Research On Virtual Assembly Technology Of Transmission Shafting Based On Assembly Features

Transmission is an important component system of vehicle,which has a large number of parts and complicated assembly process.Assembly performance simulation of transmission device based on virtual reality is one of the important components of transmission design.Currently,there are virtual assembly system only supports assembly relationships preset assembly,the assembly does not support real-time modeling simulation assembly relationships based on structural features of the parts;based only on the mounting surface sheet models can not guarantee the accuracy of the transmission assembly.The integration of virtual assembly and dynamic real-time simulation can not be realized.A modeling method of shaft assembly assembly based on assembly feature is proposed.The part information is constructed from part layer,feature layer,geometry layer and display layer.The data exchange mode between CAD system and virtual assembly system is analyzed,and the interactive establishment process of hierarchical parts information model is given.The relationship between components is described by assembly feature pairs.The assembly method of the assembly model of the transmission shafting based on the assembly feature is obtained.Based on the assembly geometry constraint,parameter-based assembly constraint management and quaternion interpolation transform algorithm,the collision-based algorithm of cylindrical bounding box,non-directional coaxial,directional coaxial,surface fitting,face blocking and gear meshing are studied.Assembly Modeling of Transmission Shaft Parts.The virtual assembly prototype system is realized by tools such as OSG,Altova XMLSpy and Visual Studio,which provides a platform for the study of assembly process planning of automotive transmission parts.The virtual assembly environment and the actual assembly environment are used to assemble the same parts of the transmission device.By comparing the two assemblies,it is shown that the virtual assembly method can realize the shaft parts of the transmission device: the transmission shaft parameter error checking,the free predefined part assembly,simplify the virtual assembly,for the smooth transformation in the virtual environment.Which not only realizes the flexible assembly of the shafting parts of the transmission device,but also guarantees the precision and real-time requirements of the virtual assembly simulation.The results of DOF analysis can be transmitted to the dynamic simulation module,which provides the technical guarantee for the good integration of virtual assembly and dynamic real-time simulation.