Patent Description:
Access control systems in buildings, for example, are principally concerned with physical security and the selective access to, restriction of, and/or notification of access to a place or other resource. Historically, the main components of the access control systems were access control readers and possibly door controllers. The access control readers were often installed to enable presentation of credentials to obtain access to restricted areas, such as buildings or areas of the buildings. The readers were installed near access points, such as doors or hallways or elevators. Typically, individuals would interact with the access control readers by swiping keycards or bringing contactless smart cards within range (approximately <NUM>-<NUM> inches or <NUM> centimeters) of the reader. The access control readers would read the credential information of the keycards and validate the information possibly by reference to a verification system that confirmed the credentials and determined if the individuals were authorized to access the restricted areas. If the individuals were authorized, then the access control readers might signal door controller to unlock doors or not generate alarms, for example.

More recently, frictionless access control systems are being proposed and designed. These systems typically rely on individuals carrying beacon devices that can broadcast credentials, such as dedicated fob devices or personal mobile computing devices such as tablet or smart phone computing devices. The access control systems will then monitor and track the individuals as they move through the buildings and automatically open access points such as doors when approached, assuming that the individuals are authorized to pass through those access points.

<CIT> discloses an access device for checking access entitlement which detects people in a checking area against the number of transponders carried by those people.

<CIT> discloses a camera-based system for detection of tailgating and reverse entry to a controlled area.

When security systems implement more "frictionless" the operation, the intention of the individuals to access a restricted area, for example, is inferred to some or even a large extent. Because the systems are frictionless, the individual may not have made any overt gesture indicating a desire to access the restricted area, e.g., the individuals did not swipe a keycard. Therefore, the security systems should be intelligent to assess whether there is an intention to enter the restricted area.

At the same time, the systems need to be more intelligent to handle more complex situations. For example, the access control systems need to determine whether to unlock a door, for example, when some individuals near the door are authorized and some are not and also deal with the situations where the identity of some of the individuals cannot be determined.

In general, according to one aspect, the invention features a security system as defined in claim <NUM>.

The access control system can infer that the individuals are carrying the user devices by reference to image data from the surveillance camera. The access control system can then further control the access point in response to determining that the user devices have entered the threshold and determining that the individuals are not passing by the threshold area. It is inferred that the individuals are not passing by the access point when it is determined that an upper body of the individuals is facing the access point. In contrast, individuals are inferred to be merely passing by the access point when it is determined that an upper body of the individuals is not facing the access point.

Tailgating is also addressed in some configurations. The system infers that the individuals are tailgating in response to determining a greater number of individuals detected in the threshold than the user devices determined to be located relative to the threshold area and/or a greater number of individuals detected in the threshold than a number of the valid credentials from the user devices.

A directional antenna is preferably used for determining whether the user devices are in the threshold of the access point.

In general, according to another aspect, the invention features a method for controlling an access point as defined in claim <NUM>.

The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention as defined in the appended claims.

Further, singular forms and the articles "a", "an" and "the" are intended to include the plural forms as well, unless expressly stated otherwise.

<FIG> is a block diagram of an exemplary security system <NUM> and particularly an access control system that identifies individuals/users <NUM>, tracks locations of beacon user devices <NUM> such as fobs, smart phones or other mobile computing devices, and monitors access to restricted or different areas of a building, for example, through access points such as doors <NUM>.

The access control system includes a positioning unit <NUM> that is typically installed in room or other locations in the buildings. In the illustrated example, it is installed in connection with the door access point <NUM>. The positioning unit <NUM>, in one implementation, comprises an antenna system <NUM>-a, <NUM>-b that enables the positioning unit to <NUM> determine locations of the user devices relative to the access point <NUM>.

Different technologies could be used to locate the user devices relative to the access point <NUM>. For example, indoor GPS systems that rely on multiple antennas and triangulation are one example.

The positioning unit <NUM> in the illustrated example uses a combination of antennas and specifically a directional antenna <NUM>-b that has a projected beam aperture <NUM> that enables it to preferentially detect emissions from user devices <NUM> that are located at a threshold <NUM> of the access point <NUM>. In the illustrated example, an omnidirectional antenna <NUM>-a is also provided that enables the positioning unit <NUM> to detect the emissions from user devices beyond just the threshold to the access point <NUM> and in the room, for example, or in the whole building.

