A seismic simulation shaking table control method for combined seismic wave and current loading

Abstract

The present invention discloses a seismic simulation vibration table control method for combined seismic wave and flow loading, comprising the following steps: establishing a seismic simulation vibration table system and a control system; using the target seismic wave and the actual acceleration signal of the vibration table body as feedback signals, and inputting them into the control system; the control system comprises: an anti-disturbance control loop, a PID control loop and an acceleration outer closed loop; the acceleration outer closed loop is used to obtain a corrected actual acceleration signal; the anti-disturbance control loop is used to generate control instructions in six-degree-of-freedom directions; the PID control loop is used to convert the control instructions into control signals for each actuator in the seismic simulation vibration table system through a degree-of-freedom decomposition matrix; the present invention reduces the influence of water dynamics such as waves and flows and their internal resonance on the system accuracy by designing the PID control loop, the anti-disturbance control loop and the acceleration outer closed loop for the seismic simulation vibration table system, thereby achieving accurate tracking of the seismic wave acceleration signal.

Description

Technical Field

[0001] The present invention relates to the technical field of earthquake simulation experiments, and more particularly to a method for controlling an earthquake simulation vibration table for combined loading of earthquake waves and currents. Background Art

[0002] Earthquakes are destructive and unpredictable natural phenomena. To minimize the economic losses and casualties caused by earthquakes, it is crucial to design building structures for seismic resistance that meets the comprehensive safety and economic requirements of engineering structures under earthquakes. Due to the high uncertainty of earthquake occurrence, it is difficult to conduct structural seismic research under actual earthquake conditions. Seismic simulation shake tables can simulate ground motions in a laboratory environment and test structural reliability, thereby improving structural seismic resistance and enabling targeted reinforcement of existing structures.

[0003] The earthquake simulation vibration table is generally composed of a controller, an actuator, a vibration table body, and a building foundation. The controller obtains the actuator command through calculation, drives the actuator, and the actuator drives the vibration table surface to move. The earthquake simulation vibration table can realize the movement along the X, Y, Z, R x 、R y 、R z Movement in six degrees of freedom.

[0004] In existing control methods, the hydrodynamic effects of waves and fluids on the vibration table body / specimen are generated. These effects, together with the characteristics of the hydraulic system, the performance of the sensors, and other nonlinear factors, cause the vibration table system to exhibit obvious nonlinearity and uncertainty, making it difficult to achieve the control effect required for the experiment. Summary of the Invention

[0005] The purpose of the present invention is to provide a seismic simulation vibration table control method for combined seismic wave and current loading. By designing a PID control loop, an anti-disturbance control loop and an acceleration outer closed loop for the seismic simulation vibration table respectively, the hydrodynamic effects of waves and water currents on the seismic simulation vibration table system are reduced, and the control accuracy of the vibration table body is improved.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for controlling an earthquake simulation shaking table for combined seismic wave and current loading, comprising the following steps:

[0008] Establish earthquake simulation shaking table system and control system;

[0009] The target seismic wave is used as a reference signal, and the actual acceleration signal of the shaking table body in the earthquake simulation shaking table system is used as a feedback signal, and both are input into the control system;

[0010] The control system includes: an anti-disturbance control loop, a PD control loop and an acceleration outer closed loop;

[0011] The acceleration outer closed loop is used to compare the reference signal of the vibration table body with the feedback signal, and obtain the corrected actual acceleration signal through error correction;

[0012] The anti-disturbance control loop is used to compensate and process the corrected actual acceleration signal and the velocity signal and displacement signal of the vibration table in the six degrees of freedom directions, and generate control instructions in the six degrees of freedom directions;

[0013] The PD control loop is used to convert control instructions into control signals for each actuator in the earthquake simulation vibration table system through the degree of freedom decomposition matrix, thereby driving the vibration table body to move in six degrees of freedom directions through each actuator, and feeding back the velocity signals and displacement signals of the vibration table body in the six degrees of freedom directions to the anti-disturbance control loop.

