Is there a possibility for an N-dimensional lookuptable in Simscape?

Hello everybody,

I am constructing an emperical model within simhydraulics for a project. For the emperical model I currently use a 2dimensional lookup table (PS lookup) as follows:

http://nl.mathworks.com/help/physmod/simscape/ref/pslookuptable2d.html

This works well for my model, however I now want to add an additional variable to the model to implement another influence. Unfortunately there is as far i can see no n-D lookuptable available in the Simscape library.

I tried using an 'ordinary' Simulink n-dimensional look up table and using convertion blocks (PS-Simulink block --> n-D lookup --> Simulink-PS block) to overcome my problem, however now my model becomes unstable, or at least the automatic stepsize becomes really (unworkable) small.

Does anybody have a solution for my problem?

thank you very much in advance,

Wouter

Answer 1

[noman shah]

i am not understanding why you need an n-dimensional lookup table but the thing you can do is to proveide trend line for your data, eg

x=[1 3 4 5 6 8 9] y=[9 9 8 5 3 4 4]

this will convert your output value to according to input value in the lookup table but if the input value less than 1 or greater than 9 will always gives the result 9 and 4 respectivley.

also try it.

x=[0 1 3 4 5 6 8 9 10] y=[6 9 8 5 3 4 5 6 7]

with allowing interpolation and extrapolation and using saturation block with your desire max and min value,may be you get your required result you want to do