Order pick system

• US 6,377,867 B1
• Filed: 04/03/2000
• Issued: 04/23/2002
• Est. Priority Date: 07/18/1997
• Status: Expired due to Fees

• Current Assignee: St. Onge Company
• Original Assignee: St. Onge Company
• Inventors: Loy, David H., Bradley, Robert E.
• Primary Examiner(s): Ellis, Christopher P.
• Assistant Examiner(s): Tran, Khoi H.
• Application Number:
  US09/542,704
• Time in Patent Office: 750 Days
• Field of Search: 700/216, 700/214, 414/273, 414/280, 414/626, 414/627, 414/416
• US Class Current: 700/216
• CPC Class Codes: B65G 1/1376 the orders being assembled on a commissioning conveyor
• CPC Class Codes: B65G 2209/08 Orders with a high and a low volume

Abstract

An automated storage and retrieval system (ASRS) wherein individual identical articles are disposed in vertical stacks stored in cells of movable totes. The totes are movable into and out of storage racks by an automated storage/retrieval vehicle. The ASRS includes an order picking system having at least two zones disposed along an order-collecting conveyor system. One zone picks low-demand articles, and the other zone employs high-speed dispensers which support plural upright stacks each containing identical high-demand articles for dispensing of such articles onto the conveyor system. A controller assigns order-collecting areas along the conveyor system so that picked or dispensed articles within the zones are deposited into a preassigned area for assembly of an order. The pick zone for low-demand articles preferably includes several subzones arranged serially of the conveyor system, and each subzone includes a picker mechanism which includes a picking head which moves longitudinally and transversely of the conveyor. A plurality of totes are supported adjacent and longitudinally along at least one side of the conveyor system, with the cells in each tote typically defining plural stacks of different articles all having a preassigned position relative to the movement of the picking head. The controller causes the picking head to remove a desired article from a specific cell for transfer to the preassigned area of the conveyor system. This process can be repeated within one subzone, and sequentially within several subzones, for filling a single order with low-demand articles which are deposited into the preassigned area.

Claims

1. A process for automated filling of orders which each contain one or more items selected from an inventory of such items, which said inventory includes a first plurality of different high frequency selection items and a second plurality of different low frequency selection items, the number of different low frequency selection items defining said second plurality being several times greater than the number of high frequency selection items defining said first plurality, comprising the steps of:

storing said items in vertical stacks so that the items in a respective stack are identical;

storing said stacks in totes which define therein a plurality of upwardly opening storage cells each adapted to contain a single said stack therein;

storing said totes containing said stacks therein in a storage rack so that the totes are disposed in horizontally elongate rows which are disposed vertically one above the other with said rows being accessible from an aisle which extends along one side thereof;

providing an elongate and moving conveyor system having first and second generally elongate conveyor sections which-connect with one another along said system;

providing a first pick zone in association with said first conveyor section for selecting individual low frequency selection items and for depositing such items onto said first conveyor section;

providing a second pick zone located in series with said first pick zone relative to said conveyor system for permitting individual high frequency selection items to be deposited on said second conveyor section;

defining on said conveyor system an assigned order-receiving space which is moved sequentially through both said pick zones so as to be defined on said first and second conveyor sections at sequentially different times;

providing a pick interface for said first pick zone which is adjacent and extends longitudinally along at least one side of said first conveyor section;

automatically transferring totes containing said low frequency selection items from said storage rack to said pick interface so that the cells of the totes in said pick interface are vertically accessible from above;

automatically picking individual items from the cells at the pick interface and transferring the picked items toward the first conveyor belt section for subsequent deposit on the assigned order-receiving space;

providing in said second pick zone an item dispensing mechanism which contains therein a plurality of upwardly arranged columns of identical items; and

selectively dispensing a lowermost item from a column of the dispenser for deposit on the assigned order-receiving space on said second conveyor section.

2. A process according to claim 1, including the steps of:

providing a replenishment zone adjacent and extending longitudinally along at least one side of said second conveyor section;

automatically transferring totes containing said high frequency selection items from said storage rack to said replenishment zone so that the cells of the totes is said replenishment zone are vertically accessible from above; and

automatically transferring stacks of items from the totes in the replenishment zone to the columns of the dispensing mechanism to replenish the supply of items therein.

3. A process according to claim 1, including the steps of:

dividing said first pick zone into a plurality of subzones which are disposed generally in series with one another relative to said conveyor system so that said first conveyor section has subsections which are associated with and extend through a respective said subzone;

providing each subzone with a said pick interface adjacent and extending longitudinally along at least one side of the respective conveyor subsection;

providing said subzone with totes containing low frequency selection items which are different from the low frequency selection items contained in the totes associated with the pick interfaces of the other subzones; and

providing each subzone with a moving article pick mechanism for effecting picking of individual articles from the pick interface of the respective subzone, and thereafter depositing the picked articles onto the assigned order-receiving space of the conveyor system.

