  The time-varying output formation tracking for the heterogeneous multi-agent
systems (MAS) is investigated in this paper. First, a distributed observer is
constructed for followers to estimate the states of the leader, which can
ensure that the estimation error converges to the origin in the prescribed
time. Then, the local formation controller is designed for each follower based
on the estimation of the observer, under which, the formation errors converge
to the origin in the prescribed time as well. That is, the settling time of the
whole system can be predefined in advance. It's noted that not only the
uncertainties in the state matrix but also the uncertainties in the input
matrix are considered, which makes the problem more practical. Last, a
simulation is performed to show the effectiveness of the proposed approach.
