Patent Application
20060208893
This disclosure relates generally but not exclusively to data readers such as optical code readers or RFID (radio frequency identification) readers, and more particularly, to object tracking using data readers.
An RFID system typically employs at least two components: a “transponder” or “tag,” which is attached to the physical item to be identified, and an “interrogator” or “reader,” which sends an electromagnetic signal to the transponder and then detects a response. A typical tag stores useful information such as an identification code for the item to which it is attached. A typical reader emits an RF (radio frequency) signal that is received by the tag after the tag comes within an appropriate range. In response to the signal from the reader, the tag sends back to the reader a modulated RF signal containing the tag's information. The reader detects this modulated signal and can identify the tag by demodulating and decoding the received signal. After identifying the tag, the reader can either store the decoded information or transmit the decoded signal to a computer.
The tag used in an RFID system may be either “passive” or “active.” A passive tag can be a simple resonant circuit, including an inductive coil and a capacitor. Passive tags are generally powered by the carrier signal transmitted from the reader. Active tags, on the other hand, generally include transistors or other active circuitry, and require their own battery source. Moreover, a tag's memory may be writable, and an RFID reader may transmit data to an RFID tag to overwrite the tag's memory.
According to one embodiment, a method reads data encoded on a pallet loaded with bulk articles and determines, based on the data, an expected weight of the pallet and bulk articles. The method weighs the pallet and bulk articles, thereby generating a measured weight, and compares the expected weight and the measured weight. The method conditionally issues a signal if the expected weight and the measured weight differ by at least a threshold amount.
According to another embodiment, a method moves a data reader within a reading range of a container loaded with articles, reads data encoded on the container by use of the data reader, and determines, based on the data, an expected weight of the container and articles. The method moves a scale underneath the container, weighs, by use of the scale, the container and bulk articles, thereby generating a measured weight, and compares the expected weight and the measured weight. The method conditionally issues a signal if the expected weight and the measured weight differ by at least a threshold amount.
According to another embodiment, a mobile device comprises a data reader, a scale, an indicator, and a processor. The data reader is capable of reading data encoded on an item within a reading zone, thereby generating read data, wherein the mobile device is positionable such that the item is within the reading zone. The scale generates measured weight data of an item placed on the scale, wherein the mobile device is positionable such that the item is on the scale. The processor, which is connected to the data reader, the scale, and the indicator, is configured to access the read data and the measured weight data, to determine based on the read data an expected weight of the item, to compare the expected weight and the measured weight data, and to conditionally activate the indicator if the expected weight and the measured weight data differ by at least a threshold amount.
According to yet another embodiment, a device comprises a data reader, a scale, an indicator, and a processor. The data reader is capable of reading within a reading zone data encoded on a pallet loaded with bulk articles, thereby generating read data. The scale generates measured weight data of the pallet and any items loaded on the pallet when the pallet is placed on the scale. The processor, which is connected to the data reader, the scale, and the indicator, is configured to access the read data and the measured weight data, to determine based on the read data an expected weight of the pallet and its loaded items, to compare the expected weight and the measured weight data, and to conditionally activate the indicator if the expected weight and the measured weight data differ by at least a threshold amount.
Details concerning the construction and operation of particular embodiments are set forth in the following sections with reference to the below-listed drawings.
With reference to the above-listed drawings, this section describes particular embodiments and their detailed construction and operation. The embodiments described herein are set forth by way of illustration only. Those skilled in the art will recognize in light of the teachings herein that variations can be made to the embodiments described herein and that other embodiments are possible. No attempt is made to exhaustively catalog all possible embodiments and all possible variations of the described embodiments.
For the sake of clarity and conciseness, certain details of components or steps of certain embodiments are presented without undue detail where such detail would be apparent to those skilled in the art in light of the teachings herein and/or where such detail would obfuscate an understanding of more pertinent aspects of the embodiments.
As one skilled in the art will appreciate in view of the teachings herein, certain embodiments may be capable of achieving certain advantages, including by way of example and not limitation one or more of the following: (1) better tracking of items; (2) earlier detection of error conditions in item handling; (3) labor saving by, for example, facilitating weighing, data reading, and audit operations during normal item handling and transport operations; and (4) deterrence of theft and encouragement of more careful item handling. These and other advantages of various embodiments will be apparent upon reading the following.
Between the moveable element 120 and the forks 130 is a scale 140, which can weigh a pallet, container, or other load on the forks 130. For example, the scale 140 may be a forklift truck scale manufactured by Avery Weigh-Tronix, LLC, Fairmont, Minn., such as its model QTLTSC scale.
