Abstract:
A dynamically-reconfigurable production line includes an item-interaction unit and an item-identification unit configured to read item data from an item approaching the item-interaction unit. On the basis of the item data, a processor accesses a memory to select particular configuration data stored therein provided by the item-identification unit. The processor then causes an actuator to reconfigure the production line consistent with the particular configuration data.

Description:
TECHNICAL FIELD 
   This invention relates to systems for managing the distribution of manufactured products, and in particular, to production lines. 
   BACKGROUND 
   In the course of its distribution, an item often finds itself moving along a production line. As it does so, it encounters item-interaction units. Examples of such item-interaction units include printers or RFID stations for encoding information on the item, or scales that weigh the item, or various mechanical actuators to move the item in particular ways. 
   A production line typically includes a conveyor belt that transports items past these item-interaction units. As the item approaches an item interaction unit, a sensor detects its arrival. The sensor signals the item-interaction unit, which then waits for a suitable interval to allow the item to reach an optimal interaction position. Once the item reaches that position, the item-interaction unit executes an interaction. 
   In many cases, a successful interaction with an item requires that the relative locations of the item-interaction unit and the item at the moment of interaction be correct. For example, if the item-interaction unit is a printer, and if a mark is to be printed on the top of a box, the print head should be at the top of the box at the moment of interaction. If the item-interaction unit is a weighing scale, the item should be centered on the scale&#39;s platform at the moment of interaction. 
   Since items can have many different sizes and shapes, the location of an item-interaction unit may have to change from time to time. For example, for tall items, a print-head may have to be moved up; whereas for short items, the print-head may have to be moved down. Without some means for reconfiguration, a production line will therefore accommodate only limited types of items. 
   In known production lines, such item-specific reconfiguration is a difficult procedure carried out manually at infrequent intervals. Because of the difficulty associated with reconfiguration, such production lines are typically dedicated to one type of item. As a result, production lines lack the flexibility to accommodate many different types of items on an as-needed basis. 
   SUMMARY 
   The invention provides a method and apparatus for re-configuring a production line dynamically, in response to changing requirements imposed by different items that may share a single production line. 
   In one aspect, the invention features a dynamically-reconfigurable production line having an item interaction unit; an item-identification unit configured to read item data from an item approaching the item-interaction unit; a memory for storing configuration data; an actuator for reconfiguring the production line; and a processor for accessing the memory to select particular configuration data on the basis of the item data and causing the actuator to configure the production line consistent with the particular configuration data. 
   In some embodiments, the memory includes a local memory, a central memory, or any combination thereof. 
   Other embodiments include those having a network interface. 
   Various types of actuators can be used. For example, in some embodiments the actuator is configured to cause a shift in a position of an item relative to a position of the item-interaction unit. 
   A variety of item-interaction units can be used. For example, embodiments of the invention include those in which the item-interaction unit includes a printer, as well as those in which the item-interaction unit includes an RFID programmer. 
   Similarly, a variety of item-identification units can be used. For example, embodiments, include those in which the item-identification unit is an optical reader, such as a bar-code scanner, or an item counter. 
   The location of the processor can also be varied. In some embodiments, the processor is local to the production line. In others, the processor is remote from the production line. Other embodiments also include those having a supervising processor for causing the configuration data to be stored in the memory. 
   In another aspect, the invention features a method for re-configuring a production line by identifying an item on the production line; retrieving configuration data associated with the item; and adaptively reconfiguring the production-line consistent with the configuration data. 
   Practices of the invention include those in which retrieving configuration data includes accessing a configuration file, those in which retrieving configuration data include accessing locally stored data, and those in which retrieving configuration data includes accessing data over a network. 
   In some practices of the invention, identifying the item includes reading a bar code associated with the item. However, in other practices, identifying the item includes reading RFID data associated with the item. 
   In another aspect, the invention features a computer-readable medium having encoded thereon software for causing dynamic reconfiguration of a production line. The software include instructions for identifying an approaching item; retrieving configuration data associated with the approaching item; and reconfiguring the production-line consistent with the data. 
   The term “production line” is intended to refer to devices that cause relative motion between items and item-interaction units. In some cases, items are conveyed past an item-interaction unit, in other cases, it is the item-interaction units that move and the items that remain stationary. 
   Production lines need not be restricted to lines used in production, but can also include lines used in connection with distribution and packaging of items. In addition, the term “line” is not intended to be restricted to mean linear. Production lines can traverse paths of various shapes, and may include structures such as carousels and the like. 
   Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
   Other features and advantages of the invention will be apparent from the following detailed description, and from the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a production line; and 
       FIG. 2  shows an item-interaction unit from the production line of  FIG. 1 . 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , a dynamically-reconfigurable production line  10  includes a conveyor belt  12  that conveys items  14  in a downstream direction past an item-interaction unit  16 . 
   A typical item-interaction unit  16 , as shown in  FIG. 2 , includes an item interface  22  that interacts with an item  14 , and a local processor  24  that controls the interaction. The local processor  24  is in communication with a local memory  26  for temporary storage of any interaction data, and with a network interface  28  for communication with a supervising processor  30 . 
