Patent Application
20100176947
n/a
n/a
The present invention relates generally to a method and system to detect electronic article surveillance (“EAS”) marker shielding and more specifically to a method and system for detecting EAS marker shielding using a combination of metal detection, radio-frequency identification (“RFID”) and video sensors to identify detected metal items and prevent false alarms.
A growing method to defeat electronic article surveillance (“EAS”) systems is the use of readily available metal foils such as aluminum foil to shield EAS markers from detection by an EAS system. Thieves often line the insides of shopping bags, handbags and backpacks with metal foil to provide a concealed compartment for placing items to be stolen while inside the store so that they can exit through the detection zone of an EAS exit systems without detection. In response to this problem, retailers are increasingly using metal detection systems tuned to detect metal foil so that they can be alerted if a foil lined bag or backpack passes through the exit.
A major problem with this approach is that there are many metal objects and products that pass through the EAS system detection zone that are not related to theft. Some examples of these items are shopping carts, wheel chairs, products that have metal or aluminized packaging, and foil bags used for keeping hot serve deli items warm, etc. The effectiveness of a metal detection system is dependent on reducing alarms from non-theft items that pass through the detection zone and increasing detection of actual foil lined bags and backpacks.
Metal detectors are typically formed with a transmitter and receiver pair. The transmitter transmits a signal and the receiver receives the transmitter signal which is attenuated and/or shifted in phase when metal is inside the interrogation zone. Traditionally, these systems discriminate between foil lined bags and other metal objects by only alarming when detecting metals that have a responsive signal with amplitudes that fall in a range that is indicative of foil lined bags rather than other items. Unfortunately, relying on amplitude is not entirely reliable because a foil lined bag that is physically close to a metal detector antenna may exhibit a responsive signal strength similar to that of a shopping cart that is located further away from the metal detector. This problem forces the metal detection systems to be confined to narrow openings and to narrowly limit the range for positive detection of foil lined bags which causes the sensitivity of the system to be degraded.
As another attempted solution, retailers sometimes place metal detection systems so that shopping carts cannot pass. In other words, the metal detectors and/or EAS systems are arranged such that shopping carts will not fit through the exits. However, controlling the flow of traffic to eliminate false alarms from shopping carts interferes with the normal behavior of customers and degrades the customer experience. Since a positive customer experience is extremely important to retailers, this approach is usually undesirable.
Retailers may also eliminate products that cause false alarms, such as metallic or metalized packaging, or foil lined bags for keeping hot serve deli items warm, etc. Eliminating products that cause false alarms also degrades the shopping experience and limits the customer choices that are extremely important to retailers. Thus, this approach is also undesirable to retailers.
Therefore, what is needed is a system and method that can identify items that are likely to be used as foil lined containers so that metal detector signals can be confirmed, as well as automatically identifying items entering a detection zone that could cause false alarms and inhibiting these false alarms.
The present invention advantageously provides a method and system for detecting electronic article surveillance marker shielding by coordinating inputs from a variety of subsystems including an electronic article surveillance subsystem, a metal detection subsystem, a video analysis subsystem and a radio-frequency identification subsystem. Correlating known conditions to predefined object classes advantageously allows more accurate shielding detection and prevents false alarms.
In accordance with one aspect of the present invention, a system for detecting electronic article surveillance marker shielding includes an electronic article surveillance subsystem, a metal detection subsystem, a video analysis subsystem and a system controller. The system controller is communicatively coupled to the electronic article surveillance subsystem, to the metal detection subsystem and to the video analysis subsystem. The electronic article surveillance subsystem detects electronic article surveillance markers within a detection zone. The metal detection subsystem includes at least one transmitting antenna and detects a metallic objects within the detection zone. The video analysis subsystem captures at least one video image of the metallic object. The system controller determines a first probable classification for the metallic object and calculates a confidence weight for the first probable classification. The system controller further identifies the metallic object as electronic article surveillance marker shielding according to the first probable classification and the corresponding confidence weight and generates an alert.
