摘要为了解决传统三轴连续纤维 3D 打印复杂轨迹精确成型困难的问题，设计搭建了五轴连续纤维 3D 打印机，该3D 打印机具有 5 个联动轴（XYZBC）以及 1 个树脂螺杆挤出装置辅助轴。针对典型的 3D 打印控制方案存在可联动轴数少、可扩展性差、实时性差等问题，对全软件型开放式数控系统进行了研究，并将其应用于连续纤维增材制造领域。基于开源数控平台 LinuxCNC 及 EtherCAT 工业以太网设计开发了面向五轴连续纤维 3D 打印机的全软件型开放式数控系统。通过优化 RT–Preempt 实时内核、开发集成 IgH–EtherCAT 的 HAL 模块，完成五轴联动控制，并将螺杆挤出轴作为主轴以实现其转速的精准控制。经测试，用户层与内核层调度最大抖动控制在 5μs 以内，集成 EtherCAT 的数控系统最大抖动＜50μs，实时性较好。最后通过标准拉伸性能试验和空间点阵结构的成型试验验证了五轴连续纤维 3D 打印系统方案的可行性。
Abstract：In order to solve the difficult problem of precisely forming complex trajectory in 3D printing of traditional 3-axle continuous fiber, a 5-axis continuous fiber 3D printer with 5 linkage shafts (XYZBC) and 1 auxiliary shaft of resin screw extruder was designed and built. Aiming at the problems of typical 3D printing control scheme, such as small number of linkable shafts, poor expandability and poor real-time performance, the full-software open CNC system was studied and applied in continuous fiber material increment manufacturing. Based on open-source CNC platform LinuxCNC and EtherCAT industrial Ethernet, a full-software open CNC system for 5-axis continuous fiber 3D printer is designed and developed. By optimizing the RT–Preempt real-time core, the HAL module integrated with IgH–EtherCAT was developed to complete the 5-axis linkage control, and the screw extruding shaft was used as the spindle to achieve the accurate control of its speed. The maximum dither control of user-level and core-level scheduling is tested within 5μs, the maximum dither of CNC system with integrated EtherCAT is less than 50μs, which prove that the CNC has good real-time performance. Finally, the feasibility of the 5-axis continuous fiber 3D printing system scheme is verified by standard tensile property test and forming experiment of space lattice structure.
2022, 
