BRaVO: Biased Reciprocal Velocity Obstacles Break Symmetry in Dense Robot Populations

We present an extension to the Reciprocal Velocity Obstacles (RVO) approach to multi-robot collision avoidance with the aim of alleviating the problem of congestion caused by symmetrical situations in dense conditions. We show that in a resource transportation task RVO robots are unable to make progress due to crowds of robots with opposing navigation goals at source and sink. We introduce Biased Reciprocal Velocity Obstacles (BRVO), which breaks the symmetry among robots by giving priority to the robots leaving a task-related place of interest. BRVO is compared to RVO in two experiments and it is shown that BRVO is able to resolve the congestion much more quickly than RVO.