How to use 3D surface from cftool in Simulink lookup table?

Hello! I am designig a battery model with an internal resistance which is dependant on two variables: SoC and temperature. I have interpolated the data I have with MATLAB's curve fitting toolbox and was able to generate the desired 3D map of that dependence (see attached picture). My question is how can I use that map now for my Simulink model? As input parameters I will have SoC and temperature and the resistance in ohm should be the output. However, I have not been able to find a convenient way to export the data in a suitable lookup table (or similarly useful, my first guess was that I should use a 2-D lookup table in this case) in Simulink. What approach do you suggest for this? Thanks in advance

Answer 1

[Ville Kumlander]

Hi! I had the same kind of problem in a different topic. I had measurement data of two variables giving the third one as wished output. I interpolated that measurement data with 'scatteredInterpolant' at predefined points. Then I was able to insert those values at given points into 2-D lookup table. This solution is not using the 3D map/surface as an input to lookup table, but it was accurate enough to overcome my problem.

[Alex Cascatau]

Yep, that's the solution I used in the end as well. I used two for-loops to populate my table data matrix from the 'fittedmodel' output and it worked.