covariance calculation on the difference sequences to obtain the cross-covariance matrix;

[0039] S415, Perform eigenvalue decomposition on the differential sequence to obtain an eigenvalue sequence and a set of eigenvectors;

[0040] S416, perform fusion calculation on the cross-covariance matrix, eigenvalue sequence and eigenvector set to obtain the evaluation value sequence.

[0041] The expression for the fusion calculation process is:

[0042]

[0043] Where, q i To evaluate the i-th element in the value sequence, T i () denotes the i-th order polynomial of the first kind of Chebyshev polynomial, λ i μ represents the mean of the i-th eigenvector. i Let v represent the i-th eigenvalue. i Let represent the mean of the elements in the i-th row of the cross-covariance matrix.

[0044] The step of performing fusion feedback calculation on the evaluation value sequence, the motion value sequence set, and the motor drive value set for the current time period to obtain the motor drive value set for the next time moment includes:

[0045] S421, obtains the standard gravity value and the standard acceleration values ​​of the X-axis, Y-axis and Z-axis under standard gravity;

[0046] S422, for each sequence in the received motion value sequence set, subtract the standard value of the corresponding type to obtain the corresponding difference sequence;

[0047] S423, Perform feature transformation on each differential sequence to obtain the corresponding differential feature value;

[0048] S424, construct a sequence of differential feature values ​​using all differential feature values;

[0049] S425, perform feedback calculation processing on the evaluation value sequence and the difference feature value sequence to obtain the fusion feedback quantity sequence;

[0050] S426, perform feedback fusion calculation processing on the fused feedback quantity sequence and the motor drive value set of the current time period to obtain the motor drive value set of the next time period.

[0051] The expression for the feedback calculation is:

[0052]

[0053] Where pi represents the i-th fusion feedback quantity in the fusion feedback quantity sequence;

[0054] The expression for the feedback fusion calculation process is:

[0055]

[0056] Among them, f i (t) represents the drive value of the motor of the i-th bearing at the current time t, f i (t+1) represents the driving value of the motor of the i-th bearing at time t+1, where i can be 1, 2, 3 or 4, and η is a preset proportional constant.

[0057] The beneficial effects of this invention are as follows:

[0058] This invention discloses a microgravity simulation device and method, realizing a device developed and manufactured based on the ground environment that can simulate microgravity conditions for a long time.

[0059] In the process of realizing the microgravity mode, this invention measures the gravity value and acceleration value in real time and introduces a feedback control mechanism to perform feedback calculation on the received motion value sequence set and the motor drive value set of the current time period to obtain the motor drive value set of the next time moment, thereby improving the durability and realism of microgravity.

[0060] In the feedback calculation process, this invention first performs microgravity evaluation processing on the received motion value sequence set to obtain an evaluation value sequence; then, it performs fusion feedback calculation processing on the evaluation value sequence, the motion value sequence set, and the motor drive value set for the current time period to obtain the motor drive value set for the next time moment. This two-step calculation method ensures the accuracy and real-time performance of the feedback processing, improving the feedback effect. Attached Figure Description

[0061] Figure 1 This is a flowchart illustrating the implementation of the method of the present invention;

[0062] Figure 2 This is a diagram showing the composition of the device of the present invention;

[0063] Figure 3 This is a schematic diagram of the overall structure of the device of the present invention. Detailed Implementation

[0064] To better understand the content of this invention, an embodiment is provided here.

[0065] Figure 1 This is a flowchart illustrating the implementation of the method of the present invention; Figure 2 This is a diagram showing the composition of the device of the present invention; Figure 3 This is a general schematic diagram of the device of the present invention. Figure 3 In the experiment, the sample stage serves as the experimental platform, and the entire microgravity simulation device can be placed on the instrument cabinet.

[0066] In a first aspect, the present invention discloses a microgravity simulation device, comprising: a mounting base, a vertical mounting bracket, a universal joint assembly, and an experimental platform;

[0067] The mounting base is used to provide a stable mounting and operating base for microgravity simulation;

[0068] The vertical mounting brackets, numbered two, are located at both ends of the mounting base and are used to mount the universal joint assembly;

[0069] The gimbal assembly, including an outer gimbal, a middle gimbal, and an inner gimbal, is used to provide a three-dimensional rotational environment for the object to be tested.

