Abstract:
A system to capture data regarding conditions in a sealed metal shipping container having: a sensor unit mountable inside the container and adapted to sense a condition inside of the container; an impulse radio transmitter receiving data from the sensor regarding the condition and transmitting an impulse radio wireless signal inside of the container; an impulse radio receiver external to the container and proximate the container, wherein the receiver is adapted to receive the impulse radio wireless signal propagating through the sealed metal shipping container, and a data device in communication with the receiver to capture the data from the sensor unit regarding the condition inside of the container.

Description:
RELATED APPLICATION  
       [0001]    This application is related to and claims priority to a provisional application serial No. 60/459,257 (attny. docket no. 3915-5) entitled “METHOD FOR ENABLING COMMUNICATION AND CONDITION MONITORING FROM INSIDE OF A SEALED SHIPPING CONTAINER USING IMPULSE RADIO WIRELESS TECHNIQUES”, filed Apr. 2, 2003, and identifying Russell N. Tice as the inventor. The entirety of this provisional application is hereby incorporated by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates in general to sensors and remote monitoring system. The invention relates, in particular, to a network, sensor and method that uses impulse radio technology to monitor and display information about cargo in a sealed steel freight container.  
         BACKGROUND OF THE INVENTION  
         [0003]    There is a need to provide wireless communications from inside a sealed steel freight container to an external receiver and an information processing device. ISO steel freight containers are commonly used to ship cargo via ships, trains and trucks. The typical dimensions of these containers are 20 feet long; 8 feet long, and 8 feet, six inches tall. These containers may be loaded with cargo and sealed shut in a foreign country. Several million cargo containers—about 95 percent of U.S. international trade—enter the United States every year through its 361 sea and river ports. Since Sep. 11, 2001, there has been a pronounced concern that terrorists might use the containers to sneak biological weapons or other arms into the country. This method allows government, port or shipping company officials to monitor a container&#39;s location—and determine whether it has been tampered with.  
           [0004]    The shipment of sealed ISO containers raises security risks and concerns about the safety and integrity of the cargo during shipment. The large number of ISO containers that are shipped worldwide cannot all be readily opened and inspected at each port, rail yard and trucking depot. It is virtually impossible for security personnel to inspect the contents of all ISO containers in transit to ensure that the containers are not being used to smuggle dangerous or illegal products, and have not been opened and tampered with during transportation. A cleaver thief, smuggler or terrorist may gain access to an ISO shipping container in transit and open the container to steal goods from the container, or insert into the container illegal products, e.g., drugs, or a bomb. By closing and resealing the container, the thief, smuggler or terrorist may avoid detection and the tainted container may continue its journey to its intended final destination. Even if the container is not intentionally opened during shipment, the inside of the container may subjected to environmental conditions, e.g., heat and humidity, that can damage the cargo in the container. In view of these dangers and the difficulty with inspecting ISO containers in transit, there is an urgent requirement for techniques and systems to inspect ISO shipping containers that are automated and do not require the container to be opened.  
           [0005]    Obtaining data about the cargo inside of a sealed ISO shipping container is problematic. The container is formed of steel which effectively blocks wireless electromagnetic signals. Wireless signals may be further blocked by contents and adjacent containers, especially while the containers are stacked on top of each other. The doors of the container have seals that block water and wind, but also block optical signals from emanating from the container. Accordingly, passing a signal trough the container without breaching the wall of the container is difficult.  
           [0006]    Prior attempts to track ISO containers have generally involved placing labels or transmitters on the outside of the containers. These external labels and transmitters may be dislodged in transit, may become damaged by weather or collisions with other containers, and do not interrogate the cargo inside of the container.  
           [0007]    To transmit an external signal from inside a sealed ISO container, a transmitter inside of the container has been directly connected to antenna that protrudes through the wall of the container. See, e.g., U.S. Pat. No. 6,492,904 at col. 15 and FIG. 11. Projecting an antenna through the container wall breaches the container and may not be acceptable for ISO compliant shipping containers. Accordingly, there is a long felt need for an non-obtrusive technique and system that monitors and collects data regarding the interior of ISO shipping containers and their cargo, and automatically conveys that data to an external data collection receiver without breaching the sealed container.  
         BRIEF DESCRIPTION OF THE INVENTION  
         [0008]    In one embodiment, the present invention provides a means for wirelessly communicating from inside a sealed steel freight container to an information processing device outside of the container via impulse radio wireless communications. The system overcomes the difficulty in transmitting through a sealed metal container by using a short range wireless transmission from inside of the container that propagates through seals, air vents and other gaps in the metal of the container. This method provides for automation of monitoring the cargo in a metal container and provides enhanced security measures, container condition monitoring and cargo tracking.  
