Research And Implementation Of Key Technologies Of Virtual Assembly

With the rapid development of industrial technology,in the field of mechanical assembly,higher and higher requirements are put forward for the precision and quality of assembly.Virtual assembly can enable engineers to find out existing problems in advance and put forward modification suggestions before setting product assembly process,thus improving assembly efficiency and reliability.Therefore,this topic starts from two key technologies in virtual assembly:assembly sequence planning and interference detection between parts.Assembly sequence planning is always a difficult point in virtual assembly research.This paper analyzes the shortcomings of some existing single algorithms in solving assembly sequence.To solve this problem,this paper puts forward an intelligent assembly sequence planning algorithm to solve the assembly sequence planning problem.Based on genetic algorithm,the algorithm adopts the classification coding of assembly structure hierarchy model and the unified coding of similar parts;Before the iteration of genetic algorithm,the feasibility of assembly sequence is analyzed by interference matrix and contact matrix,and the useless assembly sequence is eliminated The idea of simulated annealing and the acceptance of the probability of deteriorating solution by Metropolis criterion are integrated to solve the problem that genetic algorithm is easy to fall into local optimal solution.Finally,the effectiveness of the assembly sequence planning algorithm is verified by comparing the algorithm with the single genetic algorithm in the assembly sequence planning of the reducer.The accuracy of interference detection between parts is also of great significance to virtual assembly.To solve the problem of insufficient accuracy of interference detection between parts in Unity3d software,a differential triangle patch algorithm for parts is proposed.This algorithm is based on the principle of three-dimensional model generation in computer,that is,part models are assembled by multiple triangle patches,and the spatial position coordinates of each triangle patch as all vertices are extracted through the built-in components of Unity3d software.The triangular patches of all components are subjected to transverse and longitudinal equidistant differentiation according to the set precision value,and then small square patches with the precision value as the side length are generated at all segmentation points to replace the original parts for interference detection.Finally,the feasibility of differential parts triangle patch algorithm is proved by the experiment of shaft passing through shaft sleeve.Finally,a virtual assembly platform is built by combining the intelligent planning algorithm of assembly sequence and the precise interference detection technology between parts.Unity3d software and active shutter 3d display system,as the software and hardware support of the platform,can enable users to perform virtual assembly in an immersive environment,conduct deep human-computer interaction,and give full play to human factors to optimize the assembly sequence.Taking the reducer as an example,the platform shows functions such as working principle,inquiring parts details,free disassembly and disassembly animation.At the same time,the platform also supports running in Windows and Android environments.