Actor-critic (AC) methods are widely used in reinforcement learning (RL) and benefit from the flexibility of using any policy gradient method as the actor and value-based method as the critic. The critic is usually trained by minimizing the TD error, an objective that is potentially decorrelated with the true goal of achieving a high reward with the actor. We address this mismatch by designing a joint objective for training the actor and critic in a decision-aware fashion. We use the proposed objective to design a generic, AC algorithm that can easily handle any function approximation. We explicitly characterize the conditions under which the resulting algorithm guarantees monotonic policy improvement, regardless of the choice of the policy and critic parameterization. Instantiating the generic algorithm results in an actor that involves maximizing a sequence of surrogate functions (similar to TRPO, PPO) and a critic that involves minimizing a closely connected objective. Using simple bandit examples, we provably establish the benefit of the proposed critic objective over the standard squared error. Finally, we empirically demonstrate the benefit of our decision-aware actor-critic framework on simple RL problems.

我们设计了一个决策感知的联合目标来训练演员和评论家，以解决演员的最优目标与评论家的最小化TD误差目标不匹配的问题，并提出了一个通用的Actor-critic算法来处理任何函数逼近，在一些简单的赌博机示例中，我们证明了提出的评论家目标的好处。最后，我们在简单的RL问题上通过实验证明了决策感知的Actor-critic框架的好处。

具备函数逼近和理论保证的决策感知演员-评论家算法