           [0009]    In a first embodiment, the invention is a system to capture data regarding conditions in a sealed metal shipping container comprising: a sensor unit mountable inside the container and adapted to sense a condition inside of the container; an impulse radio transmitter receiving data from the sensor regarding the condition and transmitting an impulse radio wireless signal inside of the container; an impulse radio receiver external to the container and proximate the container, wherein said receiver is adapted to receive the impulse radio wireless signal propagating through the sealed metal shipping container, and a data device in communication with the receiver to capture the data from the sensor unit regarding the condition inside of the container.  
           [0010]    In another embodiment, the invention is a method to capture data regarding at least one condition in a sealed metal shipping container comprising: mounting an wireless transmitter inside of the container; mounting a sensor inside of the container to monitor the at least one condition and establishing a communication link between the transmitter and the sensor wherein the transmitter receives data from the sensor regarding the condition; sealing shut the container; transmitting an wireless signal carrying the data regarding the condition from the transmitter wherein the signal emanate from inside of sealed container, passes through walls of the container and propagates outside of the container; receiving the transmitted wireless signal by a receiver located externally of the container and proximate the container; and capturing the data from the wireless signal in a data device in communication with the receiver to store capture the data from the sensor unit regarding the at least one condition. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of an exemplary ISO shipping container, shown in a partially cut away view, having a transmitter communicating with an external receiver and database.  
         [0012]    [0012]FIG. 2 is a top view of an ISO container and signal beam patterns from internal transmitters.  
         [0013]    [0013]FIG. 3 is a perspective view of a shipping container with a cut-away view to show the cargo and transmitter inside of the container. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]    [0014]FIG. 1 is an illustration of a sealed metal shipping container  10  having an internal ultra wide-band (UWB) transmitting tag  12 , e.g., a C-Band tag, and an external receiver  14 , e.g., the C-Band receiver, that receives a wireless signal  16  transmitted by the UWB tag  12  from inside the container  10 . The transmitter  12  may be an ultra wideband (UWB) pulse radio transmitter in data communication with sensor(s)  18  (see FIG. 3) inside a sealed container  10 . These sensors monitor the container cargo and the internal environment of the container. The transmitter tag  12  collects data from the internal sensors  18  and transmit the data through the sealed container to the receiver  14 . These sensors may be transmitting tags that identify cargo  21  to which they are attached. The transmitter tag may include a antenna having a standard corner reflector  19  that broadcasts a signal within the container  10 .  
         [0015]    A UWB receiver  14  outside of the container  10  pickups the signal  16  from the inside UWB transmitter  12 . The receiver  14  is proximate the container. For example, the receiver may be positioned in front of the container and within 20 feet of the container doors  20 . Similarly, the transmitter  12  may be located on an inside wall of the container near the front doors  20  of the container. Positioning the receiver proximate the container, especially near the seals  28  on the container doors  20 , allows the receiver to pickup the weak signal that leaks through the container from the internal transmitter tag.  
         [0016]    The receiver  14  may be portable and hand carried about container. Carrying the receiver in the proximity of the container may increase the likelihood that the signal from the interior of the container will be captured at some point as the receiver traverses the beam pattern of the transmitter. A portable receiver  14  may also be used to capture data from many different containers in, for example, a shipping yard.  
         [0017]    The signal  16  is emitted by the internal transmitting tag  12  from inside of the sealed container  10 . The transmitted signal  16  leaks through the non-conductive seals  28  on the front doors  20  of the container  10 , air vents in the container, and other gaps in the metal container. The signal  16  is attenuated as in passes through the walls of the container. The metal walls of the container block much of the signal transmitted from the internal transmitter. The external receiver  14  must sense the attenuated signal  16  that leaks through the metal container  10 . Further, the receiver must capture data that is carried by the signal  16 .  
         [0018]    The external receiver  14  may connect to a data device having a database  26  or the receiver may connect to a network controller  22  that provides a remote link to the data device  16 . The data device may store the received data in the database  26 . The data device  24  may be a hand held electronic device, personal digital assistant (PDA) or a notebook computer. The data device collects the data received from the tag transmitter  12  regarding the internal conditions of the sealed container and its cargo. The network controller  22  alternatively may transmit the received data via the Internet to a specific Internet IP address for a remote data device  24  so that the database  26  may be accessed via the Internet.  
