Frequency band extension type compound vibration table control system and method based on MRAC-TVC

Abstract

The application discloses a frequency band expansion type composite vibration table control system and method based on MRAC-TVC, which is applied to a frequency band expansion type composite vibration table, and the frequency band expansion type composite vibration table comprises a lower layer low-frequency vibration table, a low-frequency long-stroke servo actuator, an upper layer high-frequency vibration table and a high-frequency short-stroke servo actuator. The control system comprises a lower layer low-frequency table control system and an upper layer high-frequency table control system. The lower layer low-frequency table control system comprises the lower layer low-frequency vibration table, the low-frequency long-stroke servo actuator, a low-frequency table inner closed loop subsystem and a low-frequency table outer closed loop subsystem. The upper layer high-frequency table control system comprises the upper layer high-frequency vibration table, the high-frequency short-stroke servo actuator, a high-frequency table inner closed loop subsystem and a high-frequency table outer closed loop subsystem. The application not only increases the robustness of a seismic simulation vibration table system to cope with load changes when the system is affected by dynamic responses of an experimental structure, but also avoids early damage of the experimental structure.

Description

Technical Field

[0001] This invention relates to the field of earthquake simulation technology, and in particular to a band-extended composite shaking table control system and method based on MRAC-TVC. Background Technology

[0002] Earthquakes are unpredictable natural phenomena, and the resulting structural damage is a major cause of loss of life and property. To ensure the reliability and necessary service life of engineering structures or buildings, shaking table testing is currently the most widely used and direct testing method. This method involves fixing the specimen to a shaking table and exciting the table to reproduce a specified vibration state through actuators. This testing method has significant advantages in studying structural dynamic characteristics, seismic performance, and structural failure mechanisms.

[0003] With the development of building structural systems, shaking table tests need to adapt to the requirements of different specimens. On the one hand, they need to be able to simulate the dynamic response of structures such as buildings and bridges under low-frequency, long-period earthquakes; on the other hand, they need to be able to simulate the dynamic response of structures such as dams and nuclear power plants under high-frequency, short-stroke earthquakes. This places demands on shaking tables for long-stroke and wide-bandwidth loading. However, traditional large shaking tables typically have a low bandwidth while performing long-stroke motion. To address this, a novel shaking table structure is used, where an upper high-frequency stage is mounted on a lower low-frequency stage, forming a composite shaking table that simultaneously includes both wide-bandwidth and long-stroke actuators—the bandwidth-extended composite shaking table. However, in actual vibration processes, the bandwidth-extended composite shaking table generates significant tracking errors due to the coupling effect between the upper high-frequency stage and the lower low-frequency stage, as well as the difference in bandwidth, thus affecting the control effect. Therefore, it is necessary to design a control algorithm to achieve long-stroke, wide-bandwidth excitation of the shaking table.

[0004] Therefore, proposing a frequency band extended composite vibration table control system and method based on MRAC-TVC to solve the difficulties existing in the prior art is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a frequency band extended composite shaking table control system and method based on MRAC-TVC, which not only increases the robustness of the earthquake simulation shaking table system to load changes when affected by the dynamic response of the experimental structure, but also avoids premature damage to the experimental structure.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A frequency band extended composite vibration table control system based on MRAC-TVC is applied to a frequency band extended composite vibration table. The frequency band extended composite vibration table includes a lower low-frequency vibration table, a low-frequency long-stroke servo actuator, an upper high-frequency vibration table, and a high-frequency short-stroke servo actuator. The control system includes a lower low-frequency table control system and an upper high-frequency table control system.

[0008] The lower-level low-frequency stage control system includes a lower-level low-frequency vibration table, a low-frequency long-stroke servo actuator, an inner closed-loop subsystem of the low-frequency stage, and an outer closed-loop subsystem of the low-frequency stage; the upper-level high-frequency stage control system includes an upper-level high-frequency vibration table, a high-frequency short-stroke servo actuator, an inner closed-loop subsystem of the high-frequency stage, and an outer closed-loop subsystem of the high-frequency stage.

[0009] The low-frequency external closed-loop subsystem is a TVC control system based on displacement, velocity, and acceleration feedback from a low-frequency long-stroke servo actuator, while the low-frequency internal closed-loop subsystem is an MRAC control system based on acceleration feedback from a low-frequency long-stroke servo actuator. The high-frequency external closed-loop subsystem is a TVC control system based on displacement, velocity, and acceleration feedback from a high-frequency short-stroke servo actuator, while the high-frequency internal closed-loop subsystem is an MRAC control system based on acceleration feedback from a high-frequency short-stroke servo actuator.

