Abstract:
An active logistical tag for cooperation with cargo elements, the tag comprising: a housing compatible for attachment of the cargo; a sensor suite for sensing logistical prompts, the prompts including at least one of motion, static magnetic fields and incident electromagnetic radiation; and a transmitter coupled to the sensor suite, for communicating logistical information in response to the logistical prompts.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of copending U.S. utility application entitled, “Active Logistical Tag for Cargo,” having Ser. No. 12/067,385, filed Jun. 23, 2009, which is a national stage entry of and claims priority to PCT International Application No. PCT/CA2006/001544 entitled “Active Logistical Tag for Cargo,” filed Sep. 20, 2006, which claims priority to U.S. provisional application, entitled “Active Logistical Tag for Cargo,” having Ser. No. 60/718,334, filed on Sep. 20, 2005, all of which are entirely incorporated herein by reference in their entireties. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates generally to a system that is used to collect logistical process information, permitting track and trace and statistical analyses, where Radio Frequency Transponders are used in conjunction with strategically or dynamically placed readers and antennas throughout a logistical process. In particular this invention relates to the ability to identify objects, but is not limited to the passage of objects through points of handover, specific location points or the location of objects with in a cellular space determined by the reception range of reading devices. 
       BACKGROUND OF THE INVENTION 
       [0003]    The present invention relates to the design of a system solution including an active tag used to track Unit Loading Devices (ULD&#39;s) and ULD pallets during the storage and cargo handling process in aviation applications. The tag is designed with unique physical and operational characteristics that when combined permit: long extended battery life, identification of pallets and ULD&#39;s at portals, track and trace of pallets and ULD&#39;s in motion on dollies when used to transport cargo to aircraft. When the defined features are used in combination, identification and tracking of the pallets and ULD is achieved during storage, processing, travel to and from and placement within aircraft without the need to transmit continuously. 
         [0004]    The objective of the stated invention is to permit automatic track and trace of Aluminum pallets and ULD&#39;s used to transport cargo in aircraft during processing and storage. Prerequisites to such an application demand a tag solution with unique and innovative features. These include: Mechanical protection of the tag without causing obstruction or altering the pallet profile and maintaining the structural integrity of the aluminum pallet; a mechanism for eliminating or control of transmission of the tag onboard the aircraft; identification of multiple pallets when stacked on one another; means of determining the direction of flow and open side of the ULD as they move down a conveyer system; identification of pallets as they pass specific points or points of handover; identification of pallets and ULD&#39;s when on the apron of the airfield being ready for loading or after being unloaded; and a 5 year operational life. 
         [0005]    There are systems in place to collect the time and position of an object automatically. This equipment is typically installed throughout industrial and commercial facilities and permits automated collection or measurement of time of arrival data. Such equipment composed of antennas and readers are positioned at portals covering points of entry or in a cellular fashion. 
         [0006]    Presently, corresponding tags are available in various formats including active tags with batteries, passive tags where the tags are powered by incident energy and semi-active tags where an integrated battery assists in the powering of the tag circuitry. Each of these solutions works well in specific environments. However the combined demands of cargo transport in the aviation environment, as enumerated above, requires a unique innovative solution. 
         [0007]    It is known in the prior art for tag reader systems to rely on the frequency independence of the incident signal to the response signal. This is referred to in the industry as a dual frequency solution or dual independent stimulus solution. There is no relationship in time or mathematically between the incident wake up signal and response signal. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention extends this concept to multiple independent means of wakeup to generate a response and manage power consumption. The wake up signal can be the result of a number of stimuli in addition to the Low Frequency disturbance field used as in the example presented in the patent. The wake up signal can be the result of multiple stimuli such as the detection of motion or the activation of a magnetic field sensitive reed switch. When these features are used in combination with innovative packaging techniques the resulting solution can be adjusted to meet the requirements of multiple applications. 
         [0009]    The addition of a motion sensor is used to generate a response. Unlike previous systems, where a Low Frequency stimulus will also generate a response, it is also used to manage power consumption through embedded software controls. The low frequency (LF) frequency circuitry can be disabled when no motion is detected, thus extending the battery life of the apparatus. The delays between beacons when in beacon mode can also be extended when the tag is not in motion. This again will minimize power consumption. 