         [0019]    The container walls effectively prevent the transmission of data from outside of the container into the transmitting tag  12  in the container. Data and commands from outside of the container are not wirelessly transmitted into the container. The transmitting tag does not receive information or commands from outside of the container, such as when to transmit a signal or whether the container is in transit or at a dock or loading yard. Accordingly, the internal transmitting tag operates without information or commands from outside of the container.  
         [0020]    The tag  12  is programmed to periodically transmit data regarding the interior of the container and cargo data. The tag may transmit a signal continuously or every second, for example. Moreover, the tag may be programmed to transmit periodically, only if certain events occur. The events may be rapid change of the temperature or humidity in the container, which would indicate the door to the container being opened. The UWB transmitter tag  12  is powered by a battery in the container. The battery is selected to have sufficient capacity to power the tag  12  for some predetermined period of time, e.g., five years.  
         [0021]    [0021]FIG. 2 is an illustration of an analysis of transmitted signal beam patterns emitted from an internal UWB transmitter tag  12  through a sealed container. The transmission pattern extends outward of the container from the front doors  30  of the container  10 . The outside of the container transmission pattern  30  for a L-Band UWB transmitter may extend one-hundred and eight six feet beyond the container  10 . The transmission pattern  32  for a C-Band UWB transmitter may extend only twenty feet from the container.  
         [0022]    An exemplary L-Band UWB transmitter tag has a peak power transmission value of approximately 250 milliwatts. An exemplary C-Band UWB transmitter has a peak of −25 milliwatts (where 10 times power corresponds to 10dB). The L-Band UWB transmitter tag has an antenna gain of approximately 8 dBi (decibels isotopic), whereas the C-Band UWB transmitter has a gain of −0 dBi. This difference in gain is due to the directional nature of the beam pattern from the L-Band transmitter and the omni-directional beam pattern from the C-Band transmitter. Both L and C-Band receivers have similar antenna gains (8 dBi) when used with a standard corner reflector  19 .  
         [0023]    An L-band transmitter tag transmitted, during an experiment, through a sealed container and gave consistent reception and data acquisition 20 feet from the containers and up to 186 feet in front of a container  10 . A C-band transmitter tag transmitted through a container and its signal  16  was received no data packet loss at 45 feet from the corner air vents in a 20 degree emission and up to 20 feet in front of the container. However, these air vents maybe be blocked when containers are stacked together. The air vents are not a reliable point of signal opportunity. While the L-Band transmitter tag has a longer transmission range, it consumes substantially more battery power than does the C-Band transmitter tag. In applications where extended battery life is a stronger concern than transmission range, the C-Band transmitter tag may be preferable to the L-Band transmitter tag. In addition, receivers that sense timing sequences in the signals transmitted by the tag transmitter have demonstrated better performance than do receivers that detect the shape of the signal transmitted by the tag receiver. It is suspected that the shape of the signal generated by the transmitter tag becomes distorted as the signal leaks through the container and, thus, receivers that rely on detecting signal shape have difficulty in recognizing the distorted signal from tags in metal containers. On the other hand, it is suspected that the timing sequences in a transmitted signal do not become distorted as the signal passes through a container. Thus, receivers that detect signal timing sequences appear to be better suited for receiving signals passing through a metal container.  
         [0024]    Given the typical stacking configuration of the shipping containers on a container ship, shipping port and at shipping depots, it is anticipated that the strongest transmitter tag beam  16  emanating from the containers will be at the front doors  20  of each container. Accordingly, the receivers  14  may be best positioned in front of the containers to receive the signals  16  from the internal transmitter tags  12 .  
         [0025]    [0025]FIG. 3 is a partially cutaway view of conventional ISO metal shipping container  10 , e.g., cargo container. The shipping container is generally sealed at a departure location and unsealed at its destination. An internal transmitter tag  12  positioned near the doors  20  monitors the contents  21  of a container between its departure and destination locations. The transmitting tag  12  may detect, for example, whether the sealed container has been opened in transit. The monitoring of the contents of the cargo container is accomplished without breaching the seal of the container. The transmitting tag  12  may receive wireless signals from transmitting data cargo tags  18  on the cargo contents in the container. The cargo tags may include information about the cargo to which the tag is attached.  
         [0026]    Further, the transmitting tag  12  may be connected to receive data from internal humidity, temperature and light sensors  34 . The transmitted data from the internal transmitter  12  may include information such as the environmental condition (current and historical) in the container, e.g., temperature, humidity and light levels, and the cargo contents in the container. The data may be loaded into a data file of the database  26  of information regarding the container and its cargo.  
         [0027]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.