Patent Publication Number: US-2022219909-A1

Title: Pickface builder for storage and retrieval systems

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Non-Provisional patent application Ser. No. 17/136,475, filed Dec. 29, 2020, (Now U.S. Pat. No. 11,286,118, issued Mar. 29, 2022), which is a continuation of U.S. Non-Provisional patent application Ser. No. 15/991,779, filed May 29, 2018, (Now U.S. Pat. No. 10,875,722, issued Dec. 29, 2020), which is a continuation of U.S. Non-Provisional patent application Ser. No. 15/332,997, filed on Oct. 24, 2016, (Now U.S. Pat. No. 9,981,808, issued May 29, 2018), which is a continuation of U.S. Non-Provisional patent application Ser. No. 13/326,869, filed on Dec. 15, 2011, (Now U.S. Pat. No. 9,475,649, issued Oct. 25, 2016), which claims priority from and the benefit of U.S. Provisional Patent Application No. 61/423,242, filed on Dec. 15, 2010, the disclosures of which are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND 
     1. Field 
     The embodiments generally relate to material handling systems and, more particularly, to automated storage and retrieval systems. 
     2. Brief Description of Related Developments 
     Warehouses for storing case units may generally comprise a series of storage racks that are accessible by transport devices such as, for example, fork lifts, carts and elevators that are movable within aisles between or along the storage racks or by other lifting and transporting devices. These transport devices may be automated or manually driven. Generally, where the case units are stored in multilevel racks, case units are placed on the different levels of the racks with a lifting device on the transport device. Where the case units are stored in racks located on different floors or levels of the storage structure the case units are generally transported between the floors while disposed on the transport devices where the transport devices travel up and down ramps spanning between the floors. In other examples the transport device with the case units disposed thereon are raised and lowered between the floors with an elevator. Generally, the case units carried by the transport devices and stored on the storage racks are contained in carriers, for example storage containers such as trays, totes or shipping cases, or on pallets. Generally, incoming pallets to the warehouse (such as from manufacturers) contain shipping containers (e.g. cases) of the same type of goods. Outgoing pallets leaving the warehouse, for example, to retailers have increasingly been made of what may be referred to as mixed pallets. As may be realized, such mixed pallets are made of shipping containers (e.g. totes or cases such as cartons, etc.) containing different types of goods. For example, one case on the mixed pallet may hold grocery products (soup can, soda cans, etc.) and another case on the same pallet may hold cosmetic or household cleaning or electronic products. Indeed some cases may hold different types of products within a single case. Conventional warehousing systems, including conventional automated warehousing systems do not lend themselves to efficient generation of mixed goods pallets. In addition, storing case units in, for example carriers, totes, trays or on pallets generally does not allow for the retrieval of individual case units within those carriers or pallets without transporting the carriers or pallets to a workstation for manual or automated removal of the individual case units. 
     It would be advantageous to be able to transport uncontained or unpalletized case units between levels of a storage facility independent of transport device movement between the levels. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and other features of the disclosed embodiments are explained in the following description, taken in connection with the accompanying drawings, wherein: 
         FIG. 1  schematically illustrates an exemplary storage and retrieval system in accordance with the embodiments; 
         FIGS. 2A, 2B, 2C, 2D, 3A and 3B  illustrate schematic views of a conveyor system in accordance with the embodiments; 
         FIG. 4  illustrates a schematic view of a conveyor shelf in accordance with the embodiments; 
         FIG. 5  schematically illustrates a conveyor system in accordance with the embodiments; 
         FIGS. 6A-6D  schematically illustrate a transfer station in accordance with the embodiments; 
         FIG. 7  is a schematic illustration of a method in accordance with the embodiments; 
         FIG. 8  is a flow diagram of a method in accordance with the embodiments; 
         FIGS. 9A and 9B  illustrate a feed station in accordance with the embodiments; 
         FIG. 10  illustrates a pickface builder in accordance with the embodiments; 
         FIG. 11  illustrates a pickface builder in accordance with the embodiments; 
         FIG. 12  illustrates a pickface builder in accordance with the embodiments; 
         FIGS. 13A-13H and 14A-14C  are schematic illustrations of exemplary operations of a portion of the storage and retrieval system in accordance with the exemplary embodiments; 
         FIG. 15  illustrates a platform in accordance with the embodiments; 
         FIG. 16  illustrates platform guides in accordance with the embodiments; and 
         FIG. 17  illustrates platform guides in accordance with the embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT(S) 
       FIG. 1  generally schematically illustrates a storage and retrieval system  100  in accordance with the embodiments. Although the disclosed embodiments will be described with reference to the embodiments shown in the drawings, it should be understood that the disclosed embodiments can be embodied in many alternate forms. In addition, any suitable size, shape or type of elements or materials could be used. 
     In accordance with the embodiments the storage and retrieval system  100  may operate in a retail distribution center or warehouse to, for example, fulfill orders received from retail stores for case units (where case units as used herein means items not stored in trays, on totes or on pallets, e.g. uncontained or items stored in trays, totes or on pallets). It is noted that the case units may include cases of items (e.g. case of soup cans, boxes of cereal, etc.) or individual items that are adapted to be taken off of or placed on a pallet. In accordance with the embodiments, shipping cases or case units (e.g. cartons, barrels, boxes, crates, jugs, or any other suitable device for holding items) may have variable sizes and may be used to hold items in shipping and may be configured so they are capable of being palletized for shipping. It is noted that when, for example, pallets of items arrive at the storage and retrieval system the content of each pallet may be uniform (e.g. each pallet holds a predetermined number of the same item—one pallet holds soup and another pallet holds cereal) and as pallets leave the storage and retrieval system the pallets may contain any suitable number and combination of different items (e.g. each pallet may hold different types of items—a pallet holds a combination of soup and cereal). In the embodiments the storage and retrieval system described herein may be applied to any environment in which items (e.g. goods units holding at least one product package therein) are stored and retrieved. 
     The storage and retrieval system  100  may be configured for installation in, for example, existing warehouse structures or adapted to new warehouse structures. In the embodiments, the storage and retrieval system  100  may be substantially similar to that described in, for example, U.S. Provisional Patent Application No. 61/423,340, filed on Dec. 15, 2010, U.S. patent application Ser. No. 13/326,674, filed on Dec. 15, 2011, and U.S. patent application Ser. No. 12/757,381, filed on Apr. 9, 2010 (now U.S. Pat. No. 8,740,538, issued Jun. 3, 2014), the disclosures of which are incorporated herein by reference in their entireties. In one example, the storage and retrieval system  100  may include in-feed and out-feed transfer devices, such as stations  170 ,  160 , multilevel vertical conveyors or picking devices  150 A,  150 B (MVCs), a storage structure  130 , and a number of autonomous vehicular transport robots  110  (referred to herein as “bots”) that may also operate as transfer devices. In the embodiments the storage and retrieval system may also include transfer devices including robot or bot transfer stations  140  ( FIGS. 6A-6D ) that may provide an interface between the bots  110  and the multilevel vertical conveyors  150 A,  150 B. In the embodiments, any suitable transfer device may be provided at any location and on either side or level of MVC  150 A,  150 B to remove or pick material from or replace or place material to MVC  150 A,  150 B at any shelf or platform level or location or otherwise. The in-feed transfer stations  170  and out-feed transfer stations  160  may operate together with their respective multilevel vertical conveyors  150 A,  150 B for transferring items to and from one or more levels of a multi-level storage structure  130 . It is noted that while the multilevel vertical conveyors are described herein as being dedicated inbound conveyors  150 A and outbound conveyors  150 B, in the embodiments each of the conveyors  150 A,  150 B may be used for both inbound and outbound transfer of case units/items from the storage and retrieval system. It is noted that while multilevel vertical conveyors are described herein in other aspects the conveyors may be any suitable conveyors or transfer/picking devices having any suitable transport path orientation. Bots  110  may be disposed on each level of the multi-level storage structure  130  so that the bots  110  on a respective level can traverse an entirety of that level. The bots  110  may be configured to place items, such as the above described retail merchandise, into picking stock as described in U.S. patent application Ser. No. 12/757,312, filed on Apr. 9, 2010 (now U.S. Pat. No. 8,425,173, issued Apr. 23, 2013), the disclosure of which is herein incorporated by reference in its entirety. Other suitable examples of bots are described in, for example, U.S. Provisional Patent Application No. 61/423,220, filed on Dec. 15, 2010, U.S. patent application Ser. No. 13/327,040, filed on Dec. 15, 2011 (now U.S. Pat. No. 9,187,244, issued Nov. 17, 2015), U.S. patent application Ser. No. 14/942,717, filed on Nov. 16, 2015 (now U.S. Pat. No. 9,676,551, issued Jun. 13, 2017, U.S. Provisional Patent Application No. 61/423,365, filed on Dec. 15, 2010, U.S. patent application Ser. No. 13/326,952, filed on Dec. 15, 2011, U.S. Provisional Patent Application No. 61/423,359, filed on Dec. 15, 2010, U.S. patent application Ser. No. 13/326,447, filed on Dec. 15, 2011 (now U.S. Pat. No. 8,965,619, issued Feb. 24, 2015), U.S. Provisional Patent Application No. 61/423,388, filed on Dec. 15, 2010, and U.S. patent application Ser. No. 13/326,993, filed on Dec. 15, 2011 (now U.S. Pat. No. 9,499,338, issued Nov. 22, 2016), the disclosures of which are incorporated herein by reference in their entireties. In the embodiments, the bots  110  may be configured to interface directly with the shelves of the multilevel vertical conveyors  150 A,  150 B. In the embodiments the bots  110  may interface indirectly with the multilevel vertical conveyors  150 A,  150 B through, for example, bot transfer stations  140  disposed on a respective level of the multi-level storage structure  130 . 
