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Function Reference


Uncertain ElementsFunctions for building uncertain elements
Uncertain Matrices and SystemsFunctions for building uncertain matrices and systems
Manipulation of Uncertain ModelsFunctions for transforming and analyzing uncertain models
Interconnection of Uncertain ModelsFunctions for connecting uncertain models
Model Order ReductionFunctions for generating low-order approximations to plant and controller models
Robustness and Worst-Case AnalysisFunctions for characterizing system robustness and worst-case performance
Robustness Analysis for Parameter-Dependent Systems (P-Systems)Functions for analyzing P-Systems
Controller Synthesis and TuningH control design functions
µ-SynthesisStructured singular value control design functions
Sampled-Data SystemsFunctions for analyzing sampled-data systems
Gain SchedulingFunctions for synthesizing gain-scheduled controllers
Frequency-Response Data (FRD) ModelsFunctions for operating on FRD models
Supporting UtilitiesAdditional functions for working with systems containing uncertain elements
LMIsFunctions for building and solving systems of Linear Matrix Inequalities
SimulinkFunctions for using with Simulink models

Uncertain Elements

ucomplexCreate uncertain complex parameter
ucomplexmCreate uncertain complex matrix
udynCreate unstructured uncertain dynamic system object
ultidynCreate uncertain linear time-invariant object
urealCreate uncertain real parameter

Uncertain Matrices and Systems

diagDiagonalize vector of uncertain matrices and systems
randatomGenerate random uncertain atom objects
randumatGenerate random uncertain umat objects
randussGenerate stable, random uss objects
ufrdUncertain frequency response data model
umatCreate uncertain matrix
ussSpecify uncertain state space models or convert LTI model to uncertain state space model

Manipulation of Uncertain Models

actual2normalizedTransform actual values to normalized values
gridurealGrid ureal parameters uniformly over their range
isuncertainCheck whether argument is uncertain class type
lftdataDecompose uncertain objects into fixed normalized and fixed uncertain parts
normalized2actualConvert value for atom in normalized coordinates to corresponding actual value
repmatReplicate and tile array
simplifySimplify representation of uncertain object
squeezeRemove singleton dimensions for umat objects
usampleGenerate random samples of uncertain variables
uss/ssbalScale state/uncertainty while preserving uncertain input/output map of uncertain system
usubsSubstitute given values for uncertain elements of uncertain objects

Interconnection of Uncertain Models

iconnectCreate empty iconnect (interconnection) objects
icsignalCreate icsignal object of specified dimension
stackConstruct array by stacking uncertain matrices, models, or arrays
sysicBuild interconnections of certain and uncertain matrices and systems

Model Order Reduction

balancmrBalanced model truncation via square root method
bstmrBalanced stochastic model truncation (BST) via Schur method
hankelmrHankel minimum degree approximation (MDA) without balancing
hankelsvCompute Hankel singular values for stable/unstable or continuous/discrete system
imp2ssSystem realization via Hankel singular value decomposition
modrealModal form realization and projection
ncfmrBalanced model truncation for normalized coprime factors
reduceSimplified access to Hankel singular value based model reduction functions
schurmrBalanced model truncation via Schur method
slowfastSlow and fast modes decomposition

Robustness and Worst-Case Analysis

cpmarginCoprime stability margin of plant-controller feedback loop
gapmetricCompute upper bounds on Vinnicombe gap and nugap distances between two systems
loopmarginStability margin analysis of LTI and Simulink feedback loops
loopsensSensitivity functions of plant-controller feedback loop
mussvCompute bounds on structured singular value (µ)
mussvextractExtract muinfo structure returned by mussv
ncfmarginCalculate normalized coprime stability margin of plant-controller feedback loop
popovPerform Popov robust stability test
robustperfRobust performance margin of uncertain multivariable system
robuststabCalculate robust stability margins of uncertain multivariable system
wcgainCalculate bounds on worst-case gain of uncertain system
wcgainplot Worst-case gain analysis for uncertain systems
wcmarginWorst-case disk stability margins of uncertain feedback loops
wcnormWorst-case norm of uncertain matrix
wcsensCalculate worst-case sensitivity and complementary sensitivity functions of plant-controller feedback loop

