| As the key area of the manufacturing industry,the assembly manufacturing industry is an important industry of national economy.The production process of assembly manufacturing includes three stages: processing,transportation and assembly.Existing research on scheduling optimization of assembly manufacturing systems mainly focuses on the three-stage workshop scheduling problem,that is,simplifying the transportation process,without considering the impact of the number of vehicles and load conditions on the transportation of workpieces.However,with the rapid development of transportation,in order to achieve the optimal allocation of resources and maximize profits,the jobs may not be in the same place from the processing to the assembly stage.Obviously,the scheduling of the transportation stage cannot be ignored.At present,scholars have conducted in-depth and extensive research on single system scheduling optimization problems involved,and the efficiency of the enterprise have been improved to a certain extent.However,for the assembly manufacturing system,the three stages of processing-transportation-assembly do not exist independently.If the mutual influence and connection between the stages are ignored,the efficiency of a single stage will achieve the local best but not the global best of the entire manufacturing system.Therefore,it is of great practical significance to study the three-stage integrated scheduling problem from the overall level of the manufacturing system for the production process of the assembly manufacturing industry to integrate workshop scheduling and transportation scheduling.Moreover,the integration problem is NP-hard.It has important theoretical significance to study the related theories and algorithm solutions of this problem.In this thesis,the three-stage integrated scheduling problem with job batches transportation(3sISP?JBT)of processing-transport-assembly and solving algorithm have been considered.Its main purpose is to deeply study the 3sISP?JBT theory,and to explore the modeling and efficient solution methods of 3sISP?JBT under different optimization goals with the estimation of distribution algorithm framework.First of all,based on the existing research results of workshop scheduling and transportation scheduling and the development characteristics of assembly manufacturing enterprises,the model of 3sISP?JBT has been designed and constructed for the problem which provids a theoretical basis for the design of solving algorithm.Then,an integrated optimization strategy has been proposed for the problem.Furthermore,based on the EDA algorithm framework,the effectiveness of the proposed integrated optimization strategy is verified through simulation experiments and comparisons,which provides a theoretical basis for the design of the solution algorithm in the following.Secondly,a rule-based hybrid estimation of distribution algorithm(HEDA?R)has been proposed to solve 3sISP?JBT with the goal of minimizing Makespan through the above research results.To reduce the problem solution space and improve the search efficiency,the first-completion-first-transport(FCFT)and first-come-first-served(FCFA)rules have been given respectively in the transportation and assembly phases based on the characteristic of the problem,and the optimality of the rules under certain conditions has been discussed to overcome the disadvantage factors by the integrated optimization strategy.Then,HEDA?R has been proposed to solve 3sISP?JBT.In HEDA?R,The Product Aggregation(PA)rule has been designed for initial population to improve the quality of the initial solution.Two neighborhood search strategies have been designed to explore the high-quality area which was discovered by HEDA?R global search in order to enhance the local search ability of the algorithm.At last,HEDA?R has been validated to solve 3sAISP?JBT effectively through simulation experiments and algorithm comparisons.Then,the multi-objective optimization is common problem in the actual production of the enterprise.The 3sISP?JBT with synchronization and punctuality(3sISP?JBTSP)of minimizing the weighted sum has been considered to solve the key problems of multi-stage production in the assembly manufacturing industry,and the corresponding modeling,solving algorithm and target weight setting of 3sISP?JBTSP have been studied.Then,based on the framework of the EDA in the previous chapter,the HEDA has been proposed to solve the problem.Furthermore,in small-scale and medium-to-large scale respectively,the effectiveness of HEDA is verified by comparison of simulation experiments.Finally,through the experimental analysis of different weight settings in the optimization objective,the reasonable range of weight settings for process-transport-assembly synchronization and delivery punctuality has been given,and the conclusion that considering assembly synchronization can beneficial to reduce intermediate inventory is drawn.After that,aiming at reduce the total energy consumption of the three stages of processing-transportation-assembly in the assembly manufacturing industry.However,the impact of transportation speed on energy consumption is not sufficient considered on green integrated scheduling of production and transportation in existing studies.A three-stage multi-objective integrated scheduling problem with job batch transportation consider energy consumption(3sMISP?JBTEC)is proposed,and a comprehensive energy consumption model with multi-stage of 3sMISP?JBTEC with an improved turn off/on strategy in the processing stage and speed in the transportation stage is formulated.Then,a hybrid estimation of distribution algorithm with variable neighborhood search(HEDA?VNS)is proposed to solve it.In HEDA?VNS,A variable neighborhood hybrid operation based on speed set is designed in Local Search to further improving the quality of the solution while balancing the optimization goals.Finally,simulations and comparisons show the efficiency of the proposed HEDA?VNS.Finally,the full study is summarized,and further research directions and contents are prospected. |
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