In the illustrated embodiment, the omnidirectional antenna system <NUM>-a and directional antenna system <NUM>-b are installed in a ceiling above the access point <NUM>. In another example, the directional antenna system <NUM>-b could be installed in the floor with its aperture directed toward the ceiling. Still other examples, the aperture <NUM> could be directed from the ceiling or floor at an oblique or slant angle but directed at the threshold.

In particular, the directional antenna system <NUM>-b detects emissions from beacon devices such as mobile computing devices <NUM>-<NUM>, <NUM>-<NUM> carried by individuals <NUM>-<NUM>, <NUM>-<NUM> typically standing at the threshold <NUM> of the access point.

The directional antenna <NUM>-b receives greater power in the direction of its projected aperture <NUM> allowing it to detect when beacon devices <NUM> enter the volumetric region above the threshold <NUM>. Different types of directional antennas could be used here such as parabolic antennas, helical antennas, yagi antennas, and phased arrays of smaller antennas of any kind. Horn antennas can also be used. A better option in some cases would be a patch or microstrip array antenna. These antennas would comprise flat metal or conductive strips mounted above a ground plane.

The radiofrequency beacon emissions detected by the directional antenna <NUM>-b are processed by the positioning unit <NUM>. In one embodiment, the user devices <NUM> broadcast using BLE (Bluetooth low energy) technology. Bluetooth is a wireless technology that operates in a <NUM> (gigahertz) short-range radio frequency band. A lower power version of standard Bluetooth called Bluetooth Low Energy (BLE), in contrast, consumes between ½ and <NUM>/<NUM> the power of classic Bluetooth. BLE is optimized for devices requiring maximum battery life instead of higher data transfer rates associated with classic Bluetooth. BLE has a typical broadcast range of about <NUM>-<NUM> feet (approximately <NUM>-<NUM> meters). In other examples, however, the directional antenna <NUM>-b detects other radiofrequency or optical emissions. Alternative implementations include other wireless technologies such as Wi-Fi (IEEE <NUM>), active RFID (radio frequency identification), or ZigBee, to list a few examples.

In general, an access controller <NUM> uses the information from positioning unit <NUM> to determine whether individuals are at the threshold to the access point <NUM>, which event may give rise to the generation of a security event based on any policies or business rules.

In the illustrated example, the access controller <NUM> also functions to verify credentials broadcast by the beacon devices <NUM> and specifically verify that the individuals to which those beacon devices are assigned are authorized to enter or transit the access point <NUM>.

In one example, the access controller <NUM> identifies the beacon devices <NUM> based on their emissions and then the individuals <NUM> to which those beacon devices <NUM> are assigned. This information would possibly be stored in a verification database <NUM>.

Based on the security credentials of the associated individuals <NUM>, it is determined whether those individuals are authorized to transit the access point <NUM>. In one specific example, the access control system <NUM>, after validating the credentials of the individuals <NUM>, signals the door controller <NUM> to unlock the door <NUM> to thereby grant access through the access point to the individuals <NUM>.

In one example, to validate the users <NUM>, the access controller <NUM> compares hashes, generated from security credentials, or security tokens assigned to the individuals, and broadcast from the beacon devices <NUM>. These hashes or tokens are compared to a list of hashes or tokens of authorized individuals. The list of hashes or tokens of authorized users is maintained in the verification database <NUM>. Often, both the hashes or tokens sent by the beacon devices <NUM> and the hashes or tokens included in the verification database <NUM> are time sensitive and will expire unless renewed.

A surveillance camera <NUM> is also provided. The surveillance camera is oriented such that its field-of-view or at least part of its field-of-view includes the threshold <NUM> to the access point <NUM>. Further, in one embodiment, the surveillance camera <NUM> is generally oriented above the access point <NUM> such that it looks down at the threshold area and the individuals <NUM> that are located or standing in the threshold area <NUM>.

Also provided is an image analytics system <NUM>. This receives the image data from the surveillance camera <NUM> and performs image analytics operations. Specifically, in one example, it tracks individuals within the camera's field-of-view and determines whether or not any individuals are entering or leaving the threshold area <NUM>. It may further be used to perform facial recognition or other biometric analysis, for example, on the individuals <NUM>.