         [0010]    The addition of a magnetic activated reed switch permits the simple activation of the apparatus—by placement of the tag close to a permanent magnet where by the tag will beacon its ID at randomized predefined intervals. With the application of the technology for tracking of aircraft pallets on shelves or on the dollies used to transport the pallets to an aircraft, permanent magnets can be mounted on the shelves or dollies causing the tags to beacon at predefined intervals. Where the pallets are made of aluminum and the tags are inserted in the aluminum channel, magnetic field penetration is still possible. 
         [0011]    This innovative yet simple solutions permits the tag to beacon when on a shelf or on dollies and avoids transmission on the aircraft. It is also possible to activate the magnetic reed switch even if the pallets are staked one on top of each other. 
         [0012]    Additional embedded software controls include the switching on and off of beacon features when exposed to Low Frequency fields with embedded address information. In order to extend battery life additional software controls can be switched on to extend the beacon interval over time or terminate after a period of time. 
         [0013]    The present invention is compatible with the concept of a dynamic reader or cell network where readers are mounted on trucks and link to a host via a wireless network and where the position of the truck is determined by a resident Global Position System receiver. A controller in the truck relays this information as well as any tag data collected by the reader to a host for presentation and analyses of the information. 
         [0014]    Other unique and innovative physical characteristics include the antenna design, which permits the tag to be imbedded in the C channel of the outer aluminum profile and yet be able to receive and radiate Electromagnetic energy used for communication also referred to Radio Frequency waves. 
         [0015]    According to one aspect of the invention, there is provided an active logistical tag for cooperation with cargo elements, said tag comprising: a housing compatible for attachment of said tag to said cargo; a sensor suite for sensing logistical prompts, said prompts including at least two of motion, static magnetic fields and incident electromagnetic radiation; and a transmitter coupled to said sensor suite, for communicating logistical information in response to said logistical prompts. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Embodiments will now be described more fully with reference to the accompanying drawings, in which 
           [0017]      FIG. 1  is various views of a Unit Loading Device (ULD) tag and its placement in an outer rail of a pallet. 
           [0018]      FIG. 2  is an orthogonal projection view of the ULD tag shown in  FIG. 1 , in isolation. 
           [0019]      FIG. 3  is a schematic diagram of a ULD tag. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0020]    In the following description, an embodiment of a Unit Loading Device (ULD) tag for automatic track and trace of Unit Loading Devices and pallets is provided. Turning now to  FIG. 1 , there is shown the form factor of the Unit Loading Device (ULD) tag  100  and corresponding C slot  110  according to the invention. 
         [0021]    The ULD tag  100  is designed to fit into the C slot  110  of the outer rail  120  of a pallet or ULD. Note that a conventional outer rail  120  is slightly modified to permit the insertion of the tag into the slot.  FIG. 1  shows the placement of the tag in the slot with the modifications described. The top part covering three position slots are removed or milled off to permit positioning of the ULD tag  100  in the C slot  110 . The integrity of the outer rail  120  is not compromised as the channel remains intact. A 1.0 mm slot is milled on the leading edge of the preferably aluminum C slot  110  to permit electro magnetic leakage. The ULD tag  100  dimensions are such that the tag fits into the channel and is protected by the walls of the channel. The tag is potted in an epoxy resin for additional protection. A film with insulator properties may be preferably applied to the top side of the rail in the area of the ULD tag  100  to prevent electrical connection in that area when ULDs or pallets are stacked one on top of the other.  FIG. 2  shows the ULD tag  100  in orthogonal projection. 
         [0022]      FIG. 3  is a schematic diagram of a ULD tag  100 . The battery  305  is preferably a 3.0 V, 200 mA Hr Lithium ion button cell. During transmission the voltage of the battery may be qualified under load. This is facilitated by a low voltage detection circuit  310  connected to a low voltage low power micro-controller  320 . 
         [0023]    The UHF antenna  330  is specifically designed to permit the maximum power radiated when the ULD tag  100  is placed in the C slot  110 . The antenna is composed of a wire mounted 3.2 mm off the printed circuit board. The UHF antenna  330  is deliberately placed perpendicular to the edge of the outer rail  120  when the ULD tag  100  is inserted in the C slot  110 . 
