Study on Control Method to Improve the Performance of Dynamic Response of Shaking Table for Earthquake Simulation

To address the problems of large-scale hydraulic shaking table for earthquake simulation, such as vibration frequency deviation, waveform distortion, seismic waves reappearance and so on, this paper is intended to develop simulation control system by applying three-parameter control technology and to calibrate and compensate the system performance. Velocity positive feedback technology is raised aiming to reduce the high hydraulic natural frequency of shaking table and increase the system damping ratio, and consequently leading to reduction of waveform distortion and improvement of system stability. Meanwhile relationship between the status variable feedback gain and the load change of shaking table is inferred. Through reasonable adjustment of the status variables gain, load change´s influence on shaking table performance is eliminated. Digital control system, using the digital iterative control technology, further increases response accuracy of shaking table.