     As described above, the storage structure  130  may include multiple levels of storage rack modules where, in the embodiments, each level includes respective picking aisles  130 A and at least one transfer deck  130 B for allowing the bots  110  to traverse respective levels of the storage structure  130  for transferring case units between any of the storage areas of the storage structure  130  and any shelf of any multilevel vertical conveyor  150 A,  150 B. The picking aisles  130 A, and transfer decks  130 B also allow the bots  110  to place case units into picking stock and to retrieve ordered case units. In the embodiments each level may include bot transfer stations  140  for allowing the exchange of items between the multilevel vertical conveyors  150 A,  150 B and a bot on a respective storage level of the storage structure  130 . The storage structure  130  may be substantially similar to the storage structure described in U.S. Provisional Patent Application No. 61/423,340, filed on Dec. 15, 2010, U.S. patent application Ser. No. 13/326,674, filed on Dec. 15, 2011, U.S. patent application Ser. No. 12/757,381, filed on Apr. 9, 2010 (now U.S. Pat. No. 8,740,538, issued Jun. 3, 2014), U.S. patent application Ser. No. 14/089,434, filed on Nov. 25, 2013 (now U.S. Pat. No. 9,051,120, issued Jun. 9, 2015), and U.S. patent application Ser. No. 14/733,341, filed on Jun. 8, 2015 (now U.S. Pat. No. 9,771,217, issued Sep. 26, 2017), the disclosures of which are incorporated herein by reference in their entireties. 
     One or more central system control computers (e.g. control server)  120  may coordinate or otherwise control the operation of the multilevel vertical conveyors  150 A,  150 B with other suitable features of the storage and retrieval system  100  in a manner substantially similar to that described in U.S. patent application Ser. No. 14/757,337, filed on Apr. 9, 2010 (now U.S. Pat. No. 8,594,835, issued Nov. 26, 2013), and U.S. patent application Ser. No. 12/757,220, filed on Apr. 9, 2010 (now U.S. Pat. No. 9,096,375, issued Aug. 4, 2015), the disclosures of which are incorporated herein by reference in their entireties. For example, the control server  120  may control the operation of the storage and retrieval system  100  through, for example, any suitable communications network  180 . 
     The storage structure  130  of the embodiments may be arranged such that if desired there is substantially no vertical or horizontal array partitioning of the storage structure. For example, each multilevel vertical conveyor  150 A,  150 B may be common to all or substantially all storage spaces (e.g. the array of storage spaces) in the storage structure  130  such that any bot  110  can access each storage space and any multilevel vertical conveyor  150 A,  150 B can receive case units from any storage space on any level so that the multiple levels in the array of storage spaces substantially act as a single level (e.g. no vertical partitioning). Conversely case units from any shelf of each multilevel vertical conveyor  150 A,  150 B can be transferred to any or each storage space throughout the storage structure or to each storage space of any level of the storage structure. The multilevel vertical conveyors  150 A,  150 B can also receive case units from any storage space on any level of the storage structure  130  (e.g. no horizontal partitioning). Suitable examples of multilevel vertical conveyors can be found in, for non-limiting exemplary purposes, U.S. patent application Ser. No. 12/757,354, filed on Apr. 9, 2010 (now U.S. Pat. No. 9,694,975, issued Jul. 4, 2017), and U.S. patent application Ser. No. 12/757,220, filed on Apr. 9, 2010 (now U.S. Pat. No. 9,096,375, issued Aug. 4, 2015), the disclosures of which are incorporated herein by reference in their entireties. 
     Referring now to  FIG. 2A , the multilevel vertical conveyors will be described in greater detail. It is noted that the input multilevel vertical conveyor  150 A and associated in-feed transfer stations  170  are described, however, the out-feed multilevel vertical conveyors  150 B, bot transfer stations  140 B and out-feed transfer stations  160  may be substantially similar to that described below for their in-feed counterparts but for the direction of material flow out of the storage and retrieval system  100  rather than into the storage and retrieval system  100 . As may be realized, the storage and retrieval system  100  may include multiple in-feed and out-feed multilevel vertical conveyors  150 A,  150 B that are accessible by, for example, bots  110  on each level of the storage and retrieval system  100  so that one or more case unit(s) can be transferred from a multilevel vertical conveyor  150 A,  150 B to each storage space on a respective level and from each storage space to any one of the multilevel vertical conveyors  150 A,  150 B on a respective level. The bots  110  may be configured to transfer the case units (alone or in combinations) between the storage spaces and the multilevel vertical conveyors with one pick (e.g. substantially directly between the storage spaces and the multilevel vertical conveyors). The case unit(s) (which may be uncontained) being so transferred at one time (e.g. as a unit) may be referred to generally as a pickface. By way of further example, the designated bot  110  picks the case unit(s) or pickface from a shelf of a multilevel vertical conveyor, transports the case unit(s) to a predetermined storage area of the storage structure  130  and places the case unit(s) or pickface in the predetermined storage area (and vice versa). 
     Generally, the multilevel vertical conveyors include payload shelves  730  ( FIGS. 2A-4 ) attached to chains or belts that form continuously moving or circulating vertical loops (the shape of the loop shown in the Figs. is merely exemplary and in the embodiments the loop may have any suitable shape including rectangular and serpentine) that move at a substantially constant rate, so that the shelves  730  use what may be referred to as the “paternoster” principle of continuous conveyance, with loading and unloading performed at any point in the loop without slowing or stopping. In the embodiments, it should be understood that the payload shelves  730  can be driven by any suitable drive mechanism such as tracks, gears, etc. The multilevel vertical conveyors  150 A,  150 B may be controlled by a server, such as for example, control server  120 , or any other suitable controller. One or more suitable computer workstations  700  may be connected to the multilevel vertical conveyors  150 A,  150 B and the server  120  in any suitable manner (e.g. wired or wireless connection) for providing, as an example, inventory management, multilevel vertical conveyor functionality and control, and customer order fulfillment. As may be realized, the computer workstations  700  and/or server  120  may be programmed to control the in-feed and/or out-feed conveyor systems. In the embodiments, the computer workstations  700  and/or server  120  may also be programmed to control the transfer stations  140 . In the embodiments, one or more of the workstations  700  and control server  120  may include a control cabinet, a programmable logic controller and variable frequency drives for driving the multilevel vertical conveyors  150 A,  150 B. In the embodiments the workstations  700  and/or control server  120  may have any suitable components and configuration. In the embodiments, the workstations  700  may be configured to substantially remedy any exceptions or faults in the in-feed and/or out-feed conveyor systems substantially without operator assistance and communicate fault recovery scenarios with the control server  120  and/or vice versa. 
