Studies On Automatic Nesting And Its Optimization For Hull Parts

Nesting is about how to arrange geometric parts in specified areas. We should not overlap parts and save raw materials as much as possible. So we can make a conclusion that nesting is a two-dimensional optimization problem. Nesting is widely used in industrial areas, such as shipbuilding industry, automobile industry, fashion producing, leather processing, paper making and so on.Now, China's shipbuilding industry is in full flower. However, this industry is influenced by two key factors: traditional manual nesting which is labor and time consuming and inefficient, and numerous parts which are shaped complicated and irregularly. So in a society advocating developing in a scientific way and thrift, it is very crucial to promote the efficiency of nesting and the yield rate of raw steel materials.Firstly the author compares several common nesting ways such as dynamic programming, simulated annealing algorithm and genetic algorithm, and analyses their characteristics. Then the author designs automatic nesting system on the basis of Japan's computing modules. This system includes three modules: data entry, nesting computing and results outputting which achieves several functions, such as automatic entry of information about parts and steel plates, parts searching, automatic generation of files, nesting computing and outputting results and blueprints of nesting. Practical application has proven that this system can cut the nesting time and promote the yield rate of steel plates greatly. The author also studies the nesting algorithm on the basis of computer graphics, has implemented automatic nesting through Visual C++ and BL tactics, and optimized results through genetic annealing algorithm which turns out positive.