Shared Network Effects in Time- versus Event-Triggered Consensus of a Single-Integrator Multi-Agent System

TL;DR

This paper analyzes how shared network effects, including delays and packet loss, impact the performance of event- versus time-triggered consensus in multi-agent systems, revealing that network congestion can negate event-triggered advantages.

Contribution

It provides a theoretical comparison of event- and time-triggered control performance considering network effects like delays and packet loss in multi-agent consensus.

Findings

Network effects can degrade event-triggered control performance.

Performance advantage of event-triggered control diminishes with more agents.

Large networks may eliminate the benefits of event-triggered control.

Abstract

Event-triggered control has the potential to provide a similar performance level as time-triggered (periodic) control while triggering events less frequently. It therefore appears intuitive that it is also a viable approach for distributed systems to save scarce shared network resources used for inter-agent communication. While this motivation is commonly used also for multi-agent systems, a theoretical analysis of the impact of network effects on the performance of event- and time-triggered control for such distributed systems is currently missing. With this paper, we contrast event- and time-triggered control performance for a single-integrator consensus problem under consideration of a shared communication medium. We therefore incorporate transmission delays and packet loss in our analysis and compare the triggering scheme performance under two simple medium access control protocols. We find that network effects can degrade the performance of event-triggered control beyond the performance level of time-triggered control for the same average triggering rate if the network is used intensively. Moreover, the performance advantage of event-triggered control shrinks with an increasing number of agents and is even lost for sufficiently large networks in the considered setup.