Evaluation of frequency evaluation index based compensation for benchmark study in real-time hybrid simulation

Actuator control plays an essential role to achieve stable and accurate real-time hybrid simulation (RTHS) results. Delay compensation is often used to minimize the desynchronization at the interface between numerical and experimental substructures. In this study, a new delay compensation method is proposed for RTHS, which integrates the inverse compensation method (IC) and frequency-domain evaluation index (FEI). Window technique is utilized to enable FEI for calculation of almost instantaneous time delay and the IC parameter is then adjusted accordingly for optimal compensation. The performance of this windowed FEI compensation (WFEI) is evaluated and compared with that of the IC and the adaptive inverse compensation (AIC) through computational simulations of a benchmark model with different initial estimates of time delay. It is demonstrated that the WFEI compensation not only provides accurate actuator control when initial estimated time delay deviates from actual values but also have good robustness under unpredicted uncertainties of the servo-hydraulic system.