Study On The Optimized Models And Algorithms For Freight Loading Problems In Distribution Center

With the development of market economy and logistics specialization level, physical distribution enterprises develop rapidly.Freight loading problem plays an important role in physical distribution,which is defined as the weight and volume of vehicle are effectively used,so that freights are reasonably loaded as many as possible.The rationalization of freight loading is to get the highest comprehensive utilization ratio in condition of the existing vehicles.A reasonable loading plan can improve the load and space utilization ratio of vehicles,reduce logistics cost of distribution enterprises,increase their competition capacity,and will bring huge economic benefits to them,and at the same time create more value for the whole society.Loading problem is a type of discrete optimization problem with strong application background,which is generally the decision-making problem with many goals and many constraints.On the basis of its inherent NP-hard,the problem gets more intricate because of the additional many complicated constraint conditions and geometry space complexity,especially with the increasing of the freight specifications to be loaded,the solution projects of the freight loading problem will increase by exponent speed.Therefore freight loading problem has become an important research direction.Aiming to the optimized models and algorithms for the freight loading problems, this paper tries to offer a total solution for the rationalization of the freight loading. First,the composing elements of freight loading problem are systematically analyzed, which provides the foundation for classifying and establishing the optimal mathematics model about freight loading problem.Secondly,the vehicle choosing problem before freight loading is defined and solved by grey clustering method according to the decision-making characteristics of the problem.And the efficiency of this method is also verified by an experimental computation case.Thirdly,the freight loading problems are abstracted and defined as three types of problems,namely one-vehicle two-dimension freight loading problem,one-vehicle three-dimension freight loading problem and multi-vehicle three-dimension freight loading problem. The mathematics models about the three typical freight loading problems are established respectively,and the genetic algorithms to solve these models are also designed.Finally,the above three typical models are solve by the genetic algorithm programs that are developed with MATLAB GA toolbox.And the efficiency of these algorithms is verified by corresponding experimental computation case.