Study Of Toleranced Products Assembly Process Planning Based On The Virtual Reality

Three-dimensional CAD softwares have found their wide application in the manufacturing industry. But Three-Dimensional Computer-Aided Assembly Process Planning technology based on Three-dimensional CAD softwares are now only in the preliminary stage of development and application. Traditional two-dimensional CAD-based CAPP can't meet the requirement of CAD/CAPP integration of process planning,thus obstructing the development of information technology in these corporations. This paper studies digital assembly process design method and its key techologies aimed to the limitations of conventional assembly process planning, and lays the foundation for the development of corresponding software system. The major research and work of this thesis includes the following aspects:The thesis analyzes the requirements of the assembly process planning on the assembly modal information,and researches the corresponding assembly information modeling theory. The thesis establishes an assembly information model with the integration of geometrical information and process-specific information to meet assembly process planning needs of the assembly model information.The mathematical model of the assembly sequence planning is analyzed. The thesis researches the methods on expressions of the assembly precedence constraint and evaluation criteria, and proposes an improved ant colony algorithm to solve the assembly sequence planning problem, and provides implementation methods such as transfer probability. At last, this improved ant colony algorithm is proved by a case.The thesis choses the method of model coordinate transformation to accomplish the assembly path planning,describe the problem of collision examination based on virtual assembly, and analyzes a kind of collision examination algorithm which is more precise and stratiform,realizes. collision examination of the assembly path planning.