     Referring still to  FIG. 2A  and also to  FIG. 4 , in the embodiments, the multilevel vertical conveyors  150 A may include a frame  710  configured to support driven members such as, for example, chains  720 . The chains  720  may be coupled to the shelves  730 , which are movably mounted to the frame  710  such that the chains  720  effect substantially continuous movement of the shelves  730  around the frame  710 . In the embodiments, any suitable drive link, such as for example, belts or cables may be used to drive the shelves  730 . Each shelf  730  may include, for example, supports  930  and a platform  900 . The supports  930  may extend from the platform  900  and be configured for attaching and mounting the shelf  730  to, for example, one or more drive chains  720 . The platform  900  may include, for example, any suitably shaped frame  911 , which in this example is generally “U” shaped (e.g. having lateral members connected by a span member at one end), and any suitable number of spaced apart fingers  910  extending from the frame  911 . The fingers  910  may be configured for supporting the pickfaces  750 ,  752  ( FIG. 2B ) where each pickface comprises at least one uncontained case unit. In the embodiments, each of the fingers  910  may be removably fastened to a frame  911  for facilitating replacement or repair of individual fingers  910 . The fingers  910 , frame  911  (and supports  930 ) may form an integral structure or platform that defines the seating surface that contacts and supports the uncontained case units. It is noted that the shelf  730  illustrates only a representative structure and in the embodiments, the shelves  730  may have any suitable configuration and size for transporting pickfaces  750 ,  752  as will be described further below. As maybe realized the fingers  910  of each of the one or more pickface support stations A-D, define the seating surface against which the one or more uncontained cases of each pickface are gated. As seen in  FIG. 5 , the pickfaces on the support station may have constraints to prevent movement of the pickface(s) relative to the support stations (A-D). The spaced apart fingers  910  are configured to interface with, for example, a transfer arm or effector of the bots  110  and the in-feed transfer stations  170  for transferring the loads  750 ,  752  between the multilevel vertical conveyor  150 A and one or more of the transfer stations  170  and bots  110 . In the embodiments, the spaced apart fingers  900  may be configured to interface with bot transfer stations  140  as described below. 
     The multilevel vertical conveyors  150 A may also include a suitable stabilizing device(s), such as for example, driven stabilizing chains for stabilizing the shelves  730  during vertical travel. In one example, the stabilizing devices may include chain driven dogs that are engaged to the shelves in both the upward and downward directions to form, for example, a three point engagement with the shelf supports  930 . The drive chains  720  for the shelves  730  and stabilizing devices may be drivingly coupled to for example, any suitable number of drive motors under the control of, for example, one or more of the computer workstations  700  and control server  120 . Further examples for effecting stability of the conveyor shelves  730  in the embodiments are described later in the specification. 
     In the embodiments there may be any suitable number of shelves  730  mounted and attached to the drive chains  720 . As can be seen in  FIG. 2B  each shelf  730  may be configured to carry, for exemplary purposes only, at least two separate pickfaces  750 ,  752  in corresponding positions A, C on the shelf  730  (e.g. a single vertical conveyor is functionally equivalent to multiple individually operated conveyors arranged adjacent one another). In the embodiments, as can be seen in  FIG. 5  the shelves  730 ′ may be configured to carry, for exemplary purposes only, four separate pickfaces  750 - 753  in corresponding positions A-D. In the embodiments, each shelf may be configured to carry more or less than four separate loads. As described above, each pickface may comprise one or more uncontained case units and may correspond to the load of a single bot  110 . As may be realized, the space envelope or area platform of each pickface may be different. By way of example, uncontained cases, such as those directly transported by the multilevel vertical conveyors have various different sizes (e.g. differing dimensions). Also, as noted each pickface may include one or more uncontained cases. Thus, the length and width of each pickface carried by the multilevel vertical conveyors may be different. In the embodiments each pickface may be broken between, for example, bots  110  where different portions of the pickface are transported by more than one bot  110  on, for example, different levels of the storage structure  130 . As may be realized when a pickface is broken each portion of the broken pickface may be considered as a new pickface by the storage and retrieval system  100 . For exemplary purposes only, referring to  FIGS. 3A, 3B  the shelves  730  of the multilevel vertical conveyors  150 A,  150 B may be spaced from each other by a predetermined pitch P to allow for placement or removal of loads  810 ,  820  from the substantially continuously moving shelves  730  as will be described below. 
     Referring now to  FIG. 5 , and as described above, the multilevel vertical conveyors, such as conveyor  150 A are supplied with case units  1000  from in-feed transfer stations  170  ( FIG. 1 ). As described above, the in-feed transfer stations  170  may include one or more of depalletizing workstations, conveyors  240 , conveyor interfaces/bot load accumulators  1010 A,  1010 B and conveyor mechanisms  1030 . As can be seen in  FIG. 5 , case units  1000  are moved from, for example depalletizing workstations by conveyors  240 . In this example, each of the positions A-D is supplied by a respective in-feed transfer station. As may be realized, while the transfer of case units is being described with respect to shelves  730 ′ it should be understood that transfer of case units to shelves  730  occurs in substantially the same manner. For example, position A may be supplied by in-feed transfer station  170 A and position C may be supplied by in-feed transfer station  170 B. Referring also to  FIG. 2A  the in-feed transfer stations  170 A,  170 B, for supplying similar sides of the shelf  730  (in this example positions A and C, which are disposed side by side, form a first side  1050  of the shelf  730  and positions B and D, which are disposed side by side, form a second side  1051  of the shelf  730 ), may be located one above the other in a horizontally staggered stacked arrangement (an exemplary stacked arrangement is shown in  FIG. 2A ). In the embodiments, the stacked arrangement may be configured so that the in-feed transfer stations are disposed vertically in-line one above the other and extend into the multilevel vertical conveyors by different amounts for supplying, for example, positions A and B or positions C and D where positions A and B (and positions C and D) are disposed one in front of the other, rather than side by side. In the embodiments, the in-feed transfer stations may have any suitable configuration and positional arrangement. As can be seen in  FIG. 5 , the first side  1050  and second side  1051  of the shelf  730  are loaded (and unloaded) in opposing directions such that each multilevel vertical conveyor  150 A is located between respective transfer areas  295 A,  295 B where the first side  1050  interfaces with a transfer area  295 B and the second side  1051  interfaces with transfer area  295 A. 
     In the embodiments, the accumulators  1010 A,  1010 B may be configured to form the case units  1000  into the individual pickfaces  750 - 753  prior to loading a respective position A-D on the multilevel vertical conveyor  730 . In the embodiments, the computer workstation  700  and/or control server  120  may provide instructions or suitably control the accumulators  1010 A,  1010 B (and/or other components of the in-feed transfer stations  170 ) for accumulating a predetermined number of items to form the pickfaces  750 - 753 . The accumulators  1010 A,  1010 B may align the case units in any suitable manner (e.g. making one or more sides of the items flush, etc.) and, for example, abut the items together. The accumulators  1010 A,  1010 B may be configured to transfer the pickfaces  750 - 753  to respective conveyor mechanisms  1030  for transferring the pickfaces  750 - 753  to a respective shelf position A-D. In the embodiments the conveyor mechanisms  1030  may include belts or other suitable feed devices for moving the pickfaces  750 - 753  onto transfer platforms  1060 . The transfer platforms  1060  may include spaced apart fingers for supporting the pickfaces  750 - 753  where the fingers  910  of the shelves  730  are configured to pass between the fingers of the transfer platforms  1060  for lifting (or placing) the pickfaces  750 - 753  from the transfer platforms  1060 . In the embodiments, the fingers of the transfer platforms  1060  may be movable and serve to insert the pickfaces  750 - 753  into the path of the shelves  730  in a manner similar to that described below with respect to the bot transfer stations  140 . In the embodiments the in-feed transfer stations  170  (and out-feed transfer stations  160 ) may be configured in any suitable manner for transferring case units (e.g. the pickfaces formed by the case units) onto or from respective multilevel vertical conveyors  150 A,  150 B. 
     It is noted that while the interface between the bot transfer stations  140  and the multilevel vertical conveyors  150 A,  150 B are described it should be understood that interfacing between the bots  110  and the multilevel vertical conveyors  150 A,  150 B occurs in a substantially similar manner (e.g. as described in U.S. patent application Ser. No. 12/757,312, filed on Apr. 9, 2010 (now U.S. Pat. No. 8,425,173, issued Apr. 23, 2013), previously incorporated herein by reference in its entirety). For exemplary purposes only, referring now to  FIGS. 2B and 6A-6D , the multilevel vertical conveyors  150 A transfer pickfaces  750 ,  752  from, for example, the in-feed transfer stations  170  (or any other suitable device or loading system) to, for example, the bot transfer stations  140  associated with each of the levels in the storage structure  130 . In other examples, the pickfaces  750 ,  752  may be transferred directly from the multilevel vertical conveyors  150 A to the bots  110  as described below. As may be realized, the bot transfer stations  140  are disposed on respective levels of the storage structure adjacent the path of travel of the shelves  730  of a respective multilevel vertical conveyor  150 A. In the embodiments, there may be a bot transfer station  140  corresponding to each of the positions A and C on the shelves  730  (and positions A-D with respect to shelf  730 ′). For example, a first bot transfer station  140  may remove load  750  from position A on shelf  730  while another bot transfer station  140  may remove pickface  752  from position C on shelf  730  and so on. In the embodiments, one bot transfer station  140  may serve to remove or place case units in more than one position A, C on the shelves  730 . For example, one bot transfer station  140  may be configured for removing pickfaces  750 ,  752  from one or more of positions A, C of shelf  730 . In the embodiments, referring also to  FIG. 5 , one bot transfer station  140  may be configured for removing pickfaces  750 ,  752  from one or more of positions A, C on a first side  1050  of the shelf  730 ′ while another bot transfer station  140  may be configured to remove pickfaces  751 ,  753  from one or more positions B, D on a second side  1051  of the shelf  730 ′. In the embodiments the bot transfer stations  140  may have any suitable configuration for accessing any suitable number of positions A-D of the shelves  730 ,  730 ′. 
