Introducing a state variable description of a system

Abstract

Although the representation of systems in terms of transfer functions is a very convenient way to describe control systems and their individual components, there is an alternative form for writing the system model. This common alternative is referred to as a state variable representation of the system. There are some advantages and disadvantages of using either transfer function or state variable representation; however, to appreciate the differences we must first learn what a state variable is and how to use state variable notation.