  Problem of damping of an arbitrary number of linear oscillators under common
bounded control is considered. We are looking for a feedback control steering
the system to the equilibrium. The obtained control is asymptotically optimal:
the ratio of motion time to zero with this control to the minimum one is close
to 1, if the initial energy of the system is large. Some of the results based
on the new lemma about sustainable observability autonomous linear systems.
