Research on the Control Strategy of Hydraulic Shaking Table Based on the Structural Flexibility

The frequency response characteristics of the hydraulic shaking table show the same as that of a two degree of freedom (DOF) resonance system due to the structural flexibility of the hydraulic shaking table. The hydraulic shaking system induces an anti-resonant peak during the working frequency band, which substantially reduces band width of the shaking table. The frequency response influence factor like mass, stiffness, and damping of the reaction wall are studied in this paper. The feed-forward control strategy is proposed in shaking system, which eliminates the effect of zero points at the anti-resonant peak and poles nearly the imaginary axis, broadens the bandwidth, and improves the control precision of the system. The notch filter is used to reduce the magnitude of resonant peak at the nature frequency of servo valve. The experimental results show that the proposed algorithm properly compensates the effect of structural flexibility and improves the bandwidth of the shaking system.