In examples, the image analytics system <NUM> could be a separate system or implemented within the surveillance camera <NUM>, or even implemented as part of the positioning unit <NUM> or the access control system <NUM>.

In general, the surveillance camera <NUM> sends captured image data to the network video recorder <NUM>, which store the image data and possibly any associated metadata. Typically, time and date information are added to image data to enable the data to be indexed and reviewed at a later date. The image analytics system <NUM> will typically analyze the image data and associate metadata to moving objects (e.g., people), identify numbers of moving objects, and identify specific users, to list a few examples.

The image analytics system <NUM> will typically further implement tripwire processing. This enables the analytics system to determine when individuals cross tripwires and to generate metadata concerning the crossing. This image analysis tripwire is preferably coextensive with the threshold <NUM> to the access point in addition to other tripwires associated with individuals nearing the access point threshold.

In one example, facial recognition information determined from the image data is used to confirm that the individuals <NUM> possessing the user devices <NUM> are the proper users. In other examples, the tracking information is combined with the video data to determine which persons in a scene are users (holding users devices) and which are non-users.

Also included in one example is a security system workstation <NUM>. This may include a display <NUM> along with user input devices <NUM>. A drawing tool application program <NUM> executing on the security system workstation <NUM> enables operators and/or installers to configure the image analytics system <NUM> and specifically inform the image analytics system as to the relationship between the field-of-view of the surveillance camera <NUM> and the area of the access point threshold <NUM> and also the projected aperture <NUM> of the directional antenna <NUM>-b of the positioning unit <NUM>. Configuring the image analytics system <NUM> with this information enables the analytics system to determine when individuals are at the threshold and further the relationship between any emissions detected by the positioning unit <NUM> from the threshold of the access point and thus the relationship to the individuals <NUM> detected within the image data from the surveillance camera <NUM>.

Also shown in this figure is one situation where two individuals 104A, 104B are both in the threshold area to the doorway <NUM>. Only one of those individuals, however, is carrying a beacon device <NUM>-S and thus is presenting security credentials for validation. The other individual 104B is also in the threshold area giving rise to a potential tailgating situation.

<FIG> illustrates a situation where two individuals 104A, 104B are both in the threshold area to the doorway <NUM>. Here, they both have beacon devices103-s, <NUM>-f. Thus the credentials of both of the individuals may be validated or not.

<FIG> illustrates a situation where two individuals 104A, 104B are both in the threshold area to the doorway <NUM>. Here, only individual 104A is carrying beacon device <NUM>-s and can thus have their credentials validated. This individual 104A, however, is oriented such that they may be merely walking past the doorway <NUM>. On the other hand individual 104B is oriented such that they appear to want to transit the access point yet they have no beacon device. Thus, generally the access control system <NUM> would not unlock the door <NUM>. This would avoid the situation of granting access through the access point merely because someone with valid credentials was passing through the threshold area <NUM> at the time when another individual was seeking to improperly transit the access point.

<FIG> illustrates the relationship between the projected aperture <NUM>, the threshold area <NUM> of the access point (which is shown to be co-extensive with the volumetric region of the projected aperture <NUM> at the level of the floor), and the image data <NUM> collected by the surveillance camera <NUM>. As shown, in a typical example, the projected aperture <NUM> is a portion of the field-of-view <NUM> of the surveillance camera <NUM>. As a result, the surveillance camera <NUM> can determine when individuals are located within the threshold area <NUM> and also possibly determine and track individuals as they approach or walk away from that threshold area.

In one embodiment, the drawing tool <NUM> is used to specify the extent of the projected aperture /threshold area <NUM> within the field of the image data <NUM>. Typically, this is performed by an operator or installer as part of a setup procedure.

<FIG> is a flow diagram illustrating the operation of the access control system <NUM> based on the information received from the surveillance camera <NUM>, the positioning unit <NUM>, and the image analytics system <NUM>.

In more detail, one or more user devices such as fobs or mobile computing devices broadcast messages or other types of beacons. These broadcasts may take place near or in the threshold area <NUM>/directional antenna coverage volume <NUM> of the access point <NUM>.