[0014] Furthermore, the earthquake simulation shaking table system includes a building foundation, a shaking table body, a plurality of lateral actuators, and a plurality of vertical actuators;

[0015] The building foundation is used to provide a support platform for the vibration table body;

[0016] The vibration table body is used to generate seismic wave motion corresponding to the target seismic wave;

[0017] The plurality of lateral actuators and the plurality of vertical actuators are used to apply force and displacement to the vibration table body to simulate seismic waves of different intensities and frequency characteristics;

[0018] The plurality of lateral actuators and the plurality of vertical actuators are each provided with a displacement sensor, and the displacement sensor is used to measure and feed back the actual displacement signal of each actuator;

[0019] The vibration table body is provided with an acceleration sensor for measuring the actual acceleration signal of the vibration table body in the six degrees of freedom directions;

[0020] The vibration table body is movably connected to the building foundation through a plurality of transverse actuators and a plurality of vertical actuators.

[0021] Furthermore, the sampling time of the target seismic wave is 0.001s, and the seismic wave in the 0.1-25 Hz frequency band is extracted by FFT / IFFT.

[0022] Furthermore, the correction strategy of the acceleration outer closed loop is:

[0023] The actual acceleration signal of the vibration table after Kalman filtering is subtracted from twice the target seismic wave signal.

[0024] Furthermore, the anti-disturbance control loop includes: an anti-disturbance controller;

[0025] The anti-disturbance controller includes: a notch filter, a signal generator and a state observer;

[0026] The notch filter is used to compensate for the resonance of the vibration table at a specific frequency to obtain a compensated acceleration signal;

[0027] The signal generator is used to process the compensated acceleration signal to obtain acceleration, velocity, and displacement signals respectively, and remove the low-frequency part to prevent the influence of zero offset;

[0028] The state observer is used to observe the velocity signal of the vibration table body in the six degrees of freedom direction and the total disturbance of the earthquake simulation vibration table system to obtain the velocity observation value and the total disturbance observation value output by the earthquake simulation vibration table system;

[0029] The anti-disturbance controller is used to design a state error feedback control law based on the acceleration, velocity and displacement signals obtained by the signal generator, combined with the velocity observation value, the displacement signal of the vibration table in the six degrees of freedom direction, and the total disturbance observation value.

[0030] Furthermore, the state observer is constructed as follows:

[0031] For any degree of freedom of the vibration table body, the earthquake simulation vibration table system is described as a system containing a total disturbance term. The expanded state space equation of the earthquake simulation vibration table system is as follows:

[0032]

[0033] Where u is the input velocity of the earthquake simulation shaking table system under this degree of freedom; x1 is the velocity of the shaking table body under this degree of freedom; is the derivative of the velocity x1 of the shaking table body under this degree of freedom; x2 is the total disturbance of the earthquake simulation shaking table system; is the derivative of the total disturbance x2 of the earthquake simulation shaking table system; y is the output velocity of the earthquake simulation shaking table system; b0 represents the characteristics of the controlled object;

[0034] The state observer is constructed using the expanded state space equation to obtain the observed values ​​of the velocity x1 and the total disturbance x2 of the vibration table body. The equation expression of the state observer is as follows:

[0035]

[0036] Where z1 is the observed value of velocity x1; is the derivative of the observed value z1 of the velocity x1; z2 is the observed value of the total disturbance x2; is the derivative of the observed value z2 of the total disturbance x2; is the observed value of the output velocity of the earthquake simulation shaking table system; β1 and β2 are the gains of the state observer.

[0037] Furthermore, the expression of the state error feedback control law is:

[0038]

[0039] Among them, k p , k i , k d are the gain of the velocity signal, the gain of the displacement signal, and the gain of the acceleration respectively. r is the velocity signal output by the signal generator, d1 is the displacement signal of the vibration table in the six degrees of freedom direction, z1 is the observed value of the velocity x1, z2 is the observed value of the total disturbance x2, b0 represents the characteristics of the controlled object, and s is the complex variable obtained by Laplace transforming the time domain function to the complex frequency domain.