[0070] An experimental platform is installed on the internal gimbal.

[0071] The experimental platform is used to provide installation space for the items to be tested;

[0072] The first and second connection points on the external universal joint are respectively connected to the upper ends of the two vertical mounting brackets through the first bearing. The line connecting the first and second connection points is the diameter of the external universal joint. The first bearing includes two sub-bearings, which are respectively connected to the first and second connection points. The second, third, and fourth bearings are similar to the first bearing, each including sub-bearings connected to two corresponding connection points.

[0073] The third and fourth connection points on the central universal joint are respectively connected to the first and second connection points on the outer universal joint via the second bearing.

[0074] The fifth and sixth connection points on the central universal joint are respectively connected to the seventh and eighth connection points on the inner universal joint via the third bearing.

[0075] The lines connecting the third and fourth connection points on the central universal joint, as well as the lines connecting the fifth and sixth connection points on the central universal joint, are both the diameter of the central universal joint.

[0076] The ninth and tenth connection points on the internal universal joint are respectively connected to the experimental platform via the fourth bearing.

[0077] The line connecting the seventh and eighth connection points on the inner gimbal, and the line connecting the ninth and tenth connection points on the inner gimbal, constitute the diameter of the inner gimbal.

[0078] Each bearing is equipped with a drive motor inside; the drive motor is used to drive the bearing to rotate.

[0079] The microgravity simulation device also includes a microgravity triaxial accelerometer, a drive module, and a control module;

[0080] The microgravity triaxial accelerometer is mounted on the experimental platform and is used to measure the set of motion value sequences of the experimental platform; the set of motion value sequences includes a gravity value sequence, an X-axis acceleration sequence, a Y-axis acceleration sequence, and a Z-axis acceleration sequence.

[0081] The drive module is used to output the corresponding motor drive value to the drive motor of each bearing according to the set of motor drive values;

[0082] The control module is used to perform feedback calculation processing on the received set of motion value sequences and the set of motor drive values ​​for the current time period to obtain the set of motor drive values ​​for the next time period.

[0083] The control module performs feedback calculations on the received set of motion value sequences and the set of motor drive values ​​for the current time period to obtain the set of motor drive values ​​for the next time moment, including:

[0084] The control module performs microgravity evaluation processing on the received set of motion value sequences to obtain an evaluation value sequence.

[0085] The evaluation value sequence, motion value sequence set, and motor drive value set of the current time period are fused and fed back to obtain the motor drive value set of the next time period.

[0086] The process of performing microgravity evaluation on the received set of motion value sequences to obtain an evaluation value sequence includes:

[0087] Obtain the standard gravity value and the standard acceleration values ​​of the X-axis, Y-axis, and Z-axis under standard gravity;

[0088] For each sequence in the received set of motion value sequences, subtract the corresponding standard value to obtain the corresponding difference sequence;

[0089] Using all the difference sequences, a difference matrix is ​​constructed; the row vectors in the difference matrix are the difference sequences.

[0090] The cross-covariance of the differential sequences is calculated to obtain the cross-covariance matrix;

[0091] The differential sequence is subjected to eigenvalue decomposition to obtain an eigenvalue sequence and an eigenvector set;

[0092] The cross-covariance matrix, eigenvalue sequence, and eigenvector set are fused and calculated to obtain the evaluation value sequence.

[0093] The expression for the fusion calculation process is:

[0094]

[0095] Where, q i To evaluate the i-th element in the value sequence, T i () denotes the i-th order polynomial of the first kind of Chebyshev polynomial, λ i μ represents the mean of the i-th eigenvector. i Let v represent the i-th eigenvalue. i This represents the mean of the elements in the i-th row of the cross-covariance matrix;

[0096] The step of performing fusion feedback calculation on the evaluation value sequence, the motion value sequence set, and the motor drive value set for the current time period to obtain the motor drive value set for the next time moment includes:

[0097] Obtain the standard gravity value and the standard acceleration values ​​of the X-axis, Y-axis, and Z-axis under standard gravity;

[0098] For each sequence in the received set of motion value sequences, subtract the corresponding standard value to obtain the corresponding difference sequence;

[0099] Each differential sequence is subjected to feature transformation to obtain the corresponding differential feature value;

[0100] A sequence of differential feature values ​​is constructed using all the differential feature values;

[0101] The evaluation value sequence and the difference feature value sequence are processed by feedback calculation to obtain the fusion feedback quantity sequence;

[0102] The expression for the feedback calculation is:

[0103]

[0104] Where, p i This represents the i-th fusion feedback quantity in the fusion feedback quantity sequence;

[0105] The fused feedback sequence and the set of motor drive values ​​for the current time period are subjected to feedback fusion calculation to obtain the set of motor drive values ​​for the next time period.

