Determine The Parameters Of The Effective Range Of The Dm Decomposition Algorithm. Parametric Design

Computer Aided Design technology is a kind of technology that use hardware and software of computer to do modeling, modify, analyze or optimize work. It widely applies to all kinds of field of scientific research and living life, the application level of CAD technology has already become one of the most important symbols to estimate the science and technology and the industry modernization of a country.The development of CAD technology has gone through four significant technology innovations, the last innovation is the appearance of variable technology. Geometric constraint solving is the core of parametric technology and variable technology. At present, there are four basic approaches to geometric constraint solving: numerical approach, symbolic approach, rule-based approach and graph-based approach. At practical engineering, W need analyze the given design graph, then produce geometric model satisfied designer's demand.A very important advantage of CAD system based parametric model is that it allows change parameter values random to modify design graph. However when we change parameter values, often it can not produce geometry graph due to irrational parameter. Therefore determining parametric effective range is very prerequisite for geometric constraints.From algebra soluble aspect, the thesis users DM decomposition and WU method to give an approach, which can determine parametric effective range for geometric constraints. This approach have important role to improve alternation and accuracy for geometric constraints, and making it is more practical significance for the research of geometric constraint solving.