nonlinear model in simulink and designing pid controller
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Hi guys
when I design for a nonlinear model in simulink a pid controller, and I want to run the simulink, it gives me bellow image.
(max step size is 0.2s , please go to configuration parameter and set "automatic solver parametric selection" to "none". although, I do that again it gives me this warning and when I see the scop, it does not give me a good result, it gives me just 0 in output instead of giving 2 things( output and input).
I attach also my slx file.
3 个评论
Enrico Anderlini
2019-8-30
The file you have attached has no PID controller.
Anyway, it looks to me that the problem is that you are using an automatic solver, which selects a very large time step. You can disable the warning, but the problem is there. If the time discretisation is too rough, you can select a solver manually. Say ode4 (4th-ordeer Runge-Kutta) with a predefined time step.
azam ghamari
2019-9-6
hello
I have a pid controller. please see the file. and also I did it( with fixed time 0.001) and it gives me this figure. while when I use the variable step, it gives me totally different result!
please see the attached files.
nor zulaiman
2021-1-2
can i get your simulink pic
回答（1 个）
Rhea Chandy
2020-9-29
0 个投票
It is my understanding that you are having some difficulty in choosing a solver for your model.
The automatic solver recommends a fixed or variable step solver based on your maximum step size. If you’re not satisfied with the results from the auto solver, I suggest manually choosing the solver and comparing the different results with the tradeoffs. For example, decreasing the step size in a fixed-step solver will increase the accuracy of the results but increases the time required to simulate the system.
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