Research Of Distributed Collaborative Virtual Assembly Simulation Based On Unity3D

Collaborative design is the development direction of today's complex product design.During the complex product assembly phase,there will inevitably emerge errors.Therefor,finding the product assembly problems in the design phase is critical.The traditional development is to complete the component design,and then produce the prototype for assembly and verification.Find the design problem and modify,then reproduce the prototype for assembly and verification again.This process is often repeated many times before get the final design results,resulting in a long development time and high cost.Using three-dimensional digital and virtual reality technology to do assembly simulation for complex product,found the design problem,rapidly modify the product's three-dimensional model,and then assembly verify it.In this process,we needn't produce physical prototype,and can reduce development time and design costs.In addition,remote designers are allowed to assemble and analyze products in the same virtual environment,further reducing the time for development verification.In response to these needs,this article mainly from three aspects to carry out relevant research,as follows:Firstly,this thesis studied the research status of distributed collaborative virtual assembly simulation,described the theory of virtual assembly and co-simulation(CSCW)and analyzed the functional requirements of the system.For the shortcomings of "replica" and "centralized" collaborative architecture,proposed a "complex" two-layer system architecture.Confirmed the key technologies to realize system,including distributed simulation cooperative mechanism,distributed collision detection algorithm and assembly sequence planning.Secondly,based on the further research and analysis of the bounding box collision detection technology,a distributed collision detection algorithm based on Unity3 D is proposed to solve the problem of real-time insufficient of collision detection caused by the large number of assembly models.This method can obtain the model hierarchical relationship by traversing the assembly model,construct the model bounding box tree,using the bounding box method to do the preliminary collision detection on the client and grid collision detection on the server so as to make full use of the system resources,reduce testing time and improved collision detection efficiency.Thirdly,In-depth studied and designed the collaborative mechanism of multi-user distributed co-simulation based on TCP.Through multi-threading technology to achieve multi-tasking,data type conversion and data encapsulate to improve transmission efficiency,state locking to resolve operational conflicts and online communication for task allocation,itsolved the multi-personnel collaborative operation of multi-tasking.Finally,the thesis focused on the study of the collaborative assembly planning,and using the demolition method to complete the assembly sequence planning.Distributed collaborative virtual assembly simulation system was constructed based on the above research and Unity3 D platform,combined with Microsoft.Visual.Studio.NET.2012 development platform.Using a large blower model as the simulation object to verify and analysis the reliability of the system.