Patent Application
20130154809
The present disclosure relates generally to remotely identifying and locating objects, and more particularly relates to remotely identifying and locating objects using radio frequency identification (RFID) signaling.
In modern supply management systems, there is often a need to determine the presence and location of a specific object, as for example, an item stored in a retail store or a warehouse. For example, a warehouse attendant may need to determine whether a particular item is present and where it is located. When there are many items that are similar in appearance, or an item has been moved or misplaced, this can be a daunting and very time consuming task.
RFID tags are often attached to an item to provide a unique identifier (e.g., an ID number) via a radio frequency (RF) signal. When the RFID tag is interrogated by an RFID reader, the RFID tag responds with at least its tag identifier. Typically, the tag identifier is associated with the item to which the tag is attached in some system controller or computer system. If the tag identifier of the desired item is among those RFID tag(s) interrogated by the RFID reader, then the user will know that the item is present, but may still not know its exact location, and thus, have to locate the item within the monitored area.
Accordingly, there is a need for a method and apparatus for locating an item within an RFID monitored area.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
Techniques are provided for locating an item within an RFID monitored area. When attempting to locate an item using an RFID reader, the RFID reader initiates the transmission of an interrogation signal for at least one RFID tag. A responsive signal from the interrogated RFID tag is processed using data from one or more orientation sensors configured within the RFID reader to determine a direction from the RFID reader toward the RFID tag. The direction toward the RFID tag is displayed and the process repeats while movement of the RFID reader is detected to assist the user in locating the RFID tag, and thus, the item.
Generally, the present disclosure describes a system and method for locating objects using RFID technology. As is known, an RFID reader has the ability to select one or more RFID tags by transmitting an identifier that specifies one or more of the tags from a plurality of tags. When an RFID reader selects an RFID tag, the RFID tag is put into a responsive mode and the tag transmits data back to the reader which is received at the RFID reader antenna.
Since an RFID reader can be used to select one or more RFID tags and retrieve data from the selected tags, an RFID reader can be used to identify and track large numbers of objects. In fact, RFID systems offer an advantage in object location due to the transmission range, lack of a line of sight requirement between a tag and its reader and high tag reading throughput.
Operationally, a user may hold the RFID reader 200 via the handle 208 thereby orienting the RFID reader 200 in an outward direction from the user. The user typically operates the RFID reader 200 through a combination of inputs and outputs with the input devices 204 and the display screen 208. According to embodiments of the present disclosure, the RFID reader 200 is configured to interrogate remote RFID tags wirelessly through the use of the various antenna designs configured within the housing 210. The particular antenna employed in any particular implementation may be realized by any number of antenna types (e.g., loop, dipole, monopole, patch or helix). Also, the antenna may have a particular polarization (e.g., vertical, horizontal or circular) in some embodiments. Additionally, the RFID reader 200 may include one or more triggers (not shown) for selecting or activating various operational modes or features of the RFID reader 200.
The RFID tag 202 may take on a variety of configurations, shapes and sizes. For example, different tags for different applications typically have a shape and size appropriate for its application. RFID tags are commonly categorized as active, passive or semi-passive. Active RFID tags include an internal battery used to power the tag and transmit data and typically include the ability to read and write greater amounts of stored data than either passive or semi-passive tags. Passive RFID tags transmit by reflecting and absorbing energy from the RF transmissions from the reader, and use absorbed energy from the reader for data storage, retrieval and manipulation. Semi-passive tags include an internal battery that is used for data storage, retrieval and manipulation, and transmit data by reflecting and absorbing energy from the reader. Any of these RFID tag types are suitable for use as the RFID tag 202 in the disclosed exemplary embodiments.
Responsive signals received from the RFID tag 202 are processed by processor 304, which in some embodiments may be realized as a digital signal processor (DSP). The processor 304 is coupled to a bus 306 (or other communication network) to be operably coupled to a memory 308, input device 204 (see
Referring still to
The responsive signals received from the RFID tag 202 are analyzed by the processor 304 to determine various receive quality indicators and compare those received quality indicators to those of prior receptions to determine (or estimate) a direction from the RFID reader 200 to the RFID tag 202. The receive quality indicators include, but are not limited to, RFID tag read rate, RFID tag read count, bit error rate and received signal strength. Thus, for example, as a user approaches the RFID tag 202, the receive quality indicators should improve between successive communication between the RFID reader 200 and the RFID tag 202. Should a user move further away from the RFID tag 202 (either in error or out of necessity due to an obstacle), the receive quality indicators should decline, allowing the processor to indicate to the user a corrective course to locate the RFID tag 202, and thus, the item 106.
In some embodiments, the processor 304 directs a user toward an item 106 via the display 206. This may be accomplished via written directions (e.g., “continue ahead”, “bear left”, “turn right”) or a graphical display as will be discussed in more detail below. Alternately (or additionally), some embodiments may incorporate an audible annunciator 314 (e.g., a “beep” sound with increasing period as the user approaches the RFID tag 202), machine-generated spoken audio and/or a visual annunciator 316 (e.g., a light flashing with increasing frequency as the user approaches the RFID tag 202).
Referring now to
As the user moves along the path 108 toward location (waypoint) 112, the RFID reader continues to communicate with the RFID tag 202 and the processor compares the receive quality indicators to those of previously received responsive signals to determine (or estimate) whether the user is moving toward, away or parallel to the RFID tag (and thus the item 106). The user is provided an indication of a direction between the RFID reader 200 (where the user is now) toward the RFID tag 202 via one or more of the annunciators 312. In one embodiment, this indication of direction is provided as illustrated in
As the user reaches location (waypoint) 112, the displayed direction may be as shown by arrow 402 since the user has moved somewhat closer to the item 106 (and its RFID tag). By location waypoint 114, the displayed direction indicator may be as shown by arrow 404 (still decreasing in size as the item is approached), however, the user is impeded from following the direction indicated by the arrow 404 due to the shelving 102 (see
However, if the determination of decision 704 is that motion has ceased, the last indicated direction continues to be displayed (step 720) and the routine jumps to decision 716 to determine whether the user has ended the search. A negative determination of decision 716 could indicate that the user has paused momentarily along the search path (108 in
In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings.
The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
Moreover in this document, relational terms, such as, first and second, top and bottom, and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” “has”, “having,” “includes”, “including,” “contains”, “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a”, “has . . . a”, “includes . . . a”, “contains . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially”, “essentially”, “approximately”, “about” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
It will be appreciated that some embodiments may be comprised of one or more generic or specialized processors (or “processing devices”) such as microprocessors, digital signal processors, customized processors and field programmable gate arrays (FPGAs) and unique stored program instructions (including both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method and/or apparatus described herein. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used.
Moreover, an embodiment can be implemented as a computer-readable storage medium having computer readable code stored thereon for programming a computer (e.g., comprising a processor) to perform a method as described and claimed herein. Examples of such computer-readable storage mediums include, but are not limited to, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a Read Only Memory (ROM), a Programmable Read Only Memory (PROM), an Erasable Programmable Read Only Memory (EPROM), an Electrically Erasable Programmable Read Only Memory (EEPROM) and a Flash memory. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.
