Synthesis and Analysis of Multirate Repetitive Control for Fractional-order Periodic Disturbance Rejection in Powder Bed Fusion
Synthesis and Analysis of Multirate Repetitive Control for Fractional-order Periodic Disturbance Rejection in Powder Bed Fusion
复制标题
粉床熔融分数阶周期抗扰多速率重复控制的综合与分析
DOI：
10.11509/isfa.2018.30
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Chen, Xu
中科院分区：
文献类型：
--
作者：
Wang, Dan;Chen, Xu
研究了粉末床熔融增材制造中提高重复能量沉积质量的控制方法。激光或电子束的重复扫描是新生制造过程中的关键模式，可以通过重复控制（RC）算法从根本上改善。然而，一个内在的限制，出现在离散时间RC时，外源信号的频率不能划分的采样频率。换句话说，内部模型1/（1-z-N）中的N不是整数。这样的挑战阻碍了高性能的应用程序的RC PBF，因为周期性的外源信号没有保证遵守熔池传感器的采样率。本文开发了一种新的多速率RC和闭环分析方法，以解决这种分数阶RC的情况下，通过产生高增益控制信号，正是在基波和谐波频率。所提出的分析方法展示了详细的多速率RC在一个新的设计空间中的干扰衰减特性。在激光PBF振镜扫描器上的数值验证揭示了所提出的多速率RC的基本优点。
This paper studies control approaches to advance the quality of repetitive energy deposition in powder bed fusion (PBF) additive manufacturing. A key pattern in the nascent manufacturing process, the repetitive scanning of the laser or electron beam can be fundamentally improved by repetitive control (RC) algorithms. An intrinsic limitation, however, appears in discrete-time RC when the exogenous signal frequency cannot divide the sampling frequency. In other words, N in the internal model 1/(1− z− N) is not an integer. Such a challenge hampers high-performance applications of RC to PBF because periodicity of the exogenous signal has no guarantees to comply with the sampling rate of molten-pool sensors. This paper develops a new multirate RC and a closed-loop analysis method to address such fractional-order RC cases by generating high-gain control signals exactly at the fundamental and harmonic frequencies. The proposed analysis method exhibits the detailed disturbanceattenuation properties of the multirate RC in a new design space. Numerical verification on a galvo scanner in laser PBF reveals fundamental benefits of the proposed multirate RC.