Controller Design of Hybrid Experimental System for Seismic Tests

Hybrid experimental system is one of powerful tools to perform various seismic tests for unknown and/or huge structures, where an actuator-excited experimental vibratory system and a computational response analysis are online combined and are simultaneously conducted. This paper presents a control methodology for high performance hybrid experimental systems. A 2-degrees-of-freedom compensator is applied from the view point of control techniques, where a FB compensator is designed according to the system stabilization analysis and a FF compensator is designed to achieve the desired servo characteristics. In the FF compensator design, an iterative learning control system is especially adopted to eliminate the time delay in actuator responses. The proposed compensation algorithm has been verified using an actual hybrid experimental set up with 2-mass structure.