     Each bot transfer station  140  may include a frame  1100 , one or more drive motors  1110  and a carriage system  1130 . The frame  1100  may have any suitable configuration for coupling the bot transfer station  140  to, for example, any suitable supporting feature of the storage structure  130 , such as a horizontal or vertical support. The carriage system  1130  may be movably mounted to the frame  1100  through, for example, rails  1120  that are configured to allow the carriage system  1130  to move between retracted and extended positions as shown in  FIGS. 6A and 6B . The carriage system  1130  may include a carriage base  1132  and fingers  1135 . The fingers  1135  may be mounted to the carriage base  1132  in a spaced apart arrangement so that the fingers  1135  extend from the carriage base  1132  in a cantilevered fashion. It is noted that each finger  1135  may be removably mounted to the carriage base  1132  for facilitating replacement or repair of individual fingers  1135 . In the embodiments the fingers and carriage base may be of unitary one-piece construction. The fingers  1135  of the bot transfer stations  140  may be configured to pass between the fingers  910  ( FIG. 4 ) of the shelves  730  of the multilevel vertical conveyors  150 A ( FIG. 1 ) for removing pickfaces such as pickfaces  1150  (which may be substantially similar to pickfaces  750 - 753 ) from the shelves  730 . The bot transfer station  140  may also include a load positioning device  1140  that retractably extends between, for example, the spaced apart fingers  1135  in the direction of arrow  1181  for effecting positioning of the pickfaces  1150  in a predetermined orientation relative to the bot transfer station  140 . In the embodiments the carriage system  1130  may have any suitable configuration and/or components. The one or more drive motors  1110  may be any suitable motors mounted to the frame  1100  for causing the extension/retraction of the carriage system  1130  and the extension/retraction of the positioning device  1140  in any suitable manner such as by, for exemplary purposes only, drive belts or chains. In the embodiments, the carriage system and positioning device may be extended and retracted in any suitable manner. 
     In operation, referring also to  FIGS. 2C, 2D, 3A and 3B , inbound pickfaces (e.g. pickfaces, which include one or more case units, that are being transferred into the storage and retrieval system) such as pickface  1150  are loaded on and will circulate around the multilevel vertical conveyor  150 A and be removed from a respective conveyor by, for example, one or more bots  110  for placement in a storage area of the storage structure ( FIG. 8 , Blocks  8000  and  8010 ). As will be described further below, in the embodiments the input loading sequencing of case units onto the multilevel vertical conveyors  150 A,  150 B (e.g. such as at corresponding feeder input sides of transfer stations  170  and bot transfer locations on respective storage levels) may be substantially independent from the output or unloading sequence of the multilevel vertical conveyors  150 A,  150 B (e.g. such as at corresponding output sides of transfer stations  160  and bot transfer locations on respective storage levels) and vice versa. In one example, the pickface  1150  may be loaded onto the shelves  730  during an upward travel of the multilevel vertical conveyor  150 A and off loaded from the shelves  730  during downward travel of the multilevel vertical conveyor  150 A. By way of example, multilevel vertical conveyor shelves  730   i  and  730   ii  ( FIG. 2D ) may be loaded sequentially, but when unloaded, shelf  730   ii  may be unloaded before shelf  730   i . It is noted that the shelves  730  may be loaded through one or more cycles of the multilevel vertical conveyor. In the embodiments the pickfaces may be loaded or off loaded from the shelves  730  in any suitable manner. As may be realized, the position of the case units on the multilevel vertical conveyor shelf  730  defines the pickface position that the bot  110  picks from. Accordingly, as may be realized, shudder of the pickface conveyor is highly undesired, especially in that a pickface(s) may remain on the conveyor for more than one cycle after being loaded. The bot may be configured to pick any suitable load or pickface from the shelf  730  regardless of the pickface position on the shelf  730  or the size of the pickface. In the embodiments, the storage and retrieval system  100  may include a bot positioning system for positioning the bot adjacent the shelves  730  for picking a desired pickface from a predetermined one of the shelves  730  (e.g. the bot  110  is positioned so as to be aligned with the pickface). The bot positioning system may also be configured to correlate the extension of a bot transfer arm with the movement (e.g. speed and location) of the shelves  730  so that the transfer arm is extended and retracted to remove (or place) pickfaces from predetermined shelves  730  of the multilevel vertical conveyors  150 A,  150 B. For exemplary purposes only, the bot  110  may be instructed by, for example, the computer workstation  700  or control server  120  ( FIG. 2A ) to extend the transfer arm into the path of travel of the pickface  1150 . As the pickface  1150  is carried by the multilevel vertical conveyor  150 A in the direction of arrow  860  fingers of the bot transfer arm (which may be substantially similar to fingers  1135  of the bot transfer station  140 ) pass through the fingers  910  of the shelf  730  for transferring the pickface  1150  from the shelf  730  to the carriage system  1135  (e.g. the pickface  1150  is lifted from the fingers  910  via relative movement of the shelf  730  and the bot transfer arm). As may be realized, the pitch P between shelves may be any suitable distance for allowing the transfer of pickfaces between the multilevel vertical conveyor and the bots  110  while the shelves  730  are circulating around the multilevel vertical conveyor at a substantially continuous rate. The bot transfer arm may be retracted (in a manner substantially similar to that shown in  FIGS. 6C, 6D  with respect to the bot transfer station  140 ) so that the pickface  1150  is no longer located in the path of travel of the shelves  730  of the multilevel vertical conveyor  150 A. It is noted that in the embodiments, where the bot transfer stations  140  are used, the positioning device  1140  may be extended through the fingers  1135  and the carriage system  1130  ( FIGS. 6A-6D ) may be moved in the direction of arrow  1180  for abutting the pickface  1150  against the positioning device  1140  effecting positioning of the pickface  1150  in a predetermined orientation relative to, for example, the bot transfer station  140 . The carriage system  1130  may be fully retracted as shown in  FIG. 6D  for transfer of the pickface  1150  to a bot  110 . 
     Referring to  FIGS. 2D and 3B , for transferring loads in the outbound direction (e.g. moving pickfaces from or out of the storage and retrieval system) the bots  110  pick one or more pickface, such as pickface  1150 , from a respective predetermined storage area of the storage structure ( FIG. 8 , Block  8020 ). The pickfaces may be extended into the path of the shelves  730  of the multilevel vertical conveyor  150 B (which is substantially similar to conveyor  150 A) by the transfer arm of bot  110  through an extension of the bot transfer arm relative to a frame of the bot  110 . It is noted that the pickfaces, such as pickface  1150 , may be placed on the multilevel vertical conveyor  150  in a first predetermined order sequence ( FIG. 8 , Block  8030 ). The first predetermined order may be any suitable order. The substantially continuous rate of movement of the shelves  730  in the direction of arrow  870  cause the fingers  910  of the shelf  730  to pass through the fingers of the bot transfer arm such that the movement of the shelf  730  effects lifting the pickface  1150  from the fingers of the bot transfer arm. The pickface  1150  travels around the multilevel vertical conveyor  150 B to an out-feed transfer station  160  (which is substantially similar to in-feed transfer station  170 ) where it is removed from the shelf  730  by a conveyor mechanism  1030  in a manner substantially similar to that described above. The pickfaces may be removed from the multilevel vertical conveyor  150 B by, for example the out-feed transfer stations  160  in a second predetermined order sequence that may be different and independent from the first predetermined order sequence ( FIG. 8 , Block  8040 ). The second predetermined order sequence may depend on any suitable factors such as, for example, the store plan rules described below. As noted before, to effect transfer of pickface(s) between conveyor stations and bot transfer arm or transfer station in a robot repeatable manner where pickface size and shape may vary with each transfer it is desired that the motion of the pickface(s) on the conveyor be substantially free of shudder of judder. 
