Practical Output Consensus of Nonlinear Heterogeneous Multi-Agent Systems with Limited Data Rate

TL;DR

This paper develops an ESO-based distributed control protocol for nonlinear heterogeneous multi-agent systems with limited data rate, achieving practical output consensus with minimal communication.

Contribution

It introduces a novel ESO-based output feedback protocol that guarantees consensus with only one-bit communication per link, even with unknown nonlinearities and disturbances.

Findings

Practical output consensus achieved with arbitrarily small steady-state error.

Consensus performance comparable to linear systems with full state measurement.

Validates the approach with simulations on third-order pendulum systems.

Abstract

This paper investigates the consensus problem for nonlinear heterogeneous multi-agent systems with limited communication data rate. Each agent is modeled by a higher-order strict-feedback continuous-time system with unknown nonlinearities andexternal disturbance, and only the first state variable being measurable. Extended state observers (ESOs) are used to estimate the unmeasurable agent states and the unknown nonlinear dynamics. An ESO-based distributed output feedback protocol with dynamic encoding and decoding is then presented. It is shown that, for a connected undirected network, the proposed protocol guarantees practical output consensus, in which the steady-state consensus error can be made arbitrarily small. The ESO-based protocol also shapes the transient consensus performance, as it is capable of recovering the consensus performance of a linear counterpart with fully measurable states. Furthermore, we prove that for higher-order uncertain nonlinear multi-agent systems, consensus can be achieved with merely one bit information exchange between each pair of adjacent agents at each time step. Finally, simulations on third-order pendulum systems are given, which verify the theoretical results.