复杂箱体零件的激光扫描测量与模型重构

复杂箱体是一种制造难度较大的重要零件，逆向设计技术可以有效缩短复杂箱体零件的设计周期、降低生产成本，箱体的数字化测量是逆向设计的关键技术之一。在对复杂箱体进行数字化测量时，选用了转站方式的激光扫描测量方法。箱体外表面的点云数据可以通过激光扫描测量直接获得；箱体内腔形状复杂，难以测量，通过将石膏灌入箱体内腔，待石膏冷却成型后取出石膏，测量石膏外表面获得石膏外表面点云数据。计算出石膏质心，将石膏表面点云依照石膏材料的收缩率进行以质心为中心的缩放处理，反求出箱体内腔表面的点云数据，最后利用特征点匹配的方法将复杂箱体的外形点云数据和内腔点云数据融合，形成完整的箱体点云模型。根据点云完成了复杂箱体零件的三维数字模型的重构和精度评价。

Research on Laser Scan Measuring and Reverse Modeling for Complex Box

Complex box is an important part that is difficult to manufacture.Using reverse design technology can effectively shorten the design cycle of complex box parts and reduce production costs.Digital measurement of box is one of the key technologies in reverse design.When making digital measurement of a complex box,a laser scanning measurement method using transfer station method was selected.The point cloud data on the outer surface of the box were directly obtained through laser scanning measurement.The shape of the inner cavity of the box is complex and difficult to measure.By pouring gypsum into the inner cavity of the box,the gypsum was taken out after it was cooled and molded,and the outer surface of the gypsum was measured to obtain point cloud data of the outer surface of the gypsum.the mass center of the gypsum was calculated,the point cloud of the gypsum surface was scaled according to the shrinkage rate of the gypsum material,and the point cloud data of the interior surface of the box were reversely calculated.Finally,the feature point matching method was used to fuse the exterior point cloud data of the complex box with the interior point cloud data to form a complete box point cloud model.According to the point cloud,the three-dimensional digital model reconstruction and accuracy evaluation of complex box parts were completed.