How to handle phyical units in Matlab / Simulink

1
votes

Simulink can be used for mathematical modelling of physical systems.

What is the native approach to support units (e.g. kg, m/s )?

I have seen following approach.

  • Append the unit to the signal name (e.g. Speed [m/s]).
  • Do conversion "manually" ( Multiply within model to convert from minutes to seconds)

This approach seems cumbersome.

If there is not native support: Is there a reason why Mathworks does not support units natively (except Simscape)?

(I am not talking about Simscape and I am not able to use it. Also I am aware of the argument that in mathematical modelling there are no such things like units. )

1
matlabsimulink
I think you've said everything in your question really: Simulink is a numerical simulation software, it does not care about units, signals are just numbers. It's up to the user to enforce correct unit conversion, except with Simscape-based products which are for modelling physical systems, and where units do matter. – am304
Thank you. Could you please add this as an answer? – ToBe

1 Answers

1
votes

As mentioned in the comments, Simulink is a general-purpose numerical simulation software, it does not care about units, signals and parameters are just numbers. It's up to the user to en force correct unit conversion, and the cumbersome approach you suggest is the only way I know to handle this problem. The only exception is Simscape, which is specifically used for modelling physical systems, and where units do matter. Unit conversion is taken care of in Simscape.