     It is noted that the respective transfer of pickfaces between the multilevel vertical conveyors  150 A,  150 B and the in-feed and out-feed transfer stations  170 ,  160  may occur in a manner substantially similar to that described above with respect to the bots  110  and bot transfer stations  140 . In the embodiments transfer of pickfaces between the multilevel vertical conveyors  150 A,  150 B and the in-feed and out-feed transfer stations  170 ,  160  may occur in any suitable manner. 
     As can be seen in  FIGS. 2C and 2D  the shelves  730  of the multilevel vertical conveyors  150 A,  150 B are loaded and unloaded by the in-feed and out-feed transfer stations  170 ,  160  and the bots  110  from a common side of the shelf  730 . For example, the shelves are loaded and unloaded in the common direction  999  (e.g. from only one side of the shelf  730 ). In this example, to facilitate loading the multilevel vertical conveyor from only one side of the shelf, the multilevel vertical conveyors  150 A,  150 B circumscribe a respective one of the in-feed and out-feed transfer stations  170 ,  160  so that the pickfaces  1150  travel around the in-feed and out-feed transfer stations  170 ,  160 . This allows the in-feed and out-feed transfer stations  170 ,  160  to be placed on the same side of the shelves  730  as the bots  110  for transferring pickfaces (and the case units therein) to and from the multilevel vertical conveyors  150 A,  150 B. 
     It is noted that the control server  120  may be configured to order the removal of case units from the storage and retrieval system for any suitable purpose, in addition to order fulfillment. In the embodiments, the distribution (e.g. sortation) of case units in the storage and retrieval system is such that the case units in the conveyor can be provided for delivery to a palletizing station in any suitable order at any desired rate using only two sortation sequences. The control server  120  may also be configured to incorporate, for example, store plan rules when fulfilling orders so that the cases are provided by the bots  110  to respective multilevel vertical conveyors  150 B in a first predetermined sequence (e.g. a first sortation of case units for optimizing the utilization and throughputs of the bots) and then removed from the respective multilevel vertical conveyors  150 B in a second predetermined sequence (e.g. a second sortation of case units for optimizing the utilization and throughput of a palletizing device and to permit arrangement of cases within the pallet in a manner optimized for facilitating unloading and distribution at a retail delivery point or facility) so that the case units may be placed on pallets or other suitable shipping containers/devices) in a predetermined order for building mixed pallets (see e.g.  FIG. 8  described above). For example, in the first sortation of case units the bots  110  may pick respective case units (e.g. case unit) in any order. The bots  110  may traverse the picking aisles and transfer deck (e.g. circulate around the transfer deck) with the picked item until a predetermined time when the item is to be delivered to a predetermined multilevel vertical conveyor  150 B. In the second sortation of case units, once the case units are on the multilevel vertical conveyor  150 B the case units may circulate around the conveyor until a predetermined time when the items are to be delivered to the out-feed transfer station  160 . Referring to  FIG. 7 , it is noted that the order of case units delivered to the pallets may correspond to, for example, store plan rules  9000 . The store plan rules  9000  may incorporate, for example, an aisle layout in the customer&#39;s store or a family group of case units corresponding to, for example, a particular location in the store where the pallet will be unloaded or a type of goods. The order of case units delivered to the pallets may also correspond to characteristics 9001 of the case units such as, for example, compatibility with other case units, dimensions, weight and a durability of the case units. For example, crushable case units may be delivered to the pallet after heavier more durable case units are delivered to the pallet. The first and second sortations of the case units allow for the building of mixed pallets  9002  as described below. 
     The control server  120  in combination with the structural/mechanical architecture of the storage and retrieval system enables maximum load balancing. As described herein, the storage spaces/storage locations are decoupled from the transport of the case units through the storage and retrieval system. For example, the storage volume (e.g. the distribution of case units in storage) is independent of and does not affect throughput of the case units through the storage and retrieval system. The storage array space may be substantially uniformly distributed with respect to output. The horizontal sortation (at each level) and high speed bots  110  and the vertical sortation by the multilevel vertical conveyors  150 B substantially creates a storage array space that is substantially uniformly distributed relative to an output location from the storage array (e.g. an out-feed transfer station  160  of a multilevel vertical conveyor  150 B). The substantially uniformly distributed storage space array also allows case units to be output at a desired substantially constant rate from each out-feed transfer station  160  such that the case units are provided in any desired order. To effect the maximum load balancing, the control architecture of the control server  120  may be such that the control server  120  does not relate the storage spaces within the storage structure  130  (e.g. the storage array) to the multilevel vertical conveyors  150 B based on a geographical location of the storage spaces (which would result in a virtual partitioning of the storage spaces) relative to the multilevel vertical conveyors  150 B (e.g. the closest storage spaces to the multilevel vertical conveyor are not allocated to cases moving from/to that multilevel vertical conveyor). Rather, the control server  120  may map the storage spaces uniformly to each multilevel vertical conveyor  150 B and then select bots  110 , storage locations and output multilevel vertical conveyor  150 B shelf placement so that case units from any location in the storage structure come out from any desired multilevel vertical conveyor output (e.g. at the out-feed transfer stations) at a predetermined substantially constant rate in a desired order for building the mixed pallets  9002 . 
     Referring now to  FIGS. 9A and 9B , there is shown feed station  141  in accordance with the embodiments. In addition to the features described below, station  141  may be substantially similar to out-feed and in-feed stations  160 ,  170 . Feed station  141  may be an automated device that can be configured to either transfer payloads referred to as pickfaces, cases or otherwise into an MVC and onto a platform or out of an MVC from the platform. In one example, the feed station  141  interfaces, for example, the pickface builder  2010  ( FIGS. 10-12 ) to the shelves  731  ( FIG. 13 ) of the multilevel vertical conveyor(s)  150  ( FIG. 10 ). In the embodiments, feed station  141  may be used to transfer material to or from any suitable device, station or otherwise. In one example, the feed station  141  receives a pickface from the pickface builder  2010 . The feed station may have any suitable pickface positioning features that position a reference datum (e.g. pickface datum) of the pickface (relative to a transfer device of the feed station) at a predetermined position on the multilevel vertical conveyor shelf  731  so that the bots  110  ( FIG. 1 ) can pick the pickfaces from the shelf  731 . It is noted that the pickface datum relates the pickface to a placement position of the cases that form the pickface along a storage surface, such as e.g. the storage shelves  600 , of the storage and retrieval system. The transfer device of the feed station  141  may translate to effect the handoff of the pickface to the shelf  731 . In the embodiments the handoff may occur in any suitable manner. The feed station  141  may have any suitable controller to operate the transfer device in a predetermined sequence with the multilevel vertical conveyor  150  and interact with the pickface builder  2010 . 
     Feed station  141  has driven roller bed  2112  to transfer in the x-axis  2014 . Feed station  141  has a set of extendable or retractable fingers and payload bed  2020  that traverses in the y-axis  2022  and PLC with controls  2030 . Rollers  2012  may be selectively driven by drive motor and transmission  2040  where sensors may be provided to detect the presence, edges or otherwise of the payload to be transported and used in conjunction with encoders or otherwise with controller  2030  to position the payload as desired. Gear motor  2050  may be provided to selectively traverse bed  2020  in the y direction  2022 . A z axis drive (not shown) may be provided to move bed  2020  in the z direction  2024  to effect a pick or place to rollers  2012 . Feed station&#39;s  141  y-axis motion may be coordinated to transfer loads, for example, payloads, cases or otherwise from or onto the MVC platforms  730 ,  731  by positioning feed station fingers  2020  to accept or pass off the payload to or from the platform  730 ,  731 . Feed station  141  transfers the payload between x and y-axis  2014 ,  2022  through a z-axis  2024  lift of the fingers  2020 . With a pickface payload on rollers  2012 , once fingers  2020  are lifted, a y-axis move in direction  2022 , that may extend fingers  2020 , may take place to allow the payload to be transported to the appropriate MVC (in a manner similar to that shown in  FIG. 5 ). An opposite sequence may take place when transferring a payload from an MVC platform, for example, platform  730  or  731  as will be described, to feed station  141  where fingers  2020  retract in the y-axis direction  2022  and then lower in the z-axis direction  2024  to transfer a pickface payload to the roller bed  2012  for removal. As such, feed station  141  provides for an automated device that can be configured to either transfer payloads or cases into an MVC and onto a platform or out of an MVC from the platform. As may be realized, the pickface payload being output by an output MVC from the storage and retrieval system different than the input pickface payload. For example, as input pickface transported and loaded to a corresponding storage space in the storage structure and comprising more than one case(s) may be portioned during retrieval so that a sub-set of the input pickface are retrieved, and the retrieved pickface is different than the input pickface. 
