Patent Application
20130015355
n/a
n/a
The present invention relates generally to people counting and in particular to a method and system for detecting an object transiting an interrogation zone of an electronic article surveillance (“EAS”) system and counting the objects when the objects are determined to be people.
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.
One characteristic of the EAS interrogation zone is that consumers usually must walk through the interrogation zone to enter/exit the facility. This characteristic provides an area where the facility can track all people that visit the facility. Tracking people transiting the interrogation zone provides valuable consumer information that enables a business to calculate the percentage of store visitors that make purchases, determine consumer traffic at certain periods of the day, determine optimum staff shifts and determine whether a store promotion increased consumer traffic, among other statistics.
Different technologies have been incorporated by retailers to track the number of entering and exiting consumers. These technologies range from video imaging to thermal imaging of consumers. For example, video imaging relies on a video stream or series of images that are produced by a security camera at the entrance/exit of the store. The video stream may be processed to enable consumer tracking. However, video imaging involves separate processing computer(s) to implement complex algorithms for digitally filtering the consumer from the background in order to track the consumer. Due to the need for digital filtering, these systems may not work in low light levels, i.e., cannot distinguish a person from the background. Also, the cost associated with video imaging systems is often substantial and may require repeat calibration. Video imaging systems are also more intrusive to consumers as these systems function by processing identifiable images of people.
Thermal imaging is another technology that may be used to track consumers. For example, thermal imaging systems may use a sensor array to detect heat sources within a given area. Thermal imaging systems are less intrusive on consumer because they do not processing identifiable images of people to track consumers. However, thermal imaging systems detect all heat sources passing an entrance such as a person, pet or even a shopping cart that has been in the sun. Therefore, the accuracy of thermal imaging systems may be lower due to their inability to distinguish between heat sources.
Therefore, what is needed is a non-intrusive system and method for detecting and counting people transiting an interrogation zone of an electronic article surveillance (“EAS”) system.
The present invention advantageously provides a method and system for detecting an object transiting an interrogation zone of an electronic article surveillance (“EAS”) system and determining whether to increment a people counter based on whether the object is a person and whether the person is entering or exiting the facility. Generally, the present invention determines the direction of movement of the object and determines whether the object is a wheeled-object or a person walking between a pair of EAS system pedestals based on 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 counting includes a first zone detector detecting motion in a first zone. The first zone detector is a first passive infrared (“PIR”) detector. A second zone detector detects motion in a second zone different from the first zone. The second zone detector is a second PIR detector. A processor is in communication with the first and second zone detectors, in which the processor receives data from the first and second zone detectors to determine whether to increment a count value based at least in part on the received data.
In accordance with another aspect of the present invention, an Electronic Article Surveillance (“EAS”) system includes a people counting device having a first object detector detecting objects located within a first zone. The first object detector transmits a signal generated in response to detecting an object. A timer starts a timing sequence upon receiving the detection signal transmitted by the first object detector. A sensor array detects the object and provides a sensor detection signal. A cart detection module differentiates between a wheeled-object and a person passing through the sensor array based on the sensor detection signal. A controller is in communication with the first object detector, cart detection module, and timer. The controller operates to receive data from the first object detector and the timer to initiate gathering information from the cart detection module to determine whether to increment a people counter value.
In accordance with yet another aspect of the present invention, a method is provided for counting objects using an Electronic Article Surveillance (“EAS”) system. An object moving within a first zone is detected. The object moving within a second zone different from the first zone is detected. A timer sequence is initiated in response to the detection of the object in at least one of the first and second zones. A determination is made as to whether the object is a wheeled device or a person. A first people count value is incremented when the object is detected in the first and second zone prior to expiration of the timer sequence and the object is determined to be a person.
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 counting people transiting an interrogation zone of an Electronic Article Surveillance (“EAS”).
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 counting people in an interrogation zone of an EAS system. The EAS system combines traditional EAS detection capability with passive infrared detectors (“PIR”) and infrared sensor arrays located near the floor on the base of the EAS pedestals to detect the movement of an object passing through the interrogation zone and to determine whether the object is a person or wheeled-object. The object is detected moving within a first zone. The object is also detected moving within a second zone different from the first zone. The initial detection of the object in either zone initiates a countdown timer sequence. The system determines whether the object is a person or wheeled-object based on a pattern of broken infrared beams caused by the object. A people count value is incremented when the object is determined to not be a wheeled-object and/or determined to be a person and the pattern of broken infrared beams occurs during the countdown timer sequence.