[0010] Preferably, an acceleration sensor is installed on the lower low-frequency vibration table to record the acceleration response of the lower low-frequency vibration table relative to the ground for each degree of freedom. The displacement signal fed back by the lower actuator is processed by the degree of freedom synthesis matrix to obtain the displacement response of the lower low-frequency vibration table relative to the ground for each degree of freedom. The velocity response of each degree of freedom is obtained by calculating the acceleration and displacement response.

[0011] Preferably, an acceleration sensor is installed on the upper high-frequency vibration table to record the acceleration response of the upper high-frequency vibration table relative to the ground for each degree of freedom. The displacement signal fed back by the upper actuator is processed by the degree of freedom synthesis matrix to obtain the displacement response of the upper high-frequency vibration table relative to the ground for each degree of freedom. The velocity response of each degree of freedom is obtained by calculating the acceleration and displacement response.

[0012] A band-extended composite vibration table control method based on MRAC-TVC, applied to any of the above-mentioned band-extended composite vibration table control systems based on MRAC-TVC, includes the following steps:

[0013] S1. Set the target seismic wave, and obtain the time domain signal of the low-frequency seismic wave and the time domain signal of the high-frequency seismic wave after frequency division of the target seismic wave.

[0014] S2. Input the time-domain signals of low-frequency and high-frequency seismic waves to the lower-level low-frequency station external closed-loop subsystem and the upper-level high-frequency station external closed-loop subsystem, respectively.

[0015] After feedforward and feedback control of the outer closed-loop subsystems of S3, the input signal of the inner closed-loop subsystem is obtained and input to the inner closed-loop subsystems of the lower low-frequency stage and the upper high-frequency stage. This results in the acquisition of control signals for driving the low-frequency long-stroke servo actuator and the high-frequency short-stroke servo actuator. The control signals are then processed by the degree-of-freedom decomposition matrix to drive the motion of each actuator, ultimately enabling the upper high-frequency vibration table and the lower low-frequency vibration table to perform three-axis six-degree-of-freedom motion.

[0016] S4. The position signals of each degree of freedom of the upper high-frequency shaking table and the lower low-frequency shaking table are obtained by the preset actuator displacement sensor after degree of freedom synthesis. The acceleration signals of each degree of freedom of the upper high-frequency shaking table and the lower low-frequency shaking table are obtained by the preset table body acceleration sensor, and the velocity signals of each degree of freedom are calculated. These signals are fed back to the control systems of the upper high-frequency shaking table and the lower low-frequency shaking table, respectively. The control system enables the frequency band extended composite shaking table to reproduce the target seismic wave signal.

[0017] Preferably, the method for frequency division of the target seismic wave in S1 is the FFT / IFFT method, and the frequency division frequency is within the frequency range that can be achieved by the lower-level low-frequency shaking table.

[0018] Preferably, the design of the MRAC controller in the low-frequency and high-frequency closed-loop subsystems of S3 specifically includes the following steps:

[0019] S301. The shaking table and test specimen are used as the controlled objects of the MRAC controller, and the low-frequency seismic wave signal and the high-frequency seismic wave signal are used as the output signals of the inner closed-loop reference models of the lower low-frequency station and the upper high-frequency station, respectively.

[0020] S302. The state equations of the inner closed-loop reference model are obtained through identification of the inner closed-loop subsystem:

[0021]

[0022] Where, x m (t) is the reference model state vector, u m (t) represents the input signal of the reference model, and y represents the acceleration time history record of the seismic wave in the seismic simulation shaking table system. m (t) is the output state vector of the reference model, A m B is the state matrix of the reference model. m and C m These are the input and output matrices of the reference model, respectively;

[0023] S303. A state-variable-based MRAC control is adopted, using an adaptive rate to adjust the parameters of the state feedback controller and the feedforward controller online; the Lyapunov function is selected as follows:

[0024]

[0025] Among them, e x (t) is the generalized error signal, and P is a symmetric positive definite matrix. and Let represent a symmetric positive definite constant matrix with appropriate dimensions. This is the parameter error vector of the state feedback controller. This is the parameter error vector of the state feedforward controller;

