Abstract:
A wireless monitoring system and method. A distributed electrical circuit can be printed on a dielectric film for wrapping pallets or containers in a logistic chain, wherein the distributed electrical circuit (e.g., a Wheatstone Bridge) detects a rupture of the film through an electrical resistance change of one or more elements of the distributed electrical circuit. The electrical resistance change is indicative of a potential tampering event. An electronic module can be provided that conditions and processes a signal transmitted from the distributed electrical circuit and thereafter transmits the signal wirelessly via an antenna to a monitoring station. Additionally, a monitoring station can be implemented, which communicates with a network and the electronic module, and permits a user in real time to receive data concerning the potential tampering event.

Description:
TECHNICAL FIELD 
       [0001]    Embodiments are generally related to tampering event detection methods and systems. Embodiments are also related to large area distributed sensors. 
       BACKGROUND 
       [0002]    Damage of goods in transportation is a major problem in the field of logistics. When a shipment is received in a damaged condition, there are usually no possibilities to track when the damage occurred, which turns the question of liability into an open question. 
         [0003]    Further, intrusion and tamper events, such as illegal opening and/or modification of the content of the shipment are major concerns when handling valuable or sensitive goods. Theft, where valuable items are removed and stolen from the shipment is one aspect and another is illegal modification of a shipment&#39;s content. If a receiver claims that a shipment was not received in an expected condition, the sender cannot resolve if the receiver fraudulently claims that a theft or damage is due to an event in the logistics chain. 
         [0004]    Rising concerns about possible hazardous contents of alien shipments, where contents may include explosives, poison, biological agents etc. poses a major threat for organizations and employees at time of arrival. 
         [0005]    Traditional means of ensuring the integrity and authenticity of a shipment include different types of sealing, where a tamper event can be visually detected at time of arrival. Holograms, lacquer sealing, security printing and other traditional methods of ensuring an item&#39;s authenticity is generally not strong enough to withstand today&#39;s sophisticated methods of counterfeiting and fraud. 
         [0006]    Automation of logistics typically includes machine readable labels, such as bar codes, data matrix codes, RFID-tags etc., where information concerning the shipment can be read and processed by a host computer system. Current solutions generally provide little or no means of active authentication of the label itself. Any attempt to illegally copy, modify or move the label should be detected as an integrity violation. 
         [0007]    It is believed that given the problems with current solutions, the ability to wirelessly monitor the integrity of wrapped pallets or containers in a logistics chain is highly desirable. Unfortunately, traditional solutions are not wireless in nature, and typically rely on off-line recording of a package violation event utilizing sensors and electronic modules composed of microprocessors and semiconductor memories. It is only at the destination of the package where the tampering event is detectable, based on a communication protocol between a receiver computer and an electronic module integrated in the package sent by an expeditor. Most often, this rather late identification of a package rupture, after the package has arrived at its destination, makes it difficult to determine retroactively the source of the tampering. 
         [0008]    Additionally, large area monitoring is difficult to achieve with present technical solutions based on printed electrical resistance and its change monitoring as a function package tearing, where the maximum sensing resistance appears to be less than 500 kohm. It is our solution that will allow large area of monitoring and real time warning of both the sender and the receiver about the tampering event of the package of interest for both of them. 
         [0009]    In summary, it would be desirable to be able to verify the integrity and authenticity of the shipment at any time during transportation and in real time before arrival to the receiver in an automated, highly secure and dependable manner. 
       BRIEF SUMMARY 
       [0010]    The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments and is not intended to be a full description. A full appreciation of the various aspects of the embodiments disclosed can be gained by taking the entire specification, claims, drawings, and abstract as a whole. 
         [0011]    It is, therefore, one aspect of the present invention to provide for improved system and method for monitoring a tampering event. 
         [0012]    It is yet another aspect of the present invention to provide for a large area distributed sensor. 
