CONTROL OF A MOVING OSCILLATOR ON AN ELASTIC CONTINUUM

An oscillator traversing an elastic continuum, often referred to as the moving-oscillator
problem, is representative of many common engineering systems. A clear example of such
a system in the civil engineering field is a vehicle crossing a bridge. Due to the dynamic
interaction between the two subsystems, vibrations generated as the vehicle traverses the
continuum cause deflections which may be significantly larger than those generated when
such interaction is neglected. The goal of this thesis is to develop a control system that can
reduce the dynamic responses of the combined system. A series expansion is used to
model the continuum, which, when combined with a single degree of freedom oscillator,
results in a time-varying, linear model describing the dynamics of the coupled system.
Three different control techniques are considered: passive, active, and semiactive. These
techniques will be applied and evaluated in terms of their ability to reduce the dynamic
response of the continuum and the oscillator. A tracking control algorithm, that uses
accelerations of both the continuum and the oscillator for feedback, is used to calculate the
optimal control action. The results indicate that the response of the system with semiactive
control approaches that of an active control, while using significantly less power. The
controllers both outperform a passive control system.