Semiactive control strategies for vibration mitigation in adaptronic structures equipped with magnetorheological dampers

Resumen

In recent years, the protection of structures against hazardous vibration has gained special interest, Structures such as buildings, bridges and vehicle suspension systems are subject to vibrations that may cause malfunctioning, uncomfort or collapse. It is an extended practice to install damping devices in order to mitigate such vibrations. Furthermore, when the dampers are controllable, the structure act as an adaptronic system. Adaptronic systems are characterized by their ability to respond to external loading conditions and adapt to these changes. These abilities can be exploited to solve the vibration mitigation problems through the installation of controllable dampers and the design of appropriate control laws for an adequate actuation. This dissertation focuses on solving the vibration mitigation problem in buildings and vehicles. Emphasis is made on systems that make use magnetorheological (MR) dampers to accomplish this objective. MR dampers are semiactive devices that can produce high damping forces with less energy requirements than other devices of its class. However, MR dampers are highly nonlinear devices whose dynamics are characterized by a hysteretic force-velocity response. Additionally, the systems where they are installed, are characterized by parametric uncertainties, limited measurement availability and unknown disturbances. The presence of all of these factors makes mandatory the use of complex control techniques in order to get a reliable performance of the control system. This research is intended to contribute with new control algorithms that incorporate these problems in their formulation, especially, the dynamics of the damper. In order to do it, three control methodologies are explored: Backstepping, Quantitative Feedback Theory and Mixed H2/H¿. The proposed control laws are applied to different structures equipped withMR dampers. In particular buildings and vehicle suspension systems are studied. Numerical simulations and experimental testing are run to evaluate the performance of the proposed control laws.