Sources of system models

Abstract

In previous chapters we have virtually ignored the system being controlled. Knowing a temperature was to be controlled, it was implicit that a temperature sensor was to be used to measure the output and a heater of some kind to cause the output to vary, but the mechanism of heat transfer was ignored. It was even suggested that the loop could be tuned by formulae that barely recognized the nature of the controlled process. None of this is completely true, of course, as a good engineer will have a notion of how the system works and how it reacts to input, and he will be influenced by this in many aspects of engineering the system. So, while the previous work did not use mathematical models of the controlled plant, these will be pervasive in what follows. In fact, the use of mathematical models is fundamental to use of control theories.