Model-based multiactuator control for real-time hybrid simulation

Hybrid simulation combines numerical simulation and experimental testing in a loop of action and reaction to capture the dynamic behavior of a structure. With an extended time scale, convergence of the desired displacements or forces can be assured in each actuator connected to the experimental component before advancing to the next time step. However, when the rate-dependent behavior of an experimental component is of interest, the hybrid simulation must be conducted in real time [i.e., real-time hybrid simulation (RTHS)]. In RTHS, the dynamic behavior of the loading system (i.e., actuators, controllers, and computers) is directly introduced into the RTHS loop. These dynamics consist of both time delays and frequency dependent time lags. At the same time, the phenomenon of control-structure interaction leads to a coupling of the dynamic behavior of the actuators and the structure. Traditional actuator control approaches for RTHS compensate for an apparent time delay or time lag rather than address the actuator dynamics directly. Moreover, most actuator control approaches focus on single-actuator systems. The RTHS control approach proposed herein directly addresses actuator dynamics through model-based feedforward-feedback control. Capturing the dynamic coupling between the actuators ensures accurate control for multiactuator systems. The proposed approach is illustrated through numerical simulation for a 3-story building with multiple actuators to provide control during RTHS.