BodyGuards: Escorting by Multiple Robots in Unknown Environment under Limited Communication

TL;DR

This paper introduces BodyGuards, a multi-robot escorting framework that enhances safety and efficiency for human operators in unknown, adversarial environments with limited communication, through task-oriented exploration and coordinated planning.

Contribution

The work presents a novel integrated escorting framework combining collaborative exploration, inter-robot-operator communication, and dynamic path planning under communication constraints.

Findings

Reduces operator risk in adversarial environments.

Decreases mission completion time compared to baseline methods.

Effective in both simulation and hardware experiments.

Abstract

Multi-robot systems are increasingly deployed in high-risk missions such as reconnaissance, disaster response, and subterranean operations. Protecting a human operator while navigating unknown and adversarial environments remains a critical challenge, especially when the communication among the operator and robots is restricted. Unlike existing collaborative exploration methods that aim for complete coverage, this work focuses on task-oriented exploration to minimize the navigation time of the operator to reach its goal while ensuring safety under adversarial threats. A novel escorting framework BodyGuards, is proposed to explicitly integrate seamlessly collaborative exploration, inter-robot-operator communication and escorting. The framework consists of three core components: (I) a dynamic movement strategy for the operator that maintains a local map with risk zones for proactive path planning; (II) a dual-mode robotic strategy combining frontier based exploration with optimized return events to balance exploration, threat detection, and intermittent communication; and (III) multi-robot coordination protocols that jointly plan exploration and information sharing for efficient escorting. Extensive human-in-the-loop simulations and hardware experiments demonstrate that the method significantly reduces operator risk and mission time, outperforming baselines in adversarial and constrained environments.