熔丝沉积成型中最优放置方向选择算法

在熔丝沉积成型制造中，调整物体放置方向可以改善制造后模型表面精确度，并能有效减少打印耗材和打印时间．但是现有最优放置角度算法很少兼顾这三因素．文中在考虑这三因素的基础上，同时分析人们对显著特征区域精细程度主观观感的不同，以及去除支撑时对模型的损害，提出了支撑体积耗材、模型表面打印耗材、打印时间、模型表面精细度、模型表面显著特征加权精细度、支撑覆着表面积等6项成型指标与放置角度的关系函数，并根据这6项成型评价指标函数构造最优放置角度目标函数；最后，求解最优化目标函数以获取最优放置角度．实验结果表明，该算法可有效计算各种条件下的物体最优放置角度，优化了制造物体表面的精确度，节约了打印耗材和打印时间，避免了部分后处理对模型造成的损害．

Optimal printing direction selection in fused deposition modeling

In Fused Deposition Modeling (FDM) manufacture, adjustment of the object printing direction can improve the surface accuracy of the manufactured model, and can effectively reduce the printing time and printing material. However, the existing algorithm seldom takes account of all these factors. Considering these three factors and analyzing the people's subjective perception of the precision of the salient features and the damage caused by removal of the supporting, we propose the relationship functions among printing direction, support structure material, model surface printing supplies, printing time, model surface accuracy, salient features of precision and the processing cost of the model. According to these functions of the six evaluation indexes, the optimal printing direction objective function is constructed, and is solved to obtain the optimal printing direction. Experimental results show that the algorithm can be used to calculate the optimal printing direction of the object in various conditions, optimize the accuracy of the surface of the object, save the printing material and printing time, and avoid the damage caused by the post processing.