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



  • M is the open-loop (stable) LTI plant
  • d is a structure with the following fields
d.nameCell with the names of the uncertainty
d.sizeCell with the sizes of the uncertainty
d.typeCell with the types of uncertainty.
Note: This cover the uncertainty objects that are available in the robust control toolbox, namely: ‘ureal’ and ‘ultidyn’.
d.occurrencesMatrix with the number of repetitions of each uncertainty
d.boundsCell 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.inCell with the input channels of M, which connect to the output channels of \delta_n.
d.outCell with the output channels of M, which connect to the input channels of \delta_n.
d.pinMatrix with the input performance channels
d.poutMatrix with the output performance channels
d.uncCell with uncertainty block created by iqcdelta
d.perfPerformance block

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.

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