[0106] The motor drive value set includes four drive values, which are used to drive the four drive motors of the first to fourth bearings respectively.

[0107] The expression for the feedback fusion calculation process is:

[0108]

[0109] Among them, f i (t) represents the drive value of the motor of the i-th bearing at the current time t, f i (t+1) represents the driving value of the motor of the i-th bearing at time t+1, where i can be 1, 2, 3 or 4, and η is a preset proportional constant, which can be 20.

[0110] The expression for the feature transformation process is:

[0111]

[0112] Among them, C iLet be the eigenvalue of the i-th difference sequence, which is also the i-th difference eigenvalue of the difference eigenvalue sequence. The integration range is -∞ to ∞. Let l represent the element index, τ represent the deviation index, Ω represent the discrete frequency variable corresponding to l, and θ represent the angle variable. Let k(θ,τ) = A(θ)g(θ,τ), where k(θ,τ) is the first kernel function and g(θ,τ) is the second kernel function. a = 0.001, β = 50, A(θ) is a Gaussian function of θ, x i () represents the i-th difference sequence, and * indicates taking the conjugate.

[0113] The cross-covariance calculation is performed using the row vectors in the difference sequence as samples.

[0114] The standard gravity value refers to the standard gravity value of Earth; the standard acceleration values ​​of the X-axis, Y-axis, and Z-axis under the standard gravity are the standard acceleration values ​​of the X-axis, Y-axis, and Z-axis under the standard gravity value of Earth.

[0115] The motor drive value is the voltage or current driving the motor;

[0116] The microgravity simulation device comprises a robust base frame, two sets (ultimately three sets) of gimbals, and an experimental platform mounted at the center of the inner rings. These gimbals are mounted using nested bearings and are individually driven by independent drive units, including programmable motors and motor controllers. The motors are controlled based on feedback signals generated by encoders mounted on the motor shafts and zero-position sensors mounted within the gimbals. The microgravity simulation prototype will be installed within the integrated environmental chamber to test the functional volume and operating angular velocities of the independently driven rings under simulated microgravity conditions, ultimately achieving an acceptable level of simulated microgravity. The microelectromechanical system (MEMS) accelerometer sensor system shown will be selected for use on the sample stage of the laboratory-scale microgravity simulator prototype to acquire microgravity acceleration data. This sensor demonstrates a novel design approach for simulating microgravity by randomly changing the direction of the gravity vector in three motion directions (3D).

[0117] The microgravity triaxial accelerometer sensor includes a gravity sensor and an accelerometer sensor. The gravity sensor can be implemented using a MEMS accelerometer sensor, which has inherent advantages such as smaller size and lighter weight. The sensitivity of this sensor is less than 10. -6 ×g, package size less than 8 cubic inches, weight less than 0.25 pounds, power consumption less than 1 watt. The MEMS accelerometer, combined with prototype electronics, can produce a general microgravity resolution of 0.1–25 Hz, scalable up to 1500 Hz.

[0118] A second aspect of this invention discloses a microgravity simulation method, implemented using the microgravity simulation device, comprising:

[0119] S1, the motors on each bearing of the universal ring assembly are used to drive each universal ring to rotate, so that the test item on the experimental platform is in a microgravity environment.