     Referring now to  FIGS. 10-14C  there is shown pickface builder arrangement  2002  having pickface builder  2010  and feed station  141 . Pickface builder  2010 , which may hereinafter be referred to as PFB may be an automated device to align a single or multiple cases or pickface units to form the single or multiple pickface payload for picking, placing or otherwise to be transferred in any suitable direction or otherwise and to be used in conjunction with any suitable conveyance, transport device or otherwise. Although pickface builder  2010  may be described with respect to transfer station  141 , pickface builder  2010  may be utilized with or without any transfer station, transport system or otherwise. Further, more or less features may be provided with pickface builder  2010 . For example, transport features such as associated with transfer station  141  or otherwise may be incorporated into pickface builder  2010  and more or less sensing, alignment or other suitable features may be provided. 
     The pickface builder  2002  may be located in any suitable area of the storage and retrieval system  100  in-feed conveyance system. In one example, the pickface builder  2010  may be located between the conveyor  240  (see also  FIG. 5 ) and the multilevel vertical conveyor  150 . For example, in the embodiments the pickface builder  2010  may be arranged downstream from (e.g. adjacent to or offset from) a turn in elbow  240 E of the conveyor  240  (e.g. to change a direction of the flow of cases for interfacing with the multilevel vertical conveyor  150 ) and upstream of the feed station  141 . In the embodiments, the conveyor  150  may not have a turn in elbow in which case the pickface builder may interface with a substantially straight conveyor. In the embodiments the pickface builder may be located downstream the multilevel vertical conveyors and upstream of a bot interface where the pickfaces are transferred to the bots. The pickface builder  2010  may be configured to arrange and compile a set (e.g. one or more) of cases to build a pickface of cases (e.g. contained or uncontained cases). Each pickface is picked (as a unit) by bots  110  for placement and retrieval in the storage racks of the storage structure  130  and/or the shelves  731  of the multilevel vertical conveyors  150 . In the embodiments shown in the figures the pickface builder  2010  communicates with the multilevel vertical conveyors  150  through the feed station  141  so that pickfaces are transferred (as a unit) to the multilevel vertical conveyors  150  after the pickface is built. In the embodiments, each pickface builder  2010  may be linked to a dedicated position of the multilevel vertical conveyor shelves  731 , such as where the shelves  731  have more than one pickface holding location  2280 ,  2290  ( FIG. 13 ). In the embodiments each pickface builder may be configured to selectively feed cases to each pickface holding location  2280 ,  2290  of the shelves  731  (e.g. a common pickface builder for one or more shelf positions). In the embodiments, the pickface builder  2010  may adjoin a side of a respective feed station  141  and be disposed so that cases of the pickface exit the pickface builder, through any suitable drive unit, and enter the feed station  141  in a direction that is angled (e.g. substantially orthogonal) relative to the direction in which the feed station transfers the pickface to the multilevel vertical conveyor. In the embodiments, the cases may be arranged at any suitable angle relative to the direction or travel of the pickface from the feed station  141  to the multilevel vertical conveyor  150 . 
     Pickface builder  2010  may have x-y axis pusher  2100  (or a single axis, e.g. y axis, pusher), y-axis snugger  2120 , roller bed  2140  and PLC controls  2160 . In one example, the pusher  2100  may have any suitable type and number of pusher plates  2100 P for pushing cases across a support surface (which may be movable) of the pickface builder  2010 . The pusher plate(s)  2100 P may be resilient and may be positioned to engage cases such that the cases can be pushed as they move along the direction of travel on the conveyor  240  (e.g. the pusher  2100  is configured to drive the pusher plates  2100 P along the x and y directions) for positioning cases on the pickface builder  2010  for building the pickface. The x-y axis pusher  2100  may be located to receive cases such that the direction of the flow of cases from the conveyor  240  is towards the pusher (e.g. the conveyor discharges cases substantially in front of or adjacent the pusher). In one example, the case configuration upon receipt by the pusher  2100  may be such that a long axis of the cases is oriented to interface with the pusher  2100 . In another example, the short axis of the cases may be oriented to interface with the pusher  2100  (e.g. the cases may have any suitable orientation relative to the pusher  2100 ). In still other examples, the cases may have mixed orientations when interfacing with the pusher  2100  (e.g. some cases interface the pusher via a long axis of the case and other cases interface with the pusher via the short axis of the case). The x-y axis pusher  2100  directs cases from the conveyor  240  towards the snugger  2120 . 
     The snugger  2120  includes any suitable type and number of snugger plates  2120 P that are positioned substantially opposite the pusher  2100  and substantially transverse to the direction of case travel between, for example, feed station  141  and the multilevel vertical conveyor  150 . In one example, the snugger establishes a pickface pick datum. For example, the snugger  2120  may be movable in at least the y direction (e.g. towards the pusher plate  2100 P) to establish a pickface datum reference when, for example, the pusher  2100  pushes cases up against the snugger  2120  (or vice versa) for substantially aligning and snugging the cases (that form a pickface) together. In one example, the snugger  2120  may be spring loaded in any suitable manner. In the embodiments the snugger may not be spring loaded. The pickface builder  2010  transfers to and collates the aligned cases (e.g. pickfaces) on the feed station  141  for subsequent transfer to the multilevel vertical conveyor  150 . In one example, the pickface builder operates so that the snugger  2120  receives an initial case of the pickface and other cases of the pickface are abutted against the initial case as will be described below. In the embodiments the cases of the pickface may be arranged so that one or more cases of the pickface are in substantial contact with the snugger plate  2120 P for establishing the pickface datum reference. 
     Pickface builder pusher  2100  and snugger  2120  have linear actuators  2162 ,  2164 ,  2166  driven by servo motors. In the embodiments, any suitable actuator, linear or otherwise may be provided, for example, any suitable other linear motion technologies. In the embodiments, PFB motion is triggered by a sensor  2170  in the pusher  2100 , which follows a payload or case throughout travel of pusher  2100  to provide positive presence detection throughout the x-y motion of pusher  2100 . PFB  2010  uses gate  2180  to halt x-axis motion of the payload until the full pickface has been built and snugged where the pickface may consist of one or more cases or payloads and where the snugging may consist of positioning cases or payloads adjacent one another or at any suitable location with respect to each other. Here, pickface builder  2010  pusher  2100  moves in an x-y motion profile that varies (depending on physical characteristics of the payload including, but not limited to, case dimensions, mass, packaging materials and fragility) and the PFB snugger  2120  moves in a y-axis profile which may be normal to the direction of payload travel or otherwise that varies depending on an aggregate of all payload or case dimensions in a given pickface. PFB snugger  2120  may compress all payloads or as is in the pickface in the y-axis to present a compact aggregate of payloads for picking, placing or subsequent transport. PFB roller bed  2140  may be a motor driven conveyor that provides payload or case motion in the x-axis. In the embodiments, any suitable form of conveyor such as belt, or a static bed with other means of x-axis conveyance may be provided for use in conjunction with pusher  2100  and/or snugger  2120 . As such, pickface builder  2010  may provide an automated device to align multiple payloads or cases to present the aggregate for picking, placing or otherwise transferring to or from MVC  150 A, B or C or other suitable transport device. 
     The pickface builder  2010  may be connected to, for example, any suitable controller such as a programmable logic controller, micro-controller or control server  120  in any suitable manner. In the embodiments, information from, for example, the control server  120  identifies any suitable ID (identification) data (e.g. SKU numbers, case dimensions, etc.) for each of the incoming cases (e.g. cases being placed on and travelling on conveyor  240 ). For exemplary purposes only, the ID data may be case specific (such as with the SKU numbers) and may also relate to storage parameters such as for example, a storage location within the storage and retrieval system the cases are to be stored and/or particulars for the pickface (e.g. case orientation, contents of a pickface, pickface configuration, etc.). In the embodiments the case ID data may be any suitable data related to the cases and/or the storage of the cases within the storage and retrieval system. The case ID data (including, but not limited to, SKU numbers, storage parameters, pickface contents, case dimensions etc.) may be stored locally such as within a memory of the pickface builder  2010  or within a memory of, for example, the control server  120  or any other suitable controller. The case ID data may be stored in any suitable format such as in lookup tables. The controller, such as controller  120  or any other suitable controller, generates, for example, an x, y movement profile of the pusher  2100  and/or a y offset of the snugger  2120  to, for example, establish the datum of the pickface based on any suitable data such as the case ID data or updated data from any suitable sensors (such as infeed resolver  2999 ) placed along the infeed path of the cases (e.g. along conveyor  240  or any other suitable area of the storage and retrieval system). 
