Feedforward design for output synchronization of nonlinear heterogeneous systems with output communication

Output synchronization of nonlinear heterogeneous networked systems has been well investigated within a two-step framework. A reference model is designed for each agent and they achieve consensus through a proper collaborative control strategy. Then, a local regulation controller is constructed to drive each agent's output to the desired trajectory generated by its reference model. The local regulation controller was studied mainly based on the internal model principle. As the two steps occur concurrently, a small gain condition must be satisfied between them when the setting is on output communication that allows only agent outputs to be transmitted over network. In this paper, we consider a novel feedforward design that does not rely on internal model but a reference model of a sufficiently high relative degree. With such a design, local regulation can be separately achieved and hence the small gain condition is no longer required, which much simplifies the design when agent dynamics do not contain uncertainties. (C) 2019 Elsevier Ltd. All rights reserved.