Research And Implementation Of Key Technologies Of Virtual Assembly

According to statistics,about 30% of the employees in the machinery industry assemble.The traditional assembly method often consumes a lot of time,and the results are difficult to verify.Once a problem occurs in the assembly process,all efforts will be lost.Virtual assembly technology is a technology that realizes the process of assembly in a virtual environment.Through the virtual assembly technology,the assembly results can be verified and the actual assembly can be guided,which greatly speeds up the assembly efficiency and reduces the operation errors.Based on the urgent needs of the electromagnetic simulation software MTSS independently designed by the computer simulation technology team of the University of Electronic Science and Technology of China for the simulation of traveling wave tube assembly,the key technologies of virtual assembly are systematically studied,and the virtual assembly prototype system is designed and implemented,and successfully applied to MTSS electromagnetic in the simulation software.The specific research content of this thesis is as follows:1.The definition of the assembly model is studied,the geometry and topology information of the assembly model construction,the material information of the engineering support and the primitive information of the model rendering are analyzed.The definition of assembly structure is studied,and the assembly tree model structure combining prototype tree and instance tree is designed based on the hierarchical model.It lays the foundation for the realization of virtual assembly prototype system.2.The key technologies of virtual assembly: collision detection and constraint solving are studied.By designing an assembly hybrid collision detection algorithm,the components are divided into hybrid bounding volumes according to the assembly level,and the component relationships are used to maintain and update their own bounding volumes,which reduces the decomposition and storage consumption of bounding volumes,and speeds up the solution of bounding volume pre-detection speed.The update strategy of the collision detection model is optimized to speed up the update speed of the model data.The assembly level constraint solving algorithm is researched and designed.Based on the constraint graph decomposition algorithm,the constraint item directed acyclic graph structure is designed,which reduces the complexity of the constraint solving algorithm.According to the structure of the assembly model,the constraints are divided into layers and processed independently,and the corresponding hierarchical constraint solving algorithm is designed to solve the conflict between the underlying geometry of each constraint layer and the prototype.3.Design and implement a virtual assembly prototype system.First,analyze the function of the prototype system,then design the data and data interface of the system,and finally code to realize the addition of components,component management,mirror components,component movement positioning,component constraint positioning,component collision detection,static interference and components of virtual assembly.explosion,etc.4.Finally,the designed virtual assembly prototype system is verified by taking the A-type traveling wave tube as an example.Through the engineering drawing of the A-type traveling wave tube,all parts of the traveling wave tube are first drawn.Then,the assembly simulation process of the A-type traveling wave tube is shown in detail,and the interference detection and explosion results of the A-type traveling wave tube are shown.