How can I count the number of times an input reaches a certain value?

Hello,

I am using Simulink where I have a model of a heat pump, where I simulate frost accumulation. What I am trying to do is count the total number of times (during the simulation) the Frost layer thickness has reached 8.25 mm for example.

I have tried various methods, such as implementing switches, sum blocks, delay blocks, nothing has worked so far. At least not properly.

I cannot provide much details as the project is confidential. But part of the task is to count how many times the frost sheet on the outdoor unit has reached a certain value.

P.S. I do not have much experience with MatLab commands and scripts. I would really appreciate solutions solely involving Simulink.

Answer 1

[Jonas]

Take the signal for the frost layer thickness, use a Relational Operator to compare if the signal is larger than a constant of 8.25 (second input). The output will be a boolean telling true or false. Connect this boolean signal to a Triggered Subsystem. Inside this triggered subsystem, you could for example use a Data Store Read and Data Store Write block, where it reads from the read block, adds 1 to it, and writes it to the write block. The Data Store Memory block should be located outside the triggered subsystem. There are also possibilities by using a Unit Delay block and adding it with one.