[0026] For any symmetric positive definite matrix Q, there exists a symmetric positive definite matrix P that satisfies the Lyapunov equation:

[0027] A m T P+PA m =-Q

[0028] The MRAC adaptive rate, used to adjust the error between the output of the controlled object and the output of the reference model, and to make the dynamic characteristics of the controlled object consistent with the reference model, is expressed as follows:

[0029]

[0030] Among them, K p [e y [t], where t] is the time-varying feedback gain matrix with m×n dimensional parameters, and K u [e y (t), where t] is the m×m dimensional time-varying feedforward gain matrix with parameters Γ p and Γ u Let represent a symmetric positive definite constant matrix with appropriate dimensions. Let e ​​be the feedforward gain at a certain time. y (t) represents the acceleration tracking error, y z (τ) is the output state vector of the controlled object, u m (τ) represents the control signal of the model reference adaptive controller, K p (0), K u (0) represents the initial time feedback and feedforward control parameters, respectively.

[0031] Preferably, the derivation process of the MRAC adaptive rate is as follows:

[0032] The MRAC adaptive rate, used to adjust the error between the output of the controlled object and the output of the reference model, and to make the dynamic characteristics of the controlled object consistent with the reference model, is expressed as follows:

[0033]

[0034] Where, x s (τ) is an n-dimensional state vector containing the table and test structure in the earthquake simulation shaking table system; the transfer function G of the reference model, i.e., the shaking table, is constructed. m (s)=C m (sI-A m ) -1 B m Since it is a strictly positive real function, the MRAC adaptive rate simplifies to: according to the Kalman-Yakubovich lemma, it is:

[0035]

[0036] In a bandwidth-extended composite vibration table system, the desired output signal is the acceleration signal from the upper high-frequency stage and the lower low-frequency stage. The inner closed-loop subsystem adjusts the control parameters in real time based on the acceleration errors of the upper high-frequency stage and the lower low-frequency stage, respectively. The outer closed-loop subsystem reproduces the velocity or displacement signal. At this time, the parameters of the MRAC controller are adjusted as follows:

[0037]

[0038] A non-transitory computer-readable storage medium storing a computer program that, when executed by a processor, implements a band-extended composite vibration table control method based on MRAC-TVC as described above.

[0039] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0040] (1) The present invention introduces an MRAC controller, which adjusts the controller parameters online in real time through adaptive rules, without the need to obtain an accurate mathematical model of the controlled object in advance. This not only increases the robustness of the earthquake simulation shaking table system in coping with load changes when affected by the dynamic response of the experimental structure, but also avoids premature damage to the experimental structure.

[0041] (2) By introducing an outer closed-loop TVC controller, the inner closed-loop MRAC controller only needs to adjust the control parameters in real time according to the acceleration error of the upper high-frequency station and the lower low-frequency station, which can effectively reduce the order of the MRAC controller parameters and improve ease of use.

[0042] (3) In view of the structure of the frequency band extended composite vibration table, the present invention adopts the MRAC-TVC joint control method for the upper high frequency table and the lower low frequency table respectively, so that it can accurately reproduce the target broadband seismic wave signal. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A schematic diagram of the mechanical structure of the frequency band extended composite vibration table applying the control algorithm of this invention;

[0045] Figure 2 A schematic diagram of the control system of the bandwidth-extended composite vibration table applying the control algorithm of the present invention;

[0046] Figure 3 This is a block diagram of a band-extended composite vibration table control system based on MRAC-TVC according to the present invention.

[0047] Figure 4 This is a block diagram of a state-variable-based MRAC system. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] Since this invention is based on the control method of the existing vibration table control system, only a brief description of the traditional vibration table mechanical structure is given. Figure 1 As shown, according to the large-load test frequency and area scalable modular vibration table disclosed in CN211784164U, a frequency-expanding composite vibration table is constructed. The lower low-frequency stage is equipped with horizontal low-frequency long-stroke servo actuators on all four sides and vertical low-frequency long-stroke servo actuators on the bottom. The upper high-frequency stage is equipped with horizontal high-frequency short-stroke servo actuators on all four sides and vertical high-frequency short-stroke servo actuators on the bottom. By inputting frequency-divided excitation to a multi-channel motion controller, the lower low-frequency stage performs long-stroke low-frequency motion, while the upper high-frequency stage performs short-stroke high-frequency motion relative to the lower low-frequency stage. This allows the acceleration response of the upper high-frequency stage to contain both high-frequency and low-frequency components of the seismic wave, ultimately accurately reproducing a wider range of seismic waves.

