A Generalized and Efficient Control-Oriented Modeling Approach for Vibration-Prone Delta 3D Printers Using Receptance Coupling
A Generalized and Efficient Control-Oriented Modeling Approach for Vibration-Prone Delta 3D Printers Using Receptance Coupling
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DOI：
10.1109/tase.2022.3197057
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发表时间：
2023-07
影响因子：
5.6
通讯作者：
Nosakhare Edoimioya;C. Okwudire
中科院分区：
文献类型：
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作者：
Nosakhare Edoimioya;C. Okwudire
与传统的串行轴3D打印机相比，Delta 3D打印机可以实现更快、更精确的运动，从而显著提高增材制造的吞吐量。通过基于模型的前馈振动控制可以进一步提高运动速度和零件质量，如在串行轴3D打印机上所展示的那样。然而，三角洲机器没有受益于基于模型的控制器，因为难以准确地建模其位置相关的，耦合的非线性动态。在本文中，我们提出了一个有效的框架，以获得准确的线性参数变化模型的三角洲3D打印机在其工作空间内的任何位置，从一些频率响应测量。我们分解成两个子模型的动态-（1）一个实验确定的子模型包含解耦的振动动力学;和（2）一个解析导出的子模型包含耦合动力学-这是结合成一个使用容受耦合。我们通过扩展（2）的分析模型来概括该框架，以考虑打印机的末端执行器的不同质量分布和动态模型。实验表明，相当准确的预测的商业三角洲打印机的位置相关的动态，增强了直接驱动挤出机，在其工作空间中的各个位置。从业者注意-这项工作旨在为高速3D打印机（如delta机器）配备基于模型的控制器，以实现高精度的速度。由于三角洲的耦合运动链，复杂的控制方法，其中一些需要实时的状态测量，经常被用来实现令人满意的控制性能。我们的建模方法提供了一种有效的方法来获得准确的线性模型，而无需实时测量，从而使从业者能够设计基于线性模型的前馈控制器，以实现增材制造（AM）所需的高吞吐量和精度。我们在本文中开发的模型旨在与前馈振动补偿方法一起使用，这对于具有高功率伺服电机和反馈控制器的工业级AM机器以及在前馈控制中使用步进电机的消费级AM机器都是有益的。
Delta 3D printers can significantly increase throughput in additive manufacturing by enabling faster and more precise motion compared to conventional serial-axis 3D printers. Further improvements in motion speed and part quality can be realized through model-based feedforward vibration control, as demonstrated on serial-axis 3D printers. However, delta machines have not benefited from model-based controllers because of the difficulty in accurately modeling their position-dependent, coupled nonlinear dynamics. In this paper, we propose an efficient framework to obtain accurate linear parameter-varying models of delta 3D printers at any position within their workspace from a few frequency response measurements. We decompose the dynamics into two sub-models–(1) an experimentally-identified sub-model containing decoupled vibration dynamics; and (2) an analytically-derived sub-model containing coupled dynamics–which are combined into one using receptance coupling. We generalize the framework by extending the analytical model of (2) to account for differing mass profiles and dynamic models of the printer’s end-effector. Experiments demonstrate reasonably accurate predictions of the position-dependent dynamics of a commercial delta printer, augmented with a direct drive extruder, at various positions in its workspace. Note to Practitioners—This work aims to equip high-speed 3D printers, like delta machines, with model-based controllers to complement their speed with high-accuracy. Due to the coupled kinematic chains of the delta, complex control methodologies, some of which require real-time state measurements, are often used to achieve satisfactory control performance. Our modeling approach provides an efficient methodology for obtaining accurate linear models without the need for real-time measurements, thus enabling practitioners to design linear model-based feedforward controllers to achieve the high throughput and accuracy desired in additive manufacturing (AM). The models we develop in this paper are intended for use with feedforward vibration compensation methods, which can be beneficial for both industrial-scale AM machines that have high-powered servo motors and feedback controllers, as well as consumer-grade AM machines which use stepper motors in feedforward control.