マルチロボットシステムにおけるデッドロックの解析と解消
Deadlock Analysis and Resolution in Multi-Robot Systems (Extended Version)
CBFを用いたマルチロボットの衝突回避制御で生じるデッドロックを双対性理論とグラフ列挙で解析し、分散型の解消アルゴリズムを提案・実機検証した論文。
著者: Jaskaran Grover, Changliu Liu, Katia Sycara
分類: cs.RO, cs.MA, cs.SY, eess.SY
原文アブストラクト
Collision avoidance for multirobot systems is a well studied problem. Recently, control barrier functions (CBFs) have been proposed for synthesizing controllers guarantee collision avoidance and goal stabilization for multiple robots. However, it has been noted reactive control synthesis methods (such as CBFs) are prone to deadlock, an equilibrium of system dynamics causes robots to come to a standstill before reaching their goals. In this paper, we formally derive characteristics of deadlock in a multirobot system uses CBFs. We propose a novel approach to analyze deadlocks resulting from optimization based controllers (CBFs) by borrowing tools from duality theory and graph enumeration. Our key insight is system deadlock is characterized by a force-equilibrium on robots and we show how complexity of deadlock analysis increases approximately exponentially with the number of robots. This analysis allows us to interpret deadlock as a subset of the state space, and we prove this set is non-empty, bounded and located on the boundary of the safety set. Finally, we use these properties to develop a provably correct decentralized algorithm for deadlock resolution which ensures robots converge to their goals while avoiding collisions. We show simulation results of the resolution algorithm for two and three robots and experimentally validate this algorithm on Khepera-IV robots.
