Limited information availability represents a fundamental challenge for
control of multi-agent systems, since an agent often lacks sensing capabilities
to measure certain states of its own and can exchange data only with its
neighbors. The challenge becomes even greater when agents are governed by
high-order dynamics. The present work is motivated to conduct control design
for linear and nonlinear high-order leader-follower multi-agent systems in a
context where only the first state of an agent is measured. To address this
open challenge, we develop novel distributed observers to enable followers to
reconstruct unmeasured or unknown quantities about themselves and the leader
and on such a basis, build observer-based tracking control approaches. We
analyze the convergence properties of the proposed approaches and validate
their performance through simulation