Research On Virtual Simulation Platform For Automatic Assembly Line

The efficiency of production line is firmly delimited by the low automaticity of traditional manufacturing methods.The research to novel manufacturing production line into which automaticity and digitization are integrated is essential for obtaining satisfactory efficiency and quality.The problems that arise from costly maintenance,disturbing scheduled overhaul and demanding expertise can be resolved by virtual simulation technique.In this dissertation,a series of complex factors such as hardware equipment,assembly objects,parts constraints,assembly sequence,production cycle adjustment and time control should be considered in the construction process of the virtual simulation platform for the automated assembly line with assembly line as its production organization form.Aiming at the automatic assembly line of circuit breakers,a virtual simulation platform construction idea based on the combination of time Petri net modeling and virtual reality is proposed,and realizes the design and development of the production status monitoring system on this platform.This dissertation mainly focuses on the following aspects:(1)After an exhausted analysis to the requirements of our system,a feasible framework is proposed which consists of the reconstruction of scenes and objects,modeling of production line logic,simulation of motion process,real-time status monitoring and designing of user interface.(2)A modeling pattern to describe the motion logic of the production line based on the nested Time Petri Net model is put forth.Using virtual reality technology,the repositories and transitions in the Petri net model are corresponded to the entity objects in Unity3 D virtual scene.In order to reproduce the production process,an automatic assembly entity is virtual reproduced in a virtual environment using the method of time series driving.(3)Aiming at the single robot of automatic assembly line to realize the assembly unit of multi-part sequential assembly,the inverse kinematics calculation and trajectory modeling of the robot are carried out by using algebraic method and cubic method,and the motion simulation of the robot in the virtual simulation system is completed.(4)Modularized the system by separating it into several submodels,including data communication,breakdown analyzing,collision detecting,overlapping eliminating,virtual roaming and visualization submodels and so forth.In the end,the system is tested and validated.