Active Control: Concepts and Strategies

This chapter describes some concepts and methods related to the design of control laws and algorithms for active control of structures. The first point will be to identify second order differential equations as models to describe the essential components of a control system. Then some issues about the state space representation of these models will be reviewed. State space is the mathematical framework most frequently used to formulate active control laws. Optimal control will be presented as a representative methodology for continuous time control. Predictive control will be formulated as representative of discrete time control methods, also pointing out the issue of the time delay and some questions about robustness.This chapter does not try to be exhaustive. Control (in general) is a very wide area of knowledge and active control of structures is adopting more and more of its concepts, methods and techniques. The purpose of this chapter is to serve as an introduction to the problem of analysis and design of control laws. Many topics are left and can be covered going through the bibliography suggested in the last Section.