[0040] Substituting the state error feedback control law into the first-order system expression, the closed-loop transfer function of the disturbance rejection controller is obtained:

[0041]

[0042] Among them, k p , k i , k d They are the gain of the velocity signal, the gain of the displacement signal and the gain of the acceleration.

[0043] Furthermore, the transfer function of the notch filter is:

[0044]

[0045] Where w is the notch frequency in rad / s, g is the notch gain, and c is the damping ratio.

[0046] Furthermore, the total disturbance includes: external disturbance and internal disturbance;

[0047] The external disturbance includes: the coupling effect of waves and water flow, the resonance effect of the test piece, each actuator and the vibration table body;

[0048] The internal disturbance includes: modeling errors and unmodeled parts of the earthquake simulation shaking table system.

[0049] Furthermore, the velocity signal and displacement signal of the vibration table in the six degrees of freedom direction are fed back to the anti-disturbance control loop; wherein the velocity signal of the vibration table in the six degrees of freedom direction is specifically:

[0050] The acceleration sensor is used to obtain the actual acceleration signal of the vibration table in the six degrees of freedom direction, and the Kalman filter is processed to obtain the velocity signal of the vibration table in the six degrees of freedom direction through the velocity synthesis method;

[0051] Among them, the velocity signal of the vibration table in the six degrees of freedom direction is obtained by the velocity synthesis method, specifically:

[0052] After low-pass filtering the actual displacement signals of each actuator, the displacement signals of the vibration table in the six degrees of freedom are obtained using the degree of freedom synthesis matrix.

[0053] The displacement signal of the vibration table body in the six degrees of freedom direction is differentiated and low-pass filtered, and the actual acceleration signal of the vibration table body in the six degrees of freedom direction is integrated and high-pass filtered. The sum of the two is then low-pass filtered to obtain the velocity signal of the vibration table body in the six degrees of freedom direction.

[0054] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0055] This method not only effectively reduces the impact of nonlinear factors on the control accuracy of seismic simulation vibration table systems during the combined loading process of seismic waves and water flows (such as the hydrodynamic effects of waves and water flows and their coupling effects, internal resonance, servo valve dead zone effects, friction, and flow nonlinearity); it also accurately tracks seismic wave acceleration signals. Furthermore, the method does not rely on a precise model of the controlled object, has low sensitivity to mathematical model parameters, facilitates parameter adjustment, and exhibits excellent anti-interference capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0057] The following further describes the earthquake simulation shaking table control method for earthquake wave and current combined loading according to the present invention with reference to the accompanying drawings;

[0058] Figure 1 Schematic diagram of the structure of the earthquake simulation vibration table in the earthquake simulation vibration table control method for earthquake wave and current combined loading provided by the present invention;

[0059] Figure 2 This is a control flow chart of the earthquake simulation shaking table control method for earthquake wave and current combined loading provided by the present invention;

[0060] Figure 3 This is a structural diagram of a signal generator in a method for controlling an earthquake simulation shaking table for combined seismic wave and current loading provided by the present invention;

[0061] Figure 4 It is a structural diagram of the velocity synthesis method in the earthquake simulation vibration table control method for earthquake wave and current combined loading provided by the present invention.

[0062] In the figure: 1. Vibration table body; 2. Horizontal actuator; 3. Vertical actuator; 4. Acceleration sensor; 5. Building foundation. DETAILED DESCRIPTION

[0063] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0064] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below with reference to the accompanying drawings.

