Safe robust multi-agent reinforcement learning with neural control barrier functions and safety attention mechanism

In this paper, a novel safe robust multi-agent reinforcement learning method integrated with decentralized robust neural control barrier functions (CBFs) and a safety attention mechanism (SAM) is proposed for the safety-critical multi-agent system (MAS). Safety is fundamental in the safety-critical MAS but can be affected by factors such as modeling errors, external unknown disturbances, and time-varying observable agents. Several appropriate measures are implemented to address these issues. First, modeling errors and external disturbances are regarded as an adversary for each agent. The agent learns a policy that is robust to disturbances created by the adversary. Accordingly, decentralized robust neural CBFs are introduced to maintain the safety of the MAS, particularly when the general handcrafted CBFs are difficult to construct. The SAM, in combination with the robust neural CBFs, provides a control policy with the capacity to handle time-varying observable agents and increases its attention to dangerous events. The online fine-tuning procedure further enhances the safety. Finally, experiments demonstrate the safety and effectiveness of the proposed method.