Robustness Analysis for Parameter-Dependent Systems (P-Systems)

aff2polConvert affine parameter-dependent models to polytopic models
decayQuadratic decay rate of polytopic or affine P-systems
ispsysTrue for parameter-dependent systems
pdlstabAssess robust stability of polytopic or parameter-dependent system
pdsimulTime response of parameter-dependent system along given parameter trajectory
polydecCompute polytopic coordinates with respect to box corners
psinfoInquire about polytopic or parameter-dependent systems created with psys
pvecSpecify range and rate of variation of uncertain or time-varying parameters
pvinfoDescribe parameter vector specified with pvec
quadperfCompute quadratic H performance of polytopic or parameter-dependent system
quadstabQuadratic stability of polytopic or affine parameter-dependent systems

Controller Synthesis and Tuning

augwState-space or transfer function plant augmentation for use in weighted mixed-sensitivity H and H2 loopshaping design
h2hinfsynMixed H2/H synthesis with pole placement constraints
h2syn H2 control synthesis for LTI plant
hinfstructH tuning of fixed-structure controllers
hinfsynCompute H optimal controller for LTI plant
loopsynH optimal controller synthesis for LTI plant
looptuneTune MIMO control systems
loopview Graphically analyze MIMO feedback loops
ltrsynLQG loop transfer-function recovery (LTR) control synthesis
mixsynH mixed-sensitivity synthesis method for robust control loopshaping design
mkfilterGenerate Bessel, Butterworth, Chebyshev, or RC filter
ncfsynLoop shaping design using Glover-McFarlane method

µ-Synthesis

cmsclsynApproximately solve constant-matrix, upper bound µ-synthesis problem
dkitoptCreate options object for use with dksyn
dksynRobust controller design using µ-synthesis
drawmagMouse-based tool for sketching and fitting
fitfrdFit frequency response data with state-space model
fitmagfrdFit frequency response magnitude data with minimum-phase state-space model using log-Chebychev magnitude design
genphaseFit single-input/single-output magnitude data with real, rational, minimum-phase transfer function

Sampled-Data Systems

sdhinfnormCompute L2 norm of continuous-time system in feedback with discrete-time system
sdhinfsynCompute H controller for sampled-data system
sdlsimTime response of sampled-data feedback system

Gain Scheduling

hinfgsSynthesis of gain-scheduled H controllers

Frequency-Response Data (FRD) Models

frd/loglogLog-log scale plot of frd objects
frd/rcondLAPACK reciprocal condition estimator of frd object
frd/schurSchur decomposition of frd object
frd/semilogxSemilog scale plot of frd object
frd/svdSingular value decomposition of frd object

Supporting Utilities

bilinMultivariable bilinear transform of frequency (s or z)
dmplotInterpret disk gain and phase margins
mktitoPartition LTI system into two-input/two-output system
sectfState-space sector bilinear transformation
skewdecForm skew-symmetric matrix
symdecForm symmetric matrix

LMIs

LMI Systems
LMI Characteristics
LMI Solvers
Validation of Results
Modification of Systems of LMIs

LMI Systems

getlmisInternal description of LMI system
lmieditSpecify or display systems of LMIs as MATLAB expressions
lmitermSpecify term content of LMIs
lmivarSpecify matrix variables in LMI problem
newlmiAttach identifying tag to LMIs
setlmisInitialize description of LMI system

LMI Characteristics

dec2matGiven values of decision variables, derive corresponding values of matrix variables
decinfoDescribe how entries of matrix variable X relate to decision variables
decnbrTotal number of decision variables in system of LMIs
lmiinfoInformation about variables and term content of LMIs
lminbrReturn number of LMIs in LMI system
mat2decExtract vector of decision variables from matrix variable values
matnbrNumber of matrix variables in system of LMIs

LMI Solvers

defcxHelp specify cTx objectives for mincx solver
feaspCompute solution to given system of LMIs
gevpGeneralized eigenvalue minimization under LMI constraints
mincxMinimize linear objective under LMI constraints

Validation of Results

evallmiGiven particular instance of decision variables, evaluate all variable terms in system of LMIs
showlmiReturn left and right sides of LMI after evaluation of all variable terms

Modification of Systems of LMIs

bilinMultivariable bilinear transform of frequency (s or z)
dmplotInterpret disk gain and phase margins
mktitoPartition LTI system into two-input/two-output system
sectfState-space sector bilinear transformation
skewdecForm skew-symmetric matrix
symdecForm symmetric matrix

Simulink

ufindFind uncertain variables in Simulink model
ulinearizeLinearize Simulink model with Uncertain State Space block
  


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