Equivalent force control with adaptive forward prediction for real-time hybrid simulation

The equivalent force control method uses feedback control to replace numerical iteration of a real-time hybrid simulation with an implicit time integration. In a real-time hybrid test, time delay typically reduces the accuracy of test results or even makes the system unstable. The outer-loop controller of the equivalent force control can reduce the effect of a small time delay, but may have limited effect for large or varying delay. The adaptive forward prediction method offers a solution for the system with varying delay and amplitude to remove errors. In this paper, the adaptive forward prediction algorithm is used to compensate the delay and amplitude errors of real-time hybrid simulation with the equivalent force control method. The advantage of the adaptive forward prediction algorithm over compensation with fixed parameters was validated through hybrid tests with a Magneto-rheological damper as the physical part of the emulated structure.