In
this
paper
the
problem
of
controlling
differential-algebraic systems with index-1 is addressed. The
proposed technique is based on the interpretation of differential-
algebraic systems as the feedback interconnection of a differ-
ential system and an algebraic system. In this framework, the
algebraic variable can be treated as an external disturbance
acting on the differential system. A direct consequence of this
approach is that the control problem reduces to a classical
disturbance attenuation problem with internal stability. We also
show that the application of the proposed theory to the linear
case yields classical results. Finally, an example inspired by an
air suspension system in a truck illustrates the technique.