Patent Application
20110109455
n/a
n/a
The present invention relates generally to electronic article surveillance (“EAS”) systems and more specifically to a method and EAS system that detects metals and magnetic materials and reduces false alarms caused by the presence of a metallic cart in the EAS interrogation zone.
Electronic article surveillance (“EAS”) systems are commonly used in retail stores and other settings to prevent the unauthorized removal of goods from a protected area. Typically, a detection system is configured at an exit from the protected area, which comprises one or more transmitters and antennas (“pedestals”) capable of generating an electromagnetic field across the exit, known as the “interrogation zone”. Articles to be protected are tagged with an EAS marker that, when active, generates an electromagnetic response signal when passed through this interrogation zone. An antenna and receiver in the same or another “pedestal” detects this response signal and generates an alarm.
Because of the nature of this process, other magnetic materials or metal, such as metal shopping carts, in proximity to the EAS marker or the transmitter may interfere with the optimal performance of the EAS system. Further, some unscrupulous individuals utilize EAS marker shielding, e.g., metal foil, with the intent of shoplifting merchandise without detection from any EAS system. The metal can shield tagged merchandise from the EAS detection system.
Current EAS systems implementing metal shielding detection mechanisms may sometimes be fooled by various cart configurations and overpowered by the response of a large mass of metal. Some systems attempt to overcome this problem by lowering the gain of the system, which limits the sensitivity and reduces the detection capability for small items, such as the metal shielding they are trying to detect.
Other conventional systems may include a “shopping cart inhibit” feature in the EAS system/metal detection configuration. By monitoring the overall mass of the metal response signal, a threshold can be implemented indicating an inhibit situation so that the system will not falsely generate an alarm. However, even with this solution implemented, some store merchandise will continue to fool the system and result in a false alarm or missed detection. For example, detection of large metal shielding positioned close to the pedestals is reduced because these shields produce readings which exceed the thresholds.
Therefore, what is needed is a system and method for independently detecting the presence of a cart or stroller within an EAS interrogation zone, thereby allowing increased sensitivity of an EAS system with metal shield detection capabilities.
The present invention advantageously provides a method and system for detecting electronic article surveillance (“EAS”) marker shielding by independently detecting the presence of a cart or other wheeled device with the EAS interrogation zone. Generally, the present invention is able to differentiate between a wheeled device and a human walking between the pedestals by examining a breakage pattern from a sensor array located on the pedestals just above the floor.
In accordance with one aspect of the present invention, a system for detecting EAS marker shielding includes an EAS subsystem, a metal detector, a cart detection subsystem and a processor. The EAS subsystem is operable to detect an EAS marker in an interrogation zone. The metal detector is operable to detect a metal object in the interrogation zone. The cart detection subsystem includes a sensor array. The cart detection subsystem is operable to differentiate between a wheeled device and a human passing through the interrogation zone based on the sensor array. The processor is electrically coupled to the EAS subsystem, the metal detector and the cart detection system. The processor is programmed to receive information outputted from the cart detection system and information outputted from the metal detector to determine whether to generate an alarm signal based on a presence of EAS marker shielding.
In accordance with another aspect of the present invention, a method is provided for detecting EAS marker shielding. A metallic object is detected within an interrogation zone. A wheeled device is differentiated from a human passing through the interrogation zone. Responsive to determining that a wheeled device is not passing through the interrogation zone, an alert signal is generated which notifies the presence of EAS marker shielding.
In accordance with yet another aspect of the present invention, an electronic EAS system controller for use with a metal detector includes an EAS subsystem, a communication interface, a cart detection subsystem and a processor. The EAS subsystem is operable to detect an EAS marker in an interrogation zone. The communication interface is operable to receive inputs from the metal detector. The cart detection subsystem includes a sensor array. The cart detection subsystem is operable to differentiate between a wheeled device and a human passing through the interrogation zone based on the sensor array. The processor is electrically coupled to the EAS subsystem, the communication interface and the cart detection subsystem. The processor is programmed to receive information outputted from the cart detection system and information outputted from the metal detector to determine whether to generate an alarm signal based on a presence of EAS marker shielding.
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 independently detecting the presence of a cart or stroller within an EAS interrogation zone, thereby allowing increased sensitivity of an EAS system having EAS marker shielding detection capabilities. 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.
One embodiment of the present invention advantageously provides a method and system for detecting a cart or stroller in an interrogation zone of an EAS system and improving the sensitivity of the EAS system to detect an EAS marker shield. The EAS system combines traditional EAS detection capabilities with a set of infrared sensor arrays located near the floor on the base of the EAS pedestals to detect the movement of a wheel passing through the interrogation zone.
Referring now to the drawing figures in which like reference designators refer to like elements, there is shown in
The metal detector 18 may be a separate unit, communicatively connected to the system controller 16, or may be integrated into the system controller 16. One exemplary metal detector 18 is disclosed in U.S. patent application Ser. No. 12/492,309, filed Jun. 26, 2009 and entitled “Electronic Article Surveillance System with Metal Detection Capability and Method Therefore,” the entire teachings of which are hereby incorporated by reference.
