Distributed output regulation design for multi-agent systems in output-feedback form

A distributed output regulation problem is studied for a class of nonlinearly coupled multi-agent systems, taking a decentralized output-feedback form. By a networked internal model with a preassigned topology and a decentralized stabilization design, a distributed regulator is constructed and solves the problem. As an illustration, for a three-mass-three-spring system, a problem of synchronizing every agent motion to a harmonic oscillator can be solved.