Adversarial Search and Track with Multiagent Reinforcement Learning in Sparsely Observable Environment

We study a search and tracking (S&T) problem for a team of dynamic search agents to capture an adversarial evasive agent with only sparse temporal and spatial knowledge of its location in this paper. The domain is challenging for traditional Reinforcement Learning (RL) approaches as the large space leads to sparse observations of the adversary and in turn sparse rewards for the search agents. Additionally, the opponent's behavior is reactionary to the search agents, which causes a data distribution shift for RL during training as search agents improve their policies. We propose a differentiable Multi-Agent RL (MARL) architecture that utilizes a novel filtering module to supplement estimated adversary location information and enables the effective learning of a team policy. Our algorithm learns how to balance information from prior knowledge and a motion model to remain resilient to the data distribution shift and outperforms all baseline methods with a 46% increase of detection rate.