Descriptor Control Systems

Descriptor state-space models can include both dynamic and algebraic equations, as is common in electrical circuits or constrained mechanical systems. This makes modeling easier and allows for more general systems. 
Wolfram Language descriptor state-space models generalize the full suite of modeling, analysis, and design functionality supported by standard state-space models.

Modeling & Simulation

(RefLink[StateSpaceModel, paclet:ref/StateSpaceModel]) — model a linear descriptor system

(RefLink[TransferFunctionModel, paclet:ref/TransferFunctionModel]) — model an improper transfer function

Controller & Estimator Design

(RefLink[StateFeedbackGains, paclet:ref/StateFeedbackGains]) — pole placement-based feedback gains

(RefLink[LQEstimatorGains, paclet:ref/LQEstimatorGains]) — LQ-based state estimator gains

Analysis & Transformations

(RefLink[KroneckerModelDecomposition, paclet:ref/KroneckerModelDecomposition]) — decouple fast and slow subsystems