Page 16 - Mechatronic Systems Modelling and Simulation with HDLs

2

Principles of Modelling

and Simulation

2.1 Introduction

The introduction of Information Technology in the last fifty years has allowed
modelling and simulation to penetrate the majority of engineering disciplines and
natural and social sciences. Regardless of whether the matter under debate is the
design of wheel suspension for a car, the metabolism of a bacteria, or the intro-
duction of a new interest formula, models of these real systems are always drawn
upon to gain an understanding of the inner relationships of the system and to make
predictions about its behaviour. The simulation is often also used as a substitute for
experiments on an existing system, which is associated with a range of benefits:

• In comparison to real experiments, virtual experiments often require a sig-
nificantly lower outlay in financial terms and in terms of time, because it is
generally considerably cheaper to model virtual prototypes than it is to build
real prototypes.

• Some system states cannot be brought about in the real system, or at least not
in a non-destructive manner.

• Normally all aspects of virtual experiments are repeatable, something that either
cannot be guaranteed for the real system or would involve considerable cost.

• Simulated models are generally completely controllable. So all input variables
and parameters of the system can be predetermined. This is normally not the
case for a real system.

• Simulated models are generally fully monitorable. All output variables and
internal states are available, whereas in the real system every variable to be
monitored involves at least a significant measurement cost. In addition, each
measurement taken influences the behaviour of the system.

Mechatronic Systems Georg Pelz
 2003 John Wiley & Sons, Ltd ISBN: 0-470-84979-7