New Approach to Selecting Multiple Tools for Milling 2.5-D Pockets

In this paper, we propose a new algorithm to select multiple tools for achieving the optimal roughing of pocket with arbitrary shape in terms of least machining time and maximum material removal from the block. Different from the existing methods, in which the tool path has to be computed, the optimal tool combination can be directly determined in proposed method. Here a pocket is assumed to have a boundary and island boundaries polygonized by given tolerance. Note that the key to selecting optimal tools is the computations of the area of the region cut by every tool. Borrowed from the theory of scale space and computer graphics, the machining procedure, in this scheme, is simulated via pixel filling. Furthermore, using pixel filling under different resolutions simulates the milling by tools with different diameters. Since the diameters, maximum depths of cut, maximum feed allowed of tools, as defined in the tool database for a specified machine tool, can be taken as known, the total machining time, therefore, can be easily computed by proposed method. Finally, the proposed method has been verified by several experiment results.