Utilization of a TSP solver for generating non-retractable, direction favouring toolpath for additive manufacturing

Abstract

Toolpath planning is a crucial part of Additive Manufacturing (AM) . It significantly affects almost every aspect of part fabrication, from part properties and dimensional accuracy to print cost and time. This works implements a Travelling Salesman Problem (TSP) based algorithm to generate a toolpath for efficient and accurate area filling with a minimum number of tool retractions and 'number of turns.' The toolpath generation process starts by first digitizing the layer being processed, i.e., given a geometric contour, a series of grid points (analogous to cities) within the boundary is generated. A deposition head sequentially traverses these grid points, filling the entire area with no voids (or porosity). A detailed investigation of the digitization process, exploring the rectangular and circular array of grid points, has been presented, which further elaborates the effect of digitization on the toolpath. A novel method of reducing the number of turns in a toolpath by appropriately positioning the grid points is highlighted in the present work. The proposed path planning method is capable of orienting the toolpath such that the deposited track (or the scan lines) favors one direction of motion over the other. Finally, an account of the successful implementation of the proposed strategy in an FDM and WAAM-based printer is also presented as a part of the study.