A semi-active control system for structures with sensitive equipments is proposed in this paper. While technology of structure control in regular buildings gradually matured and is implemented practically over the last two decades, hospitals and facilities with electronic devices are still vulnerable to seismic loadings. To solve this problem, a hybrid floor isolation system comprising a bidirectional roller pendulum system (RPS) and a controllable magnetorheological (MR) damper is proposed to ameliorate the response of structures under external excitation. For the best performance of the control system, two smart control algorithms for the MR damper are developed. The controllers are designed...