To ensure that slTuner linearizes this block correctly at all values of alpha in the design
grid, you must replace it by an array of linear models, one for each alpha value. This
block is equivalent to sending u through a gain of 1/alpha:
Therefore, you can use the following block substitution in your slTuner interface, where
alphagrid is an array of alpha values at your design points.
divsub = ss[(1/alphagrid), 0]
BlockSubs = struct('Name','mdl/div-by-alpha','Value',divsub);
st0.BlockSubstitutions = [st0.BlockSubstitutions; BlockSubs]
Each entry in model array divsub divides its first input by the corresponding entry in
alphagrid, and zeros out its second input. Thus, this substitution gives the desired
result y = u/alpha.
Resolving Mismatches Between a Block and its Substitution
Sometimes, the linear model array you have is not an exact replacement for the part of
the model you want to replace. For example, consider the following illustration of a three-
input, one-output subsystem.
Multiple Design Points in slTuner Interface