  We consider tracking control for multibody systems which are modelled using
holonomic and nonholonomic constraints. Furthermore, the systems may be
underactuated and contain kinematic loops and are thus described by a set of
differential-algebraic equations that cannot be reformulated as ordinary
differential equations in general. We propose a control strategy which combines
a feedforward controller based on the servo-constraints approach with a
feedback controller based on a recent funnel control design. As an important
tool for both approaches we present a new procedure to derive the internal
dynamics of a multibody system. Furthermore, we present a feasible set of
coordinates for the internal dynamics avoiding the effort involved with the
computation of the Byrnes-Isidori form. The control design is demonstrated by a
simulation for a nonlinear non-minimum phase multi-input, multi-output robotic
manipulator with kinematic loop.