4. A process according to claim 3, including the steps of:

moving said assigned order-receiving space on said conveyor system sequentially through said subzones of said first pick zone and sequentially depositing on said space the individual items picked in the different subzones;

moving said assigned order space into said second pick zone and depositing into said assigned order-receiving space the order items dispensed from said dispensing mechanism; and

after said order-receiving space has moved through said first and second pick zones, thereafter transferring the items collected in the assigned order-receiving space and defining said order to a packaging station.

5. An automated process for filling multiple orders containing at least one article, comprising the steps of:

storing articles with each cell containing only one type of article;

entering orders into a computer;

sorting orders to determine the ordered low frequency of selection articles required to fill the orders in the next order filling operation;

placing cells containing the low frequency of selection articles in a picking zone;

filling a dispenser with high frequency of selection articles;

assigning a drop-off zone to each individual order;

picking individual ordered articles from the cells placed in the picking zone;

transporting each picked article to the assigned drop-off zone;

releasing the picked article into the assigned drop-off zone;

moving the order drop-off zone assigned to an order containing a high frequency of selection article to the dispenser and dispensing the ordered high frequency of selection article into the assigned drop-off zone; and

transporting the filled order to a packaging station.

6. The process according to claim 5, wherein the step of picking ordered articles includes the steps of controlling movement of a picking mechanism to a location of the cell containing the ordered low frequency of selection article and activating an end effector on the picking mechanism to remove one ordered low frequency of selection article from the cell;

wherein the step of transporting the picked article includes the steps of moving the end effector toward the drop-off zone and releasing the article from the end effector; and

further comprising the step of repeating the above packaging and transporting steps until all of the low frequency of selection articles ordered are picked from the picking zone.

7. The process according to claim 5, wherein the step of storing articles in individual cells includes the steps of:

moving a tote containing at least one empty cell to a tote replenishment station having a replenishment mechanism;

gripping one stack of multiple identical articles with an end effector on the replenishment mechanism;

moving the end effector gripping the stack of multiple identical articles into an empty cell in the tote;

releasing the stack of articles from the grip of the end effector;

storing the type of article in the cell, and the location of the cell in the tote, in the computer;

tracking the location of the tote in the computer; and

placing the tote in a storage rack.

8. The process according to claim 5, wherein the step of filling the high frequency of selection article dispenser includes the steps of:

moving a tote containing a stack of the needed high frequency article to a replenishment zone;

moving a transfer mechanism over the cell in the tote containing the needed article stack;

activating an end effector to enter the tote and to grip the needed article stack;

removing the end effector gripping the needed article stack from the tote;

moving the transfer mechanism and end effector to an article magazine in the high frequency dispenser;

placing the article stack gripped by the end effector into the article magazine; and

releasing the article stack from the end effector such that the article magazine in the high frequency dispenser retains the article stack.

9. The process according to claim 5, wherein the step of assigning the drop-off zone includes the steps of determining if an order includes low frequency of selection articles, assigning a drop-off zone adjacent to the picking zone if an order includes the low frequency of selection articles, and if an order does not contain a low frequency of selection article, assigning a drop-off zone to a conveyor travelling through the high frequency article dispenser.

10. An automated process for filling multiple orders containing at least one article, comprising the steps of:

storing articles in individual cells with each cell containing only one type of article;

tracking the location of the cells, and the type of articles therein, in a computer;

entering orders into the computer;

sorting orders to determine the ordered low, intermediate and high frequency of selection articles required to fill orders in the next order filling operation;

placing cells containing the low frequency of selection articles in a picking zone;

filling an intermediate frequency of selection article dispenser with articles having an intermediate frequency of selection;

filling a high frequency of selection article dispenser with articles having a high frequency of selection;

assigning a drop-off zone to each individual order;

picking individual ordered articles from the cells placed in the picking zone;

transporting each picked article to the assigned drop-off zone;

releasing the article into the assigned drop-off zone;

moving the order drop-off zone assigned to an order containing intermediate frequency of section articles adjacent to the intermediate frequency of selection article dispenser and dispensing the ordered intermediate frequency of selection article into the drop-off zone assigned to the order;

moving the order drop-off zone assigned to an order containing high frequency of selection articles adjacent to the high frequency of selection article dispenser and dispensing the ordered high frequency of selection article into the drop-off zone assigned to the order; and

transporting filled orders to a packaging station.

