Equations of Physical Systems

Abstract

Where possible, control systems are designed and analysed on a mathematical basis, the reason being that in this way one may achieve the ‘best’ solution to the engineering problem in the least time. Even when much of the information provided is in a non-mathematical form (as is often the case in chemical process control) an intuitive mathematical understanding of the dynamic behaviour of systems is very valuable. Physically different systems may often be described by similar (or ‘analogous’) equations. Dynamic problems involving mechanical, electrical, thermal, pneumatic, hydraulic and electromechanical components may usually be phrased in mathematical form by using certain basic laws. For instance, problems on translational mechanics are usually formulated by using Newton’s second law whilst problems on electric circuits can be analysed using Kirchhoff’s laws.