Reasearch On Packing Of Apparel Shaped Parts Using Genetic Simulated Annealing Algorithm

As the global competition intensifies and the information technology develops continuously, how garment manufacturing industry adapt to the marketing rapid response to demand characterized by more variety, small-volume, personalized, high quality, low cost has become an important issue of the modern enterprise surviving and developing. Apparel products based on digital technology is one of the important technologies to adapt to the trend in development and enhance the competitiveness. Garment optimization nesting is an important part of digital garment design. Research on two-dimensional (2D) garment nesting and implement the optimization nesting assisted by the computer is of great significance to improve the productivity, technology level and reduce production costs.Nesting two-dimensional garment fabric is an issue of the flat optimization layout. It aims to find a sample layout in a certain constraints to maximum utilization of that material. Detailed research works of this paper listed below:Firstly, it presents a comprehensive analysis of research on domestic 2D nesting problems and the foreign one, describes a variety of key technologies of different 2D nesting algorithm, features and application status. Combined with the garment fabric nesting issue, it points out the hot and difficult spots of present research on nesting algorithm.Secondly, because the bump of each polygon is inconsistent, it always results to the recessed area of concave polygon couldn't be filled. And the large the number of different concave polygon is, the more the wasted area will be. It will result to reduce the efficiency and waste large of materials. Focus on this problem, the work of pretreatment to all the polygons has been carried out. In this paper, the nature for the vector cross product is used to judge whether the angles of vertex is greater than 180 degree. Based on this work, the bum determination formula can be derived and the two polygons meeting the requirements can be found. It could not only increase the utilization of material but also facilitate the work followed.Then, proposing the polygon positioning and scanning heuristic:propose an equidistant scanning interval notion to express the nesting material polygon and polygon. Basic on this notion, the determination of intersection and location algorithm of the polygon which is not relevant to the shape of the polygon is derived. Then it is combined with heuristic algorithm to form an irregular polygon positioning and scanning heuristic-based BLF strategy.Third, much work is made on the theory and technology of genetic algorithms and simulated annealing algorithm. Combining with the polygon positioning and scanning, the genetic simulated annealing algorithm has been derived. This algorithm used the global search capability to find out the optimal order and rotation of the polygon in one side. In another side, it used the polygon positioning and scanning heuristic to complete automatic nesting. By nesting model diagram of trousers using the new hybrid algorithm, the effectiveness of new algorithm has been proved.At last, the work of summarizing the main content and prospect for the next step has been made.