Complicated workpiece shape machining using optimal target shape position and orientation on a multifunctional machine tool

Abstract

In order to machine complicated workpiece shapes, it is essential for operators to avoid detrimental collisions between machine structures and workpieces. Therefore, a machine simulator based on 3D models is usually utilized prior to machining operations to ensure this problem is avoided. On the other hand, a multifunctional machine tool with both machining and additive manufacturing (AM) functions is recently developed to realize high flexibility and productivity. However, it is difficult to predict and control workpiece shapes created by AM. Such shapes are generally different from the 3D model prepared in advance. The differences may happen unexpected collisions on a multifunctional machine tool. Additionally, machining productivity may decrease when a NC program is generated with an original 3D model that is different from the actual workpiece shape. Thus, this study aims to realize highly efficient machining of complicated workpiece shapes corresponding to actual workpiece shapes as created by AM. In order to eliminate differences between the 3D model and the actual workpiece shape, a 3D model is firstly created by measuring the shape and position of the workpiece on a multi-functional machine tool. Then, appropriate position and orientation of the target shape is decided to minimize tool path distance. From results of a case study, it is appeared that the proposed machining procedure can improve machining efficiency of complicated workpieces as created by AM.