Semi-active vibration control of structural systems with a variable inerter

Abstract

We propose a design method of semi-active vibration control systems using a variable inerter for structural systems subject to seismic disturbances. The inerter is a vibration control device generating resistance force proportional to the relative acceleration between both ends. In the variable inerter, the inertia mass of the inerter can be changed by a command signal in realtime. The mathematical model of the variable inerter is defined considering the dynamic delay of the inertia mass change subject to the command signal. For the dynamic model of a structural system with the variable inerter, we propose a semi-active control law based on a reference active control system. The reference active control system is a virtual system showing the ideal control performance. In the proposed semi-active control law, the variable inertia mass is changed by considering a predicted control output, the predicted error between the control output of the semi-active and reference active control systems, and the predicted reaction force of the inerter. The characteristic of the reference active control is optimized so that the control performance of the resulting semi-active control system is close to that of the best control systems among the passive off (without control), passive on (maximum inertia mass), and reference active control systems. A simulation study shows the effectiveness of the proposed semi-active control method.