Abstract:
A method and apparatus is provided for strategically arranging ID tag antennas in a container to accommodate various sizes of tagged assets and to assure a reading of all assets in the container when the tagged assets have different packing densities. An antenna bus in each container, that is connected to a container ID tag reader, allows bus connector insertable antennas to be strategically placed for accommodating various asset packing densities. The containers are designed to readily interconnect the data outputs of all the tag readers when the containers are stacked in any of three dimensions whereby a single master unit collects data from all the readers and transmits the data to a central data collection point.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to a method of securing, monitoring the location of and/or controlling the environment of a plurality of ID tagged assets in one or more stackable or otherwise contiguous containers while the assets are being transported between locations. 
   DESCRIPTION OF THE RELATED ART 
   There are numerous prior art examples of monitoring the location of containers having specific assets. Further there are some instances of monitoring the environment both internal to and external of a container of assets while being transported between a source and a destination. 
   It is also known to employ some type of memory in conjunction with a container that incorporates a list of all the assets within the container initially. Typically some human intervention is required to update this list when assets are to be removed from or added to the container before the container arrives at its&#39; final destination. This is often true even when each of the assets is RFID tagged and there is a RFID tag reader arranged near the portal of the container. In theory the tag reader is able to update memory as RFID tagged assets are removed from or added to the container, but that does not always occur. 
   When a container has only a few ID tagged assets, it is sometimes possible to read all the ID tags in a container using conventional techniques. However, there is no known prior art that can accurately scan a large number of tagged assets packed together in a container. 
   It would thus be desirable to have a method or technique of arranging or modifying tag readers and antenna structures whereby many ID tags of tagged assets in a container may be accurately read at any time whereby an up-to-date inventory of assets may be maintained. It would further be desirable to be able to economically interconnect a plurality of containers whereby a single master device can collect data read from the plurality of containers as well as other sensed data and transmit the collected data to a central data bank. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of one or more embodiments of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
       FIG. 1  exemplifies, in perspective format, major components utilized in constructing a stackable multi-antenna container in accordance with one embodiment of the invention; 
       FIG. 2  exemplifies a top view of the container of  FIG. 1 ; 
       FIG. 3  exemplifies a rudimentary view of the manner in which the top and bottom of a container of  FIG. 1  may be constructed to pass signals from container to container; 
       FIG. 4  exemplifies a side view of a plurality of stacked containers utilizing a second embodiment of the invention using wired inter container communication; 
       FIG. 5  exemplifies a perspective view of a plurality of containers stacked in three dimensions; 
       FIG. 6  exemplifies a generalized electrical configuration for collecting and distributing ID tag data, sensed data and container access data; 
       FIG. 7  exemplifies how an antenna bus may be used to readily adjust antenna spacing to accommodate large and/or small assets in a given container while maintaining ID tag reading accuracy; 
       FIG. 8  comprises a circuit diagram that exemplifies an approach to reading tags that increases accuracy and aids in defining the exact location of a given tagged asset in a container; and 
       FIG. 9  exemplifies a second approach to reading tags that is a preferred embodiment and is faster than that shown in  FIG. 8  but features the other qualities of the multiplex features of  FIG. 8 . 
   

   DETAILED DESCRIPTION 
     FIG. 1  is a perspective view of a container, generally designated as  100  and having a front portion  102 , a first end portion  104 , a back portion  106  a second end portion  108 , a lid or cover  110  and a bottom portion  112 . In  FIG. 1 , a portion of front portion  102  is cut-away to more clearly show details of the interior of container  100 . Within container  100  there is shown a single antenna, antenna fixture or antenna structure  114  inserted into a connector  116  comprising a portion of an antenna bus utilizing a conductive medium. As shown, this bus comprises two sets of conductive paths  118  and  120  to which other connectors  122 ,  124  and  126  are attached as shown more clearly in  FIG. 2 . These sets of conductive paths allow each antenna to be isolated from other antennas while connected to a container tag reader. Also shown in both figures are antenna or antenna structure guides  128 ,  130 ,  132  and  134  to provide greater lateral stability of the antenna when the container  100  is quickly moved. While the guides  128 ,  130 ,  132  and  134  are shown to extend from the interior surface of the container, they may be recessed into the walls or eliminated altogether when other support is available or alternatively is not needed in view of the design an insertable antenna structure. It may be noted that a stability feature similar to the guide  128  may likewise or alternatively be comprise a portion of the lid  110 . 