In accordance with another aspect of the present invention, a system for detecting electronic article surveillance marker shielding includes an electronic article surveillance subsystem, a metal detection subsystem, a radio-frequency identification subsystem and a system controller. The system controller is communicatively coupled to the electronic article surveillance subsystem, to the metal detection subsystem and to the radio-frequency identification subsystem. The electronic article surveillance subsystem detects electronic article surveillance markers within a detection zone. The metal detection subsystem detects metallic objects within the detection zone. The radio-frequency identification subsystem detects a radio-frequency identification tag in the detection zone, receives a tag code from the radio-frequency identification tag and determines whether the tag code is included in a listing of false alarm item codes. If the metal detection subsystem detects a metallic object within the detection zone and the radio-frequency identification subsystem determines that the tag code is not included in the listing of false alarm item codes, the system controller generates an alarm. If the metal detection subsystem detects a metallic object within the detection zone and the radio-frequency identification subsystem determines that the tag code is included in the listing of false alarm item codes, the system controller identifies the metallic object as not electronic article surveillance marker shielding.
In accordance with yet another aspect of the present invention, a method is provided for detecting electronic article surveillance marker shielding. An electronic article surveillance subsystem is provided to detect electronic article surveillance markers within a detection zone. A metallic object is detected within the detection zone and a video image of the metallic object is captured. A first probable classification for the metallic object is determined and a confidence weight for the first probable classification is calculated. The metallic object is identified as electronic article surveillance marker shielding according to the first probable classification and the corresponding confidence weight and an alert is generated.
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
Before describing in detail exemplary embodiments that are in accordance with the present invention, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to implementing a system and method for identifying items that are likely to be used as foil lined containers and identifying items entering a detection zone that could trigger false alarms in order to distinguish between real and false alarm conditions. Accordingly, the system 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.
As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. Additionally, the terms “EAS marker,” “EAS tag,” and “EAS label” are used interchangeably herein to denote a device that is capable of being detected by an EAS detector.
One embodiment of the present invention advantageously provides a method and system to detect EAS label shielding using metal detection, RFID and video sensors. An EAS detection system designed to detect EAS markers attached to a protected item and a metal detector, which senses the presence of metal shielding materials that may be used to shield an EAS marker from detection by the EAS detection system are used in combination with one or more of an RFID reader, video sensors and a video analysis system. The RFID reader is designed to read an RFID label attached to items known to contain metal that might false alarm the metal detection system. One or more video sensors and a video analysis system determine various aspects of the environment around the other detection systems to improve the detection performance.
By using a video analysis system, the reliability of positively detecting articles in the vicinity of the detection systems which may contain EAS marker shielding, e.g., bags, backpacks, etc., is vastly improved. The video analysis system may detect the presence, location and motion of objects in the detection zone and further classify these objects to determine their type to both improve the detection of metal in the environment and identify other known metal items that may cause false alarms, e.g., metal shopping carts, wheel chairs, smaller metallic objects in close proximity to the metal detection system, etc.
Referring now to the drawing figures in which like reference designators refer to like elements, there is shown in
Referring now to
The system 10 also includes an RFID subsystem 28 coupled to an RFID antenna 30, and a video analysis subsystem 32 coupled to at least one video sensor 16. The RFID subsystem 28 collects information from active RFID tags within an interrogation or detection zone near the RFID antenna 30. The video analysis subsystem 32 collects video images from the video sensor 16 and identifies certain objects within the video images according to known video analytics techniques. In other embodiments, only one of the RFID subsystem 28 and the video analysis subsystem 32 may be deployed with the metal detection subsystem 22.
The video sensor 16 and video analysis subsystem 32 may also be used to collect other data in addition to detecting objects for use in metal detection. These uses include but are not limited to counting customer traffic through the opening, monitoring the use of shopping carts, capturing video of alarm events, etc.
