Introduction

In Simulink it is very straightforward to represent a model of a physical system in block diagram form. These blocks represent basic mathematical operations such as summation, multiplication, and integration. 

In this course we will learn how to use Simulink by an exampel:

We will solve the "Bacteria problem" ie the differential equation:

  y_dot = K*y

with K = 0.01 and with the initial condition: y_init = 1000

Time range: 0 <= tau <= 100 s   (tau is the time)

 

Solution in Matlab (Euler)

The problem can be solved in Matlab, without using Simulink, fx. by using the Euler integrating method.

Here you can upload the model: Bacteria, Euler

And if you run this script, you will get this figure:

Fig Bacteria

As you can see the analytically solution lies a little higher than the numerical solution. But if you reduce the time step in the script file - fx. to 0.1 s - the differens is much smaller.

 

Simulink

Now we will solve this problem using Simulink

Click on "2) Simulink" to continue.