The Study Of As/rs On Scheduling Optimization Based On Simulation Methods

The Automated Storage and Retrieval Systems (AS/RS) has become an essential part of logistics distribution and flexible manufacturing. The improvement of performance of the AS/RS is significant to rapid material flow and JIT.This paper concerns the scheduling optimization problem of the Unit Load AS/RS and mainly concentrates on the static storage location assignment and dynamic storage location assignment problem.The static storage location assignment is mainly applied to non-online environment, which aims to optimizing the warehouse management. We set out to study the problem by learning warehousing rules. Then we set up three models concerning the frequency, expiration date and weight of product, respectively. As to solve the multi-object problem, we design simple method, which proves to be effective through experiment.The dynamic storage location assignment is applied to online scheduling, which aims to enhance the capacity of quick response. This paper sets out the study the problem by building models based on minimum the total travel time of the crane. As to solve the model, we propose four algorithm, including NN,STT , MD and GA. Through experiment, we find that STT come up to be more effective with good result as well as simple computation.Based on NN and STT, we find ways to make improvements. Considering the retrieval sequencing, we define the fuzzy distance, which makes way for optimized sequence. Considering due time of products, we set up an effective function which controls the expiracy of products well. Finally, we observe the improvement by simulation methods. We set six simulation environments with different parameters. All of the simulation results show that the STT* algorithm runs the best. Therefore, we make a conclusion that the STT* algorithm is a rational methods for online scheduling.