Likewise, the RFID antenna 30 and the RFID subsystem 28 may be used to collect other RFID tag data in addition to that used for improving the performance of the metal detection subsystem 22. The RFID subsystem 28 is coupled to an RFID false alarm item database 34 which contains a listing of tag codes for items known to cause false alarms.
The EAS marker shield detection system 10 also includes an alarm/notification subsystem 36 which generates alarms or notifications in response to positive detection of an EAS marker shield or other defined trigger, such as detecting an active EAS tag within the interrogation zone.
Each subsystem, i.e., the EAS detection subsystem 20, the metal detection subsystem 22, the RFID subsystem 28, the video analysis subsystem 32, and the alarm/notification subsystem 36, is coupled to the EAS marker shield detection system controller 18 which controls the overall operation of the EAS marker shield detection system 10. The EAS marker shield detection system controller 18 is further coupled to a system database 38 which may contain a variety of logs, such as an object amplitude vs. distance log 40 and an alarm/notify condition log 42. The object amplitude vs. distance log 40 details the signal amplitude received from metal detection subsystem 22 as a function of distance from the metal detection antenna 24 for a variety of metals. The alarm/notify condition log 42 includes instructions for responses to different alarm conditions. It should be noted that although the RFID false alarm item database 34 is depicted as a separate entity from the system database 38, both databases may be physically located as a single device.
Referring now to
In
The outputs of the classification step (step S112) may include the probable class of the object and the confidence weight from the classification. For illustration, a high confidence number, e.g., close to 1, represents a very high probability that the classification result from the algorithm is correct. A low confidence number, e.g., close to 0, represents a very low probability that the classification result is correct.
In addition to object classification, the video analysis subsystem provides as an output a measurement of the location of the object and a measurement tolerance. Thus, if the object is classified as a cart (step S114), the relative position of the cart is measured (step S116) and the relevant information is reported to the EAS marker shield detection system controller 18 for further processing (step S118). For illustration, the position number 150 may represent that object is 150 cm from a reference point at the transmitter pedestal. A tolerance of 10 may represent that the video analysis subsystem estimates the uncertainty of the position number as ±10 cm.
Returning to decision block S114, if the video analysis subsystem 32 determines that the object is a human, a carried object detection process is performed (step S120) to determine whether the person is carrying a bag. If the person is carrying bag (step S122), the position of the bag is measured (step S124) and the relevant information, e.g., class, confidence level, bag position, bag position tolerance and direction of motion (whether the object is going into or coming out of the facility), is reported to the EAS marker shield detection system controller 18 for further processing (step S126). If the person is not carrying a bag (step S122), the position of the actual person is measured (step S128) and the relevant information, e.g., class, confidence level, position and position tolerance and direction of motion, is reported to the EAS marker shield detection system controller 18 for further processing (step S130).
Referring to
Referring now to
The EAS marker shield detection system controller 18 sends instructions to the alarm/notify subsystem 36 based on the corresponding action found in the alarm/notify condition log 42. For example, the alarm/notify subsystem 36 may enable an audible or visual alert, alert or email security or other personnel, call law enforcement authorities, etc. In certain situations, the alarm/notify subsystem 36 may only alarm when an object is moving into the store from the outside. This criterion would help to detect people bringing foil lined bags into the store so that security personnel may be notified to observe that customer and to collect evidence of shoplifting.
Referring now to
In an illustration of how the present invention improves detection discrimination between items is shown in
Referring once more to
The present invention can be realized in hardware, software, or a combination of hardware and software. Any kind of computing system, or other apparatus adapted for carrying out the methods described herein, is suited to perform the functions described herein.
A typical combination of hardware and software could be a specialized or general purpose computer system having one or more processing elements and a computer program stored on a storage medium that, when loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which, when loaded in a computing system is able to carry out these methods. Storage medium refers to any volatile or non-volatile storage device.
Computer program or application in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form.
In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. Significantly, this invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof, and accordingly, reference should be had to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.