         [0013]    The aforementioned aspects of the invention and other objectives and advantages can now be achieved as described herein. A wireless monitoring system and method is disclosed. A large area distributed electrical circuit can be printed on a dielectric film for wrapping pallets or containers in a logistic chain, wherein the distributed electrical circuit detects a rupture of the film through an electrical resistance change of one or more elements of the distributed electrical circuit. The electrical resistance change is indicative of a potential tampering event. An electronic module can be provided that conditions and processes a signal transmitted from the distributed electrical circuit and thereafter transmits the signal wirelessly via an antenna to a monitoring station. Additionally, a monitoring station can be implemented, which communicates with a network and the electronic module, and permits a user in real time to receive data concerning the potential tampering event associated the pallets or containers based on the electrical resistance change of the element(s) of the large area distributed electrically circuit, thereby permitting wireless monitoring of the integrity of the film and the pallets or containers in the logistic chain. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the principles of the disclosed embodiments. 
           [0015]      FIGS. 1(   a ),  1 ( b ), and  1 ( c ) illustrate schematic diagrams of respective large area conductive traces printed on a dielectric substrate in accordance with or more varying embodiments; 
           [0016]      FIG. 2  illustrates a schematic diagram of a large area distributed sensing system, which can be implemented in accordance with a preferred embodiment; 
           [0017]      FIG. 3  illustrates a schematic diagram of an array of sensing systems composed of a plurality of sensors, each of which communicates wirelessly with a single unit for system monitoring and transmission, whose signal is then sent wirelessly to a central monitoring station, in accordance with a preferred embodiment; and 
           [0018]      FIG. 4  illustrates a schematic diagram of an ultra large array of sensing systems composed of a plurality of arrays of sensing systems, in accordance with a preferred embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope of the invention. 
         [0020]      FIGS. 1(   a ),  1 ( b ), and  1 ( c ) illustrate schematic diagrams of respective sensing dielectric substrate systems  100 ,  120 , and  130 , which can be implemented in accordance with varying embodiments. System  100  generally includes a dielectric film  102  upon which a printed electrically conductive trace  104  can be configured. Note that in  FIGS. 1(   a ),  1 ( b ), and  1 ( c ), identical or similar parts or elements are indicated generally by identical reference numerals. In  FIG. 1(   a ), a dielectric layer  105  can be deposited between two conductive traces for electrical isolation between two conducting traces  104 . System  120  depicted in  FIG. 1(   b ) includes the same dielectric substrate  102  depicted in  FIG. 1(   a ), but with a different large area printed electrically conductive trace  124  pattern. System  130  depicted in  FIG. 1(   c ) includes the dielectric substrate  102  and a different printed electrically conductive trace  134 . 
         [0021]      FIG. 2  illustrates a schematic diagram of a mechanical integrity wireless sensing system  200 , which can be implemented in accordance with a preferred embodiment. Again, note that in  FIGS. 1(   a ),  1 ( b ),  1 ( c ) and  FIGS. 2-3  and  4 , identical or similar parts or elements are generally indicated by identical reference numerals. The configuration of sensing systems  200  is based on the configuration depicted in  FIG. 1(   c ). The sensing system  200  generally includes the large area distributed conductive trace  134 , which forms a distributed integrity sensing electrical circuit  209  that is electrically connected by the pads  216  to an electronic module  203 , which includes a transceiver  208  connected to a signal conditioning circuit  206 . Both the transceiver  208  and the signal condition circuit  206  are connected to a power module  214  that functions as a combined power supply and power management unit. The transceiver  208  can be connected to an antenna  210 ,  212  that can wirelessly transmit data. The power module  214 , the signal conditioning circuit  206 , and the transceiver  208  are attached to a Printed Circuit Board (PCB)  204  and together form the electronic module  203 . 
         [0022]      FIG. 3  illustrates a schematic diagram of an array  300  composed of a plurality of sensing systems  200 ,  220 ,  224 , a unit  302  for system monitoring and transmission, and a central monitoring station  304 , in accordance with a preferred embodiment. Note that the sensing systems  220  and  224  are analogous to sensing system  200 , and include the same basic type of components as sensing system  200 . For example, sensing system  200  includes electronic modules  203 , while systems  220  and  224  respectively contain electronic modules  207  and  225 , which are each identical to electronic module  203 . Thus, systems  220  and  224  are identical to system  200 . Systems  200 ,  220  and  224  can each respectively wirelessly communicate with the unit  302 , which in turn is connected to the central monitoring station  304 . 