         [0024]    The UHF transmitter  340  is powered by the battery  305 , driven by the micro-controller  320  and outputs signal to the UHF antenna  330 . The UHF transmitter  340  can be constructed from discrete circuitry on integrated components. For the preferred embodiment the selected frequency of operation is 433.93 MHz where the selected modulation is FM and the deviation is 20 KHz. 
         [0025]    The micro-controller  320  is preferably a low power, 8 bit device with internal clock features that permit intermittent or predefined wake up for regular polled transmission as well as interrupt enable inputs for event driven transmissions. The micro-controller  320  takes input from the sensor section which preferably includes an LF antenna  350  amplified by an amplifier  355 , a motion switch  360  and a magnetic reed switch  370 . 
         [0026]    The LF antenna  350  and amplifier  355  are preferably designed to receive signals at 125 KHz as low as 2.0 mV. This amplifier section is designed to operate in standby mode in the absence of a signal with current consumption of less than 2 μA. The power to the amplifier  355  is preferably supplied under the control of the micro-controller  320 . The power to the amplifier is preferably shut off when in the presence of the field or alternately may be powered only when motion is detected. This feature permits management of power and minimizes the consumption of power. The amplified signal is fed to a detection signal shaping circuit (not shown separately, but incorporated with amplifier  355 ) that is connected to the input of the micro-controller  320 . Preferably that signal is connected to an interrupt driven port of the micro-controller  320 , which gets serviced based on a transition. The signal presented to the port is decoded. Preferably, upon successful detection of a signal indicative of LF reception, the micro-controller  320  will active the UHF transmitter  340  and generate the signals required to transmit a unique ID and the ID of the LF transmitter that turned it on. In this case, the activating LF signal requires an embedded corresponding ID. The number of messages may vary and may preferably be user programmed. Preferably, random intermittent delays of message packet lengths are inserted between transmissions to avoid message collision. 
         [0027]    The magnetic reed switch  370  is connected to another input of the micro-controller  320 . That input is preferably an event (interrupt) driven port where, when a transition occurs, the micro wakes up and responds as programmed. If the magnetic reed switch  370  corresponding feature is enabled, the closing of the magnetic reed switch  370  results in the generation of beacon UHF transmissions at predefined intervals. Preferably, the interval between the beacon transmissions is software controllable and may be defined by the user. 
         [0028]    The motion sensor switch  360  is connected to again another input of the micro-controller  320 . The motion sensor switch  360  may include some conditioning circuit (not shown) to minimize false triggering. The addition of the motion sensor permits better power management. As mentioned above, with reference to the LF Antenna  350  and amplifier  355 , as these components are powered by the micro-controller  320 , it is possible to only provide power only when motion is detected. If the ULD tag  100  is at rest the amplifier  355  can be switched off. If the ULD tag is left in the presence of a low frequency field power consumption may also be kept to a minimum as, again, the amplifier  355  can be shut off. When motion is detected the ULD tag  100  may be programmed to beacon. In the case where the ULD tag  100  is already in beacon mode due the activation of the magnetic reed switch  370  the interval between beacons may be altered, preferably decreased. If no motion is sensed the interval between beacons can be altered, preferably increased. By better management of the beacon interval transmission clash and power consumption can be minimized. 
         [0029]    Preferably, included with every transmission is a flag byte that defines the means of the transmission as to whether it is the result of motion, magnetic reed switch activation or LF field detection. In addition to the ID information and Flag byte the ULD tag  100  may preferably echo back the last exciter address seen with every transmission. 
         [0030]    Tag readers for the ULD tag  100  that are mounted on trucks may be controlled by software running on resident computer on the truck. Such readers and software may include the capacity to connect to wireless networks, and to employ a connected global positioning receiver that provides latitude and longitude coordinates as to the position of the vehicle. These features may provide a dynamic infrastructure for reading tags. 
         [0031]    Other software controllable features may preferably include the ability to enable or disable the beaconing feature by exposure to specific LF frequency fields with specific embedded addresses. 
         [0032]    The above-described embodiment illustrates a tag for use in logistical track and trace compatible with aviation requirements. Although particular embodiments have been described, those of skill in the art will appreciate that variations and modifications may be made without departing from the spirit and scope thereof as defined by the appended claims.