In this paper inverse dynamics of flexible multibody systems for the r
ealization of the prescribed motion tasks is formulated. The number of
actuators is equal to the dimension of the task space which is usuall
y equal to the rigid body degrees of freedom. Since the control forces
and the prescribed accelerations are noncausal due to the elastic med
ia, the dynamical equation set of the system becomes singular. To avoi
d the singularities in the numerical solution higher order derivative
information are utilized. The conditions for the existence of solution
and for the control force directions are also presented. A flexible m
anipulator is analyzed to illustrate the methods proposed.