[0051] like Figure 2 As shown, the present invention provides a frequency band extended composite vibration table control system based on MRAC-TVC, which consists of a host computer / controller and a drive device, forming a lower-level low-frequency table control system and an upper-level high-frequency table control system, respectively, to realize the control of the frequency band extended composite vibration table (controlled object).

[0052] It is applied to a frequency band extended composite vibration table, which includes a lower low-frequency vibration table, a low-frequency long-stroke servo actuator, an upper high-frequency vibration table, and a high-frequency short-stroke servo actuator. The control system includes a lower low-frequency table control system and an upper high-frequency table control system.

[0053] The lower-level low-frequency stage control system includes a lower-level low-frequency vibration table, a low-frequency long-stroke servo actuator, an inner closed-loop subsystem of the low-frequency stage, and an outer closed-loop subsystem of the low-frequency stage; the upper-level high-frequency stage control system includes an upper-level high-frequency vibration table, a high-frequency short-stroke servo actuator, an inner closed-loop subsystem of the high-frequency stage, and an outer closed-loop subsystem of the high-frequency stage.

[0054] The low-frequency station's external closed-loop subsystem is a TVC control system based on displacement, velocity, and acceleration feedback from long-stroke servo actuators, while the low-frequency station's internal closed-loop subsystem is an MRAC control system based on acceleration feedback from long-stroke servo actuators. The high-frequency station's external closed-loop subsystem is a TVC control system based on displacement, velocity, and acceleration feedback from short-stroke servo actuators, while the high-frequency station's internal closed-loop subsystem is an MRAC control system based on acceleration feedback from short-stroke servo actuators. Input / output is achieved through corresponding I / O ports within the lower-level low-frequency station control system and the upper-level high-frequency station control system, enabling operators to build a bandwidth-extended composite vibration table control system based on the existing vibration table control system.

[0055] Furthermore, an acceleration sensor is installed on the lower low-frequency vibration table to record the acceleration response of the lower low-frequency vibration table relative to the ground. The displacement signal fed back by the lower actuator is processed by the degree-of-freedom synthesis matrix to obtain the displacement response of the lower low-frequency vibration table relative to the ground. The velocity response of each degree of freedom is obtained by calculating the acceleration and displacement response.

[0056] Furthermore, an acceleration sensor is installed on the lower low-frequency vibration table to record the acceleration response of the lower low-frequency vibration table relative to the ground for each degree of freedom. The displacement signal fed back by the lower actuator is processed by the degree of freedom synthesis matrix to obtain the displacement response of the lower low-frequency vibration table relative to the ground for each degree of freedom. The velocity response of each degree of freedom is obtained by calculating the acceleration and displacement response.

[0057] A band-extended composite vibration table control method based on MRAC-TVC, such as Figure 3As shown, the MRAC-TVC-based band-extended composite vibration table control system applied to any of the above includes the following steps:

[0058] S1. Set the target seismic wave, and obtain the time domain signal of the low-frequency seismic wave and the time domain signal of the high-frequency seismic wave after frequency division of the target seismic wave.

[0059] S2. Input the time-domain signals of low-frequency and high-frequency seismic waves to the lower-level low-frequency station external closed-loop subsystem and the upper-level high-frequency station external closed-loop subsystem, respectively.

[0060] After feedforward and feedback control of the outer closed-loop subsystems of S3, the input signal of the inner closed-loop subsystem is obtained and input to the inner closed-loop subsystems of the lower low-frequency stage and the upper high-frequency stage. This results in the acquisition of control signals for driving the low-frequency long-stroke servo actuator and the high-frequency short-stroke servo actuator. The control signals are then processed by the degree-of-freedom decomposition matrix to drive the motion of each actuator, ultimately enabling the upper high-frequency vibration table and the lower low-frequency vibration table to perform three-axis six-degree-of-freedom motion.

[0061] S4. The position signals of each degree of freedom of the upper high-frequency shaking table and the lower low-frequency shaking table are obtained by the preset actuator displacement sensor after degree of freedom synthesis. The acceleration signals of each degree of freedom of the upper high-frequency shaking table and the lower low-frequency shaking table are obtained by the preset table body acceleration sensor, and the velocity signals of each degree of freedom are calculated. These signals are fed back to the control systems of the upper high-frequency shaking table and the lower low-frequency shaking table, respectively. The control system enables the frequency band extended composite shaking table to reproduce the target seismic wave signal.

