A challenge in Multi-Robot Exploration (MRE) tasks is formulating efficient distributed exploration strategies since, in general, robots cannot communicate freely and the environment can be dynamic and unknown. Most solutions deliver good performance at the cost of adding more robots or network relays while exploring, which helps to connect the robots through time. This paper proposes a novel intermittent rendezvous method that allows robots to explore an unknown environment while sharing maps at rendezvous points without adding relays or other robots. We propose dynamically updating the rendezvous locations throughout the exploration and designing an exploration strategy that prioritizes future rendezvous. We generate our rendezvous strategies automatically by reducing the MRE to instances of the Job Shop Schedule Problem (JSSP) with temporal connectivity graphs. We evaluate our method in simulation in various virtual urban environments and in a Gazebo simulation using the Robot Operating System (ROS). Our results suggest that our method can be better than using relays or maintaining intermittent communication with a base station since we can explore faster without additional hardware to create a relay network.

翻译：多机器人探索任务中的一大挑战在于制定高效的分布式探索策略，因为通常情况下机器人间无法自由通信，且环境可能动态未知。多数解决方案虽能实现良好性能，但需在探索过程中额外部署机器人或网络中继设备，以维持机器人间的时域连通性。本文提出一种新颖的间歇性会合方法，使机器人无需添加中继节点或其他机器人即可在未知环境中进行探索，并在会合点共享地图。我们提出动态更新探索过程中的会合位置，并设计一种优先考虑未来会合的探索策略。通过将多机器人探索问题归约为含时域连通图的作业车间调度问题实例，我们能够自动生成会合策略。我们分别在多种虚拟城市场景仿真环境及基于机器人操作系统的Gazebo仿真中评估了该方法。结果表明，相较于使用中继节点或与基站保持间歇通信，本方法无需额外硬件构建中继网络即可实现更快的探索速度。