  Multi-robot collaboration has become a needed component in unknown
environment exploration due to its ability to accomplish various challenging
situations. Potential-field-based methods are widely used for autonomous
exploration because of their high efficiency and low travel cost. However,
exploration speed and collaboration ability are still challenging topics.
Therefore, we propose a Distributed Multi-Robot Potential-Field-Based
Exploration (DMPF-Explore). In particular, we first present a Distributed
Submap-Based Multi-Robot Collaborative Mapping Method (DSMC-Map), which can
efficiently estimate the robot trajectories and construct the global map by
merging the local maps from each robot. Second, we introduce a
Potential-Field-Based Exploration Strategy Augmented with Modified Wave-Front
Distance and Colored Noises (MWF-CN), in which the accessible frontier
neighborhood is extended, and the colored noise provokes the enhancement of
exploration performance. The proposed exploration method is deployed for
simulation and real-world scenarios. The results show that our approach
outperforms the existing ones regarding exploration speed and collaboration
ability.
