Design And Implementation Of A Method On Intelligent Dynamic Dimensioning In CAPP System

With the continuous development of manufacturing industry these years, a variety of Computer-Aided Process Planning(CAPP) systems has emerged. However, most of them don’t have the capability of automatic cartography, due to the poor degree of integration with Computer Aided Design(CAD) software. Most commonly, technologists have to switch from CAPP to specific graphic software(such as CAD, etc.) when they need to generate the process graphics, in which the generation of dimensioning is the most sophisticated and time-consuming. A slight negligence may lead to mistaken dimensioning. There are complicated dependence relations in characteristic of component、process and dimension. Rich experience in process of production is needed to make perfect dimensioning. The thesis focuses on the problem and research on dynamic intelligent generation of dimensioning, the sub-problem of automatic generation of process diagram by considering a common type of components in a large state-owned enterprise.Firstly, in the first chapter, the thesis reviews the CAPP system in its concept, principles, classification and composition and gives a profile of its current research progress. Then, the second chapter gives a sketch of the meaning of dimensioning and analyzes the general artificial way of dimensioning. In the third chapter, an intelligent dynamic generation method of dimensioning, based on knowledge, is presented. Then the thesis analyzes the extraction of knowledge associated with the intelligent generation of dimensions, including the knowledge on dimension themselves and the dependencies in dimension 、 characteristic of component and process. What’s more, the algorithm procedure on the extraction of the dependency knowledge is provided. Meanwhile, the graphic features of dimensions are extracted and packed to consist of the graphics library on dimensions. Based on the analysis above, a dynamic intelligent generation method of dimensions via knowledge base is proposed. In the subsequent chapter, the thesis improves the method by introducing elements of human-computer interaction in the process of dimensioning generation. And then, function of customizable dimensioning and function on optimization of dimensioning layout via drag-and-drop operations on a dimension’s important-area are implemented.At last, with a type of planetary gear as an example, an intelligent CAPP system which can generate process graphics automatically, is designed and implemented, taking actual demands of enterprises into consideration. And the thesis has provided detailed description on modules related to the dynamic intelligent generation of dimensioning. The system is in service and performing well.