[0065] The present invention provides a method for controlling an earthquake simulation shaking table for combined seismic wave and current loading, comprising the following steps:

[0066] like Figure 1 and Figure 2 As shown, an earthquake simulation shaking table system and a control system are established;

[0067] The target seismic wave is used as a reference signal, and the actual acceleration signal of the shaking table body in the earthquake simulation shaking table system is used as a feedback signal, and both are input into the control system;

[0068] The control system includes: an anti-disturbance control loop, a PID control loop and an acceleration outer closed loop;

[0069] The acceleration outer closed loop is used to compare the reference signal of the vibration table body with the feedback signal, and obtain the corrected actual acceleration signal through error correction;

[0070] The anti-disturbance control loop is used to compensate and process the corrected actual acceleration signal and the velocity signal and displacement signal of the vibration table in the six degrees of freedom directions, and generate control instructions in the six degrees of freedom directions;

[0071] The PID control loop is used to convert control instructions into control signals for each actuator in the earthquake simulation vibration table system through a degree of freedom decomposition matrix, thereby driving the vibration table body to move in six degrees of freedom directions through each actuator, and feeding back the velocity signals and displacement signals of the vibration table body in the six degrees of freedom directions to the anti-disturbance control loop.

[0072] It should be noted that the PID control loop designs PID feedback by measuring the speed / displacement signal of each actuator, and controls each actuator to perform linear motion according to the control signal.

[0073] like Figure 1 As shown, the earthquake simulation shaking table system includes a building foundation 5, a shaking table body 1, a plurality of lateral actuators 2, and a plurality of vertical actuators 3;

[0074] The building foundation 5 is used to provide a support platform for the vibration table body 1;

[0075] The vibration table body 1 is used to generate seismic wave motion corresponding to the target seismic wave signal;

[0076] The plurality of lateral actuators 2 and the plurality of vertical actuators 3 are used to apply force and displacement to the vibration table body 1 to simulate seismic waves of different intensities and frequency characteristics;

[0077] The several horizontal actuators 2 and the several vertical actuators 3 are each provided with a displacement sensor, which is used to measure and feed back the actual displacement signal of each actuator;

[0078] The vibration table body 1 is provided with an acceleration sensor 4 for measuring the actual acceleration signal of the vibration table body 1 in the six degrees of freedom direction;

[0079] The vibration table body 1 is movably connected to the building foundation 5 through a plurality of transverse actuators 2 and a plurality of vertical actuators 3.

[0080] The sampling time of the target seismic wave is 0.001s, and the seismic wave in the 0.1-25 Hz frequency band is extracted by FFT / IFFT, and the seismic wave peak value is set.

[0081] In this embodiment, the purpose of removing the low-frequency portion below 0.1 Hz is to prevent zero point drift.

[0082] The correction strategy of the acceleration outer closed loop is:

[0083] The actual acceleration signal of the vibration table body 1 after Kalman filtering is subtracted from twice the target seismic wave signal.

[0084] The anti-disturbance control loop is specifically: anti-disturbance controller;

[0085] The anti-disturbance controller includes: a notch filter, a signal generator and a state observer;

[0086] The notch filter is used to compensate for the resonance of the vibration table body 1 at a specific frequency to obtain a compensated acceleration signal;

[0087] The signal generator is used to process the compensated acceleration signal to obtain acceleration, velocity, and displacement signals respectively, and remove the low-frequency part to prevent the influence of zero offset;

[0088] The state observer is used to observe the velocity signal of the vibration table body 1 in the six-degree-of-freedom direction and the total disturbance of the earthquake simulation vibration table system to obtain the velocity observation value and the total disturbance observation value output by the earthquake simulation vibration table system;

[0089] The anti-disturbance controller is used to design a state error feedback control law based on the acceleration, velocity and displacement signals obtained by the signal generator, combined with the velocity observation value, the displacement signal of the vibration table body 1 in the six degrees of freedom direction, and the total disturbance observation value.

