Abstract
A new closed-open-loop optimal control algorithm is proposed that has been derived by minimizing the sum of the quadratic time-dependent performance index and the seismic energy input to the structural system. This new control law provides feasible control algorithms that can easily be implemented for applications to seismic-excited structures. To apply the developed continuous-time control algorithms to a real structural system we must take into account the time delay not only for digitizing the observed input motion and system response but for calculating the control force and for applying it in the form of stepwise functions through A/D converters. We developed the discrete-time formulations of active structural control which include the time delay compensation.
To compensate the time delay of control force the input earthquake motion must be predicted for the period to be used for generating the control force. We assumed an earthquake ground motion to be defined as an autoregressive process. We also developed a prediction method of earthquake motion for a few time step ahead of observation time by using Kalman filtering technique.
