  This paper addresses the oscillatory synchronization problem for multiple
uncertain mechanical systems with a virtual leader, and the interaction
topology among them is assumed to contain a directed spanning tree. We propose
an adaptive control scheme to achieve the goal of oscillatory synchronization.
Using the similarity decomposition approach, we show that the position and
velocity synchronization errors between each mechanical system (or follower)
and the virtual leader converge to zero. The performance of the proposed
adaptive scheme is shown by numerical simulation results.
