Sewing Trajectory Planning Of A Large Area Of ​​upper Surface And Automatic Programming Techniques

Computer aided automatic sewing technology of the uppers of shoes based on vision is a kind of technologies combined with optics, mechanics and electronics which can be used to sew the complex uppers of shoes. So far the technology has not been studied by other universities or institutions in China. In this dissertation, some key technologies related to this process is carried out and the utomatic sewing software is developed.First of all, the structure and characteristics of DXF file is analyzed in detail. The DXF file is used as the interface format of the system. The general analysis and design for the automatic sewing software are done, and some reasonable data structures are designed for several main functions that the software will achieve. Based on the establishment of basal topologic information, the topologic information about the point elements with other graphics elements is rebuilded. Considering the characteristics of uppers of shoes graphics, element points are selected as studying objects. A two-step strategy is presented in order to program the optimal sewing path for uppers of shoes. The main problem in the first step is similar with the problem of TSP. After comparing many kinds of current popular algorithm for TSP, the ant colony algorithm is selected for solving this main problem, and the optimal access sequence for points is obtained. In the second step, the optimal sewing path is obtained based on the optimal access sequence for points.Secondly, because only linear and circular interpolation can be done in the majority of numerical control system, an effective way is presented to approach NUBRS curve. Because the sewing path is the isometric offsetting contour of the uppers of shoes, a direct offsetting algorithm is adopted to offset the profiles on the uppers of shoes based on the analysis of all sorts of offsetting algorithms.