Introduction

Simulating the dynamical behavior of a system is important in engineering. Many systems can be written as a differential equation, such as:

describing the movement of a single mass, on which an actuation force

However, many systems found in engineering or physics are described by more complex differential equations, for which no analytical solution is known or even exists. Trajectories of these systems can be approximated numerically. Hereto, solvers are developed that approximate the change of the state variables over a small time step. Herewith, step by step, an approximation of the trajectory is found. For example, the MATLAB functions *ode23* and *ode45* are numerical solvers. Simulink is an other tool in MATLAB using numerical solvers.

Use of simulink has some advantages over the use of the functions *ode23* and *ode45*. Simulink has a graphical interface, such that the structure of the system can be clearly visible. Inputs, such as a discontinuous signal

Before we start using Simulink, we first show how to represent a system such as (7.1) in a block diagram.

Esteur 2010-03-22