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Nonlinear modeling and control of a hydraulic seismic simulator

Hydraulic actuators, in combination with servo valves, are used to drive unidirectional seismic simulators. The fluid flow within the hydraulic actuator inherently leads to nonlinear behavior for the system. This paper presents a nonlinear model of the seismic simulator at the University of Notre Dame. The validity of the model is demonstrated experimentally. A control strategy uses a desired earthquake acceleration response to generate specific reference inputs by means of an open loop optimization. A Kalman-filter-based controller is employed. The control strategy is implemented and tested by experiment.