Robust Redesign of Distributed Adaptive Consensus Protocols for Linear Multi-agent Systems

This paper revisits the distributed adaptive consensus protocols proposed in [1], [2]. It is shown that under the adaptive protocols in [1], [2] the parameter drift phenomenon takes place when external disturbances are present, implying that those adaptive protocols are not robust with respect to external disturbances. By using the sigma modification technique, distributed robust adaptive protocols are designed, which can guarantee the ultimate boundedness of both the consensus error and the adaptive gains in the presence of bounded disturbances. The upper bounds of the consensus error are further derived. Simulation examples are finally presented for illustration.