     In one example, the infeed resolver  2999  may be configured to confirm the ID data of the incoming cases. The data obtained from, for example, the infeed resolver (such as, for example, the case dimensions and/or any other suitable case information) may be transmitted in any suitable manner to the pickface builder  2010  (e.g. directly to the pickface builder or through, for example, control server  120 ) so that the motion profiles of the pusher  2100  and snugger  2120  are updated to correspond to any observed variances of the cases (with respect to, for example, predetermined case values stored in, for example, the control server or any other suitable controller) as determined by the infeed resolver  2999 . In the embodiments, the pickface builder  2010  may be configured in any suitable manner to redirect or discard cases that are determined to be erroneous based on predetermined case data (e.g. expected case data) and, for example, actual case data obtained from the resolver  2999 . In the embodiments a separate case inspection station may be provided adjacent the pickface builder  2010  for redirecting and discarding cases. In one example, the pickface builder  2010  may have a gate or other selectably operable unit for removing the erroneous cases from the pickface builder  2010 . 
     As described above, the pickface builder  2010  may be configured to communicate in any suitable manner with, for example, the control server  120  and also a controller  150 PLC of an associated multilevel vertical conveyor(s)  150 . The pickface builder  2010  may obtain information from the controller  150 PLC and/or the control server  120  as to which shelves  731  (see e.g.  FIG. 13 ) of the multilevel vertical conveyor  150  are occupied (e.g. have pickfaces located on the shelves). The pickface builder  2010  may be configured so that pickfaces are not fed to feed station  141  unless an empty shelf  731  is provided on the multilevel vertical conveyor to which the pickface will be transferred. In the embodiments, the pickface builder may be in communication with the feed station  141  so that when a pickface is transferred from the pickface builder  2010  to the feed station  141  the feed station  141  will not transfer the pickface to the multilevel vertical conveyor unless instructed to by the pickface builder  2010 . In one example, the pickface builder may be configured to receive data from, for example, the multilevel vertical conveyor  150  and or control server  120  for tracking pickfaces that are transferred to the multilevel vertical conveyor  150 . For example, when a pickface is transferred to the multilevel vertical conveyor  150  an identification of the shelf  731  to which the pickface is transferred may be communicated to the pickface builder  2010  so that the pickface builder knows where each pickface is on the multilevel vertical conveyor  150  and which shelves  731  are empty. As another example, in addition to or in lieu of communicating the identification of the shelf to the pickface builder, an identification of the pickface is communicated to the conveyor so that the conveyor knows which pickface, if any, is on each conveyor shelf. As each pickface is removed from the multilevel vertical conveyor  150  the pickface builder  2010  and/or the multilevel vertical conveyor  150  may receive data that indicates the shelf from which the pickface was taken is now empty and available to receive another pickface(s). In the embodiments, the status of the multilevel vertical conveyor shelves may be tracked in any suitable manner (such as with, e.g. any suitable sensing devices disposed along a path of the conveyor shelves  731 ). 
     In one exemplary operation of the pickface builder (and in-feed conveyor system) cases such as cases  1301 ,  1302  travel along conveyor  240  in the direction of arrow  1399  towards the pickface builder  2010  ( FIG. 13A ). The pusher  2100  pushes, for example, a first case  1301  of a pickface towards the snugger  2120  so that the case  1301  is in substantial contact with the snugger  2120  ( FIG. 13B ). The snugger may also move towards the pusher  2100  to, for example, establish the pickface reference datum. The pusher retracts in the direction of arrows  1388 ,  1389  away from the case  1301  and returns to its initial position ( FIGS. 13C and 13D ) so that a second case  1302  of the pickface can be pushed up against (e.g. snugged) against case  1301  ( FIGS. 13E and 13D ). As may be realized, as the cases are pushed by the pusher  2100  the pusher may move two-dimensionally so that the cases being pushed are also travelling in the direction of travel along the conveyor  240  (e.g. in the direction of arrow  1399 ). In this example cases  1301 ,  1302  form pickface  1350  ( FIG. 13G ) which is held on the pickface builder by gate  2180  until an open shelf of the multilevel vertical conveyor  150  is available. The gate  2180  may be lowered or otherwise moved so that the pickface  1350  is driven off of the pickface builder  2010  in any suitable manner and onto the feed station  141 . The feed station may be arranged to transfer the pickface in one or more directions A 13 , B 13  ( FIG. 13H ), depending on a location of one or more multilevel vertical conveyors  150  for transferring the pickface  1350  to a desired shelf  731  ( FIG. 15 ). As may be realized, as the pickface  1350  is being moved off of the pickface builder another pickface may start to form such that case  1303  (the next case in the line of cases moving along the conveyor  240 ) is moved adjacent the pusher  2100  so that pickfaces are substantially continuously being built. 
       FIGS. 14A-14C  illustrate another exemplary formation of a pickface but with smaller cases  1401 - 1402 . In this example cases  1401 - 1403  are shown moving along the conveyor  240 . The formation of the pickface of  FIGS. 14A-14C  occurs in substantially the same manner as that described above with respect to  FIGS. 13A-13H . It is noted that all dimensions and time information shown in  FIGS. 13A-14C  are exemplary only and that any suitable dimensions and time values can be used. 
     Referring now to  FIG. 15 , there is shown an exemplary platform  731  of the MVC. In addition to the features described below, platform  731  may have similar features as described previously with respect to shelf or platform  730 . Referring also to  FIGS. 16 and 17 , there is shown MVC  150 C having platform guides  2200 . In addition to the features described below, MVC  150 C may have similar features as described with respect to MVC  150 A or MVC  150 B. In the embodiments platform  731  has guide wheels  2210 ,  2220 ,  2230  and  2240  mounted to frame  2250 . In the embodiments, any suitable guide interface (e.g. single or multiple rollers, bearings), may be used in place of wheels. Chain couplers  2260  and  2270  are provided between rollers  2210 ,  2230  and frame  2250  respectively. Payload support surfaces  2280  and  2290  are provided coupled to frame  2250 . Though the payload support surfaces or stations are shown, the platform may have more or fewer in the embodiments. MVC  150 C has suitable motor drive  2300  which drives chain drives  2310  and  2320  (through shaft  2330  which in turn drive chain systems  2335  and  2340  respectively). Platform  731  may be coupled to chain systems  2335  and  2340  with couplings  2270  and  2260  respectively. Although guides  2200  are shown for the upper portion of MVC  150 C, similar features may be provided on a lower portion of MVC  150 C to provided continuous guidance of platform  731 . Although a single platform  731  is shown on MVC  150 C, multiple platforms may be provided at a common or multiple intervals. Guides  2200  are shown having generally four guide portions  2350 ,  2360 ,  2370  and  2380  corresponding to guide rollers  22210 ,  2220 ,  2230  and  2240  respectively and coupled to frame  2205  of MVC  150 C. Guides  2350  and  2370  are provided offset at a wider stance with respect to guides  2360  and  2380 . Guides  2350  and  2370  provide substantially continuous guidance of rollers  2210  and  2230  throughout the path of travel through MVC  150 C and with breaks at the corners where sprockets in combination with chain couplings  2260  and  2270  provide continued guidance of platform  731  and where the breaks prevent an over constraint. Guides  2360  and  2380  provide substantially continuous guidance of rollers  2220  and  2240  throughout the path of travel through MVC  150 C and with breaks where couplings  2260  and  2270  would interfere with guides  2360  and  2380  during passage and where guides  2360  and  2380  provide continued guidance of platform  731  and where the breaks prevent interference but also where guide wheel  2220  (see  FIG. 15 ) is actively guided when guide wheel  2240  passes a break and where guide wheel  2240  is actively guided when guide wheel  2220  passes a break. As such, a substantially continuous three-point guidance is accomplished during the entire path of travel. In the embodiments, one or more of the motor  2300  chain drives  2310 ,  2320  and chain systems  2335 ,  2340  may include an active braking mechanism and velocity control. It is noted that the chain systems  2335 ,  2340  and the platforms generally revolve around the conveyor path at a substantially constant velocity to, for example, allow the bots to rendezvous with a platform. The braking mechanism and/or velocity control may substantially prevent the platforms from “free-wheeling” (e.g. moving without being driven by the motor  2300  and drive chains) if power is lost when a number of platforms are heavily loaded while others are substantially empty. Here, platform  731  travel may be guided by two sets of guide wheels  2210 ,  2220  and  2230 ,  2240  that travel within channels  2350 ,  2360  and  2370 ,  2380  on a predetermined path defined by the channels and drive system. Hence, the guide wheels  2210 ,  2220 ,  2230 ,  2240  and correspondingly the platform (and pickface(s) supported thereby) traveling along the path resist binding due to a balanced cantilevered arrangement and where transitions through corners are made by substantially continuously having three points (wheels) of contact within the roller guides  2350 ,  2360 ,  2370 ,  2380 , providing smooth (substantially shudder/judder free) transition of platform  731  through the entire path of travel within MVC  150 C. In the embodiments, one or more MVC(s)  150 C enable loading and unloading of payloads, cases or pickfaces in storage racks of storage levels. 