   Normally, the added stability, provided by antenna guides, is highly desirable if there are a large number of heavy objects, whether or not ID tagged, located between antenna  114  and the end  108  when the container is moved suddenly or repositioned so that end  108  becomes an upper surface. This becomes especially desirable when additionally there are no objects on one side of an antenna such as  114  and many heavy objects on the other side. 
   A wandering line  136  is shown on one surface of antenna  114  as being representative of the conductive path used to transmit or receive RF signals. It is to be understood that the antenna conductive element may be on the surface of a supportive backing, protected from abrasion by being intermediate two insulating supportive layers or in some instances may be self supporting. Thus the line  136  is merely intended to illustrate that an antenna inserted into a connector such as  116  is readily able to detect signals from tags located at any height within container  100 . 
   A tag reader  138  is illustrated as being embedded on a lower portion  138  of end  104  of container  100 . The tag reader may vary in complexity depending upon application. Thus in some instances, where the container will not be stacked or otherwise combined with other similar containers, the tag reader  138  may include GPS circuitry, satellite or other wireless communication capability to a central or handheld database, a CPU, electronic memory, access authorization circuitry for verifying that an entity attempting access is authorized to do so and so forth. However, in a first preferred embodiment, the reader will merely read tagged assets in the container and provide that information to a master unit that is in communication with at least one other similar container. The sets of conductive paths  118  and  120  previously mentioned allow each antenna to be isolated from other antennas while selectively connected to tag reader  138 . An electrically or electronically controlled lock  140  is shown incorporated into the lid  110 . A mating portion of the lock  140  is shown on end portion  104  as  140 ′. Although no lock details are shown, the lock  140  merely needs to lock or unlock only after an authorization signal is received from some entity such as the tag reader  138  or from a device external to the container  100 . A portal  142  on end  104  is used to represent an authorization port. This may preferably constitute a USB (Universal Serial Bus) port for connection to a computer, a card reader, a finger print scanner and so forth. The portal  142  may actually comprise a unit such as a card reader or similar authorization device. 
   The container  100  is designed to electrically connect to a data or reader bus of other containers. This interconnection may be provided by wires, cables or other mating connectors having male and female portions and extending from an outer surface of the container. In such a configuration, these cables or connectors will need to be interconnected as the containers are stacked one upon another or adjacent one another. To reduce the amount of attention required to interconnect the containers, the container  100  is shown as having two electrical contacts  144  and  146  extending through the lid  110  to an upper surface of the lid  110 . When a second (not shown) container is stacked on the lid  110  of container  100 , contacts on the underside of the second container will make contact with the contacts  144  and  146 . A container internal cable  148  will then electrically connect a data or reader bus of the second container to the reader  138  by hidden wires not specifically shown in  FIGS. 1 and 2 . At some point, a master unit or controller, such as later shown  FIGS. 4 ,  5  and  6 , is connected to this data or reader bus. The mating contacts, also connected to the data or reader bus, used on the base or bottom of a container is more clearly shown in  FIG. 2  as contacts  150  and  152 . 
     FIG. 3  is illustrative of the upper surface of the lid  110  or container  100  and shows contacts  144  and  146 . While the design of these contacts is not explicitly shown, they may be merely contact surfaces or may be male and female as mentioned supra with respect to external cables. Also while shown as two separate contacts for clarity, a single interconnection area may also be used to provide any number of electrical signal transfer contacts. 
   An embodiment of this invention using cable to provide the reader or data bus interconnect between containers may be of a form shown in  FIG. 4 . As shown three containers  402 ,  404  and  406  are stacked one on top of the other. At the bottom of each container there is a recessed male connector portion. An unused one of such recessed male connector portion is designated as  408  on container  406 . A cable  410  extends from an upper portion of container  406 . Cable  410  has a female connector portion on the end (not specifically shown) which is connected to a mating connector, like connector  408 , on a lower portion of container  404 . In similar manner, a cable  412  electrically connects container  404  to container  402 . As no further containers are shown stacked upon container  402 , a further cable  414  is shown connected to a “master” unit  415  from an upper portion of container  402 . The master unit retrieves data from each of the tag readers and any authorization portals connected to the reader bus of cable  414 . A tag reader  416  is shown for reading ID tags within container  402 . Similarly, tag readers  418  and  420  are attached to containers  404  and  406  respectively. Container locking mechanisms  422 ,  424  and  426 , each similar in operation to lock  140  of  FIG. 1 , are shown attached respectively to containers  402 ,  404  and  406 . Authorization portals  428 ,  430  and  432 , operating in the same manner as portal  142  of  FIG. 1 , are shown between the lock and reader portions of containers  402 ,  404  and  406  respectively. The cables, such as cable  410 , may be flat. Thus similar additional connecting cable and connector assemblies may be used on the remaining surfaces of the containers of  FIG. 3  to stack adjacent containers in three dimensions in a manner similar to that shown in  FIG. 5 . 
