US-12619948-B2 - Slot allocation and work instructions method for sorting system

US12619948B2US 12619948 B2US12619948 B2US 12619948B2US-12619948-B2

Abstract

A method for sorting a plurality of items and slot allocation in association with the plurality of items. The method may include collecting order data and slot data, wherein the slot data is information associated with a plurality of slots, each slot of the plurality of slots allows for placement of item bag over slot, and the plurality of items is to be sorted and inserted into bags associated with the plurality of slots; calculating combinations of order-slot allocation based on the order data and the slot data to estimate total time; and selecting a combination of the combinations of order-slot allocation with minimal total time and applying the selected combination.

Inventors

Daisuke KATSUMATA
Takaharu MATSUI
Takafumi Chida
Norisuke FUJII
Kohei Miyata

Assignees

HITACHI, LTD.

Dates

Publication Date: 20260505
Application Date: 20230426

Claims (14)

1 . A method for sorting a plurality of items and slot allocation in association with the plurality of items, the method comprising: collecting order data and slot data, wherein the slot data is information associated with a plurality of slots, each slot of the plurality of slots allows for placement of an item bag over the slot, and the plurality of items is to be sorted and inserted into bags associated with the plurality of slots; calculating combinations of order-slot allocation based on the order data and the slot data to estimate total time, wherein calculating the combinations of order-slot allocation comprises performing mixed integer programming to calculate total sorting time using a cycle time of sorting for each slot multiplied by number of orders assigned to each slot, and calculating a number of bag replacements for each slot using weight capacity estimation or volume capacity estimation, wherein the total time is calculated based on the total sorting time, a cycle time of bag replacement, and the number of bag replacements; selecting a combination of the combinations of order-slot allocation with minimal total time and; and controlling a robot to insert the plurality of items into the bags associated with the plurality of slots according to the selected combination; wherein the number of bag replacements for each slot is an expected value of number of bags to be replaced derived by performing the weight capacity estimation associated with each of the plurality of slots.
2 . The method of claim 1 , wherein the slot data comprises capacity data, cycle time of sorting, and cycle time of item bag replacement.
3 . The method of claim 1 , wherein the order data comprises processing time, item weight, and item dimensions associated with each item.
4 . The method of claim 1 , wherein the total time is calculated based on the total sorting time, the cycle time of bag replacement, and the number of bag replacements, and wherein the number of bag replacements is calculated by performing at least one of the weight capacity estimation associated with the plurality of slots or the volume capacity estimation associated with the plurality of slots.
5 . The method of claim 4 , wherein the weight capacity estimation, for each slot of the plurality of slots, is generated using a weight sum of items assigned to the slot over weight capacity of the slot, and wherein the volume capacity estimation, for each slot of the plurality of slots, is generated using a volume sum of items assigned to the slot over volume capacity of the slot, the volume sum is sum of assigned items' volumes, and each item's volume is derived from product of the item's item length, item width, and item height.
6 . The method of claim 1 , further comprising displaying the selected combination and slot layout of the plurality of slots on a graphic user interface (GUI).
7 . The method of claim 6 , further comprising displaying the bag replacement instructions and the slot layout of the plurality of slots on the GUI.
8 . A non-transitory computer readable medium, storing instructions for sorting a plurality of items and slot allocation in association with the plurality of items, the instructions comprising: collecting order data and slot data, wherein the slot data is information associated with a plurality of slots, each slot of the plurality of slots allows for placement of an item bag over the slot, and the plurality of items is to be sorted and inserted into bags associated with the plurality of slots; calculating combinations of order-slot allocation based on the order data and the slot data to estimate total time, wherein calculating the combinations of order-slot allocation comprises performing mixed integer programming to calculate total sorting time using a cycle time of sorting for each slot multiplied by number of orders assigned to each slot, and calculating a number of bag replacements for each slot using weight capacity estimation or volume capacity estimation, wherein the total time is calculated based on the total sorting time, a cycle time of bag replacement, and the number of bag replacements; selecting a combination of the combinations of order-slot allocation with minimal total time; and controlling a robot insert the plurality of items into the bags associated with the plurality of slots according to the selected combination; wherein the number of bag replacements for each slot is an expected value of number of bags to be replaced derived by performing the weight capacity estimation associated with each of the plurality of slots.
9 . The non-transitory computer readable medium of claim 8 , wherein the slot data comprises capacity data, a cycle time of sorting, and a cycle time of item bag replacement.
10 . The non-transitory computer readable medium of claim 8 , wherein the order data comprises processing time, item weight, and item dimensions associated with each item.
11 . The non-transitory computer readable medium of claim 8 , wherein the total time is calculated based on the total sorting time, the cycle time of bag replacement, and the number of bag replacements, and wherein the number of bag replacements is calculated by performing at least one of the weight capacity estimation associated with the plurality of slots or the volume capacity estimation associated with the plurality of slots.
12 . The non-transitory computer readable medium of claim 11 , wherein the weight capacity estimation, for each slot of the plurality of slots, is generated using a weight sum of items assigned to the slot over weight capacity of the slot, and wherein the volume capacity estimation, for each slot of the plurality of slots, is generated using a volume sum of items assigned to the slot over volume capacity of the slot, the volume sum is sum of assigned items' volumes, and each item's volume is derived from product of the item's item length, item width, and item height.
13 . The non-transitory computer readable medium of claim 8 , further comprising displaying the selected combination and a slot layout of the plurality of slots on a graphic user interface GUI.
14 . The non-transitory computer readable medium of claim 8 , further comprising displaying bag replacement instructions and a slot layout of the plurality of slots on a graphic user interface GUI.

