Can Decentralized Control Outperform Centralized? The Role of Communication Latency

TL;DR

This paper investigates how communication latency impacts the performance of networked control systems, revealing that under certain delay conditions, decentralized control can outperform centralized approaches.

Contribution

It demonstrates that increasing communication delays can lead to scenarios where sparse, decentralized controllers outperform centralized ones, highlighting a fundamental performance trade-off.

Findings

Sparse controllers can outperform centralized ones with high delays

Performance trade-offs depend on how delays scale with network size

Decentralized control can be advantageous in latency-affected networks

Abstract

In this paper, we examine the influence of communication latency on performance of networked control systems. Even though distributed control architectures offer advantages in terms of communication, maintenance costs, and scalability, it is an open question how communication latency that varies with network topology influences closed-loop performance. For networks in which delays increase with the number of links, we establish the existence of a fundamental performance trade-off that arises from control architecture. In particular, we utilize consensus dynamics with single- and double-integrator agents to show that, if delays increase fast enough, a sparse controller with nearest neighbor interactions can outperform the centralized one with all-to-all communication topology.