Impedance matching control design for the benchmark problem in real-time hybrid simulation

This paper presents an application of impedance matching to the benchmark control problem in real-time hybrid simulation (RTHS). Impedance matching is conceptually different from conventional approaches to designing controllers for RTHS. Rather than view the transfer system merely as a device to realize prescribed boundary conditions between the virtual and physical substructures, the controller is designed to match the impedance of transfer system as closely as possible to that of the virtual substructure. Some of the key features of impedance matching are—(i) it does not explicitly require a tracking controller, greatly simplifying the control design process, (ii) control design is decoupled from the physical substructure (demonstrated in this paper by introducing nonlinearity in the physical substructure), (iii) the controller is easy to evaluate and implement, (iv) performance is less sensitive to the choice of partitioning configuration compared to provided sample controller, and (v) exhibits robust stability. Overall, controllers designed based on impedance matching are found to result in stable and accurate RTHS.