Simulink: Generated C code for a PID controller is delayed compared to its model

Hi,

For an embedded project we created a PID controller with Simulink. Then, we generated C code from this model and integrated it into our embedded project. However, when we tested the controller on our hardware (AVR microcontroller), we noticed a rather large overshoot. Since the model has no such problem, we plotted our measured controller output and compared it with the model. We noticed that our measured data is delayed by ~120 seconds compared to the modelled data. This is even the case when we only locally test the generated C code with the measured input values (thus, the error does not lie in our hardware/controller, but in the generated C code).

Does someone has an idea, what could be configured wrong in Simulink, such that this happens?

Thanks in advance, Moritz

Answer 1

[Sarthak]

Hi Moritz,

I faced a similar issue. The variable I was using for indexes was of type double. I was able to resolve the issue after changing it to int32 type. If this doesn't resolve your issue, you can create a technical support service request at the following link:

http://www.mathworks.com/support/servicerequests/index.html

I hope this helps!