Research On Melting And Pouring Charge Plan For Single Piece And Small Batch Sand Casting Enterprise

The smelting and pouring charge plan is a key part of the production plan for the single piece and small batch sand casting enterprise,which belongs to multi-constrained combinational optimization problem with incompatible casting families.The charge plan is to produce castings in different orders with complex constraints.However,the smelting and pouring charge plan mainly relies on manual experience to schedule for single piece and small batch sand casting enterprise at present,which easily leads to the problems such as sub-optimal charge plan,inefficient scheduling,inadequate capacity utilization of the melting furnace.Therefore,the melting and pouring charge plan for single piece and small batch sand casting enterprise has been studied in this thesis.The main research is as follows.Firstly,the smelting and pouring charge plan priority model and the charge plan mathematical model have been established for single piece and small batch sand casting enterprise.The priority model was developed based on the delivery date,customer credit rating,and production load to quantitatively characterize the casting priority value.The mathematical model was constructed based on the characteristics and assumptions of charge plan,which aims to optimize casting priority value and the capacity utilization of the melting furnace and takes the sand box constraint,the die moulding ability constraint,consistent material in a furnace constraint,the melting furnace capacity constraint into consideration.Secondly,a greedy rule solution strategy based on the improved binary bat algorithm has been proposed,and the improved the binary bat algorithm is to solve charge plan in each casting family.The improvements of binary bat algorithm include introducing state vector to construct global and local search in binary search space to balance the exploration and exploitation ability,improving accepting new solution scheme to solve the problem of obtaining partial optimal solutions,hybridized with cuckoo algorithm to solve slow convergence.The simulation experiments show that the improved binary bat algorithm proposed in this thesis can better balance the accuracy of solution and the consuming time compared with the branch and bound algorithm and the original binary bat algorithm.Finally,the smelting and pouring intelligent charge plan system was developed and applied.The demand analysis of smelting and pouring charge plan system was carried out for the casting enterprise,and the overall scheme of the charge plan system including the architecture,database,function and process was designed.Based on the proposed charge plan model and solution strategy,an intelligent charge plan system was developed and applied to a single piece and small batch sand casting enterprise.Compared with the manually making charge plan,the application results show that this system can obtain the better charge plan,reduce the scheduling time from 6-8 minutes to 2 seconds per furnace,and improve nearly 5% for the capacity utilization of the melting furnace.