Distributed control is the most popular control strategy for controlling numerous slave devices. However, the performance of slave devices is hard to improve because the control algorithm is handled by the commercial slave devices. Therefore, this paper proposes a hybrid control structure that follows the concept of centralized control strategy and handles part of the control loop on the master computer in a distributed control system through EtherCAT fieldbus. In this study, different advanced control methods such as robust control and learning control were applied to handle the position control loop of a scanning mirror system in a selective laser melting (SLM) system with stringent demand of position error around 40 µ m based on EtherCAT fieldbus. By designing a proper controller, the experiment results showed that the tracking performance was significantly improved. The tracking error dropped by about 80% after the proposed hybrid control structure was applied. By applying the proposed hybrid control structure, one can improve the high-performance-requirement devices, while reducing the calculation burden of the master computer for other low-performance-requirement devices by retaining the benefit of distributed control.

中文翻译：

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基于EtherCAT现场总线的扫描镜系统集中控制的高级应用

分布式控制是控制众多从设备的最流行的控制策略。但是，从设备的性能很难提高，因为控制算法是由商业从设备处理的。因此，本文提出了一种混合控制结构，遵循集中控制策略的概念，通过EtherCAT现场总线处理分布式控制系统中主计算机上的部分控制回路。在本研究中，基于 EtherCAT 的选择性激光熔化 (SLM) 系统中，应用鲁棒控制和学习控制等不同的先进控制方法来处理扫描镜系统的位置控制回路，该系统的位置误差要求严格要求约为 40 µm。现场总线。通过设计合适的控制器，实验结果表明，跟踪性能得到显着提高。应用所提出的混合控制结构后，跟踪误差下降了约 80%。通过应用所提出的混合控制结构，可以改进高性能要求的设备，同时通过保留分布式控制的优势，减少主计算机对其他低性能要求的设备的计算负担。