Maintaining Team Coherence under the Velocity Obstacle Framework
|Title||Maintaining Team Coherence under the Velocity Obstacle Framework|
|Publication Type||Conference Paper|
|Year of Publication||2012|
|Authors||Kimmel, A, Dobson, A, Bekris, KE|
|Conference Name||Eleventh International Conference on Autonomous Agents and Multiagent Systems (AAMAS)|
|Conference Location||Valencia, Spain|
Many multi-agent applications may involve a notion of spa- tial coherence. For instance, simulations of virtual agents of- ten need to model a coherent group or crowd. Alternatively, robots may prefer to stay within a pre-specified communica- tion range. This paper proposes an extension of a decentral- ized, reactive collision avoidance framework, which defines obstacles in the velocity space, known as Velocity Obsta- cles (VOs), for coherent groups of agents. The extension, referred to in this work as a Loss of Communication Ob- stacle (LOCO), aims to maintain proximity among agents by imposing constraints in the velocity space and restricting the set of feasible controls. If the introduction of LOCOs results in a problem that is too restrictive, then the proximity con- straints are relaxed in order to maintain collision avoidance. If agents break their proximity constraints, a method is ap- plied to reconnect them. The approach is fast and integrates nicely with the Velocity Obstacle framework. It yields im- proved coherence for groups of robots connected through an input constraint graph that are moving with constant veloc- ity. Simulated environments involving a single team moving among static obstacles, as well as multiple teams operating in the same environment, are considered in the experiments and evaluated for collisions, computational cost and prox- imity constraint maintenance. The experiments show that improved coherence is achieved while maintaining collision avoidance, at a small computational cost and path quality degradation.