Research On Multi Robot Scheduling For Grid Warehouse

Under the influence of e-commerce and epidemic situation,the rise of community group buying and the development of commodity sales mode from offline to Online +offline increase the number of industries that need to carry out a large number of split and pick-up of commodities,and promote the development of warehouses in these industries towards automation,intensive and intelligent.It is not only necessary to reduce the floor space,but also to increase the vertical reserves as much as possible and improve the utilization of space Moreover,it needs to be suitable for processing a large number of SKUs,and has a certain caching effect.The grid stereoscopic warehouse can meet these needs.This kind of grid stereoscopic warehouse is generally completed by automatic equipment such as picking robot.The picking robot works in the plane on the top of the shelf.When the materials are stored in the non surface of the grid warehouse,there will be circulation transportation phenomenon.When multiple robots work,there may be idle,resulting in resource shortage waste.Research on multi robot scheduling is to study how the picking robot allocates and sorts the order tasks,optimizes the robot operation path,and completes the warehouse in the shortest time under the surface and non surface operations of the grid warehouse shelves.First of all,the dense storage system is introduced to understand the use scenarios of various kinds of dense storage systems.Then,the composition and use scenarios of grid stereoscopic warehouse are analyzed and described.Then,the process of picking robot in the grid stereoscopic warehouse is analyzed.According to the operation tasks in the grid stereoscopic warehouse,the operation is divided into: multi robot surface operation And multi robot non surface operation mode.In the storage allocation strategy,two strategies of random storage and classified storage are introduced.Combined with the analysis of the historical order data of the warehouse,it is concluded that the classified storage can reduce the operation time of the robot in the grid warehouse.Then,based on the classified storage,the multi robot scheduling model is constructed.Through the analysis of the factors that affect the operation time,the basic time model of robot operation is obtained.On the basis of the basic time model,the number of robots is increased to find the possible path conflicts when multiple robots work in the same operation plane,and the types of path conflicts are classified After that,the strategy to solve the conflict is put forward.The objective function of the mathematical model is set with the shortest in and out time.In the single robot operation,the influence of storage allocation on the operation time is discussed.In the multi robot operation time,the order tasks are classified and sorted to optimize the robot's walking path,so as to improve the operator's operation efficiency.In order to verify the model,this paper selects the grid format three-dimensional out and in warehouse operation of a shoe e-commerce warehouse as an example to analyze,transforms the historical order data into the out and in warehouse frequency of each commodity and the proportion of each commodity order number in the total number of orders,and obtains four clustering centers by using the fuzzy clustering method.Therefore,the storage location of the grid three-dimensional warehouse is divided into four parts,which are distributed in a single robot Under the setting of jobs,the discovery classification storage mode can reduce the time for robots to complete orders.Through the analysis of robot operation process,the time model of robot operation is obtained,and the classified storage strategy is selected to increase the number of robots to 2 and 4.When increasing the number of robots,it is found that there are conflict points during robot operation,and with the increase of the number of robots,the possibility of conflict points increases.In order to make the robot in the shortest time The ant colony algorithm is used to solve the robot's working time.When the number of robots increases,the robot's working time will decrease.When the number of robots increases to 2,the robot's working time will decrease by 49.7%;when the number of robots increases to 4,the robot's working time will decrease to 54.9%.Compared with the original operation data of the robot,the operation time of the robot in different numbers is less than the original operation time of the robot.