arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2211.09545cs.LGcs.AIcs.NAmath.NAmath.OCstat.ML
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增材制造工艺参数优化的强化学习方法

A Reinforcement Learning Approach for Process Parameter Optimization in Additive Manufacturing

Pennsylvania State University(宾夕法尼亚州立大学)

Susheel Dharmadhikari, Nandana Menon, Amrita Basak

摘要:

金属增材制造(AM)的工艺优化对于确保可重复性、控制微观结构和最大限度地减少缺陷至关重要。尽管通过传统的实验设计和统计过程映射来解决这个问题,但对可以集成到金属AM系统中的动态优化框架的了解有限。此外,由于预算限制,这些方法中的大多数是数据密集型的,不能由金属AM合金或系统支持。为了解决这个问题,本文介绍了一种强化学习(RL)方法,该方法转化为金属AM领域的优化问题。提出了一种基于Q学习的离线强化学习框架,以保持稳态熔池深度为目标,寻找最佳激光功率($P$)-扫描速度($v$)组合。为此,使用实验验证的Mesar-Tsai公式来模拟激光定向能量沉积环境,其中激光器作为跨$P-v$空间的代理操作,使得其最大化对于接近最佳的熔池深度的奖励。训练过程的顶点产生Q表,其中具有最高Q值的状态($P,v$)对应于优化的过程参数。由此产生的熔池深度和映射的Q值的$P-v$空间与实验观察一致。因此,该框架提供了一种无模型的学习方法,而无需任何先验知识。

英文摘要:

Process optimization for metal additive manufacturing (AM) is crucial to ensure repeatability, control microstructure, and minimize defects. Despite efforts to address this via the traditional design of experiments and statistical process mapping, there is limited insight on an on-the-fly optimization framework that can be integrated into a metal AM system. Additionally, most of these methods, being data-intensive, cannot be supported by a metal AM alloy or system due to budget restrictions. To tackle this issue, the article introduces a Reinforcement Learning (RL) methodology transformed into an optimization problem in the realm of metal AM. An off-policy RL framework based on Q-learning is proposed to find optimal laser power ($P$) - scan velocity ($v$) combinations with the objective of maintaining steady-state melt pool depth. For this, an experimentally validated Eagar-Tsai formulation is used to emulate the Laser-Directed Energy Deposition environment, where the laser operates as the agent across the $P-v$ space such that it maximizes rewards for a melt pool depth closer to the optimum. The culmination of the training process yields a Q-table where the state ($P,v$) with the highest Q-value corresponds to the optimized process parameter. The resultant melt pool depths and the mapping of Q-values to the $P-v$ space show congruence with experimental observations. The framework, therefore, provides a model-free approach to learning without any prior.

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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