Research On Split Delivery Vehicle Routing Problem With Two-Dimensional Loading Constraint

In providing delivery services,the distribution center must consider how to make full use of existing transportation resources to meet customers’ needs and adhere to the principle of providing the best service to customers at minimal cost.And with the distribution of goods are becoming more and more rich,the existence of fragile should also be considered,that is,the goods in the box should also have some constraints,such as the goods cannot be stacked,the goods in the compartment Of the loading and unloading route to the shortest and so on.In life,retailers or customers’ needs are already packaged,they are pieces of goods,so the demands can be used to count the integer.In this paper,the K-SDVRP model is established,the customers’ demand are solved as an integer,and design an improved genetic algorithm to solve the split vehicle routing problem that customers’ demand are solved as an integer.The coding rules are carefully designed to determine the genetic operators,including the selection of operator,crossover operator and mutation operator.The choice of these operations determines whether the algorithm can find the optimal solution at the fastest speed.The numerical results show that the improved genetic algorithm has a good optimization effect.Based on the K-SDVRP model and the improved genetic algorithm,the 2L-SDVRP model which considers the two-dimensional packing constraints.The BLF-GA algorithm is designed and the algorithm’s effectiveness is also checked.Through the numerical results of K-SDVRP and 2L-SDVRP,the following conclusions are drawn:(1)The optimal route obtained when the packing constraint is not considered does not satisfy the packing constraint,and the optimal value obtained when the packing constraint is considered is larger than the optimal value when the packing is not taken into account(2)When exciting the situation that vehicles cannot load it’s goods,there are two solutions: First,when the vehicles’ type is consistent(vehicle load and the size of the car is exactly the same),the number of delivery vehicles should be increased;another solution is that setting various types of vehicles if the distribution center allows.These two approaches can solve the situation that the optimal route does not meet the packing constraints when the packing constraints are not considered,but there will be rewinding,which increases the loading and unloading costs of the distribution center and increases the risk of damage to the goods(3)In the case of the split delivery vehicle routing problem with two-dimensional loading constraint,when the size of the goods tends to infinity,is equivalent to split delivery vehicle routing problem without two-dimensional loading constraint,.The target value of the split delivery vehicle routing problem is lower than the vehicle routing problem,but the optimal route obtained does not take into account the relationship between the size of the loaded cargo and the size of the vehicle,and often the distribution task assigned to a vehicle Because cannot be boxed and re-allocation,the phenomenon of repeated loading and unloading of goods,not only will increase the loading and unloading costs,but also reduce the distribution center’s service level.After considering the two-dimensional packing constraints,each route can be arranged reasonably,the vehicle can fully cover all the goods of the route,distribution centers successfully avoids the phenomenon of repeated loading,and gets a significant reduction in the cost.the research gives logistics and distribution areas a certain reference.