fLFTdata – IQClab

This function extracts the LFT data from an uncertain object (uobject) and generates the following information as input for an IQC-analysis:

[M,d]=fLFTdata(uobject)

Here

$M$ is the open-loop (stable) LTI plant
$d$ is a structure with the following fields

Given the uncertainty and performance bocks, it remains to combine uncertainties into larger blocks (optionally) and assign IQC-multipliers using the function iqcassign. Subsequently, one can directly run the IQC-analysis with the function iqcanalysis.

Field	Description
d.name	Cell with the names of the uncertainty
d.size	Cell with the sizes of the uncertainty
d.type	Cell with the types of uncertainty. Note: This cover the uncertainty objects that are available in the robust control toolbox, namely: ‘ureal’ and ‘ultidyn’.
d.occurrences	Matrix with the number of repetitions of each uncertainty
d.bounds	Cell with the bounds of the uncertainty Note: In case of ‘ureal’ these are given by the range $\delta_i\in[-b,b]$ and in the case of ‘ultidyn’ these are given by the norm-bound $\\|\delta_j\\|\leq b$ .
d.in	Cell with the input channels of $M$ , which connect to the output channels of $\delta_n$ .
d.out	Cell with the output channels of $M$ , which connect to the input channels of $\delta_n$ .
d.pin	Matrix with the input performance channels
d.pout	Matrix with the output performance channels
d.unc	Cell with uncertainty block created by iqcdelta
d.perf	Performance block