Theory to Practice

Theory Shortfall Most good models of physical plants are continuous-time models and most physical plants are, in fact, nonlinear. The continuous-time models we use are very often linear because we are not skilled enough to handle nonlinear models. Here I will discuss the linear case. Let us suppose, then, that we have a linear model of a physical plant. There are three aspects of the controller design I want to point to: A great many physical plants are modeled with high-order equations. If you use a typical commercial software design package, MATRIXx for example. you will typically produce, using robust control or HI design methods, a controller which is also high-order. Physical plants are nonnally modeled using continuoustime models, with the coefficients in the models often corresponding to physical parameters. The result of using a