Servo-hydraulic actuator control for real-time hybrid simulation

Real-time hybrid simulation combines experimental testing with numerical simulation, enabling the complete structural system to be considered in an experiment. The method presents an economical and effective technique to physically evaluate the behavior of rate-dependent seismic devices and to validate performance-based design procedures. Accurate servo-hydraulic actuator control is necessary for a successful real-time hybrid simulation. Inherent servo-hydraulic actuator dynamics can lead to actuator delay that results in a desynchronization between the measured restoring force(s) and the integration algorithm, leading to inaccurate results and possible instability in the simulation. This paper presents an adaptive compensation scheme to achieve accurate actuator control in real-time hybrid simulation. Experimental evaluation of the proposed adaptive scheme is conducted for a single-degree-of-freedom moment resisting frame with an elastomeric damper. The performance of the adaptive compensation scheme is compared with other compensation methods. It is shown that the adaptive compensation scheme is able to achieve accurate actuator control in real-time hybrid simulation.