This article proposes a support diminution design method for layered manufacturing of manifold surface based on variable orientation tracking (VOT). We aim at reducing the external support or upholders to a minimum with maximum possibility theoretically to save material and diminish material stripping effect (MSE), thereby improving the bilateral surface precision either exterior or interior. The cosmic gravity effect criterion is first used to extract surface need support from manifold surface with various materials by considering the balance force involving material characteristics and inclination angle. In the light of this criterion theory, varying the substrate normal orientation (SNO), namely workbench, for each layer in printing coordinate system, may break the balance between gravity and its equilibrium force. Therefore, the optimal SNO can be rigorously calculated using mathematical harmonic analysis among the continuous domain. To serve for the multidegree of freedom (DOF) on account of SNO, a reconfigurable VOT robot with six-axis DOF is developed for 3D printing (3DP). The matched servo controller is successfully implemented to accurate tracking of both orientation and Cartesian coordinates, using forward kinematic chains as well as reverse kinematic tracking. What is more, the end-effector (extruder) is holding perpendicular to the substrate workbench. The physical experiment that takes human external ear auricle, for example, using a layer-based process is implemented via VOT. The MSE due to supporting material can be clearly observed and diminished using an optical microscope. The stripped material from external support via diminution design can be evaluated quantitatively by electronic weighting balance. All of which indicate the findings that external support in 3DP can be virtually reckoned and diminished using VOT rather than the so-called build orientation traversal method. The VOT method upon which we touched can be widely applied to various layered manufacturing of accurate structure, for instance, cantilever, sandwich, and scaffolds in the occasion needing precise curtailment of outer support multimaterial.

中文翻译：

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基于变方位跟踪的流形曲面分层制造支持减量化设计

本文提出了一种基于可变方位跟踪（VOT）的流形表面分层制造的支撑缩减设计方法。我们的目标是在理论上最大限度地减少外部支撑或支撑件，以节省材料并减少材料剥离效应 (MSE)，从而提高外部或内部的双边表面精度。考虑材料特性和倾角的平衡力，首先采用宇宙引力效应准则从各种材料的流形表面中提取需要支撑的表面。根据该准则理论，改变印刷坐标系中每一层的基板法线方向（SNO），即工作台，可能会打破重力与其平衡力之间的平衡。所以，可以使用连续域之间的数学调和分析来严格计算最佳 SNO。为了服务于 SNO 的多自由度 (DOF)，开发了一种用于 3D 打印 (3DP) 的具有六轴自由度的可重构 VOT 机器人。匹配的伺服控制器成功地实现了方向和笛卡尔坐标的精确跟踪，使用正向运动链和反向运动跟踪。更重要的是，末端执行器（挤出机）垂直于基板工作台。以人的外耳耳廓为例，使用基于层的过程的物理实验是通过 VOT 实现的。使用光学显微镜可以清楚地观察和减少由于支撑材料引起的 MSE。通过微细化设计从外部支撑剥离的材料可以通过电子天平进行定量评估。所有这些都表明，使用 VOT 而不是所谓的构建方向遍历方法实际上可以计算和减少 3DP 中的外部支持。我们接触到的VOT方法可广泛应用于各种精密结构的分层制造，如悬臂、三明治、脚手架等需要外支撑多材料精确裁剪的场合。