Control Theory Sources in Active Control of Civil Engineering Structures

Abstract

Research in system analysis and control theory has lead to a broad variety of methods over the last four decades. Many of those have been transferred to (and even motivated by) different areas of science and technology. Within this scenario, feedback control has grown in the field of structural dynamics as an innovative mean to reduce vibrations produced by dynamic loads. Control systems in this field have been referred to as active control systems as counteracting to the passive systems based on absorbing or dissipating energy, both classes of systems, plus combinations such as hybrid and semiactive systems, delimiting the field labeled to as structural control. Structural control had origins in flexible space structures and rapidly extended to civil engineering structures [1] as a promising tool to protect bridges, buildings and other structures against loads induced by earthquakes, wind, etc. It is an always incomplete task to review the research effort in structural control, which nowadays involves a variety of disciplines and technologies such as mechanics, structures, materials, sensors, actuators, mathematics, computation and control theory, among others. We can mention a number of books and proceedings of structural control conferences [2-8] and recent review papers [9,10]. This paper will focus on control theory issues outlining some of the most relevant methods adopted to cope with specific features of civil engineering active structural control.