Adaptive synchronisation of unknown nonlinear networked systems with prescribed performance

TL;DR

This paper introduces an adaptive control method for highly nonlinear multi-agent systems that ensures prescribed performance in tracking, even with unknown dynamics and external disturbances, validated through simulations.

Contribution

It develops a novel adaptive control approach that guarantees prescribed performance and boundedness for unknown nonlinear networked systems with a structured communication topology.

Findings

Successfully confines tracking error within predefined bounds.

Ensures uniform ultimate boundedness of errors and parameters.

Demonstrates robustness against nonlinearities and disturbances.

Abstract

This paper proposes an adaptive tracking control with prescribed performance function for distributive cooperative control of highly nonlinear multi-agent systems. The use of such approach confines the tracking error within a large predefined set to a predefined smaller set. The key idea is to transform the constrained system into unconstrained one through the transformation of the output error. Agents' dynamics are assumed unknown, and the controller is developed for a strongly connected structured network. The proposed controller allows all agents to follow the trajectory of the leader node, while satisfying the necessary dynamic requirements. The proposed approach guarantees uniform ultimate boundedness for the transformed error as well as a bounded adaptive estimate of the unknown parameters and dynamics. Simulations include two examples to validate the robustness and smoothness of the proposed controller against highly nonlinear heterogeneous multi-agent system with uncertain time-variant parameters and external disturbances. Keywords: Prescribed performance, Transformed error, Multi-agents, Distributed adaptive control, Adaptive Consensus, Transient, Steady-state error, Semi-global asymptotic stability, uniformly ultimately bounded, Nonlinear Networked Systems, Distributed Control, Robustness.