[0090] It should be noted that the output of the anti-disturbance controller is decomposed into the degree of freedom matrix to obtain the input signal of each actuator, and the displacement signal of each actuator is low-pass filtered and then the degree of freedom synthesis matrix is ​​used to obtain the displacement of the vibration table body 1 in the six degrees of freedom direction. The acceleration sensor 4 is then used to obtain the acceleration of the vibration table body 1 in the six degrees of freedom direction and the acceleration signal is processed by Kalman filtering. The velocity synthesis method is used to obtain the velocity of the vibration table body 1 in the six degrees of freedom direction as feedback for the anti-disturbance controller, as shown in FIG. Figure 4 The anti-disturbance controller outputs six-degree-of-freedom commands and generates control signals for each actuator through the degree-of-freedom decomposition matrix. By controlling each actuator, the vibration table body 1 is controlled to move in the six-degree-of-freedom directions.

[0091] The construction method of the state observer is:

[0092] For any degree of freedom of the vibration table body 1, the earthquake simulation vibration table system is described as a system containing a total disturbance term. The expanded state space equation of the earthquake simulation vibration table system is as follows:

[0093]

[0094] Where u is the input velocity of the earthquake simulation shaking table system under this degree of freedom, that is, the output of the anti-disturbance controller; x1 is the velocity of the shaking table body under this degree of freedom; is the derivative of the velocity x1 of the shaking table body under this degree of freedom; x2 is the total disturbance of the earthquake simulation shaking table system; is the derivative of the total disturbance x2 of the earthquake simulation shaking table system; y is the output velocity of the earthquake simulation shaking table system; b0 represents the characteristics of the controlled object.

[0095] Where b0 represents the gain of the controlled object or the zero-point gain of the transfer function between the input and output of the earthquake simulation shaking table system. b0 is an adjustable parameter. The larger the value, the more stable it is. As the value decreases, the control accuracy improves. It is selected from large to small according to the situation of the earthquake simulation shaking table system.

[0096] The state observer is constructed using the expanded state space equation to obtain the observed values ​​of the velocity x1 and the total disturbance x2 of the vibration table body. The equation expression of the state observer is as follows:

[0097]

[0098] Where z1 is the observed value of velocity x1; is the derivative of the observed value z1 of the velocity x1; z2 is the observed value of the total disturbance x2; is the derivative of the observed value z2 of the total disturbance x2; is the observed value of the output velocity of the earthquake simulation shaking table system; β1 and β2 are the gains of the state observer, which are related to the convergence speed of the state observation value.

[0099] Among them, β1 is the gain related to z1; β2 is the gain related to Z2, which can be determined by the linear observer design method according to the frequency bandwidth requirements, that is, all the characteristic roots of the state matrix are configured to the same point -w on the negative half axis of the real axis o At , the Lyapunov first stability condition is satisfied and the observed value can converge to the actual value.

[0100] The expression of the state error feedback control law is:

[0101]

[0102] Among them, k p , k i , k d are the gain of the velocity signal, the gain of the displacement signal, and the gain of the acceleration respectively. r is the velocity signal output by the signal generator, d1 is the displacement signal of the vibration table in the six degrees of freedom direction, z1 is the observed value of the velocity x1, z2 is the observed value of the total disturbance x2, b0 represents the characteristics of the controlled object, and s is the complex variable obtained by Laplace transforming the time domain function to the complex frequency domain.

[0103] In this embodiment, the various parameters of the anti-disturbance controller are determined according to the frequency bandwidth requirement of the seismic wave recurrence. For example, the upper limit of the angular frequency of the seismic wave recurrence bandwidth is m, in rad / s. The bandwidth of the anti-disturbance controller can be w c =1.3*m, the state observer bandwidth can be 4 times the controller bandwidth, that is, w o =5.2*m; then calculate the parameter β1 of the state observer matrix =2*wo , β2=w o 2 , b0 is selected from large to small according to the system stability, and the gain k can be determined by designing the closed-loop transfer function characteristics of the anti-disturbance controller p , k i , k d The value of k is usually p =2*0.707*w c , k i =w c 2 / 4, k d =1.

[0104] Substituting the state error feedback control law into the first-order system expression, the closed-loop transfer function of the disturbance rejection controller is obtained:

[0105]

[0106] Among them, k p , k i , k d They are the gain of the velocity signal, the gain of the displacement signal and the gain of the acceleration.

