A Study Of The Generation Of Assembly Lllustrations

We see all kinds of illustrations in our usual life. There are many kinds of illustrations, such as maps, textbook illustrations, and assembly illustrations on use instructions and maintenance instructions. Traditional illustration production fully dependent on human work, it needs much efforts, gives different styles and quality. With the development and spread of CAD technology, more and more 3D models formed an accurate and abundant library for automation of illustrations' generation, and the development of computer processing ability and relational study makes it possible to generate illustrations automatically. The study on automation of illustrations' generation involves many study fields such as cognitive theory, robot, mechanical engineering and computer science. The generated illustration can be widely used in textbooks, exponents, manuals and other illustrative material.The automatic generation of assembly illustrations involves two problems: the generation of the illustration sequence and the painting of the illustration sequence. According to the condition that existing assembly sequence study can only process simple assemblies which is restricted in two layers, we base our algorithm on general format of complex model which is exported from CAD software, mainly study the automatic and fast generation of illustration sequence, giving out the corresponding model data representation model and the computing flow of the illustration sequence. The generation of the illustration sequence involves the classic problem in robotics and mechanical - Assembly Sequence Planning. We base our study on present sequence planning algorithm, extract some assembly restrictions according to the exhibition ofcomplex assembly, establish the model data structure using Motion Space Approach, propose the definition of un-separate subassembly and assembly layer and depth, giving out corresponding algorithms. Finally we discuss some other problems in the sequence generation flow and give out resolve plans.The innovation of this article is summarized below:Predigest of the establishment of NDBG structureDuring the establishment of NDBG, which is the main data structure of the algorithm, we simplified the procedure so that the complexity of the structure generation algorithm is not so high. By analyzing the assembly relationship, we restrict the blocking relationship to two mating relationship - planer mating relationship and axial mating relationship. Using both the relationship to get all the blocking relations of the parts, and restrict the assembly operation directions, we simplifies the generation of NDBG much.Algorithm for illustration sequence generation of complex assemblyFacing the automatic generation of illustration sequence, based on the present cognitive study, we extract some assembly restrictions from the procedure of people's cognition on complex assembly, and add some new cognitive restrictions to the sequence generation procedure. We propose the definition of assembly layer and assembly complexity, discuss the method to extract subassemblies and order assembly layers, so that the algorithm can apply to general complex assembly. We discussed relational problems which are involved in the sequence generation procedure and give out plans to solve them .The assembly discussed in this article is complex assembly with some restrictions, not all kinds of the assemblies. Far more work should be done on improvement of the algorithm efficiency, increase of the assembly condition that this algorithm can deal with, and the painting of the illustration sequence.