Research On Hybrid Welding Flow-shop Scheduling Problem

Welding is a crucial procedure for the most manufacture assembly processes,and is widely used in many industries;the ascension of its efficiency is of great significance to improve entire manufacturing productivity.However,there is a common phenomenon in production management that the efficiency of production is low,the production in the backlog is high and so on.All this problem need to be solved by the corresponding scheduling management methods.Besides,there is a big difference between welding process and the traditional process.For example,in the welding process,you may see more than one welding machine welding the same artifacts,while in the traditional process,this can’t happen at any time.Therefore,the traditional scheduling model is no longer adapted to the welding workshop.At present,the research on the welding workshop scheduling problem is few,it has great significance not only to the development of the theory of scheduling but to solve practical production problem in-depth study of hybrid flow-shop scheduling problem(HFSP)for welding production.In this paper,a welding hybrid flow-shop scheduling model is established considering of the production status of the large structure welding workshop and for further study of HFSP for welding production,the mathematical model of HFSP which considering the sequence-independent preparation time is built.Besides,a dynamic allocation strategy of machine resource is proposed.What’s more,an improved cuckoo search(ICS)algorithm is presented to solve the model mentioned above.Finally a welding shop scheduling prototype system is developed based on an actual welding workshop.First of all,according to the practical production,it exist that there is more than one welding machine handle the same task at the same time,the HFSP and the HFSP with sequence-independent setup-time for welding production are defined and mathematical model of the two problem are proposed;At the same time,in view of this characteristic,the machine dynamic allocation strategy is proposed,laying a foundation for subsequent research.Secondly,to solve the two model proposed above,in this study,the distribution of parallel workstation and the process sequence of job in the same station are considered,the allocation of machine resource of the plant is considered also.Meanwhile,an improved cuckoo search(ICS)algorithm which accelerates the convergence speed of CS is designed to solve the problem;through solving three different scale problems with ICS and CS,numerical experiment contrast analysis is carried out which verifies the effectiveness and superiority of the proposed algorithm.What’s more,according to a practical welding workshop,welding shop scheduling prototype system is designed.The system is not only adapted to the type of hybrid flow shop but also adapted to the permutation flow shop type.It offers different solutions to different kinds of welding workshop which can provides theoretical basis and technical support for intelligent production scheduling of large structural welding productionFinally,made a summary of this paper and discussed the future research direction.