[0107] In this embodiment, the parameters of the anti-disturbance controller are determined according to the frequency bandwidth requirement of the seismic wave recurrence. For example, if the frequency bandwidth requirement of the seismic wave recurrence is 0-25Hz, the bandwidth of the anti-disturbance controller can be 1.3 times the bandwidth, that is, 32.5Hz. The angular rate is expressed as w c =32.5*2*π, the gain k can be taken according to the closed-loop transfer function of the anti-disturbance controller p =2*0.707*w c , k i =w c 2 / 4,k d =1. Based on experience, the observer bandwidth is taken as 4 times the anti-disturbance controller bandwidth, that is, w o =4*w c , observer matrix parameter β1=2*w o , β2=w o 2 , b0 is selected from large to small according to the stability of the earthquake simulation shaking table system. In this case, b0=800.

[0108] The transfer function of the notch filter is:

[0109]

[0110] Where w is the notch frequency in rad / s, g is the notch gain, and c is the damping ratio.

[0111] In this example, w is the notch frequency (unit: rad / s), g is the notch gain, and c is the damping ratio. Input white noise and identify the resonance peak frequency, amplitude, and bandwidth of each component and the vibration table body in the earthquake simulation vibration table system. These parameters are used to set the notch filter parameters. In this example, w = 2*π*18, g = 6, and c = 0.01.

[0112] The total disturbance includes external disturbance and internal disturbance;

[0113] The external disturbance includes: the coupling effect of waves and water flow, the resonance effect of the test piece, each actuator and the vibration table body 1;

[0114] The internal disturbance includes: modeling errors and unmodeled parts of the earthquake simulation shaking table system.

[0115] Feedback the velocity signal and displacement signal of the vibration table body 1 in the six degrees of freedom direction to the anti-disturbance control loop; wherein the velocity signal of the vibration table body 1 in the six degrees of freedom direction is specifically:

[0116] The acceleration sensor 4 is used to obtain the actual acceleration signal of the vibration table body 1 in the six degrees of freedom direction, and the acceleration signal is processed by Kalman filtering to obtain the velocity signal of the vibration table body 1 in the six degrees of freedom direction by the velocity synthesis method;

[0117] Among them, the velocity signal of the vibration table body 1 in the six degrees of freedom direction is obtained by the velocity synthesis method, specifically:

[0118] After low-pass filtering the actual displacement signals of each actuator, the displacement signals of the vibration table body 1 in the six degrees of freedom directions are obtained using the degree of freedom synthesis matrix;

[0119] The displacement signal of the vibration table body 1 in the six degrees of freedom direction is differentiated and low-pass filtered, and the actual acceleration signal of the vibration table body 1 in the six degrees of freedom direction is integrated and high-pass filtered. The sum of the two is then low-pass filtered to obtain the velocity signal of the vibration table body 1 in the six degrees of freedom direction.

[0120] In summary, the operating mechanism of the present invention for inputting target seismic waves into the entire control system is as follows:

[0121] The target seismic wave acceleration signal in the six-degree-of-freedom direction is input into the control system. For each degree of freedom, the actual acceleration signal of the vibration table body 1 is first corrected by the acceleration external closed-loop feedback, and then compensated for the resonance of the specimen by the notch filter. The signal generator processes the compensated acceleration signal to obtain acceleration, velocity, and displacement signals and removes the low-frequency part to prevent the influence of zero-point offset. The control quantity in the six-degree-of-freedom direction is obtained through state error feedback. The control quantity in the six-degree-of-freedom direction is decomposed into the direction of each actuator through the degree-of-freedom decomposition matrix, and the movement of each actuator is controlled to drive the movement of the vibration table body 1. The displacement signal fed back by each actuator is passed through the degree-of-freedom synthesis matrix to obtain the displacement of the table body in the six-degree-of-freedom direction. The acceleration sensor signal installed on the table top of the vibration table body 1 is processed by Kalman filtering to obtain the acceleration of the table body in the six-degree-of-freedom direction. Figure 4 As shown in the figure, the velocity synthesis method is used to perform low-pass filtering after the displacement differential operation and high-pass filtering after the acceleration integral operation. The cutoff frequencies of the two filters are consistent. After summing, low-pass filtering is performed to obtain the velocity signal in the six-degree-of-freedom direction for feedback.

