Sudden Increases in Computational Noise During Simulation
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
In my Simulink model, a signal of interest should occur to be zero. Due to computational errors, it has some noise, I understand that. The thing I do not understand is that this computational noise level is suddenly increased multiple times during the simulation. As the picture below shows, at least 4 update in the noise amplitude can be counted. If the increase in the noise amplitude was continuous, it could have been explained as accumulation of errors, but here I see sudden changes as if Simulink decides to increase computational error tolerance.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/861350/image.png)
The model generating this result seems like this:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/861355/image.png)
I am using variable-step solver (ode45). Duration of the simulation is 100000 seconds. I tried disabling absolute tolerance auto scaling but it did not change anything. Also, I suspected accumulation of error at the sinusoidal wave, but the reason is not that either.
I wonder why this happens and how to avoid it. I have attached the simulink model for reproducability.
2 Kommentare
Mathieu NOE
am 20 Jan. 2022
hello
I would prefer to run a fixed step solver - can you try this ?
IMHO, I would go for discrete models + fixed step solver
Antworten (1)
Rangesh
am 29 Sep. 2023
Bearbeitet: Rangesh
am 30 Sep. 2023
Hi tkarg,
I understand that you want to reduce the noise in the Simulink computations. To reduce noise in simulations, consider using a fixed step solver instead of a variable step solver. Variable step solvers can introduce more noise when there are numerical instabilities or rapid transitions in the system. By using a fixed step solver, you can mitigate these issues and achieve more stable and accurate results.
Attached below is the result generated by your model obtained using fixed step solver:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1496604/image.png)
You can refer to the following documentation on the usage of different solvers:
I hope this resolves your query.
Thanks,
Rangesh
0 Kommentare
Siehe auch
Kategorien
Mehr zu Sources finden Sie in Help Center und File Exchange
Produkte
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!