I recommend to use a Fuzzy Number representation of your model and I would try to focus on Interval-Value Type-2 Fuzzy Sets to get the best solution in the inference machine. I know that there are Matlab code with this kind of inference machine with IV2FS that I recommend to use in order to check the performance of the solution. On the other hand, intuitionistic fuzzy sets + interval-value (IVIFS) is another alternative but I don't find any good work in fuzzy inference machines