Design And Development Of Conveying System For Body In White Flexible Welding Workshop

With the development of the economy,the demand of customers and the market is becoming more and more individualized and diversified.The demand for automobile model updating speed is increasing.The traditional rigid welding line of automobile production model can not meet the needs of development.Under the intelligent factory environment,the flexible welding production line has become the main trend of the development of the production line.The conveying system of flexible welding production line is the key basic equipment to ensure the production of high tempo,flexible production,optimal scheduling of workshops and improvement of production efficiency.At present,the conveying system of flexible welding production line is still rigid,and all kinds of spare parts assembly must be equipped with a dedicated conveying system.The special equipment and the fixed transport program seriously restrict the optimization and dispatch of processing and logistics transportation,and have been unable to meet the flexible delivery demand of small batch and customized production in the market.In order to solve the above problems,this paper makes an in-depth study on the key equipment,optimal scheduling and logistics transportation simulation of the transportation system on the basis of the analysis of the location information of the components needed to be transported in the welding line.Combined with the research results in this paper,the conveying system is developed and applied to actual production.The flexible equipment of the conveying system is the foundation of the flexible welding production line.The conveying system in this paper is made up of flexible arms,accompanying toolings and transfer station fixtures,among which the flexible arm is the concentrated embodiment of the flexibility of the conveying system.In an intelligent factory,a welding line workshop only needs a flexible arm,and the different types of components are taken in the way of switching and positioning,and the logistics optimization and scheduling of the conveying system can be completed.It is the basis of designing flexible equipment to analyze the location information of the parts and components to be conveyed in the welding production line.In this paper,on the basis of detailed analysis of the location information of various components,the CAD/CAE method is used to optimize the design of the accompanying tooling,the transfer station fixture and two kinds of flexible arms.On the basis of analyzing the requirements of electrical drive and control,a servo driving speed governing subsystem is designed.The above research provides the equipment foundation for flexible conveying and scheduling of conveying system.Flexible welding shop scheduling is an important task of welding production line optimization.On the basis of the detailed analysis of the characteristics and classification of the flexible shop scheduling,this paper uses the conveying system designed in this paper to schedule.In the intelligent factory environment,the scheduling optimization problem of the Smart Factory 's Flexible Job Shop Scheduling Problem with High Production Beat(SFFJSP)is proposed.Considering that the working hours of each station in the parts assembly area not only have a great influence on the production beat of the workshop,but also play an important role in the transfer scheduling of the flexible arms in the automatic adjustment line of the body.Therefore,in order to ensure the unified and high production beat of the workshop,a hierarchical scheduling model is set up in this paper.On the basis of the established scheduling model,the hybrid algorithm,multi-layer coded genetic algorithm and ant colony algorithm,are used to solve the hierarchical scheduling problem of flexible workshops.In order to make the chromosomes fully express the solution of the problem,the multi-layer coding genetic algorithm in the combination algorithm divides the chromosome coding into several layers representing different meanings,and optimizes the processing order and machine selection and so on.It can fully guarantee the production beat of each processing station and timely bring up the transfer stations.The supply of goods ensures the timely initialization of the main workstation scheduling in the workshop.The ant colony algorithm in the combination algorithm simulates the foraging behavior of the ant colony in nature,and can quickly search for the optimal path of the flexible embrace to traverse all the transshipment sites,and has a strong global search ability.Under the high production beat,the combined optimization algorithm realizes the hierarchical production scheduling of flexible welding production line.The simulation of the flexible welding line is an effective way to verify whether the operation parameters of the production line can be bottlenecks in the whole production process.Only the operating parameters with balanced equipment utilization can be applied to the actual production process.On the basis of the detailed analysis of the whole operation process of the flexible welding line,this paper analyzes the hybrid characteristics of the transport system,and proposes a Decision-Control Hybrid Petri Net(DCHPN).In this paper,DCHPN is used to systematically describe the decision-making control process of the flexible welding production line conveying system,and according to the established DCHPN model,a hierarchical coupling simulation model of the micro-decision control logic and the macro-logistics transportation process of the flexible welding production line is established.The simulation model was used to verify the optimized operation parameters of the combined algorithm.The simulation results verify the feasibility and effectiveness of the proposed combined algorithm for hierarchical optimization of the production line.Based on the research results,the conveying system is developed by integrating the flexible equipment,the intelligent scheduling module and the production line simulation module.The software development environment of the flexible welding line conveying system is introduced.The communication mode of the flexible equipment and the conveying system is analyzed.The control software system of the conveying system is designed to realize the two-way perception control of the conveying process and the running state of the intelligent transportation system.The practice of a car factory shows that the conveying system designed in this paper can realize the efficient and orderly welding production of the whole workshop by optimizing the hierarchical welding sequence,and ensure the unified high production beat and improve the production efficiency.The monitoring module of the transmission system realizes the real-time visual perception and control of the processing process and the running state of the logistics transportation,and can meet the personalized and diversified processing and transportation requirements of the flexible welding line.