Cooperative collision avoidance between robots in swarm operations remains an open challenge. Assuming a decentralized architecture, each robot is responsible for making its own control decisions, including motion planning. To this end, most existing approaches mostly rely some form of (wireless) communication between the agents of the swarm. In reality, however, communication is brittle. It may be affected by latency, further delays and packet losses, transmission faults, and is subject to adversarial attacks, such as jamming or spoofing. This paper proposes Contingency Model-based Control (CMC) as a communicationless alternative. It follows the implicit cooperation paradigm, under which the design of the robots is based on consensual (offline) rules, similar to traffic rules. They include the definition of a contingency trajectory for each robot, and a method for construction of mutual collision avoidance constraints. The setup is shown to guarantee the recursive feasibility and collision avoidance between all swarm members in closed-loop operation. Moreover, CMC naturally satisfies the Plug \& Play paradigm, i.e., for new robots entering the swarm. Two numerical examples demonstrate that the collision avoidance guarantee is intact and that the robot swarm operates smoothly under the CMC regime.

翻译：机器人集群操作中的协同避障仍是一个开放挑战。在去中心化架构下，每个机器人需自主做出控制决策，包括运动规划。为此，现有方法大多依赖集群个体间某种形式的（无线）通信。然而在实际中，通信具有脆弱性：可能受延迟、额外时延与丢包、传输故障的影响，且易遭受干扰或欺骗等对抗性攻击。本文提出基于应急模型的控制作为无需通信的替代方案。该方法遵循隐式协作范式，其机器人设计基于共识性（离线）规则，类似于交通规则。这些规则包括为每个机器人定义应急轨迹，以及构建相互避障约束的方法。该框架被证明能在闭环操作中保证所有集群成员的递归可行性及相互避障。此外，CMC天然满足即插即用范式，适用于新加入集群的机器人。两个数值算例表明，该方法能完整保持避障保证，并使机器人集群在CMC机制下平稳运行。