Controller design of hybrid experimental systems with adaptive algorithm in seismic tests

Hybrid experimental systems are a promising approach to conduct a wide variety of seismic tests for large structures with uncertainties, where an actual experiment for a part of structure involving the use of an actuator and a numerical simulation on computer are simultaneously combined to scale down the test system. In the hybrid experimental systems, the correspondence of boundary displacement between numerical structure and physical structure is required to accurately verify the seismic responses in the test. However, it is widely-known that response delay including actuator dynamics causes deterioration in vibration responses and system instability. This study presents a controller design based on a two-degree-of-freedom control structure in hybrid experimental systems. Feedforward and feedback compensators are designed based on the model of the experimental part to correspond to the boundary displacement. Moreover, an adaptive algorithm is introduced to reduce the error signal due to parametric error of the model during the test. The designed control system is verified by conducting experiments involving the use of a basic experimental setup with a simple mass-spring-damper system.