Tier-to-tier Shuttle-based Storage And Retrieval System Composite Operation Modeling And Optimization

With the rapid development of modern new retail and E-commerce industries,the fragmentation of orders,timely delivery and quantification of items have become recognized problems in warehouse storage and picking system.In this context,the emergence of a Multi-tier Shuttle-based Srorage and Retrieval System has attracted close attention in E-commerce warehousing industry because of the high-density storage and high-efficiency picking.In this paper,the author studies on Tier-to-tier Shuttle-based Storage and Retrieval System(TSS/RS),the system is designed based on the "goods to people" concept,integrating storage and picking to a distributed automatic logistics system.The system makes full use of the stereo storage space,uses high-level dense storage shelves,intelligent shuttle,hoist and other automation equipments work together to complete the inbound and outbound.The main research contents and results of this paper are as follows:Firstly,the composite operation mathematical model of TSS/RS was established,and the factors affecting the cargo space allocation performance of the TSS/RS were analyzed.A mathematical model was established with the optimization objectives of task balancing rate,the deviation of the center of gravity of the shelf and the average single operation path of the composite operation.Tabu search algorithm is used to solve the model to obtain the optimal allocation scheme of compound operation,the effectiveness of the model and algorithm is verified by the simulation experiment.Secondly,a compound task scheduling model of TSS/RS was established,and a discrete particle swarm optimization algorithm based on random variation is designed to solve the model.At the same time,in order to solve the time-out problem of outbound orders under the constraint of delivery time in dynamic task scheduling,three time-out order insertion strategies are designed,and a time-out order insertion model is established to obtain the optimal order insertion scheme.The effectiveness of the model and algorithm is verified by using Python to write a simulation program.Finally,the composite task goods allocation,task scheduling and timeout single integrated optimization model of TSS/RS was established,a three stage tabu search algorithm was designed to solve the model,and the integrated optimization results was compared with the single problem optimization results.The design of simulation experiments under different operation scene operation proves that the presented integrated optimization scheme in order to improve the working efficiency of the composite task,reduce overtime rates all have good performance.