[0122] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling an earthquake simulation shaking table for combined seismic wave and current loading, characterized in that: The following steps are involved: Establish earthquake simulation shaking table system and control system; The target seismic wave is used as a reference signal, and the actual acceleration signal of the vibration table body (1) in the earthquake simulation vibration table system is used as a feedback signal, and both are input into the control system; The control system includes: an anti-disturbance control loop, a PID control loop and an acceleration outer closed loop; The acceleration outer closed loop is used to compare the reference signal of the vibration table body (1) with the feedback signal, and obtain a corrected actual acceleration signal through error correction; The correction strategy of the acceleration outer closed loop is: The actual acceleration signal of the vibration table body (1) after Kalman filtering is subtracted from the double of the target seismic wave signal; The anti-disturbance control loop is used to compensate and process the corrected actual acceleration signal and the velocity signal and displacement signal of the vibration table body (1) in the six-degree-of-freedom direction, and generate control instructions in the six-degree-of-freedom direction; The anti-disturbance control loop includes: an anti-disturbance controller; The anti-disturbance controller includes: a notch filter, a signal generator and a state observer; The notch filter is used to compensate for the resonance of the vibration table body (1) at a specific frequency to obtain a compensated acceleration signal; The signal generator is used to process the compensated acceleration signal to obtain acceleration, velocity, and displacement signals respectively, and remove the low-frequency part to prevent the influence of zero offset; The state observer is used to observe the velocity signal of the vibration table body (1) in the six-degree-of-freedom direction and the total disturbance of the earthquake simulation vibration table system, so as to obtain the velocity observation value and the total disturbance observation value output by the earthquake simulation vibration table system; The anti-disturbance controller is used to design a state error feedback control law by combining the acceleration, velocity and displacement signals obtained by the signal generator with the velocity observation value, the displacement signal of the vibration table body (1) in the six degrees of freedom direction and the total disturbance observation value; The PID control loop is used to convert the control instructions into control signals of each actuator in the earthquake simulation vibration table system through the degree of freedom decomposition matrix, thereby driving the vibration table body (1) to move in the six-degree-of-freedom directions through each actuator, and feeding back the speed signal and displacement signal of the vibration table body (1) in the six-degree-of-freedom directions to the anti-disturbance control loop.

2. The earthquake simulation shaking table control method for earthquake wave and current combined loading according to claim 1, characterized in that: The earthquake simulation vibration table system comprises a building foundation (5), a vibration table body (1), a plurality of lateral actuators (2), and a plurality of vertical actuators (3); The building foundation (5) is used to provide a support platform for the vibration table body (1); The vibration table body (1) is used to generate seismic wave motion corresponding to the target seismic wave; The plurality of lateral actuators (2) and the plurality of vertical actuators (3) are used to apply force and displacement to the vibration table body (1) to simulate seismic waves with different intensities and frequency characteristics; The plurality of lateral actuators (2) and the plurality of vertical actuators (3) are each provided with a displacement sensor, and the displacement sensor is used to measure and feed back an actual displacement signal of each actuator; An acceleration sensor (4) is provided on the vibration table body (1) for measuring actual acceleration signals of the vibration table body (1) in six degrees of freedom directions; The vibration table body (1) is movably connected to the building foundation (5) via a plurality of lateral actuators (2) and a plurality of vertical actuators (3).

3. The earthquake simulation shaking table control method for earthquake wave and current combined loading according to claim 1, characterized in that: The sampling time of the target seismic wave is 0.001 s , extract seismic waves in the 0.1-25Hz frequency band through FFT / IFFT.

