Model predictive control schemes for the mitigation of natural hazards: Theoretical and experimental studies

Active and semi-active control devices, e.g., active mass dampers and dampers with controllable damping, respectively, have been studied to enhance the performance of structures during earthquakes and strong winds. Efficient control schemes are needed to drive these control devices. The focus of this study is on the development of Model Predictive Control (MPC) based schemes for earthquake and wind excited structures. The MPC scheme is based on an explicit use of a prediction model of the system response to obtain control actions by minimizing an objective function. Optimization objectives include minimization of the difference between the predicted and reference responses and minimization of the control effort subjected to prescribed constraints.; A general form of the MPC scheme was first employed for controlling building response under earthquake excitation using active control devices. The constrained MPC scheme was then investigated. This scheme takes into account hard constraints to accommodate the physical limits on the control force and structural response. In addition to the active systems, semi-active control devices, e.g., semi-active mass dampers and semi-active tuned liquid column dampers were also studied using the constrained MPC scheme.; An autoregressive (AR) model that uses real-time ground motion measurements to model ground motions as a feedforward link in the MPC based feedforward-feedback scheme was employed for controlling earthquake induced response. This MPC based feedforward-feedback scheme offers an adaptive control action essential for effectively mitigating the load effects induced by evolutionary ground motions. For wind excited structures, an efficient wind loading model based on a combination of AR and Karhunen-Loeve expansion was developed. The MPC based feedforward-feedback control scheme, based on this wind loading model, effectively reduces the wind induced structural response.; A shaking table and a small-scale structural model with an active mass damper were utilized for experimentally validating these control schemes. Experimental validation of MPC based schemes provides proof-of-concept, and facilitates prototyping of this control strategy for full-scale implementation to reduce damage caused by natural hazards through response reduction. Finally, a full-scale building for wind-excited benchmark problem was investigated to implement MPC based schemes for a range of prescribed parameters.; The numerical and experimental studies conducted here suggest that MPC is a simple, effective, economical control scheme that can take into consideration practical design and implementation issues in structural control applications. This study has laid a foundation for the development of future applications of MPC based schemes on full-scale structures.