   Item-interaction units  16  differ primarily in the nature of their respective item interfaces  22 . For example, if the item-interaction unit  16  is intended to mark the item  14 , then the item interface  22  may include a printer positioned close to a conveyor belt  12 . If the item-interaction unit  16  is intended to weigh the item  14 , the item-interaction unit  16  may be a scale. Or, the item-interaction unit  16  may be intended to move the item  14 , for example from one conveyor belt  12  to another, or to pick up an item  14  and put it into a box. In this case, the item-interaction unit  16  may include a robotic arm or other mechanical effector. The particular nature of the item-interaction unit  16  depends on details of the production line  10 . 
   An item-identification unit  32  generates, reads, or infers item-identifying data  34  from which the identity of the item  14  can be derived. As used herein, “identity” is not restricted to mean a particular item but can also refer to the type of item. Exemplary item-identification units  32  include bar code scanners, RFID (“Radio Frequency Identification”) readers, machine-vision systems, or simply item counters. The identification data can be a serializing code, such as the electronic product code (“EPC”), or a count indexed to a serializing code. 
   The item-identification unit  32  can include any kind of sensor that reads information from an item  14 . Examples include machine vision systems, bar code scanners, or RFID (“Radio Frequency Identification”) readers, all of which can be deployed as sensors for communication with the local processor  24 . The item-identification unit  32  can also be as simple as an array of electric-eyes that determines the dimensions of the approaching item  14  on the basis of how many electric-eyes are obscured and the spatial location of that item  14 , i.e. whether it is to be shifted left or right on the conveyor belt  12 , on the basis of which electric-eyes are obscured. 
   The local processor  24 , which is in communication with both the item-interface  22  and the item-identification unit  32 , receives the item-identifying data  34  from the item-identification unit  32 . The local processor  24  then determines whether the approaching item  14  is of the same type as an item  15  that has just interacted with the item-interaction unit  16 . 
   If the approaching item  14  is of the same type as that item  15 , the local processor  24  causes the item-interaction unit  16  to interact with the approaching item  14 . 
   If not, the local processor  24  retrieves, from the local memory  26 , a configuration file  36  that includes configuration data associated with a variety of items. The local processor  24  then obtains, from the configuration file  36 , configuration data corresponding to the approaching item  14 . On the basis of the configuration data, the local processor  24  causes one or more actuators  38  to reconfigure the production line  10 , for example by changing the relative position of the item-interaction unit  16  and the conveyor belt  12 , so as to place the approaching item  14  in proper spatial relation with the item-interaction unit  16 . Alternatively, the local processor  24  can reconfigure the production line  10  by adjusting the characteristics of the item-interaction unit  16 . 
   Actuators  38  suitable for use with the production line  10  include those that move the item interface  22  relative to the conveyor belt  12  and those that move the conveyor belt  12  relative to the item interface  22 . Other actuators  38  can adjust the position of the item  14  as it approaches the item interface  22 . Examples of such actuators  38  include bars or rods that push or pull the item into a desired position. The actuator  38  may also be a speed governor that controls the rate at which the conveyor belt  12  conveys items  14  past the item interface  22 . 
   Typical item-interaction units  16  include printers, such as ink jet printers or thermal printers. The term “printer” is intended to encompass all devices that mark items  14 . In many cases, the item interface  22  is a print-head. For example, a printer can be one that embosses an item  14 , or one that encodes data onto an RFID tag associated with the item  14 . 
   The local processor  24  uses item-identifying data  34  from the item-identification unit  32  to retrieve, from the configuration file  36 , configuration data corresponding to the approaching item  14 . That configuration data is then used to dynamically reconfigure some aspect of the production line  10  to facilitate interaction between the approaching item  14  and the item-interaction unit  16 . 
   The term “item” includes more than individual product units as sold at the retail level. The “item” being marked might be a box containing several retail units, or a palette containing several such boxes. The term “item” can thus refer to a consumer unit, a distribution unit, or a palette unit. 
   The supervising processor  30  can periodically download the configuration file  36  to the local memory  26  through the network interface  28 . Alternatively, the local processor  24  can obtain configuration data from a configuration file  36  stored in a central memory  40 , thereby eliminating the need to maintain a local copy of the configuration file  36 . 
   The dynamically reconfigurable production line  10  as described herein can thus accommodate items  14  of various types on an as-needed basis. In such a production line  10 , items  14  need not be placed at precise locations on the production line  10  for the item-interaction to take place correctly. Instead, the production line  10  dynamically reconfigures itself, either by shifting the item  14  appropriately, or by changing some other aspect of the production line  10  to accommodate the item  14 . In addition, such a production line  10  can easily be switched to accommodate different types of items  14  even without having to be shut down for reconfiguration. To do so, the production line  10  identifies what type of item  14  is approaching, determines the optimal configuration associated with that item  14 , and reconfigures itself accordingly.