   In  FIG. 5  there is shown an assembly of twelve containers generally designated as  510 . These containers are stacked three high, two wide and two deep. A container comprising an upper left front portion of the container assembly is further designated as  512 . Each of the containers in the assembly has identical electrical signal contacts for interconnecting a reader or data bus to a master unit  514  shown in position on top of container  512  and in electrical contact with the reader or data bus of container  512  as well as the rest of the container assembly  512 . Although the upper reader bus contacts of container  512  are not specifically shown they would occur in a manner identical to those shown as  516  on other container surfaces in  FIG. 5 . In a manner similar to that of  FIG. 4 , each of the containers in the container assembly  510  has an antenna bus connected ID tag reader  518 , an authorization portal  520  and an electronically operated lock mechanism  522 . 
   In  FIG. 6 , a master unit  600  is shown in more detail. While the components combined and/or assembled to provide the functions required of a master unit vary according to specific application, it will typically include a CPU (central processing unit)  602 , random access and/or hard disk memory  604 , GPS (ground position sensing) circuitry  606 , wireless transceiver apparatus  608  and environmental or other sensing means  610 . Also shown in the drawing are a plurality of solid line blocks representing containers designated as  612 ,  614  and  616 . A further plurality of dash line blocks  618 ,  620  and  622  each represent one or more further containers stacked upon the respective containers  612 ,  614  and  616 . Each of the blocks has a slave ID tag reader connected to a data or reader bus  626 . The slave reader in container  612  is designated as S 1 . The slave reader in container  614  is designated as S 2 . An Nth slave reader in container block  616  is designated as Sn. Each of the container blocks includes a portion designated as  624 . The portion  624  includes a locking function as well as an authentication or authorization function and thus is further labeled as “L&amp;A”. A sensing element  628  is additionally shown in container block  612 . Although the only container block shown with a sensor is block  612 , it should be apparent that any or all of the containers may include one or more sensing elements in accordance with any individual requirement of specific assets being secured or otherwise held within a given container. As shown, any data output by the one or more sensing elements is provided to the slave tag reader of that container for transmission to a master unit on the reader or data bus  626 . As illustrated in  FIG. 6 , the master unit  600  receives data from each of the slave units via the data bus  626  and a data bus reader portion of the master  600 . 
   As illustrated in  FIGS. 1 and 2 , an antenna bus, such as represented by conductor elements  118  and  120  along with the connectors  116 ,  122 ,  124  and  126  allow any combination of from one to four antennas in the container  100  in accordance with the size and number of tagged objects to be read. Where appropriate, the conductive elements may be connected to any number of further antennas including antennas embedded in or on the walls, bottom and top of the container although not specifically shown as such in  FIG. 1 . 
   This adaptability to tagged object size is illustrated in  FIG. 7  where a container  700  is shown with an antenna  702  near the left end of container  700  and a second antenna  704  near the middle of the container  700 . With this arrangement of the antennas, large packages such as ID tagged assets  706  and  708  may be positioned over unused antenna bus connectors (not shown). With only two tagged assets between antenna  704  and the right end of container  700 , it is very likely that both tags will be read by a tag reader when it is connected to antenna  704 . While there are a large number ID tagged assets shown on the left side of antenna  704 , the ones not read by antenna  704  and between antenna  702  and  704  are very likely to be read by antenna  702 . If it appears, while packing the container, that some of the ID tagged assets located between antenna  702  and the left side of the container, are not being read by antenna  702 , another antenna may need to be inserted adjacent the left hand wall of container  700  in instances where additional antennas are not part of the walls of the container. However, since antennas comprising a portion of the walls of the container  700  are shown as  710 ,  712 ,  714  and  716  and since these antennas are also connected, or are connectable via a switch or DEMUX (multiplexer/demultiplexer), to the ID tag reader, no further plug-in antennas need be added to read all the tagged assets to the left of antenna  702 . It should further be noted, that a single large tagged asset in the container may be monitored without any plug-in antennas having to be utilized in view of wall, bottom and lid antennas that may desirably be incorporated into the construction of the container. 