Referring now to the drawing figures in which like reference designators refer to like elements, there is shown in
The zone entry detector 22 may include passive infrared (“PIR”) detectors, among other zone entry detectors. The zone entry detector 22 may be mounted on the infrared sensor array 20, directly on pedestals 12, among other locations. According to one embodiment, the zone entry detector 22 includes PIR detectors 22a and 22b positioned on infrared sensor array 20 at the same or different heights. For example, PIR detectors 22a and 22b may be positioned at ankle level or approximately 2 inches from floor level. Each PIR detector may include a lens and/or light baffle to establish its respective detection area. For example, a PIR detector using a Fresnel lens may only accept emitted infrared (“IR”) signals incident within the acceptance angle of the lens. In other words, the PIR detectors may sense infrared emission changes occurring within the acceptance angle of the lens, i.e., creates an IR sensing “curtain” 28 across an area as discussed below. Furthermore, PIR detectors with different lenses or without lenses may be used in accordance with the invention. The PIR detectors 22a and 22b may be mounted on a detector side of the infrared sensor panels and may be positioned on infrared sensor array 20 at opposite sides of infrared sensor array 20 in a lateral direction and at a height and direction. Alternatively, PIR detectors may be mounted on the transmitter side of the infrared sensor panels or on different pedestals 12.
The PIR detectors 22a and 22b detect infrared emissions of an object passing through their respective detection zone, i.e., detect movement of the object. For example, PIR detectors 22a and 22b may detect movement of the object based on a change in detected infrared emissions caused by the object moving through their respective detection zone. The amount of detected infrared emission change needed to determine movement of the object may be varied based on design need. In other words, PIR detectors 22a and 22b may detect infrared emission of an object within the interrogation zone followed by the exit of the object out of the interrogation zone. According to one embodiment, detection signals from PIR detectors 22a and 22b detectors may be processed to determine the direction of movement of the object, i.e., whether the detected object is entering/exiting the facility. Specifically, PIR detector 22a, PIR detector 22b and infrared sensor array 20 produce temporally displaced detection signals that indicate the direction of movement of an object in the interrogation zone, i.e., the object is detected by one detector before the other. For example, the object triggers PIR detector 22a before PIR detector 22b so as to indicate that the object is entering the facility. For example, the object is determined to be entering the building when PIR detector 22a is triggered before infrared beams 26 are broken. Alternatively, the entering object may trigger infrared beams 26 before triggering PIR detector 22b. In other words, the entering object may trigger PIR 1 before triggering PIR 2 or vice-versa thereby indicating the direction of movement, but the pattern of broken infrared beams 26 will determine whether the object is person 24 or not. Accordingly, the people counter criteria may rely on infrared beams 26 detection signal and at least one PIR detection signal to determine whether to increment the counter (e.g., IN counter) and may also use all three detection signals.
Reversing the temporal order in which the detection signals of the entering object were triggered may be used as the people counter criteria for determining whether to increment the counter, e.g., OUT counter. For example, the object is determined to be exiting the building when PIR detector 22b is triggered before any of infrared beams 26 are broken. Alternatively, the two PIR detectors may be operated individually to detect entry or exit of an object through the interrogation zone.
Furthermore, infrared sensor array 20 detection signals in combination with at least one of the PIR detectors signals allows the system to accurately count people even with PIR detector “bleed” through. Generally, “bleed” through refers to a PIR detection zone covering an area outside of the desired interrogation zone. Bleed through may be caused by PIR detector misalignment or simply due to pedestals 12 not being completely solid so as to allow IR emissions to penetrate from behind the pedestal, among other reasons. For example, person 24 walking behind pedestals 12 and not within the interrogation zone, may trigger one or both PIR detectors because PIR detection zones 28a and 28b bleed through past pedestals 12. However, using the broken IR beam 26 pattern or lack thereof will indicate whether person 24 or object is actually within the interrogation zone. For example, person 24 may be in an adjacent interrogation zone as used in a three pedestal EAS system.
In particular, people counter 18, discussed in detail with reference to people counter module 50 in
Referring now to
For example, since the wheels of a cart never leave the floor, the cart will break infrared beams 26 sequentially and will pass through each infrared beam 26. In contrast, person 24 walking through infrared beams 26 may break several infrared beams 26 simultaneously and does not necessarily break each infrared beam 26 in infrared sensor array 20. By recognizing the differences in these breakage patterns, an embodiment of the present invention is able to distinguish between a person and a cart, stroller and other wheeled-objects, as discussed below in detail with reference to
Referring to
Referring now to
Transceiver 34 may include a transmitter 42 electrically coupled to one or more transmitting antennas 44 and a receiver 46 electrically coupled to one or more receiving antennas 48. Alternately, a single antenna or pair of antennas may be used as both transmitting antenna 44 and receiving antenna 46. The transmitter 42 transmits a radio frequency signal using transmit antenna 44 to “energize” an EAS marker within the interrogation zone of the EAS detection system 10. The receiver 46 detects the response signal of the EAS marker using receive antenna 48. It is also contemplated that an exemplary system 10 could include a transmitting antenna 44 and receiver 46 in one pedestal, e.g., pedestal 12a and a reflective material in the other pedestal, e.g., pedestal 12b.