[0062] Furthermore, in S1, the frequency division of the target seismic wave in the frequency domain adopts the FFT / IFFT method, and the division frequency is within the achievable frequency range of the lower low-frequency shaking table. The time-domain signals of the low-frequency and high-frequency seismic waves are input to the outer closed-loop subsystems of the lower low-frequency table and the upper high-frequency table, respectively. After feedforward and feedback control by the outer closed-loop subsystems of the lower low-frequency table and the upper high-frequency table, the input signal of the inner closed-loop subsystem is obtained, and finally, the control signals used to drive the low-frequency long-stroke servo actuator and the high-frequency short-stroke servo actuator are obtained, which drive the upper high-frequency table and the lower low-frequency table to move, respectively. The position, velocity, and acceleration signals of the upper high-frequency table and the lower low-frequency table are obtained by sensors and fed back to their respective control systems, enabling the frequency band extended composite shaking table to reproduce the target seismic wave signal.

[0063] Furthermore, the design of the MRAC controller in the S3 low-frequency and high-frequency closed-loop subsystems is as follows: Figure 4 As shown, the specific steps include the following:

[0064] S301. The shaking table and test specimen are used as the controlled objects of the MRAC controller. Furthermore, for the shaking table system, the desired output of the controlled object is very clear, which is the desired seismic wave time history record. Therefore, the low-frequency seismic wave signal and the high-frequency seismic wave signal are used as the output signals of the inner closed-loop reference model of the low-frequency table and the high-frequency table, respectively.

[0065] S302. The state equations of the inner closed-loop reference model are identified through the inner closed-loop subsystem (no exact model required):

[0066]

[0067] Where, x m (t) is the reference model state vector, u m (t) represents the input signal of the reference model, and y represents the acceleration time history record of the seismic wave in the seismic simulation shaking table system. m (t) is the output state vector of the reference model, A m B is the state matrix of the reference model. m and C m These are the input and output matrices of the reference model, respectively;

[0068] S303. A state-variable-based MRAC control is adopted, using an adaptive rate to adjust the parameters of the state feedback controller and the feedforward controller online; the Lyapunov function is selected as follows:

[0069]

[0070] Among them, e x (t) is the generalized error signal, and P is a symmetric positive definite matrix. and Let represent a symmetric positive definite constant matrix with appropriate dimensions. This is the parameter error vector of the state feedback controller. This is the parameter error vector of the state feedforward controller;

[0071] To ensure stable convergence of the system, for any symmetric positive definite matrix Q, there exists a symmetric positive definite matrix P that satisfies the Lyapunov equation:

[0072] A m T P+PA m =-Q

[0073] The MRAC adaptive rate, used to adjust the error between the output of the controlled object and the output of the reference model, and to make the dynamic characteristics of the controlled object consistent with the reference model, is expressed as follows:

[0074]

[0075] Among them, K p [e y (t), where t] is the m×n dimensional time-varying feedback gain matrix, K u [e y (t), where t] is the m×m dimensional time-varying feedforward gain matrix with parameters Γ p ,Γ u To represent a symmetric positive definite constant matrix with appropriate dimensions, Let e ​​be the feedforward gain at a certain moment. y (t) represents the acceleration tracking error, y z (τ) is the output state vector of the controlled object, u m (τ) represents the control signal of the model reference adaptive controller, K p (0), K u (0) represents the initial time feedback and feedforward control parameters, respectively.

[0076] Furthermore, the derivation process of the MRAC adaptive rate is as follows:

[0077] The MRAC adaptive rate, used to adjust the error between the output of the controlled object and the output of the reference model, and to make the dynamic characteristics of the controlled object consistent with the reference model, is expressed as follows:

[0078]

[0079] Where, x s (τ) is an n-dimensional state vector containing the table and test structure in the earthquake simulation shaking table system; the transfer function G of the reference model, i.e., the shaking table, is constructed. m (s)=c m (sI-A m ) -1 B m Since it is a strictly positive real function, the MRAC adaptive rate simplifies to: according to the Kalman-Yakubovich lemma, it is:

[0080]