Description

BACKGROUND Field The present disclosure is generally directed to a method and a system for sorting a plurality of items and slot allocation in association with the plurality of items. Related Art The number of internet shoppers has rapidly increased with the recent expansion of the internet environment, the spread of smartphones, and the entry of a wide variety of industries into the market. In addition, the recent spread of COVID 19 has made online shopping more active than ever. Because of this rapid increase in the number of online shoppers, logistics is under a heavy load. Especially in warehouses, the need for small-lot, multi-variety shipments and same-day deliveries has risen tremendously. However, the use of operators and manual labor generally limits throughput and tends to have high costs while being error prone. With the increase of delivered goods/products and increase of labor cost, there has been an increase in the demand for efficient sorting equipment. In the related art, a distance sorting method is utilized in item delivery across different supply stations. After determining the total delivery distances of all orders to be sorted in the item transfer container, the obtained total delivery distances corresponding to different supply stations is sorted, and the target supply station for the item transfer container is selected from the plurality of supply stations of the target sub-area according to the sorting result. Using the method, the sum of delivery distances when delivering a plurality of items to be sorted at the target supply station is the shortest compared with the sum of the delivery distances when delivering a plurality of items to be sorted at each other supply station. This in turn reduces the total distance of the delivery path of a plurality of items to be sorted. The supply station with the smallest total delivery distance is selected from the plurality of supply stations of the target sub-area as the target supply station. If the workload of the supply station with the smallest total delivery distance is saturated, that is, there are already a large number of items waiting for sorting and delivery at the supply station, then the supply station with the second smallest total delivery is selected as the target supply station. Generally, in a sorting system, each item to be sorted is inserted into a bag for each destination. When this bag is full or reaches a certain threshold, it must be replaced with an empty bag. This replacement may be performed by a machine or by an operator. In either case, the amount of replacement work can reduce overall throughput. But, as the related art considers only the distance involved without taking the number of bag replacement into consideration in deciding target destination, this leads to decrease in throughput. In addition, if the bag replacement process is not performed at the right time, since the destination of an item at the target destination may be temporarily lost, the sorting system will cease to function until the bag replacement is completed. But because the related art does not mention the timing of bag replacement, throughput may be further decreased. Therefore, a new method/solution to enable logistics to become more efficient by providing efficient sorting method or work instructions is needed. SUMMARY Aspects of the present disclosure involve an innovative method for sorting a plurality of items and slot allocation in association with the plurality of items. The method may include collecting order data and slot data, wherein the slot data is information associated with a plurality of slots, each slot of the plurality of slots allows for placement of item bag over slot, and the plurality of items is to be sorted and inserted into bags associated with the plurality of slots; calculating combinations of order-slot allocation based on the order data and the slot data to estimate total time; and selecting a combination of the combinations of order-slot allocation with minimal total time and applying the selected combination. Aspects of the present disclosure involve an innovative non-transitory computer readable medium, storing instructions for sorting a plurality of items, and slot allocation in association with the plurality of items. The instructions may include collecting order data and slot data, wherein the slot data is information associated with a plurality of slots, each slot of the plurality of slots allows for placement of item bag over slot, and the plurality of items is to be sorted and inserted into bags associated with the plurality of slots; calculating combinations of order-slot allocation based on the order data and the slot data to estimate total time; and selecting a combination of the combinations of order-slot allocation with minimal total time and applying the selected combination. Aspects of the present disclosure involve an innovative server system for sorting a plurality of items and slot allocation in