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Proceedings of the International Conference on
Advances and New Challenges in Earthquake °
Engineering Research, Hong Kong Volume
SLIDING MODE SEMI-ACTIVE BASE ISOLATION USING THE
SWITCHING HYPERPLANE DESIGNED BY DISTURBANCE-
ACCOMMODATING BILINEAR CONTROL
Norihiro SANTO, Kazuo YOSHIDA
l Keio University, Deparment of System Design Engineering, 3-14-1,
Hiyoshi, Kouhoku-kn, Yokohama, Japan
2 Keio University, Deparment of System Design Engineering, 3-14-1,
Hiyoshi, Kouhoku-ku, Yokohama, Japan
ABSTRACT
In vibration isolation control problem, the semi-active control methods in which coefficient of viscous
damping is varied effectively have been proposed and expected to realize a high performance. However, the
semi-active system is classified into a bilinear system which belongs to a nonlinear system. In this study, the
switching hyperplane of sliding mode control is designed by the disturbance-accommodating bilinear optimal
control theory, and it is applied to a semi-active base isolation problem. The proposed method adopts the
damping force in criteria function, and the controller takes into account the disturbance dynamics by difining an
augemented bilinear system. This study deals with a ten-degree-of-freedom structural model with base isolation.
And the computer simulation is carried out by taking account of the delay of switching the coefficient of
dampers. As a result, the usefulness of the present method was demonstrated.
INTRODUCTION
Recently the technologies on active or semi-active vibration control methods have widely spread and some
of them have been put into pracice.tn the field of building structure, a semi-active vibration control of high-rise
building was put into practice 1979 for the first time, and then an active vibration control of pencil building was
realized in 1989 for the first time. These vibration control systems belong to a type of dynamic vibration
absorber which is installed at the top ofbuilding. The number of buildings with active vibration absorber
exceeded 20. Since the Kobe earthquake occurred in 1995, passive base isolation systems with lead damper,
high damping rubber and so on have been used as a damping element. These passive dampers are designed
for the large seismic wave. Therefore, the base isolation system is not necessarily effective resonance transmissibility,
while it raises the transmissibility in the higher frequency range.
Semi-active control method which is a method to control the parameters of control device such as spring