Random variation in a signal in Simulink

I need to solve this problem in simulink.

I want to create a signal like the one in the picture, that at instant 4 sec change from 1 to 0 in 0.3 sec and then return to 1 from 5.7 sec to 6 sec. In this case the sequence starts at instant 4 sec.

The problem is that this sequence has to be introcuced in a simulink simulation at different time instants, that occurs randomnly. I tried to utilize some triggered blocks, but without success.

Has anyone a solutions?

Answer 1

[Giuseppe Inghilterra]

Hi,

if you can use stateflow in your simulink model, following chart could be a solution:

As you can see you start from state A where yout = 1. Then if a trigger input changes to true you pass to state A1 where yout starts to decrease by 0.01/0.3 at each simulation step. When yout reaches zero you pass to A2 state. Wait for 0.4 seconds and then you pass to state A4, where yout is incremented by 0.01/0.3 at each simulation step until it reaches one. Then you come back to state A.

This cycle is activated when trigger becomes true.

For example my trigger is generated by a sine wave function as shown below:

obtaining the following result:

Note that I run simulation with fixed step solver type and 0.01 as fixed step size.

[davide]

I tested your solution and it works properly.

Thank you very much.