Method Of Identifying Motion Constraints In Virtual Prototyping And The Application Of Performance Analysis

This dissertation presents an arrangement-recursive method of identifying motion constraints, base on which a real-time kinematics and dynamics solving method is proposed. Both of the methods are applied in VR based virtual prototyping system. The research includes the expression of motion unit, motion constraint, kinematics solving and dynamics solving methods of multi-rigid body. The research is applied in several products. The result shows the methods are flexible and intellective. Real-time solving of a complex model is realized.In chapter 1, the technology of virtual reality and virtual prototyping and their application background are presented. The background and content of modeling, intellective identify, solving methods are also summarized in this chapter.In chapter 2, the research of the whole analysis process is presented. First, model expression in virtual prototyping is described. Second, the methods of construction and storage of assembly constraint are described. Third, the methods of construction and storage of motion constraint are described. After the DOF analysis, kinematics and dynamics analysis begins.In chapter 3, an intellective identifying method in virtual prototyping is proposed. Based on the assembly semantic identifying method, motion unit combining with joint part intellective identifying method is proposed. By arrangement recursive method of motion unit and simple mutual interface, construction and identification of motion constraint are realized. The result is displayed in the way of motion bone, through which the speed and veracity of physical model are both improved.In chapter 4, the research of automatic display problem of motion diagram of mechanism is presented. A new method of drawing the motion diagram based on graphics elements is proposed.In chapter 5, the research is around kinematics and dynamic real-time solving. It begins with the linkage group analysis method, and the basic linkage group separate functions are used to solving in order to realize the real-time feature. An improved method of machine dynamics solving is proposed. The whole solving process turns into several math equation solving. An improved solving method is discussed at theend of this chapter.In chapter 6,the methods mentioned above are applied in VIRDAS system. The intellective identifying method is applied in the experiment of mobile engine, steering system, wheeling transmission, differential. The solving methods are applied in crusher machine and rank block linkage module.Finally, conclusions are given along with recommendation for future research in chapter 7.