         [0023]      FIG. 4  illustrates a schematic diagram of an ultra large array  400  composed of a plurality of sensors, such as sensing system  200 , in accordance with a preferred embodiment. The configuration depicted in  FIG. 4  serves to illustrate how a variety of similar components or sensing system  200  can be utilized to form a distributed monitoring system, and each such sensing system comprising a large area distributed sensing circuit. 
         [0024]    In general, for monitoring the integrity of the dielectric film  102  wrapped about a pallet or container, the printed large area distributed electrical circuit  209  and the electronic module (not shown in  FIGS. 1(   a ),  1 ( b ) and  1 ( c ))  203  can be utilized. Such a distributed circuit  209  can be utilized to detect a rupture of the dielectric film  102  through an electrical resistance change of one or more elements of the circuit  209 . The electronic module  203  can condition and process one or more signals output from the distributed circuit  209  and then transmit the processed and conditioned signal wirelessly through the antenna  212 ,  210  to a monitoring station. This monitoring station can be connected to a networked service (e.g., computer network), such as the Internet, for real time warnings at both the sender and receiver portions of a logistic chain. The electronic module  203  and the antenna  210 ,  212  can be attached to or on the dielectric film  102  in a manner that ensures a good electrical connection with the printed electrical circuit (e.g., electrically conductive traces  104 ,  124  and/or  134 )  209 . 
         [0025]    Such a configuration can be realized utilizing a “flip-chip” approach and a low temperature curing electrically conductive epoxy paste. Alternatively, the antenna can be directly printed on the dielectric film  102 . The electrical circuit  209  generally comprises printed electrical conductive traces such as, for example, conductive traces  104 ,  124  and/or  134 . Such printed electrically conductive traces  104 ,  124  and/or  134  can be printed on dielectric film  102 . The film  102  can be used as a pallet wrapping either before or after the wrapping process. For this purpose, an electrically conductive ink can be printed by screen-printing, flexography, ink-jet or other printing technologies. In case the printed electrically conductive traces are realized after wrapping, ink-jet printing technology is preferably used. When the conductive traces  104 , 124  and/or  134  are printed before the wrapping process, large area printing technologies such as screen printing or flexography are preferably utilized. 
         [0026]    Various conductive inks such as, for example, metallic nanoparticle based inks, inherently conductive polymers and/or metal-filled polymer based inks, can be adapted for use in printing the electrically conductive traces  104 ,  124  and/or  134 . Such printed electrically conductive traces  104 ,  124  and/or  134  can be implemented in accordance varying configurations, some examples of which are shown in  FIGS. 1(   a ),  1 ( b ), and  1 ( c ). In the configuration depicted in  FIG. 1(   a ), the electrically conductive trace  104  can be disposed in two layers separated by an isolator. The two layers can be also printed on one of the different foils from which the wrapping film  102  is composed. Such layers can be printed on each side of the same dielectric foil. In this manner, an electrically conductive network can be obtained, which realizes the monitoring of dielectric film integrity with a high accuracy. 
         [0027]    In the case of printing a conductive ink on both sides of a dielectric material, vias-type electrical contacts can be utilized to configure an electrical connection between an upper side and a lower side (not shown in  FIG. 1(   a )). The configurations depicted in  FIGS. 1(   a ),  1 ( b ), and  1 ( c ) generally include a single layer of electrically conductive traces, which have the advantage of an easier and less expensive implementation. While not as accurate for detecting ruptures as the configuration of  FIG. 1(   a ), the configurations of  FIGS. 1(   b ) and  1 ( c ) nevertheless detect with high probability a tentative theft or an involuntary rupture of the wrapping dielectric film  102 , taking into account the fact that such a rupture tends to propagate far away from its initial point on the surface of the film  102 . 
