Control method for seismic simulation shaking table under combined loading of seismic waves and currents

A control method for a seismic simulation shaking table under combined loading of seismic waves and currents, comprising the steps of:

• establishing a seismic simulation shaking table system and a control system;
• and
• taking a target seismic wave as a reference signal, taking an actual acceleration signal of a shaking table body (1) in the seismic simulation shaking table system as a feedback signal, and jointly inputting the two into the control system, wherein
• the control system comprises a disturbance rejection control loop, a proportional-integral-derivative (PID) control loop and an acceleration outer closed loop;
• the acceleration outer closed loop is used for comparing the reference signal of the shaking table body (1) with the feedback signal, and obtaining a corrected actual acceleration signal through error correction;
• a correction strategy of the acceleration outer closed loop is as follows:
• an actual acceleration signal of the shaking table body 1 after Kalman filtering is subtracted from twice the target seismic wave signal;
• the disturbance rejection control loop is used for compensating and processing the corrected actual acceleration signal and velocity signals and displacement signals of the shaking table body (1) in six-degree-of-freedom (6-DOF) directions to generate control instructions in the 6-DOF directions;
• the disturbance rejection control loop comprises a disturbance rejection controller;
• the disturbance rejection controller comprises a notch filter, a signal generator and a state observer;
• the notch filter is used for compensating the resonance effect of the shaking table body (1) at a specific frequency to obtain a compensated acceleration signal;
• the signal generator is used for processing the compensated acceleration signal to obtain acceleration, velocity and displacement signals, and removing the low-frequency portion to prevent the influence of zero drift;
• the state observer is used for observing the velocity signals in the 6-DOF directions of the shaking table body (1) and the total disturbance of the seismic simulation shaking table system to obtain a velocity observation value and a total disturbance observation value output by the seismic simulation shaking table system;
• the disturbance rejection controller is used for designing 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 signals in the 6-DOF directions of the shaking table body (1), and the total disturbance observation value;
• and
• the PID control loop is used for converting the control instructions into control signals of each actuator in the seismic simulation shaking table system through a DOF decomposition matrix, thereby driving the shaking table body (1) to move in the 6-DOF directions through each actuator, and feeding back the velocity signals and the displacement signals in the 6-DOF directions of the shaking table body (1) into the disturbance rejection control loop.