[0120] S2, using the microgravity triaxial accelerometer, the set of motion value sequences of the experimental platform is measured;

[0121] S3, using the drive module, output the corresponding motor drive value to each bearing according to the set of motor drive values;

[0122] S4, using the control module, perform feedback calculation processing on the received motion value sequence set and the motor drive value set of the current time period to obtain the motor drive value set of the next time moment;

[0123] The step of performing feedback calculations on the received set of motion value sequences and the set of motor drive values ​​for the current time period to obtain the set of motor drive values ​​for the next time period includes:

[0124] S41, perform microgravity evaluation processing on the received set of motion value sequences to obtain an evaluation value sequence;

[0125] S42, perform fusion feedback calculation processing on the evaluation value sequence, motion value sequence set and motor drive value set of the current time period to obtain the motor drive value set of the next time moment;

[0126] The process of performing microgravity evaluation on the received set of motion value sequences to obtain an evaluation value sequence includes:

[0127] S411, obtains the standard gravity value and the standard acceleration values ​​of the X-axis, Y-axis and Z-axis under standard gravity;

[0128] S412, for each sequence in the received motion value sequence set, subtract the standard value of the corresponding type to obtain the corresponding difference sequence;

[0129] S413, using all the difference sequences, construct the difference matrix; the row vectors in the difference matrix are the difference sequences;

[0130] S414, Perform cross-covariance calculation on the difference sequences to obtain the cross-covariance matrix;

[0131] S415, Perform eigenvalue decomposition on the differential sequence to obtain an eigenvalue sequence and a set of eigenvectors;

[0132] S416, perform fusion calculation on the cross-covariance matrix, eigenvalue sequence and eigenvector set to obtain the evaluation value sequence;

[0133] The expression for the fusion calculation process is:

[0134]

[0135] Where, q i To evaluate the i-th element in the value sequence, T i () denotes the i-th order polynomial of the first kind of Chebyshev polynomial, λ i μ represents the mean of the i-th eigenvector. i Let v represent the i-th eigenvalue. i This represents the mean of the elements in the i-th row of the cross-covariance matrix;

[0136] The step of performing fusion feedback calculation on the evaluation value sequence, the motion value sequence set, and the motor drive value set for the current time period to obtain the motor drive value set for the next time moment includes:

[0137] S421, obtains the standard gravity value and the standard acceleration values ​​of the X-axis, Y-axis and Z-axis under standard gravity;

[0138] S422, for each sequence in the received motion value sequence set, subtract the standard value of the corresponding type to obtain the corresponding difference sequence;

[0139] S423, Perform feature transformation on each differential sequence to obtain the corresponding differential feature value;

[0140] S424, construct a sequence of differential feature values ​​using all differential feature values;

[0141] S425, perform feedback calculation processing on the evaluation value sequence and the difference feature value sequence to obtain the fusion feedback quantity sequence;

[0142] The expression for the feedback calculation is:

[0143]

[0144] Where pi represents the i-th fusion feedback quantity in the fusion feedback quantity sequence;

[0145] S426, Perform feedback fusion calculation processing on the fused feedback quantity sequence and the motor drive value set of the current time period to obtain the motor drive value set of the next time period;

[0146] The expression for the feedback fusion calculation process is:

[0147]

[0148] Among them, f i (t) represents the drive value of the motor of the i-th bearing at the current time t, f i (t+ 1 ) represents the driving value of the motor of the i-th bearing at time t+1, where i can be 1, 2, 3 or 4, and η is a preset proportional constant, which can be 20.

[0149] The expression for the feature transformation process is:

[0150]

[0151] Among them, C i Let be the eigenvalue of the i-th difference sequence, which is also the i-th difference eigenvalue of the difference eigenvalue sequence. The integration range is -∞ to ∞. Let l represent the element index, τ represent the deviation index, Ω represent the discrete frequency variable corresponding to l, and θ represent the angle variable. Let k(θ,τ) = A(θ)g(θ,τ), where k(θ,τ) is the first kernel function and g(θ,τ) is the second kernel function. a = 0.001, β = 50, A(θ) is a Gaussian function of θ, x i () represents the i-th difference sequence, and * indicates taking the conjugate.