The forklift 100 is also equipped with a data reader 150, which is preferably an RFID reader but may be a data reader of any type, such as an optical code reader (e.g., bar code). The data reader 150 is preferably positioned on the front of the forklift 100 facing forward to enable it to read data from a pallet, container, load, or other item on the forks 130. For reading pallets, the data reader 150 is preferably positioned low, such as below the movable element 120 and/or the scale 140.
The data reader 150 is electrically connected to a computer or other data processor (not shown) on the forklift 100 or a remote computer. Alternatively, the computer may be integrated within the data reader 150. The computer may display data on an electronic display 320 and/or may communicate the data wirelessly to another computer, such as a central computer in a warehouse, store, or other setting in which the forklift 100 operates.
The pallet 200 also has placed on it a tag 240, such as a code or identification tag, which is preferably placed on or near a side or sides of the pallet 200 that is faced by the forklift 100 during a lifting operation.
The data reader 150 in this embodiment is an RFID reader comprising an antenna 160, a transceiver 170, a decoder 180, and a controller 190. The antenna 160 may be any suitable antenna that can transmit and receive electromagnetic signals within a reading volume. Typical RFID systems operate in the following frequency bands: 125-134 kHz (kiloHertz or thousands of cycles per second), 13.56 MHz (megaHertz or millions of cycles per second), UHF (ultra high frequency) (400-930 MHz), 2.45 GHz (gigaHertz or billions or cycles per second), and 5.8 GHz. The antenna 160 is typically chosen for a desired performance in one or more of those bands. The transceiver 170 generates an activation/interrogation signal and receives response(s) from one or more RFID tags. The transceiver 170 typically includes a modulator, filter(s), and amplifiers for transmission, as well as an amplifier, demodulator and filter(s) for reception. The transceiver 170 also typically includes a frequency synthesizer or RF oscillator shared by both the transmission and reception circuitry. This data reader 150 also comprises a decoder 180, which decodes a demodulated signal supplied from the transceiver 170 to determine the data transmitted by the RFID tag(s). Alternatively, the function of the decoder 180 may be incorporated within the processor 310 rather than as part of the data reader 150. This data reader 150 also comprises a controller 190 that controls the operation of the transceiver 170 and the decoder 180. The controller 190 also provides an interface to the processor 310 from the data reader 150 for setup, status, command, control, and the like. The data reader 150 or just the antenna 160 may be mobile, removable, handheld, tethered by an electrical cable, etc.
The processor 310 may be any form of processor and is preferably a digital processor, such as a general-purpose microprocessor or a digital signal processor (DSP), for example. The processor 310 may be readily programmable; hard-wired, such as an application specific integrated circuit (ASIC); or programmable under special circumstances, such as a programmable logic array (PLA) or field programmable gate array (FPGA), for example. Program memory for the processor 310 may be integrated within the processor 310, permanently connected separately from the processor 310, or externally removable. The processor 310 executes one or more programs to control the operation of the other components, to transfer data between the other components, to associate data from the various components together (preferably in a suitable data structure), to perform calculations using the data, to otherwise manipulate the data, and to present results and significant conditions to the user or to other equipment. For example, the processor 310 preferably determines an expected weight for an item or set of items based on the data read from one or more RFID tags associated with the item or set of items, compares that expected weight to the weight as measured by the scale 140, and issues a signal (e.g., raises an alarm) or takes other actions based on that comparison, as described in greater detail below with reference to the flowchart shown in
Connected to the processor 310 are a display 320, a speaker 330, a network interface 340, a user input device 350, and a memory 360. The display 320 may display such information as measured weight; data, such as identification data, read from the RFID tag(s), alarm conditions, such as when the measured weight does not match the expected weight for the item; pickup and drop-off instructions, and any variety of status information. The speaker 330 may be activated to audibly alert the user or other persons of an alarm condition or for other purposes.
The network interface 340 may be a plug-in port or a wireless communications point. In one preferred embodiment, the network interface is a wireless network interface operating in accordance with a standard wireless network protocol such as the Institute of Electrical and Electronics Engineers (IEEE) 802 standards (e.g., IEEE 802.11 standard for wireless local area networks (WLAN)). In one embodiment, the processor 310 accesses expected weight data stored on another computer, such as a central computer, for comparison with the weight measured by the scale 140, via the network interface 340. The processor 310 may also send measured weight data, data read by the data reader 150, and/or alarm conditions to another computer via the network interface 340.
The user input device 350 may be any device used by a user to input data or commands to the processor 310. Examples of the user input device 350 include keypads, keyboards, pointing devices (e.g., mouse, joystick, trackball), buttons, and a touch screen. The memory 360 may store programs executed by the processor 410, expected weight data for a set of items, and/or other data. The memory 360 may be permanent or removable.