11. An automated process for filling orders of articles with one order having both a high frequency of selection article and a low frequency of selection article, comprising the steps of:

storing articles in individual cells in storage cells with each cell having only one type of article;

entering orders into a computer;

determining the low frequency of selection articles required for filling the orders in the next order filling operation;

positioning cells containing the low frequency of selection articles required for filling the orders in the next order filling operation in a pick zone adjacent a picking mechanism;

filling a high volume dispenser with high frequency of selection articles;

providing a conveyor belt system running adjacent the picking mechanism and the high volume dispenser;

assigning a drop-off zone for the one order having both high and low frequency of selection articles on a first segment of the conveyor belt system adjacent one of the picking mechanism and the high volume dispenser;

filling the one order with at least one article from the adjacent one of the picking mechanism and the high volume dispenser;

moving the drop-off zone to be adjacent to the other of the picking mechanism and the high volume dispenser;

filling the one order with at least one article from the other of the picking mechanism and the high volume dispenser; and

transporting the drop-off zone containing the order filled by both the picking mechanism and high volume dispenser to a packaging station.

12. A process for automated filling of orders which each contain one or more articles selected from an inventory of such articles, comprising the steps of:

storing the articles in stacks so that the articles in a respective stack are identical;

storing the stacks in a plurality of storage cells each adapted to contain a single stack therein;

providing an article pick zone in association with a conveyor for selecting individual articles and for depositing such articles onto the conveyor;

defining on the conveyor an assigned order-receiving space which is moved through the pick zone;

providing a pick interface for the pick zone which is adjacent and extends longitudinally along at least one side of the conveyor;

positioning a plurality of cells each containing a stack of articles therein at said pick interface so that the cells are positioned in adjacent relationship lengthwise along the pick interface; and

automatically picking individual articles from the cells at the pick interface and transferring the picked articles toward the conveyor for subsequent deposit on the assigned order-receiving space.

13. A process according to claim 12, including the steps of:

dividing said pick zone into a plurality of subzones which are disposed generally in series with one another relative to the conveyor so that the conveyor has subsections which are associated with and extend through a respective subzone and which move sequentially through the subzones;

providing each subzone with a pick interface adjacent and extending longitudinally along at least one side of the respective conveyor subsection;

providing at least one subzone with cells containing articles which are different from the articles contained in the cells associated with the pick interfaces of the other subzones; and

providing each subzone with a moving article pick mechanism for effecting picking of individual articles from the pick interface of the respective subzone, and thereafter depositing the picked articles onto the assigned order-receiving space of the conveyor.

14. A process according to claim 13, including the steps of:

moving the assigned order-receiving space on the conveyor sequentially through the subzones of the pick zone and sequentially depositing on the space the individual articles picked in the different subzones;

after the order-receiving space has moved through the pick zone, thereafter transferring the articles collected in the assigned order-receiving space and defining the order to a packaging station.

15. A process according to claim 12, including positioning the cells containing stacks therein at the pick interface in a gridlike pattern so that plural rows of cells are disposed in side-by-side relationship lengthwise along the conveyor with individual rows extending transverse to the direction of conveyor movement and containing therein a plurality of adjacent cells.

16. A process according to claim 12, including effecting three-dimensional movement of an article pick mechanism as associated with the pick zone for effecting removal of individual selected articles from selected cells for subsequent deposit on the assigned order-receiving space.

17. A process according to claim 12, including arranging the cells in the pick interface along the direction of movement of the conveyor in accordance with a predefined pattern which takes into account the frequency of selection of the various articles.

18. A process for automated filling of orders which each contain one or more articles from an inventory of such articles, comprising the steps of:

entering orders of articles into a computer;

storing the articles in stacks so that the articles in a respective stack are identical;

removably storing the stacks in a plurality of storage cells each adapted to contain a single stack therein;

arranging the cells, which contain the ordered articles, in rows and columns so that one end of the cells defines a two dimensional pick face;

storing the location of each cell and the type of article in each cell in the computer;

providing a conveyor moving generally parallel to and adjacent the pick face;

assigning an order receiving space on the conveyor; and

moving an automated article pick mechanism along the pick face to align a pick head with an ordered one of the articles, and moving the pick head transverse to the pick face to remove the ordered article from the associated cell for subsequent deposit in the order receiving space.

19. The process according to claim 18, wherein the step of moving the pick head includes aligning a gripper with the cell containing the ordered article, activating the gripper to grip the article at the end of stack, removing the article from the cell, and moving the pick head and article for subsequent article drop off into the order receiving space.

20. The process according to claim 19 wherein the step of arranging the cells includes positioning the pick face so as to be horizontally elongated, and the step of moving the pick head includes moving the pick head both parallel to and perpendicular to the direction of conveyor movement.

21. The process according to claim 19, wherein the step of arranging the cells includes arranging cells on both sides of the conveyor, and the step of moving the pick head includes moving the pick head across the conveyor to align the pick head with cells on either side of the conveyor.