[0081] In a frequency band-extended composite shaking table system, the desired output signal is the acceleration signal from the upper high-frequency stage and the lower low-frequency stage. The inner closed-loop subsystem adjusts its control parameters in real time based on the acceleration errors of the upper high-frequency stage and the lower low-frequency stage, respectively. The outer closed-loop subsystem reproduces the velocity or displacement signal, thereby ensuring accurate reproduction of the target seismic wave. At this time, the parameters of the MRAC controller are adjusted as follows:

[0082]

[0083] A non-transitory computer-readable storage medium storing a computer program that, when executed by a processor, implements a band-extended composite vibration table control method based on MRAC-TVC as described above.

[0084] The MRAC-TVC joint control method combines the MRAC controller with the TVC controller in a traditional seismic simulation shaking table to achieve better control performance. This method enables precise control and optimization of the bandwidth-extended composite shaking table system, effectively ensuring system stability and robustness.

[0085] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0086] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A MRAC-TVC-based band-expanded compound shaker control system applied to a band-expanded compound shaker, the band-expanded compound shaker comprising a lower layer low-frequency shaker, a low-frequency long-stroke servo actuator, an upper layer high-frequency shaker, and a high-frequency short-stroke servo actuator, characterized in that, The control system comprises a lower low-frequency table control system and an upper high-frequency table control system; The lower low-frequency table control system comprises a lower low-frequency vibration table, a low-frequency long-stroke servo actuator, a low-frequency inner-loop subsystem and a low-frequency outer-loop subsystem; the upper high-frequency table control system comprises an upper high-frequency vibration table, a high-frequency short-stroke servo actuator, a high-frequency inner-loop subsystem and a high-frequency outer-loop subsystem. The low-frequency outer-loop subsystem is a TVC control system based on displacement, velocity and acceleration feedback of the low-frequency long-stroke servo actuator; the low-frequency inner-loop subsystem is an MRAC control system based on acceleration feedback of the low-frequency long-stroke servo actuator; the high-frequency outer-loop subsystem is a TVC control system based on displacement, velocity and acceleration feedback of the high-frequency short-stroke servo actuator; and the high-frequency inner-loop subsystem is an MRAC control system based on acceleration feedback of the high-frequency short-stroke servo actuator.

2. The MRAC-TVC based frequency band extended compound shaker control system of claim 1, wherein, An acceleration sensor is mounted on the lower low-frequency vibration table to record acceleration responses of each degree of freedom of the lower low-frequency vibration table relative to the ground; displacement signals fed back by the lower actuator are subjected to a degree-of-freedom synthesis matrix to obtain displacement responses of each degree of freedom of the lower low-frequency vibration table relative to the ground; and velocity responses of each degree of freedom are obtained by calculating the acceleration and displacement responses.

3. The MRAC-TVC based frequency band extended compound shaker control system of claim 2, wherein, An acceleration sensor is mounted on the upper high-frequency vibration table to record acceleration responses of each degree of freedom of the upper high-frequency vibration table relative to the ground; displacement signals fed back by the upper actuator are subjected to a degree-of-freedom synthesis matrix to obtain displacement responses of each degree of freedom of the upper high-frequency vibration table relative to the ground; and velocity responses of each degree of freedom are obtained by calculating the acceleration and displacement responses.

4. A MRAC-TVC-based frequency band extension type compound shaker control method, applied to the MRAC-TVC-based frequency band extension type compound shaker control system of any one of claims 1-3, characterized in that, The method comprises the following steps: S1, a target seismic wave is set, and the target seismic wave is divided into a low-frequency seismic wave time-domain signal and a high-frequency seismic wave time-domain signal in the frequency domain; S2, the low-frequency and high-frequency seismic wave time-domain signals are input into the lower low-frequency outer-loop subsystem and the upper high-frequency outer-loop subsystem, respectively; S3, after feedforward and feedback control of the outer-loop subsystems of the lower low-frequency table and the upper high-frequency table, input signals of the inner-loop subsystems are obtained, which are input into the inner-loop subsystems of the lower low-frequency table and the upper high-frequency table, and then control signals for driving the low-frequency long-stroke servo actuator and the high-frequency short-stroke servo actuator are obtained, the control signals are subjected to a degree-of-freedom decomposition matrix to drive each actuator to move, and finally the upper high-frequency vibration table and the lower low-frequency vibration table are enabled to move in three directions and six degrees of freedom; S4, position signals of each degree of freedom of the upper high-frequency vibration table and the lower low-frequency vibration table are obtained through preset actuator displacement sensors and degree-of-freedom synthesis, acceleration signals of each degree of freedom of the upper high-frequency vibration table and the lower low-frequency vibration table are obtained through preset table body acceleration sensors, and velocity signals of each degree of freedom are calculated and fed back to the control systems of the upper high-frequency vibration table and the lower low-frequency vibration table, respectively, so that the frequency band expansion type compound vibration table can reproduce the target seismic wave signal through the control systems.

