ELA, Volume 7, pp. 152-173, September 2000, abstract.

Disturbance Decoupling for Descriptor Systems by 
Measurement Feedback

Delin Chu and Volker Mehrmann

In this paper, the disturbance decoupling problem for 
descriptor systems via feedbacks that are based on 
measurements is discussed. Necessary and sufficient 
conditions are derived for the existence of feedbacks so 
that the disturbances do not influence the input/output 
behavior. At the same time, the closed-loop system 
becomes regular, of index at most one, and possibly also 
stable. The construction is based on a transformation to 
condensed form under orthogonal equivalence 
transformations that can be directly implemented as a 
numerically stable method.