モデル不確実性推定を用いた安全強化学習
Safe Reinforcement Learning with Model Uncertainty Estimates
MC-Dropoutとブートストラップで計算可能な不確実性推定を安全強化学習に組み込み、未知の歩行者行動に対して慎重に衝突回避する方策を実現した。
著者: Björn Lütjens, Michael Everett, Jonathan P. How
分類: cs.RO, cs.AI, cs.LG
原文アブストラクト
Many current autonomous systems are being designed with a strong reliance on black box predictions from deep neural networks (DNNs). However, DNNs tend to be overconfident in predictions on unseen data and can give unpredictable results for far-from-distribution test data. The importance of predictions that are robust to this distributional shift is evident for safety-critical applications, such as collision avoidance around pedestrians. Measures of model uncertainty can be used to identify unseen data, but the state-of-the-art extraction methods such as Bayesian neural networks are mostly intractable to compute. This paper uses MC-Dropout and Bootstrapping to give computationally tractable and parallelizable uncertainty estimates. The methods are embedded in a Safe Reinforcement Learning framework to form uncertainty-aware navigation around pedestrians. The result is a collision avoidance policy that knows what it does not know and cautiously avoids pedestrians that exhibit unseen behavior. The policy is demonstrated in simulation to be more robust to novel observations and take safer actions than an uncertainty-unaware baseline.