     As noted before, MVC platforms  731  may have more than one pickface station, for example, for pickfaces of at least one case(s). Platforms  731  are cycled by chain drive  2335 ,  2340  and use guides  2200  such that the stations maintain stability capable of desired positioning of pickfaces through substantially the full motion cycle within MVC  150 C and without over constraints that may cause shuddering, jamming or other unsuitable or undesired motions of the pickface(s) to occur. Here, the MVC platform connection to MVC drive system  2260 ,  2270 , and MVC platform guides  2200  are configured to effect three (3) point contact between platform  731  and MVC structure through full motion cycle and without over constraints. The platform supports, formed by the guides  220  and drive system coupling  2260 ,  2270  form what may be referred to as a guided cantilever restraint that is movable through complete cycle without over-constraints, and, as a result without undesirable motion, such as shudder or judder through cycle motion. Accordingly a smooth and effective load and unload MVC cycle (e.g. infeed to off load for infeed MVC and vice versa for outfeed MVC) as well as MVC sorter (e.g. pickface payload moves through more than one cycle) may be provided. In the embodiments, MVC  150 C has frame  2205 , drive system  2300  and platforms  731  that are mounted to the frame and coupled to the drive system  2300  so the platforms  731  are cycled vertically in a closed loop. Platform(s)  731  may have one or more pickface payload holding stations (e.g. two  2280 ,  2290 ) that are located offset from each other, for example, positionally distributed on platform. In the embodiments, more or less locations may be provided. Each holding station may be configured for holding pickface of (one or more) uncontained cases(s). Each holding station may independently fed and offloaded. Independent feeds may have pickface builders that may be accommodated by MVC structure and motion path profile(s). Further, MVC  150 C may be both a multilevel loader/unloader and sorter. In the embodiments, frame  2205  and drive  2300  may be configured to effect platform  731  motion that results in a vertical or horizontal cycle component in a same direction as load/unload transfer axis for a given pickface, for example, front-back. In the embodiments, the interface may be to warehouse conveyors, for example, a load station for infeed to MVC  150 C or an unload station for outfeed from MVC  150 C as may be located interior to frame  2205  and transport loop path of platforms  731  of MVC  150 C. Interface with rack storage and retrieval system, for example, bot to MVC transfer locations may be provided on an outside of the transport loop path of platforms  731  of MVC  150 C. In the embodiments, any suitable in feed or out feed may be provided on the inside, outside or otherwise of the transport path of platforms  731  of MVC  150 C. 
     In a first aspect of the embodiments a pickface builder for a storage and retrieval system for storing goods units and having an in-feed conveyor and a picking device is provided. Each goods unit holds at least one product package therein. The pickface builder includes a frame, a pusher member movably coupled to the frame, and a snugger member movably coupled to the frame, wherein the pickface builder is configured to receive goods units from the in-feed conveyor and the pusher member and snugger member are movable at least in a direction transverse to a direction of goods unit travel on the in-feed conveyor and configured to form the goods units into a pickface picked by the picking device as a unit and having a predetermined reference datum relating the pickface to a placement position of goods units forming the pickface along a storage surface of the storage and retrieval system. 
     In accordance with a first sub-aspect of the first aspect of the embodiments the pusher member may be movable in at least two orthogonal directions for pushing the goods units towards the snugger member. 
     In accordance with the first sub-aspect of the first aspect of the embodiments, the snugger member is positioned to create the predetermined reference datum as the pusher member pushes goods units towards the snugger member. 
     In accordance with the first aspect of the embodiments, the pickface builder further includes a movable gate disposed adjacent the snugger member for retaining at least one goods unit as a pickface is formed from the at least one goods unit. 
     In accordance with a second sub-aspect of the first aspect of the embodiments, the pickface builder further includes a resolver member configured to obtain case goods unit as goods units are transferred to the pickface builder from the in-feed conveyor. 
     In accordance with the second sub-aspect of the first aspect of the embodiments, the pickface builder is configured to form pickfaces based on at least the goods unit data obtained from the resolver member. 
     In accordance with the second sub-aspect of the first aspect of the embodiments, the resolver member is configured to confirm an identity of the goods units being transferred to the pickface builder from the in-feed conveyor. 
     In accordance with the second sub-aspect of the first aspect of the embodiments, the pickface builder is configured to modify motion profiles of at least one of the pusher member and snugger member based on the goods unit data from the resolver member. 
     In accordance with the first aspect of the embodiments, the pickface builder further comprises a controller in communication with a controller of the picking device, the controller being configured to associate pickfaces with shelves of the picking device for tracking a position of the pickfaces on the picking device. 
     In accordance with a third sub-aspect of the first aspect of the embodiments, the pickface builder includes a controller configured to create motion profiles for the pusher member and snugger member based at least on predetermined goods unit data accessible by the controller. 
     In accordance with the third sub-aspect of the first aspect of the embodiments, wherein the controller includes a memory configured to store the predetermined goods unit data. 
     In accordance with the third sub-aspect of the first aspect of the embodiments the storage and retrieval system includes a system controller wherein the pickface builder is in direct or indirect communication with the system controller and the predetermined goods unit data is stored in a memory of the system controller. 
     In accordance with a fourth sub-aspect of the first aspect of the embodiments the pickface is formed from uncontained goods units. 
     In accordance with the fourth sub-aspect of the first aspect of the embodiments the pickface is a surface of the uncontained goods units forming the pickface. 
     In a second aspect of the aspect of the embodiments a storage and retrieval system is provided. The storage and retrieval system includes an in-feed conveyor, an in-feed station, a pickface builder disposed between the in-feed conveyor and in-feed station, and picking device connected to the in-feed station, the in-feed station being configured to transfer goods units to the picking device where each goods unit holds at least one product package therein. The pickface builder includes a frame, a pusher member movably coupled to the frame, and a snugger member movable coupled to the frame, wherein the pickface builder is configured to receive goods units from the in-feed conveyor and the pusher member and snugger member are movable at least in a direction transverse to a direction of goods unit travel on the in-feed conveyor and configured to form the goods units picked by the picking device as a unit into a pickface having a predetermined reference datum relating the pickface to a placement position of goods units forming the pickface along a storage surface of the storage and retrieval system. 
     In accordance with the second aspect of the embodiments, the pickface builder is located downstream of an elbow in the in-feed conveyor so that the pusher member and snugger member are substantially transverse to a direction of travel of the goods units from the in-feed station to the picking device. 
     In accordance with a first sub-aspect of the second aspect of the embodiments, the pickface builder further includes a controller configured to create motion profiles for the pusher member and snugger member based at least on predetermined goods unit data accessible by the controller. 
     In accordance with the first sub-aspect of the second aspect of the embodiments the controller includes a memory configured to store the predetermined goods unit data. 
     In accordance with the first sub-aspect of the second aspect of the embodiments the storage and retrieval system includes a system controller wherein the pickface builder is in direct or indirect communication with the system controller and the predetermined goods unit data is stored in a memory of the system controller. 
     In accordance with a third aspect of the embodiments, a pickface builder for a storage and retrieval system for storing goods unit and having an in-feed conveyor and a picking device is provided. Each goods unit holding at last one product package therein. The pickface builder includes a frame, a pusher member movably coupled to the frame, and a snugger member movably coupled to the frame, wherein the pickface builder is configured to receive goods units from the in-feed conveyor and the pusher member and snugger member are configured to form the goods units into a pickface picked by the picking device as a unit and having a predetermined reference datum where the predetermined reference datum depends on at least one predetermined pickface characteristic and relates the pickface to a placement position of goods units forming the pickface along a storage surface of the storage and retrieval system. 
     In accordance with a first sub-aspect of the third aspect of the embodiments the pickface builder further includes a controller configured to create motion profiles for the pusher member and snugger member based on the at least one predetermined pickface characteristic. 
     In accordance with the first sub-aspect of the third aspect of the embodiments the controller is in direct or indirect communication with a system controller of a storage and retrieval system and is configured to access the at least one predetermined pickface characteristic from a memory of the system controller. 
     It should be understood that the embodiments described herein may be used individually or in any suitable combination thereof. It should also be understood that the foregoing description is only illustrative of the embodiments. Various alternatives and modifications can be devised by those skilled in the art without departing from the embodiments. Accordingly, the embodiments are intended to embrace all such alternatives, modifications and variances within the scope of the appended claims.