[0152] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A microgravity simulation device, characterized in that, include: Mounting base, vertical mounting bracket, universal joint assembly, experimental platform; The mounting base is used to provide a stable mounting and operating base for microgravity simulation; The vertical mounting brackets, numbered two, are located at both ends of the mounting base and are used to mount the universal joint assembly; The gimbal assembly includes an outer gimbal, a middle gimbal, and an inner gimbal, used to provide a three-dimensional rotational environment for the object to be tested; the gimbals are installed using inner and outer nested bearings; each bearing has a drive motor inside; the drive motor is used to drive the bearing to rotate; An experimental platform is installed on the internal gimbal. The experimental platform is used to provide installation space for the items to be tested; The microgravity simulation device also includes a microgravity triaxial accelerometer, a drive module, and a control module; The microgravity triaxial accelerometer is mounted on the experimental platform and is used to measure the set of motion value sequences of the experimental platform; the set of motion value sequences includes a gravity value sequence, an X-axis acceleration sequence, a Y-axis acceleration sequence, and a Z-axis acceleration sequence. The drive module is used to output the corresponding motor drive value to the drive motor of each bearing according to the set of motor drive values; The control module performs microgravity evaluation processing on the received set of motion value sequences to obtain an evaluation value sequence, including: S411, obtains the standard gravity value and the standard acceleration values ​​of the X-axis, Y-axis and Z-axis under standard gravity; S412, for each sequence in the received motion value sequence set, subtract the standard value of the corresponding type to obtain the corresponding difference sequence; S413, using all the difference sequences, construct the difference matrix; the row vectors in the difference matrix are the difference sequences; S414, Perform cross-covariance calculation on the difference sequences to obtain the cross-covariance matrix; S415, Perform eigenvalue decomposition on the differential sequence to obtain an eigenvalue sequence and a set of eigenvectors; S416, perform fusion calculation on the cross-covariance matrix, eigenvalue sequence and eigenvector set to obtain the evaluation value sequence; The expression for the fusion calculation process is: ， in, To evaluate the i-th element in the value sequence, Let represent the i-th order polynomial of the first kind of Chebyshev polynomial. Let represent the mean of the i-th eigenvector. This represents the i-th eigenvalue. This represents the mean of the elements in the i-th row of the cross-covariance matrix; The evaluation value sequence, motion value sequence set, and motor drive value set for the current time period are fused and fed back to obtain the motor drive value set for the next time period.

2. A microgravity simulation method, characterized in that, This is achieved using the microgravity simulation device described in claim 1, comprising: S1, the motors on each bearing of the universal ring assembly are used to drive each universal ring to rotate, so that the test item on the experimental platform is in a microgravity environment. S2, using the microgravity triaxial accelerometer, the set of motion value sequences of the experimental platform is measured; S3, using the drive module, output the corresponding motor drive value to each bearing according to the set of motor drive values; S4. Using the control module, perform feedback calculation processing on the received motion value sequence set and the motor drive value set of the current time period to obtain the motor drive value set of the next time moment.

3. The microgravity simulation method as described in claim 2, characterized in that, The step of performing feedback calculations on the received set of motion value sequences and the set of motor drive values ​​for the current time period to obtain the set of motor drive values ​​for the next time period includes: S41, perform microgravity evaluation processing on the received set of motion value sequences to obtain an evaluation value sequence; S42, perform fusion feedback calculation processing on the evaluation value sequence, motion value sequence set and motor drive value set of the current time period to obtain the motor drive value set of the next time moment.

4. The microgravity simulation method as described in claim 3, characterized in that, The step of performing fusion feedback calculation on the evaluation value sequence, the motion value sequence set, and the motor drive value set for the current time period to obtain the motor drive value set for the next time moment includes: S421, obtains the standard gravity value and the standard acceleration values ​​of the X-axis, Y-axis and Z-axis under standard gravity; S422, for each sequence in the received motion value sequence set, subtract the standard value of the corresponding type to obtain the corresponding difference sequence; S423, Perform feature transformation on each differential sequence to obtain the corresponding differential feature value; S424, construct a sequence of differential feature values ​​using all differential feature values; S425, perform feedback calculation processing on the evaluation value sequence and the difference feature value sequence to obtain the fusion feedback quantity sequence; S426, perform feedback fusion calculation processing on the fused feedback quantity sequence and the motor drive value set of the current time period to obtain the motor drive value set of the next time period.

5. The microgravity simulation method as described in claim 4, characterized in that, The expression for the feedback calculation is: ， in, This represents the i-th fusion feedback quantity in the fusion feedback quantity sequence; The expression for the feedback fusion calculation process is: ， in, This represents the drive value of the motor at the current time t for the i-th bearing. This represents the drive value of the motor at time t+1 for the i-th bearing, where i can be 1, 2, 3, or 4. This is a preset proportionality constant.

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