Research On Virtual Commission Technology Of Automobile Assembly Line

Virtual Commission,through establishing a virtual mapping of the actual manufacturing system,replaces the real commission to carry out workshop debugging.There are several purposes of the Virtual Commission:verifying the structural design of the equipment,validating the solution of equipment layout system in the workshop,debugging the the control program of the equipment,confirming the production rhythm.In order to shorten the time before the Virtual Commission is widely used in the production process,the technologies of modeling,collision detection,simulation and debugging in Virtual Commission are studied in this paper.The main works are as follows:(1)Firstly,Virtual and Physical System(VPS)model of automobile assembly shop is established.The physical system model is divided into product model and equipment model.The product model includes product geometry model and product flow model and the equipment model is composed of geometry model,action model and logic model.Then the DEVS atomic model is used to model the product and the equipment respectively.Finally,the product model and the equipment model are coupled to the virtual physical system model through the coupling characteristics.(2)In order to reduce the modeling time of virtual equipment model,a reusable and fast modeling method is proposed.Based on the functional characteristics of the equipment,the method establishes a parameterization framework of the action model and the logical model and realizes the equipment’s reusability by changing the geometric model and the parameters of the framework.Then the method is implemented and verified.(3)In order to verify the model of automobile assembly shop in Virtual Commission,AABB-OBB collision detection algorithm is proposed,which adopts hybrid bounding box method and improves the construction of OBB bounding box based on RAPID algorithm.Finally,the algorithm is implemented and verified.(4)Taking an automobile assembly workshop as an example,the VPS communicats with the control system by using OPC technology.Then a hierarchical approach is applied to debug the program of the equipment and confirm the production rhythm.Finally the simulation results are summarized and analyzed.