5. The MRAC-TVC-based frequency-banded composite shaker control method of claim 4, wherein, The method for frequency division of the target seismic wave in the S1 adopts an FFT / IFFT method, and the frequency division frequency is located in the frequency range that can be realized by the lower layer low-frequency shaking table.

6. The MRAC-TVC-based frequency-banded composite shaker control method of claim 4, wherein, The design of the MRAC controller in the low-frequency table inner closed-loop subsystem and the high-frequency table inner closed-loop subsystem in the S3 specifically includes the following steps: S301, taking the shaking table and the test specimen as the controlled object of the MRAC controller, and taking the low-frequency seismic wave signal and the high-frequency seismic wave signal as the output signals of the inner closed-loop reference model of the lower layer low-frequency table and the upper layer high-frequency table respectively; S302, obtaining the state equation of the inner closed-loop reference model through identification of the inner closed-loop subsystem: where x m (t) is the reference model state vector, u m (t) is the input signal of the reference model, which is the acceleration time history record of the seismic wave in the seismic simulation shaking table system, y m (t) is the output state vector of the reference model, A m is the state matrix of the reference model, B m and C m are the input and output matrices of the reference model, respectively; S303, adopting the MRAC control based on the state variable, and using the adaptive rate to adjust the parameters of the state feedback controller and the feedforward controller online; selecting the Lyapunov function as: where e x (t) is a generalized error signal, P is a symmetric positive definite matrix, and denotes a symmetric positive definite constant matrix of appropriate dimension, is a parameter error vector for the state feedback controller, is a parameter error vector for the state feedforward controller; For any symmetric positive definite matrix Q, there exists a symmetric positive definite matrix P satisfying the Lyapunov equation: A m T P+PA m = -Q The MRAC adaptive rate for adjusting the error between the output of the controlled object and the output of the reference model, and making the dynamic characteristics of the controlled object consistent with the reference model is obtained, and the expression is as follows: where K p [e y (t), t] is an m x n dimensional parameter-varying feedback gain matrix, K u [e y (t), t] is an m x m dimensional parameter-varying feedforward gain matrix, and is a symmetric positive definite constant matrix with appropriate dimension, is the feedforward gain at time t, e y (t) is the acceleration tracking error, y z (τ) is the output state vector of the controlled object, u m (τ) is the control signal of the model reference adaptive controller, K p (0), K u (0) are the initial feedback and feedforward control parameters, respectively.

7. The MRAC-TVC-based frequency-banded composite shaker control method of claim 6, wherein, The MRAC adaptive rate derivation process is as follows: The MRAC adaptive rate for adjusting the error between the output of the controlled object and the output of the reference model, and making the dynamic characteristics of the controlled object consistent with the reference model is obtained, and the expression is as follows: where x s (τ) is the n-dimensional state vector of the table and the test structure in the seismic simulation shaking table system; the transfer function G m (s) of the shaking table is constructed as the reference model m (sI-A m ) -1 B m is a strictly positive real function, then the MRAC adaptive rate is simplified according to the Kalman-Yakubovich lemma: In the frequency band expansion type composite shaking table system, the expected output signal is the acceleration signal of the upper layer high-frequency table and the lower layer low-frequency table, the inner closed-loop subsystem adjusts the control parameters in real time according to the acceleration error of the upper layer high-frequency table and the lower layer low-frequency table, and the outer closed-loop subsystem reproduces the velocity signal or the displacement signal; at this time, the parameter adjustment of the MRAC controller is:

8. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize a frequency band expansion type composite shaking table control method based on MRAC-TVC according to any one of claims 4 to 7. The computer program is executed by the processor to realize a frequency band expansion type composite shaking table control method based on MRAC-TVC according to any one of claims 4 to 7.

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