The people counting system 20 may be a separate device, such as an overhead people counter, or may be physically located in one or more pedestals 12 and/or integrated into the system controller 16. The people counting system may include, for example, one or more infrared sensors mounted approximately 8 to 14 feet (2.5 m to 4.3 m) above the retailer's entrance/exit. Integrating people counting sensors into the EAS detection pedestal 12 helps to ensure a simple and effective method of delivering essential operational information. In operation, the people counter detects the movement of a person into, through, or out of the predetermined area. That information is collected and processed by the people counting system 20, e.g., using a programmed microprocessor. People counting data may then be transmitted using conventional networking means to other portions of the EAS detection system 10, and/or through the store's internal network or across wide area networks such as the Internet, where it can be sorted, reported and studied.
Referring now to
Referring now to
The transceiver 32 may include a transmitter 40 electrically coupled to one or more transmitting antennas 42 and a receiver 44 electrically coupled to one or more receiving antennas 46. Alternately, a single antenna or pair of antennas may be used as both the transmitting antenna 42 and the receiving antenna 46. The transmitter 40 transmits a radio frequency signal using the transmit antenna 42 to “energize” an EAS marker within the interrogation zone of the EAS system 10. The receiver 44 detects the response signal of the EAS marker using the receive antenna 46. It is also contemplated that an exemplary system 10 could include a transmitting antenna 42 and receiver 44 in one pedestal, e.g., pedestal 12a and a reflective material in the other pedestal, e.g., pedestal 12b.
The memory 34 may include a metal detection module 48 for detecting the presence of metal within the interrogation zone and a cart detection module 50 for determining if the detected metal is a cart, stroller or other wheeled object, e.g., a wheel-chair, hand-truck, etc. Operation of the metal detection module 48 and the cart detection module 50 is described in greater detail below. The metal detection module 48, in conjunction with the cart detection module 50, may determine whether to trigger the alarm 38 by analyzing output information received from the metal detector 18, the people counting system 20 and the infrared sensor arrays 22 via the communication interface 36. For example, if the cart detection module 50 has detected the passage of a person through the interrogation zone and the metal detector 18 has just detected a source of metal that fits the characteristics of a metal shield, the metal detection module 48 may trigger the alarm 38 by sending an alarm signal via the controller 28. The alarm 38 alerts store security or other authorized personnel who may monitor or approach the individual as warranted.
The controller 28 may also be electrically coupled to a real-time clock (“RTC”) 52 which monitors the passage of time. The RTC 52 may act as a timer to determine whether actuation of events, such as metal detection or person counting, occurs within a predetermined time frame. The RTC 52 may also be used to generate a time stamp such that the time of an alarm or event detection may be logged.
Referring now to
The infrared sensor array 22 may be configured in a variety of manners. For example, as shown in
While sensors having focused elements are preferred, the present invention can be implemented using non-focused elements. Also, while automatic gain control (“AGC”) circuitry can be used as part of the sensor circuit, the present invention can be implemented using a sensor circuit that does not include an AGC circuit. It has been found that the latter embodiment allows operation at a faster cycle time as compared with the former embodiment, thereby providing improved accuracy. In the configuration shown in
Returning now to
Returning to decision block S106, if the current breakage pattern matches the expected pattern for a wheel, the system controller 16 determines whether the metal detection module 48 has detected the presence of metal within the interrogation zone (step S112). The metal detection module 48 may simply indicate the presence of metal within the interrogation zone or may return a response reading proportional to the amount of metal detected, in which case, the system controller 16 determines whether the response reading is greater than a predetermined threshold indicative of a response generated by a large metal object, such as a cart. If metal is not detected, the process ends. However, if there is metal present (step S112), the system controller 16 prevents the metal detection module 48 from generating an alarm indicating the presence of a metal shield (step S114). Similarly, if the metal detection module 48 detects metal in the interrogation zone and the cart detection module 50 determines that no cart is present, the system controller 16 may instruct the metal detection module 48 to generate an alarm indicating the presence of a metal shield. The process illustrated in
Referring now to
Referring now to
The countdown timer may be set for a predetermined amount of time, e.g., 30 seconds, 1 minute, etc. The countdown timer is started as soon as a beam is broken. As long as the countdown timer has not reached a terminal count (step S122), i.e. t=0, then the cart detection module 50 continues to monitor the blocked sensor to determine if the sensor becomes unblocked (step S124). If the sensor becomes unblocked, then the system controller 16 sets the status of the sensor to active (step S126) and returns to decision block S118 to continue monitoring for blocked sensors. However, if the countdown timer reaches the terminal count without the blocked sensor becoming unblocked (step S124), the cart detection module 50 sets the status of the blocked sensor to inactive and does not use the blocked sensor in the cart detection process (step S128). The blocked sensor may be returned to active status if the previously blocked sensor has become unblocked by repeating the blocked sensor process. It is noted the starting value of the countdown timer can be set sufficiently large as to not create fall blockage triggers.
In the case where the blocked sensor process determines that multiple beams are blocked, such as might occur if a cart is left in the interrogation zone, a person lingers in the interrogation zone too long or even where some other object is blocking multiple sensors, it is contemplated that the system can alert the store manager or some other designated personnel.
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 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.
