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Model And Algorithm For The Scheduling Of Automated Double-rail-mounted Gantry Cranes

Posted on:2018-07-27Degree:MasterType:Thesis
Country:ChinaCandidate:Y J FengFull Text:PDF
GTID:2322330542467859Subject:Transportation planning and management
Abstract/Summary:PDF Full Text Request
Yard operation is a critical step limiting the overall efficiency of automatic container terminals(ACTs).Generally,the yards of ACTs use twin cranes operation technology.The main problem is that cranes cannot cross each other,leading to low efficiency.To increase the yard operation efficiency,some ACTs introduced automated double-rail-mounted gantry cranes(ADRMG).ADRMG reduces the interferences between cranes greatly and helps to increase yard efficiency.However,the scheduling of ADRMG is challenging because it needs to consider the coexistence of crossover and interferences.Therefore,this paper carries out the research of ADRMG scheduling to support its application.First,an ADRMG scheduling model with the aim of minimizing the makespan is developed to optimize the job assignment and operation sequences of the assigned jobs,as well as the delay time of the interrupted cranes.The model can deal with the three types of potential interferences,which copes with the coexistence of crossover and interferences efficiently.Next,the nonlinear constraints of the model are linearized,and the complexity of the model is analyzed.Secondly,a heuristic algorithm is designed.In other to verify the effectiveness of the developed algorithm,the model lower bound is deduced,and the algorithm solutions are compared with the optimal solutions,the model upper bound and the model lower bound.Meanwhile,in order to verify the effectiveness of the developed algorithm in terms of avoiding interferences,the solutions of the developed algorithm and the existing algorithm are compared by using the instances of the existing research.Finally,a comparing algorithm is designed to test the effects of interferences on the yard operation.The experiment results indicate that the developed model can avoid all interferences and balance the workload between two cranes and thus improve the yard efficiency.The proposed algorithm is quick and competitive for solving realistically sized instances.For larger instances,it can yield solutions close to the lower bound.Moreover,a large number of experimental results reveal the effects of the interferences on the yard operation,which provides some managerial implications for ACTs.This paper makes some contributions.From theoretical aspect,the proposed scheduling model and algorithm help to increase the science of ADRMG scheduling and are beneficial to enrich and improve the theory and method of double cranes scheduling.From application aspect,this research can ensure the efficiency,stability and security of ADRMG's operation,which help to promote the wide application of ADRMG in our country and improve the efficiency of the ACTs in our country.
Keywords/Search Tags:Double Cranes Scheduling Automated Container Terminal, Container Yard, Mixed Integer Linear Programming, Heuristic Algorithm
PDF Full Text Request
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