Consensus of hierarchical multi-agent systems with a time-varying set of active agents

TL;DR

This paper introduces a switching algorithm for hierarchical multi-agent systems with a time-varying set of active agents, ensuring consensus despite changing active agent subsets, with applications demonstrated in converters and water systems.

Contribution

It proposes a novel switching algorithm for consensus in multi-agent systems with dynamic active agents, extending existing methods to more practical scenarios.

Findings

The algorithm guarantees convergence to a leader-defined consensus state.

Effective in systems with intermittent agent activity.

Validated through two real-world benchmarks.

Abstract

Time-varying hierarchical multi-agent systems are common in many applications. A well-known solution to control these systems is to use state feedback controllers that depend on the adjacency matrix to reach consensus. This solution has been applied so far to multi-agent systems with fixed or time-varying communication topologies. In this paper, we consider single-integrator multi-agent systems where only a subset of the agents are active at any given time and the set of active agents is time-varying. This type of multi-agent system is relevant in applications such as modular multilevel converters and water pumping systems. We develop a switching algorithm that periodically selects a set of active agents through a set of graphs that connect the follower agents with a leader agent. We further prove that the developed switching algorithm combined with a classic consensus protocol yields convergence to a consensus state defined by the leader despite a time-varying set of active agents. The effectiveness of the switching algorithm is illustrated in two benchmark examples: a modular multilevel converter and a water pumping system.