Model of Simulation

MODEL OF SIMULATION

In any simulation experiment we have a system whose behavior we are studying.  Loosely speaking, a system is a collection of distinct objects which interact with each other.  In the pure-pursuit example, the system consists of the two aircraft.  In order to study a system we generally gather some relevant information about it.  For most studies it is not necessary to consider all the detail of the system. We did not get the information about the sizes or weights of the aircraft.  Such a collection of pertinent information about a system is called a model of the system.

The construction of an appropriate model of a system under study is a delicate and an all important affair in simulation.  For example, we have assumed that the target takes no evasive action, nor does the pursuer use any predictive technique.  We assumed that the pursuer corrects its course only once a minute.  Thus we know the ‘law’ that governs the system.  The same system may be described by different models.  Several variations of the pure pursuit model are considered in problems at the end.

Constructing appropriate mathematical models of complex, real life systems are a vast and intricate subject in it.  It requires a thorough knowledge of the system as well as of modeling techniques.  In this book, we will in most cases assume that a model has been arrived at and our concern is how to program the computer so that it behaves like the model as the time progresses.

For a given system there are a number of variables that describe what is known as the state of the system at any given time.  For example, the state of our system is described by the positions of the two aircraft and their velocities.

For further undertaking these and other concepts, let us simulate another very simple system, which is different in a fundamental sense for the pure pursuit system.