Tractor Scheduling Optimization Based On The Tractor-and-Trailer Transportation Network And Operation Mode

The tractor-and-trailer transportation is a new mode in which the tractor deliberately drops the trailer at the customer,pulls on another trailer(or just the tractor)and goes on to the next customer as the operation schedule.The mode integrates the technology of vehicle transportation and the technology of loading,unloading,coupling and uncoupling operation in a whole body,which makes it an intensive and efficient transportation organization mode.The tractor-and-trailer transportation mode can significantly improve the transport efficiency,reduce the logistics costs,and promote energy-saving and emission-reduction et al..At present there are few researches on the construction of the tractor-and-trailer transportation network or the design of the corresponding operation mode for a network in a specific region.Meanwhile,in terms of the operation system with multi trailer exchange centers,there is no in-deepth research on the scheduling of the tractors.Additionally,the alliance which is commonly used in the vehicle routing problem has not been introduced into the tractor-and-trailer transportation.At first,the thesis develops the fuzzy c-means clustering algorithm to construct the tractor-and-trailer transportation network,and introduces the typical operation modes.Considering the actual situation,the Northeast area,Shandong,Jiangsu and other regions are taken as practical cases to carry out the research of roll-on-roll-off tractor-and-trailer transportation,and the roll-on-roll-off tractor-and-trailer transportation network across the Bohai Sea is planed and designed.The qualitative method and the quantitative method are combined in selecting the tractor-and-trailer transportation network nodes' location.The fuzzy c-means clustering algorithm is used to select and analyze the sample cities,and the results are research basis for the selection of transportation station construction site.Then,combined with the characteristics of roll-on-roll-off transportation and tractor-and-trailer transportation,the mode of roll-on-roll-off tractor-and-trailer transportation is designed.Second,in the tractor-and-trailer transportation hub-and-spoke network,considering the multi operation routes,the thesis formulates a scheduling optimization model for tractors with multi depots under the port's collection and distribution system.Through the shortest distance cluster analysis method,the scheduling optimization problem of multi depots is transformed into the scheduling optimization problem of a single depot.Thereafter,a heuristic rule based on the simulated annealing algorithm is designed to solve the problem.Eventually,a non-empty trailer communion tractor-and-trailer transportation scheduling optimization model is set up under the shortest path hub-spoke network.A three-stage heuristic algorithm is developed to solve the problem.By analyzing the further optimization space,under the hub-and-spoke network,the thesis puts forward a tractor-and-trailer transportation mode with empty trailer communion operation,and formulates the model of the corresponding scheduling problem,then solves it.A series of numerical experiments have been conducted to analyze the influence of the key parameters on the overall scheduling.The results verify the validation of proposed algorithm.In the end,the costs of two the different operation modes,empty trailer communion mode and non-empty trailer communion mode,have been compared,quantitatively certifying the former is superior to the latter.