  The robot exploration task has been widely studied with applications spanning
from novel environment mapping to item delivery. For some time-critical tasks,
such as rescue catastrophes, the agent is required to explore as efficiently as
possible. Recently, Visit Frequency-based map representation achieved great
success in such scenarios by discouraging repetitive visits with a
frequency-based penalty. However, its relatively large size and single-agent
settings hinder its further development. In this context, we propose Integrated
Visit Frequency Map, which encodes identical information as Visit Frequency Map
with a more compact size, and a visit frequency-based multi-agent information
exchange and control scheme that is able to accommodate both representations.
Through tests in diverse settings, the results indicate our proposed methods
can achieve a comparable level of performance of VFM with lower bandwidth
requirements and generalize well to different multi-agent setups including
real-world environments.
