Introduction to Active Vibration Control
This chapter is intended to give a flavor of active vibration control and, at the same time, to illustrate how active control is primarily based on understanding the system dynamics, rather than on a blind application of control recipes. This is done through four sections borrowed from different fields of engineering. The first section highlights the virtue of collocated control: a collocated control configuration should always be preferred to a non-collocated one if possible. The second section uses the quarter-car model developed in the previous chapter to analyze the active suspension known as sky-hook damper. The third section re-examine the n-storey building of the previous chapter, but actively controlled with an inertial actuator. Finally, the fourth section analyzes the dynamics and active damping of an active truss (representative of a large space structure) equipped with an active strut consisting of a displacement actuator (e.g. piezoelectric) collocated with a force sensor; the choice of the active strut location and the trade-off between damping and static stiffness is discussed. A set of problems is proposed at the end of the chapter.