Research And Realization Of Virtual Assembly In Augmented Reality

Virtual assembly is an important part of virtual manufacturing technology. We can check for interference among part models, and avoid the use of physical prototypes by using virtual assembly technology. Moreover, it not only can improve the assembly process to meet the assembly requirements of the design, but also reduce the time required for design and development to minimize assembly cost and total product cost. If we introduce augmented reality technology into the virtual assembly systems, and hold the real environment as a virtual assembly scene, which greatly improve the sense of immersion in virtual assembly, so as to enhance the user’s perception; and furthermore, it eliminates the trouble of creating a virtual assembly environment, and reduces the need of computer memory and CPU consumption, so that the virtual assembly scene rendering can be achieved on a common PC. Therefore, the purpose of this subject is to develop a virtual assembly system based on AR environment by using mouse and keyboard input device on a common PC.The thesis had researched the elements and process of AR, and related key technologies, including video capture, identification of markers, track registration, transformation among multiple coordinates, as well as several commonly used display technology and human computer interaction technology. Owing to the interaction disadvantage of Win32application that most AR software adopt, the thesis putted the means that integrate OSGand osgART into the MFC application framework. On the basis, we developed the human-computer interaction interface, and designed the interaction modules, including model import, picking, operating and remove module. Then, the paper analysed the definition and content of virtual assembly according as GB, comprising the modeling of virtual assembly, sequence planning and path planning, and introduced the virtual assembly method of ourselves. By extracting the vertex coordinates and normal vector of each polygon facet which is the integral part of model’s surface, we built a local collision detection grid in the front surface of a moving model by using the line intersection test provided by OSG. Besides, we devoted our attention to research the collision response according to the constraint model’s freedom in the assembly process.Finally, the design virtual assembly system had been tested. An example of the ternary rotor pump’s assembly was used to demonstrate the process of this platform, which verified the rationality and feasibility of the proposed design, and achieved good results.