   In  FIG. 8 , a tag reader, such as the type of tag reader  138  of  FIG. 1 , is designated as  800 . In the right hand portion of this figure a plurality of antennas are shown using the same designations as used in  FIG. 7 . Also in this portion of the figure, antenna buses and plug-in connectors are given the same designations as in  FIG. 1 . Between reader  800  and the antenna bus there is a DEMUX (multiplexer/demultiplexer)  802 . Although not shown in the circuit diagram, each of the antenna connections, or alternatively the antennas themselves, is provided with a unique identification such that the DEMUX  802  may sequentially detect and apply power to each antenna. 
   While  FIG. 8  exemplifies an embodiment having a single set of antenna bus connectors and unique IDs for each antenna or it&#39;s connection to the bus, a separate set of electrical conductors may also be used for each embedded antenna and each plug-in connector to eliminate the need for unique IDs. Such an approach, which is actually the preferred embodiment since reading and switching may be accomplished much faster, is shown with minimal components in  FIG. 9 . A tag ID reader  902  is connected to a master unit data or reader bus. The reader  902  supplies signals to a DEMUX  904  to initiate a read operation as previously described. The DEMUX has separate sets of conductors going to each of any antenna plug-in connectors such as  906  and  908 . Additionally, there are separate sets of conductors going to each of the embedded antennas such as those illustrated by indicators  910  and  912 . Upon request, the DEMUX  904  sequentially, or in some other predetermined order, connects each embedded antenna or plug-in connector to the reader  902 . When the tag reader is connected to an unused plug-in connector, the reader merely indicates that no tags were read at that position in the container and proceeds to the next antenna or connector. While the preferred embodiment uses more wires, it reduces the time to read data from a given antenna, supplies a more predictable and/or controllable power level to a given antenna and eliminates having to uniquely identify each antenna or antenna connection point to an antenna bus. 
   As is known, when a given power is supplied to an antenna bus, the power available for each antenna is reduced as additional antennas are connected to the bus. Thus, while a more simplistic approach shown in  FIGS. 1  and  6  will operate satisfactorily in many applications, the application of power to a single antenna at a time will assure adequate power to each antenna and increase the likelihood of detecting all tagged assets in a container. An embodiment using the DEMUX  802  of  FIG. 8  (or the DEMUX of  FIG. 9 ) may also be used to indicate that a given tagged asset, as an example, is located between antenna  702  and the left side of the container. This determination will be reinforced when, or if, it is determined that the given asset tag was not detected by antennas  704  and  714 . 
   From the above it will be apparent that the use of an antenna bus comprising a multitude of connectors, may be used to readily adapt a given size container to be able to accurately maintain an inventory of either large loosely packed or small closely packed ID tagged assets by altering the number and spacing of plug in antennas whereby each antenna is able to retrieve signals from all nearby tagged assets. 
   An RFID reader that can wirelessly maintain contact with a central computer and provide that central computer with global reader location coordinates and sensed environmental data as well as up to date container inventory data is much more costly than a reader that only collects and outputs tag data to a local data sink. Thus, it is very cost effective when a single device can be used to collect data from a large number of containers and transmit all of the collected data as well as location and other sensed data to a central computer in a single transmission burst. 
   The stacking of containers in up to three dimensions as shown in  FIGS. 4 and 5  is thus illustrative of how data obtained from tag ID readers associated with a plurality of containers may be readily communicated over a data bus to a single master unit for collection before transmission. 
   A single master unit collecting data from a plurality of containers and transmitting the collected data is one preferred embodiment of the invention. However there are certainly instances where the location, access authorization and environmental conditions of a single container using the antenna bus structure of the present invention needs to be monitored. Thus a second preferred embodiment of the invention comprises modifying the reader of a single container, such as shown in  FIG. 1 , to include the transceiver, GPS and sensor portions of the master unit  600  of  FIG. 6 . 
   As is known in the industry, the shipment of many assets require temperature control of the shipping container. The control may be heating, cooling or a combination of heating and cooling in accordance with the environment external the shipping container. Such control is especially critical when pharmaceuticals are being shipped. Thus the smart containers shown in  FIGS. 1 and 6  may be adapted from existing temperature controlled containers to additionally include the plug-in and/or permanent antenna structures, ID tag readers, multiplexers and so forth of the present invention. Such containers would incorporate at least temperature monitoring sensors. Some pharmaceuticals are sensitive to one or more of light, shock, vibration and humidity. Thus the circuitry in the tag reader and the master unit needs to be able to monitor many environmental conditions internal to and external to a given container and report the environmental data along with container location and tag asset data to a central database whereby any remedial action necessary to maintain the security as well as the quality of any assets in the container. In a preferred embodiment, the circuitry of the tag reader is operable to control the temperature and/or other internal environmental conditions of the container and well as monitor same. 
   Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.