The Study And Realization Of Several Key Technologies In 3-D Dimensioning

Analyze the relation between geometry constraints and dimensions. Get the dimensioning answer in 3D space by using the dimension model based on the functional semantics, from the point of constraint modes of primitive and its geometry elements. Display the dimensions and adjust the dimensions in 3D space to make the dimension marking more perfect and rational. Then project the 3D dimensions to 2D space to get final dimensioning answer.In chapter 1, the thesis discusses the meaning and current research status of automatic dimensioning, and then introduces the main content of the thesis.In chapter 2, the thesis analyzes the constraint modes of primitive and its geometry elements. Complete the data structure design of all elements providing for the next step.In chapter 3, the thesis designs a new algorithm to generate 3D dimensions and the repeating dimensions are reduced. By using pattern base, size dimensions are generated. Introduce the concept of constraint and classify it into hard constraint, soft constraint and none constraint. Natural location dimensions are generated first according to the analysis of degrees, and then practice dimensions are generated considering the total number of part degrees. Next the thesis generates the general dimensions of part. Finally, display the dimensions in 3-D space use MDT.In chapter 4, the thesis adjusts current dimensions in 3-D space. And make the dimension marking more perfect and rational. Analyses all factors that impact dimension projecting. Compare the importance of each factor on the point of associating semantics and design a weighted adaptive method to project the dimensions.In chapter 5, the structure of prototype and examples are presented.In chapter 6, the work of the thesis is summarized and the future research work is put forward.