ABSTRACT
An engineer must understand the dynamic behavior of a physical system in order to design the equipment, select its operating conditions, and properly implement an automatic control strategy. Such an understanding is acquired by observing the system over time, by making changes in the system, and monitoring the consequences of these changes. This leads to an abstraction of the behavior of the system in the engineer's mind. Another expression of the system is the use of mathematical relationships that explain the physical and chemical phenomena underlying the performance of the system. This yields mathematical models that can be used to improve process understanding, optimize process operation, train personnel and design and evaluate control systems. This chapter introduces the idea of mathematical modeling as one of the first steps in solving a process control design problem. It is important to understand the types of models one can develop, especially keeping in perspective their final application. The state-space and input–output models constitute the majority of modeling approaches.
