FDM打印双材料小腿假肢接受腔的算法研究

Research on the Algorithm of the Calf Prosthesis Receiving Cavity Based on FDM Printing

提出适合于FDM打印双材料小腿假肢接受腔的放置方向、分层方法和路径规划,提高FDM工艺打印软、硬双材料接受腔的可行性和实用性。模型放置方向主要遵循使打印方向和模型的特征面最多的成垂直或平行的原则,减少阶梯现象的产生;打印分层方法主要是利用Z轴特征曲线确定模型的外轮廓曲线,进行分段处理后,分析外轮廓曲线与打印正向间的夹角关系,确定外轮廓分层厚度,最后运用概率统计、叠加求和等方法得出;打印路径规划,则以髌韧带为分界线,根据上下2部分的形状特征和性能需求,采用多种扫描方式相结合来得出。根据以上方法提出,沿打印Z方向的模型放置方向;根据模型轮廓而改变层厚的自适应分层方法;对于接受腔下部分截面轮廓是环形形状的,采用优化的螺旋偏置扫描方式,对于髌骨两侧的接受腔部分,采用复合扫描和分层扫描相结合的方式。

This student proposes the plac ement direction,layering method and path planning suitable for FDM printing bi-material calf prosthesis cavity,so as to improve the feasibility and practicability of printing soft-and hard-material receiving cavity in FDM process.The placement direction of the model mainly follows the principle of making the printing direction and the feature surface of the model vertical or parallel to reduce the occurrence of ladder phenomenon,and the printing layering method mainly uses the Z-axis characteristic curve to determine the outer contour curve of the model.After segmenting,the angle relationship between the outer contour curve and the printing positive direction is analyzed,and the thickness of the outer contour layer is determined,and finally obtained by using the methods of probability statistics,superposition summation and so on.The print path planning will be conducted by taking the patellar ligament as the dividing line,according to the shape characteristics and performance requirements of the upper and lower parts,and using a variety of scanning methods to get.According to the above methods,the placement direction of the model along the print Z-direction;an adaptive layering method to change the layer thickness according to the model profile;and for the lower part of the receiving cavity,the profile is circular,the optimized spiral offset scanning mode is adopted,and the combination of compound scanning and layered scanning is used for the receiving cavity on both sides of the patella.