Column-by-Column (SIMULINK)

Hey guys,

I would like to do a "slow" iteration..

As far as I know Simulink first executes a block and passes its value over. Which means, If I have a loop it finishes the loop and gives out the last value. But I need to give specific elements from my array as a command and send it. Which means I need to execute element 1 followed by element 2 in a ordered manner.

I would like to have sth like this pseudocode

A = 2x6 (like a constant block [1 2 3 4 5 6; 0 0 0 0 0 0])

for i = 1:6 do / or while loop

output col 1 of A

wait like 5 seconds or if-condition (like if trigger == 1 -> only(!) next col and wait for next trigger to output next col)

output col 2 of A

wait like 5 seconds or if-condition

output col 3 of A

..etc..

end loop

I already tried an assignment block.. but it outputs the full matrix

..and I tried direct look-up table... but I do not know how to get a right counter/incrementer for it.. sth like a triggered or slow incrementation..

In MATLAB you can write a pause and some commands in each loop step but a pause in simulink pauses the whole simulation and that is not what I want at all..

any tips?

[Domi]

I need this because I have a 2xN array of pathpoints which I want to send via UDP Send/Receive from my raspberry to my robot, both running simulink. I know I can send a hugh Nx1 array and make it back to 2xN on the robot side.. but the next problem is, that I need to go through every column on robot.. which leads to the same problem as above :/

Answer 1

[Jonas]

You need the Selector block to capture the column you need, and then a Trigger Subsystem which executes on your command. You can also use a subsystem triggered by a function call. You can control the time delay between executions by using a Stateflow with the state transition 'after(5,sec)' for example, or implement an integrator block with gain 1, which will build up in real-time and you then trigger based on when it reaches a threshold.

You can also in Stateflow maintain a counter and increment with each sample time. Since you know your sample time, you can let the UDP Send trigger after the counter has reached a value.

[Domi]

Thank you sir! I managed to get it done with the direct lookup table and a resetable counter system based on switches and delays. Stateflow was a good input for me, because I looked up how it works. Thanks