How to Make a Simulink Scheduler for a Matlab Block Function to run each 40 ms of simulation?

Hello, I am trying to make a controller for a system that must run every 40-50 ms. I am having difficulties with Stateflow because if I try to adapt the example given by Mathworks the matlab blocks runs just once.

In the picture you see the controller that I adapted from the example

this is "Edge to Function" block

and this is the simple subsystem called by Call() event

inside the matlab block there is only

j = 0;

for i = 1:10

j = j+1;

end

and here the plot of the output j, as you can see the block is triggered just once

Can you please help me to understand how to call the matlab block every 40 seconds or address me to a good stateflow scheduler tutorial? I haven't been lucky

Answer 1

[Fangjun Jiang]

Use a Function-call Generator block, specify the sample time. Put the MATLAB Function block inside a triggered subsystem, specify the trigger as Function-call.

[Gianluca Mammone]

Ty it works, but I am having problems inserting this triggered system in a loop with a Matlab Function Block +integrator. Simulink ask me to add a Function-Call Feedback Latch to the input of the triggered subsystem, but then when I run it, it complains that is not a function call enabled system but a triggered system... Can you help me?

[Fangjun Jiang]

"triggered system in a loop"?? It sounds too complicated. Please state your task, there might be a better way to construct the model to implement it.

[Gianluca Mammone]

My task is to create a controller that runs every 40 Ms. The dynamic differential model of the plant is a matlab function followed by integrators that calculate the state.

This controller every 40 ms is triggered, collect the actual state (the output of the integrator which is the output of the Matlab Function Block), and gives the value of the controlled variable.

The controller is quite heavy (MPC with QP), so I am not too prone to use zero-older hold block

EDIT: I think I solved it, thank you for your patience.

One of the inputs (let's call it dx) of the triggered block was the direct output of the matlab function. Since the matlab function needed the output of the controller to run, there was this data dependency where dx was not initialized or defined.