4. The earthquake simulation shaking table control method for earthquake wave and current combined loading according to claim 1, characterized in that: The construction method of the state observer is: For any degree of freedom of the vibration table body (1), the earthquake simulation vibration table system is described as a system containing a total disturbance term. The expanded state space equation of the earthquake simulation vibration table system is as follows: ; ； in, u is the input velocity of the earthquake simulation shaking table system under this degree of freedom; x 1 is the velocity of the vibration table body in this degree of freedom; is the velocity of the vibration table body under this degree of freedom x The derivative of 1; x 2 is the total disturbance of the earthquake simulation shaking table system; is the total disturbance of the earthquake simulation shaking table system x The derivative of 2; y is the output velocity of the earthquake simulation shaking table system; b 0 indicates the characteristics of the control object; The state observer is constructed using the expanded state space equation to obtain the velocity of the vibration table x 1 and total disturbance x 2 The observed value of the state observer is as follows: ； ； in, z 1 is speed x Observation value of 1; It's speed x Observation value of 1 z The derivative of 1; z 2 is the total disturbance x 2 observations; is the total disturbance x Observation value of 2 z The derivative of 2; is the observed value of the output velocity of the earthquake simulation shaking table system; β 1 and β 2 is the gain of the state observer.

5. The earthquake simulation shaking table control method for earthquake wave and current combined loading according to claim 4, characterized in that: The expression of the state error feedback control law is: in, k p , k i , k d They are the gain of velocity signal, the gain of displacement signal and the gain of acceleration, r is the speed signal output by the signal generator, d 1 is the displacement signal of the vibration table in the six degrees of freedom direction, z 1 is speed x The observed value of 1, z 2 is the total disturbance x 2 observations, b 0 indicates the characteristics of the control object, s It is a complex variable obtained by Laplace transforming the time domain function into the complex frequency domain; Substituting the state error feedback control law into the first-order system expression, the closed-loop transfer function of the disturbance rejection controller is obtained: in, k p , k i , k d They are the gain of the velocity signal, the gain of the displacement signal and the gain of the acceleration.

6. The earthquake simulation shaking table control method for earthquake wave and current combined loading according to claim 5, characterized in that: The transfer function of the notch filter is: ; in, w is the notch frequency in rad / s , g is the notch gain, c is the damping ratio.

7. The earthquake simulation shaking table control method for earthquake wave and current combined loading according to claim 5, characterized in that: The total disturbance includes external disturbance and internal disturbance; The external disturbance includes: the coupling effect of waves and water flow, the resonance effect of the test piece, each actuator and the vibration table body (1); The internal disturbance includes: modeling errors and unmodeled parts of the earthquake simulation shaking table system.

8. The earthquake simulation shaking table control method for earthquake wave and current combined loading according to claim 1, characterized in that: The velocity signal and displacement signal of the vibration table body in the six degrees of freedom direction are fed back to the anti-disturbance control loop; wherein the velocity signal of the vibration table body (1) in the six degrees of freedom direction is specifically: Using an acceleration sensor (4) to obtain actual acceleration signals of the vibration table body (1) in the six degrees of freedom direction, and performing Kalman filtering processing, and obtaining velocity signals of the vibration table body (1) in the six degrees of freedom direction by a velocity synthesis method; Among them, the velocity signal of the vibration table body (1) in the six degrees of freedom direction is obtained by the velocity synthesis method, specifically: After the actual displacement signals of each actuator are processed by low-pass filtering, the displacement signals of the vibration table body (1) in the six degrees of freedom directions are obtained by using the degree of freedom synthesis matrix; The displacement signals of the vibration table body (1) in the six degrees of freedom are differentiated and low-pass filtered, and the actual acceleration signals of the vibration table body (1) in the six degrees of freedom are integrated and high-pass filtered. The sum of the two is then low-pass filtered to obtain the velocity signals of the vibration table body (1) in the six degrees of freedom.

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