The memory 36 may store a people counter software module 50 for tracking people entering and exiting the interrogation zone, a zone entry detector software module 52 for determining the presence and direction of movement of an object proximate to an access point of the interrogation zone and a cart detection software module 54 for determining whether the detected object is person 24, cart, stroller or other wheeled-object, e.g., a wheel-chair, hand-truck, etc. In particular, a software module is a set of computer program instructions stored in memory that when executed by a computer processor causes the processor to perform certain steps, e.g., determining presence and direction of movement. In particular, the software modules may be executed by controller 30.
The people counting module 50 may include an IN counter and an OUT counter. Specifically, the IN counter corresponds to the number of people that enter the facility through the interrogation zone and the OUT counter corresponds to the number of people that exit the facility through the interrogation zone. The people counting module 50 may also have more counters and may reset the counters periodically or as indicated by the system administrator. The counters may be stored in memory 36.
The people counter module 50 may determine whether to increment the counter based on determinations made by the zone entry detector module 52 and cart detection module 54. For example, the zone entry detection module may determine an object has entered the interrogation zone based on zone entry detector 22 signals. Also, the cart detection module may determine the object is person 24 based on detection signals received from infrared sensor array 20. The people counter module 50 may use these determinations in order to determine whether to increment the counter, as discussed in greater detail below. This information may be communicated via communication interface 38. While people counter module 50 is shown stored in memory 36, people counter module 50 may alternatively be stored in memory of an EAS system add on device having processing and communicating capabilities similar to system controller 16. The controller 30 may also be electrically coupled to a real-time clock (“RTC”) 56 which monitors the passage of time. The RTC 56 may act as a timer for controller 30 to determine whether actuation of events, such as person counting, occurs within a predetermined time frame, e.g., countdown or count up timer. The RTC 56 may also be used to generate a time stamp such that the time of an event detection may be logged, e.g. time stamp incrementing the counter.
Referring to
Referring to
The process of
However, if infrared beams 26 are broken, a determination is made as to whether PIR 2 detects an object (step S108). For example, the object moving through the interrogation zone may move into PIR 2 detection zone. If PIR 2 detects an object, a determination is made as to whether the object is a wheeled-object, i.e., a determination is made based on the process of
Referring back to step S100, when no object is detected by PIR 1, a determination is made whether an object is detected by PIR 2 (step S114). In particular, a determination is made that no object is entering the building due to the lack of a PIR 1 detection signal. In other words, the object may be exiting the building. If PIR 2 does not detect the object, a determination is made whether PIR 1 detects the object, i.e., alternate between checking PIR 1 and PIR 2. However, if PIR 2 detects an object (step S114), a PIR 2 timer is started (step S116). The PIR 2 timer may be a countdown timer that counts down from predetermined time or up to a predetermined time. Next, the PIR 2 timer is checked to determine whether it has expired (step S118). If the PIR 2 timer is determined to have expired, PIR 1 and PIR 2 flags and timers are reset. If PIR 2 timer is determined not to have expired, a determination is made as to whether infrared beams 26 are broken (step S120). In other words, whether the object that was detected by PIR 2 continues to move through the interrogation zone. If no infrared beams 26 are broken, a determination is made whether the second timer has expired (step S118).
However, if infrared beams 26 are determined to be broken, a determination is made as to whether PIR 1 detects the object (step S122). If PIR 1 does not detect the object, a determination is made whether the second timer has expired (step S122, S118). However, if PIR 1 detects the object, a determination is made as to whether the object is a wheeled-object or person 24 by performing the wheel detection process of
While the present embodiment describes the use of PIR 1, PIR 2 and infrared sensor array 20 detection signals to determine whether to increment one of the people counters, the use of the third detection signals are optional, e.g., steps S108 and step S122 are optional. For example, referring to step S106, once infrared beams 26 are determined to be broken, a determination is made whether the object is a wheeled-object or person 24, step S110. In other words, detection signals from PIR 1 and the broken infrared beams 26 provide sufficient information to determine the direction of movement of the object, i.e., the object is entering the building, and whether the object is not a wheeled object and/or person 24. Using the third detection signal at steps S108 and/or S122 may provide for greater accuracy, e.g., can detect whether the object turns back midway through the interrogation zone, but is not required. The third detection signal in conjunction with the infrared beams may also be used to count people or objects traveling in opposite directions at the same time. Also, at step S120, a determination whether the object is person 24 or a wheeled-object (step S124) may be made after infrared beams 26 are determined to be broken (step S120), i.e., skip step S122. Also steps S106 and S110 (and conversely S120 and S124) may be skipped, relying only on PIR 1 and PIR 2 detection signals for people counting. Accordingly, the people counting method uses at least two detection signals to determine whether to increment one of the people counters.
Referring to
For example, an expected pattern for a wheel may be that each beam is broken sequentially for a given number of beams, up to and including all beams, and only a given number of beams are broken at any time. If the pattern does not match the expected pattern for a wheeled-object (step S138), it is determined that the object is not a wheeled-object (step S140). The determination that the object is not a wheeled-object is sufficient to determine the IN counter or OUT counter should be incremented, i.e., steps S142 and S144 may be optional steps.
Moreover, for additional people detection accuracy, the process of
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.