         [0028]    In any of configurations of distributed conductive traces  100 ,  120 , and/or  130 , the pattern dimensions of respective electrically conductive traces  104 ,  124  and/or  134  can be selected as a function of the desired spatial resolution for monitoring the area of the dielectric film  102 . For example, if the desired spatial resolution is x (the size in any direction of any rupture in the film which should be detected), in the configurations from  FIGS. 1(   a ) and  1 ( b ), the pattern dimension “d” is selected to be x/sqrt(2). In the case of system  130  of  FIG. 1(   c ), the pattern dimension “d” can be selected as equal to x/3. 
         [0029]    As a function of the desired film area to be monitored, any of the above configurations can be easily spatially extended by increasing the number of patterns (indicated by “n” in  FIG. 1(   b )) in the configuration. Additionally any of these electrically conductive traces can be an element of a printed electrically circuit as schematically illustrated, for example, in  FIG. 2  with respect to the configuration of system  130  of  FIG. 1(   c ). The conductive traces can be arranged in the circuit in such a manner so that a trace configuration forms one arm of a Wheatstone bridge circuit. In this manner, a very large printed distributed Wheatstone bridge circuit can be obtained. For maximum sensitivity of the Wheatstone bridge to any change in any of the resistance due to tampering, equal values can be implemented for the four distributed resistances forming the circuit bridge. 
         [0030]    During a tampering event, a rupture may appear in the dielectric film  102 , which also indicates the interruption of a conductive trace, thereby changing the electrical resistance of one arm of Wheatstone bridge circuit. The electronic module  203  that conditions and processes the signal from the distributed Wheatstone bridge circuit can detect the event and wireless transmit data concerning the event through the antenna  210 ,  212  to the real time monitoring station  304 , which is connected to networked services (e.g., the “Internet”). The novelty of using a large area distributed Wheatstone bridge as a self-monitoring circuit for a  2 D structural integrity sensor eliminates the use of a single resistor with a resistor value below 500 kohm, as described in the prior art. 
         [0031]    There are several advantages to using a large area distributed Wheatstone bridge. For example, as the differential voltage signal offered by the Wheatstone bridge is measured, one can increase the resistance range of the value of a constituent distributed resistor to large values of approximately hundreds of mega ohms. The only limitation is that the output impedance of the Wheatstone bridge may be ten fold times lower than the input impedance of an instrumentation amplifier (IA) used for the signal conditioning from Wheatstone bridge. This input impedance of IA in prior art devices is even higher than 1 Gohm. 
         [0032]    Additionally, using four large area distributed resistances of equal value and configured from the same material and technology results in the aging process influencing in the same manner all the resistances and the differential operation of the Wheatstone bridge. This makes the aging essentially “invisible” to the IA. Thus, a robust solution is disclosed for tampering detection, which is insensitive to aging/drift phenomena in the conductive traces. 
         [0033]    Using four large area distributed resistances of equal value and made from the same material and technology also permits the temperature variation in the ambient (increase or decrease) to influence in the same manner all the resistances and the differential operation of Wheatstone bridge. This in turn also makes the temperature effect essentially “invisible” to the IA. Thus, by using the large area Wheatstone bridge, a robust solution for tampering detection can be provide with a temperature compensation capability. 
         [0034]    On very large area films, an array of such distributed sensors (printed electrically circuits+electronic module) can be deployed. The array  300  of sensing systems depicted in  FIG. 3  represents an example of such an array. Such an array  300  of sensing systems can be wirelessly monitored by an individual monitoring and transmitter unit  302 , which can also be wirelessly linked to the central station  304 . Very large area films with printed distributed circuits can be used for wrapping very large pallets or containers, realizing in this manner their structural integrity and anti-theft monitoring during transportation and storage. 
         [0035]    Additionally, such arrays of distributed sensors can be implemented in the context of a very large area “smart carpet”, as schematically depicted by an ultra large array of sensing systems  400  of  FIG. 4 . Such a “smart carpet” or ultra large array  400  can be formed from a very large area dielectric film  102  having distributed circuits that function as a sensor for monitoring their mechanical integrity. Such an ultra large array  400  can also be utilized for wirelessly monitoring the structural integrity of tents, truck&#39;s cover, or other large area surfaces in the assets monitoring field. 
         [0036]    It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.