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arXiv 2111.06211eess.SYcs.LGcs.SY
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基于随机混合模型的模型强化学习

Model-Based Reinforcement Learning via Stochastic Hybrid Models

Aalto University(阿尔托大学);Technical University of Darmstadt(达姆施塔特工业大学)

Hany Abdulsamad, Jan Peters

AI总结:

本文提出基于随机混合模型的强化学习方法,通过EM算法分解非线性动力学,结合行为克隆提取局部反馈控制器,并引入Hb-REPS策略优化,实现层次化控制。

摘要:

一般非线性系统的最优控制是自动化领域的核心挑战。得益于强大的函数逼近器,数据驱动的控制方法最近成功解决了许多具有挑战性的应用问题。然而,此类方法常常将动力学和控制的结构隐藏在黑箱过参数化表示之后,从而限制了我们对闭环行为的理解能力。本文采用混合系统视角来看待非线性建模与控制,为问题赋予显式的层次结构,并将复杂动力学分解为更简单的局部单元。我们考虑一种序列建模范式,以捕捉数据的时间结构,并推导出一种期望最大化(EM)算法,该算法自动将非线性动力学分解为具有非线性转移边界的随机分段仿射模型。此外,我们证明这些时间序列模型自然地允许闭环扩展,我们利用该扩展通过行为克隆从非线性专家中提取局部多项式反馈控制器。最后,我们引入一种新颖的混合相对熵策略搜索(Hb-REPS)技术,该技术融合了混合模型的层次特性,并优化一组从全局状态值函数的分段多项式近似中导出的时不变分段反馈控制器。

英文摘要:

Optimal control of general nonlinear systems is a central challenge in automation. Enabled by powerful function approximators, data-driven approaches to control have recently successfully tackled challenging applications. However, such methods often obscure the structure of dynamics and control behind black-box over-parameterized representations, thus limiting our ability to understand closed-loop behavior. This paper adopts a hybrid-system view of nonlinear modeling and control that lends an explicit hierarchical structure to the problem and breaks down complex dynamics into simpler localized units. We consider a sequence modeling paradigm that captures the temporal structure of the data and derive an expectation-maximization (EM) algorithm that automatically decomposes nonlinear dynamics into stochastic piecewise affine models with nonlinear transition boundaries. Furthermore, we show that these time-series models naturally admit a closed-loop extension that we use to extract local polynomial feedback controllers from nonlinear experts via behavioral cloning. Finally, we introduce a novel hybrid relative entropy policy search (Hb-REPS) technique that incorporates the hierarchical nature of hybrid models and optimizes a set of time-invariant piecewise feedback controllers derived from a piecewise polynomial approximation of a global state-value function.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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