As an alternative to what is illustrated in
As yet another alternative, the system 300 may comprise multiple different types of data readers, such as a combined RFID reader and bar code reader. Such a multiple-technology reader is described, for example, in U.S. Pat. No. 6,415,978, entitled “Multiple Technology Data Reader for Bar Code Labels and RFID Tags,” which is incorporated herein by reference. One example of a multiple-technology reader for use in a weight-audit system is illustrated in
A change of weight might indicate theft, mislocation of one or more items, or other mishandling. By facilitating more convenient, more frequent, earlier, and more precise detection of those problems, the systems and methods described herein can enable a business to better respond to those problems, thereby lessening their impact on the business.
To begin, the method 600 moves (step 610) the data reader 150 within a reading range (or volume) of the pallet 200. This moving step 610 may occur when the data reader 250 on the forklift 100 or other mobile platform in maneuvered within proximity of the pallet 200. Alternatively, the moving step 610 may occur when the pallet 200 is transported and placed within the reading range of a stationary data reader 150. Thus, the moving step may entail moving one or both of the data reader 150 and/or the pallet 200 such that the pallet 200 is within a reading range of the data reader 150. Once within range, the method reads (step 620) the encoded data on the pallet 200 or its loaded items. The data may be encoded in the RFID tags 240, in optical codes, or by other means. The data may be encoded on the pallet, container, or other carrier, or it may alternatively or additionally be on each item loaded on the pallet or the like. After reading the data, the method 600 determines (step 630) an expected weight for the pallet. The determining step 630 may be performed in various ways. For example, the data read in step 620 may comprise the expected weight. As another example, utilizing identification data read in step 620, the determining step 630 can look up a corresponding expected weight in either a local database or a database on a remote computer. In either case, an advantage of pallet-based encoding is that one read provides the data for the entire pallet. If the data is encoded at a finer level (e.g., item level), then the data reader 150 or the processor 310 may need to sum the multiple weights for each item to get a total weight for the collection.
The method 600 also moves (step 640) the scale 140 underneath the pallet 200. As with the moving step 610, the moving step 640 does not necessarily imply motion of the scale 140 with respect to a stationary pallet 200. For example, by using a stationary scale and by moving the pallet 200 onto the scale, the moving step 640 may also be accomplished. After the moving step 640, however accomplished, the method 600 weighs (step 650) the pallet and compares (step 660) the expected weight to the measured weight. The method 600 can then issue (step 670) one or more signals as necessary, such as if the measured weight and the expected weight deviate by more than a predetermined threshold. Such a threshold hold may be based on the precision of the scale 140 or business considerations (e.g., how much of a deviation constitutes a financially significant difference given the cost of responding to the alarm and the value of the item). Different items may have different thresholds, and threshold data may be stored in a database with other item data. The signal may be raised locally (e.g., at the forklift 100), remotely, or at both locations. The signal may be a message on a display screen, a light that turns on, a light that blinks, a sound, or any sort of alarm.
The steps of the method 600 may be performed in an order different from what is illustrated, or steps may be performed simultaneously. For example, simultaneously weighing and data reading may provide an efficient sequence. Performing those steps just before, after, or during movement or other necessary handling of the items may also efficiencies. The method 600 may perform other steps not illustrated, such as writing the newly measured weight on the RFID tag 240, storing the measured weight and other tracking data, etc.
The algorithms for operating the methods and systems illustrated and described herein can exist in a variety of forms both active and inactive. For example, they can exist as one or more software or firmware programs comprised of program instructions in source code, object code, executable code or other formats. Any of the above can be embodied on a computer-readable medium, which include storage devices and signals, in compressed or uncompressed form. Exemplary computer-readable storage devices include conventional computer system RAM (random access memory), ROM (read only memory), EPROM (erasable, programmable ROM), EEPROM (electrically erasable, programmable ROM), flash memory and magnetic or optical disks or tapes. Exemplary computer-readable signals, whether modulated using a carrier or not, are signals that a computer system hosting or running a computer program can be configured to access, including signals downloaded through the Internet or other networks. Concrete examples of the foregoing include distribution of software on a CD ROM or via Internet download. In a sense, the Internet itself, as an abstract entity, is a computer-readable medium. The same is true of computer networks in general.
The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Similarly, the embodiments described herein are set forth by way of illustration only and are not the only means of practicing the invention. Those skilled in the art will recognize that many variations can be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the invention should therefore be determined only by the following claims (and their equivalents) in which all terms are to be understood in their broadest reasonable sense unless otherwise indicated.
This application claims priority to U.S. Patent Application No. 60/714,543, entitled “RFID Weight Audit,” filed on Feb. 28, 2005, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60714543 | Feb 2005 | US |
