Regarding discrete integration through ode45

Hi,

I am studying a software written in simulink, which includes the signal integration block. The entire system is in a closed loop, where the current input to the integration block is dependent on the previous value given at the output of the block. Basically, the input to the block is a complex function. It is mentioned in the solver pane that the ode method used is ode45.

My intention is to convert the entire simulink block to a pure MATLAB/C code. Is it possible to know how the discrete integration is implemented by MATLAB/Simulink?

Thank you, Varad.

Answer 1

[Arnaud Miege]

Can I ask why you want to convert the Simulink model to MATLAB or C code?

Simulink use complex semantics and mechanisms to solve the underlying mathematical equations of the system (see How Simulink Works and Choosing a Solver in the documentation for more details). It's not possible to convert a Simulink model to MATLAB code, which is why I ask what are the reasons for doing so.

It is however possible to automatically generate C code from Simulink models with Real-Time Workshop. This is typically for embedding control or signal processing algorithms onto real-time embedded systems, but can also be use for speeding-up simulations, integrating in larger simulation environments, batch processing, etc...

HTH,

Arnaud

[Varad]

Hi Arnaud,

My main intent is to convert the whole software to C. The main reason is that some of the functions the MATLAB part implements are very slow, and I have managed to optimize a great deal of it in C. However, the simulink part is the toughest to translate. Also, since I am translating manually, I'd really like to understand how it works. Is that possible?

Thanks for your time,

Varad Deshmukh

[Arnaud Miege]

I wouldn't recommend doing a manual translation. Express your software in Simulink and then use Real-Time Workshop to generate the C code. Once the model is configured correctly to generate the C code, it's very easy to make modifications to the model and regenerate the code, rather than having to manually recode it and introducing potential coding errors.

Arnaud