Abstract:Shaking table test is a direct and effective means of seismic response simulation and seismic performance observation of engineering structures,but because the electro-hydraulic servo shaking table system is complex nonlinear system,the performance of shaking table system is apparently affected by the servo valve when the 90° phase-shift frequency of the servo valve is near to the oil-column resonance frequency of shaking table system,so that the effective frequency band of shaking table system is severely affected.The effective frequency band of existing electro-hydraulic servo shaking table is generally from 0.4 Hz to 50 Hz,which is not enough to satisfy the demand of the seismic test of large reduced scale structure.In order to decrease the adverse effect of the servo valve of existing electro-hydraulic servo shaking table system on the system performance,and to broaden the effective frequency band of existing shaking table system,a new control algorithm was proposed by introducing the jerk feedback and jerk feed-forward into the controlling unit on the basis of the three-variable control algorithm.The control effect of the proposed control algorithm was deduced theoretically and analyzed by the system simulation.It was revealed that the oil-column resonance frequency was reduced by the jerk feedback so that the influence of servo valve characteristics on the system performance was decreased,and the effective frequency band of shaking table system was widen from 0.35~54 Hz for the three-variable control algorithm to 0.35~64 Hz for the jerk feed-forward control algorithm,and it was proved that the control performance of the shaking table system was obviously improved by the proposed control algorithm.