Laplacian Spectral Shaping for Non-Uniform Scaling Formation Control of Open Multi-Agent Systems

2026-07-18

AI Summary

This work addresses the challenge of maintaining non-uniform scaling formations in open multi-agent systems, where dynamic changes in agent count, communication topology, and leadership can disrupt essential spectral properties of the Laplacian matrix—such as positive semi-definiteness, nullspace structure, and positive definiteness of the follower subblock. To overcome this, the authors propose a distributed weight adaptation protocol that employs spectral shaping to dynamically adjust selected Laplacian weights, thereby preserving the required spectral structure in arbitrary-dimensional spaces. The approach enables any agent to act as a leader without predefined hierarchies and accommodates sparse sensing graphs and dynamic leader reassignment. By doing so, it transcends the limitations of existing affine formation control methods that rely on fixed communication structures and static leadership. Theoretical analysis and simulations demonstrate the method’s effectiveness in achieving flexible and robust non-uniform scaling formation control under time-varying topologies.

Abstract

Non-uniform scaling control enables a multi-agent formation to adjust its shape by compressing or stretching independently along different coordinate axes through inter-agent interactions, offering high flexibility in complex environments. The fundamental idea is encoding the desired formation shape as the kernel of a matrix-valued Laplacian. In open multi-agent systems, however, changes in number of agents, number of edges, and leader selection dynamically alter this Laplacian, destroying the required spectral properties: positive semidefiniteness, correct kernel, and positive definiteness of the follower block (we summarize these properties as the formation spectrum). In this paper, we develop distributed protocols to strategically adjust partial weights of the Laplacian matrix for formation control in arbitrary dimensional space. By implementing the protocols, the desired formation spectrum can be preserved under dynamic topology changes including agent joining, edge addition, agent leaving, and edge removal, while any pair of agents can serve as leaders. Unlike existing Laplacian design methods for affine formation control under topology changes, the proposed approach requires a sparser sensing graph, avoids a predefined parent-child hierarchical structure, and supports leader reassignment. The effectiveness of the proposed protocols is validated through both theoretical analysis and numerical simulations.

Problem

• Laplacian spectral shaping
• non-uniform scaling formation control
• open multi-agent systems
• formation spectrum
• dynamic topology changes

Innovation

• Laplacian spectral shaping
• non-uniform scaling formation control
• open multi-agent systems
• distributed protocols
• dynamic topology