In step <NUM>, the antennas <NUM>-a, <NUM>-b of the positioning unit <NUM> receive the beacons and/or credentials broadcast from the user devices <NUM>. At the same time, in step <NUM>, the surveillance camera <NUM> of the positioning unit <NUM> captures frames of image data. This image data includes the threshold area <NUM> and the volumetric region of the projected aperture <NUM> of the directional antenna <NUM> of the positioning unit <NUM>. In addition, the frames also include the area around the threshold area <NUM>, in one embodiment. These frames of image data are sent to the analytic system <NUM> for analysis.

In step <NUM>, the positioning unit <NUM> detects the existence of one or more user devices <NUM> in the threshold area <NUM> of the access point <NUM> if such devices are detected, then the access control system <NUM> begins the process of confirming whether or not the access point, such as the door, should be unlocked to allow those individuals to pass. Otherwise, processing returns back to step <NUM> to continue to track the user devices.

Upon detection of the user devices in the threshold area <NUM>, the access control system <NUM> receives image information and/or video primitives from the image analytics system in step <NUM>. The video primitive sent to the access control system include one or more of the following: <NUM>) the number and location of individuals in the threshold area, <NUM>) the number and location of individuals near the threshold area, <NUM>) the identity of those individuals based on facial recognition, for example, and/or <NUM>) the orientation of each of the individuals relative to the plane <NUM> of the access point <NUM>, for example.

In some examples, the access control system <NUM> may try to determine which of the individuals <NUM> at the threshold area <NUM> are in possession of which of the detected user devices <NUM>. This may be accomplished through the use of additional directional antennas that can identify specific locations for the user devices <NUM> within the threshold area. Steerable antennas such as phased array antennas are used in some cases to scan individuals for possession of beacon devices and then attribute specific beacon devices to specific individuals identified in the image data from the surveillance camera <NUM>.

In any event, in step <NUM> the access control system <NUM> determines whether or not there are more individuals detected within the area of the projected aperture than the number of beacon devices <NUM>.

If it is determined that more individuals are detected by the image analytics system <NUM> than beacon devices <NUM>, the access control system <NUM> concludes that a possible tailgating event is taking place. In one example, a message is sent to the security system workstation <NUM> indicating this security event. Further, in one embodiment, access to the access point is denied in step <NUM>.

In other examples, depending on the business rules and security policies, an alarm may be generated instead of blocking transit through the access point. In still other examples, metadata is added to the image data stored in the network video recorder. In still other examples, a welcome message could be displayed to the unknown individual.

In any event, in the illustrated example, a timeout is implemented in step <NUM> in which no access is granted through the access point to thereby block the improper tailgating, according to one possibly policy.

On the other hand, with respect to step <NUM>, if the number of individuals detected within the threshold area is a same as number of beacon devices detected in that area, then in step <NUM>, the orientation of any individuals within the threshold area <NUM> is determined. Specifically, if the individuals are determined to be facing the door, i. e, their shoulders are parallel to the plane <NUM> of the access point <NUM> based on the analytics system's analysis of the image data, then access control system <NUM> infers that they desire access through the access point. An example of this scenario is illustrated in <FIG>.

On the other hand, if the body orientations are determined to be such that some of the individuals are not seeking access, such as merely walking in front of the access point, in step <NUM>, then a message can be sent to the security workstation <NUM>. This scenario is shown in <FIG>. Metadata indicating a "passing event" can also be added to the image data in step <NUM>. Further, access is denied in step <NUM> according to one exemplary policy.

In the illustrated example, in step <NUM>, message is sent, for example, to the security system workstation <NUM> that one or more individuals have entered the threshold area for the purpose of the obtaining access through the access point <NUM>. Surveillance images from the camera <NUM> are further sent to the workstation in some cases.

If it is determined that the individual are oriented such that they are seeking access, it is determined whether of the individuals are authenticated by the access control system. That is, if the credentials are not authenticated in step <NUM>, then in step <NUM> messages sent to the security workstation <NUM> indicating a likely unauthorized attempt to access the access point. Further, metadata can be added to the image data stored in the network video recorder <NUM> in connection with this event and the image data from surveillance camera <NUM>.

On the other hand, if the credentials are authenticated in step <NUM>, an additional facial recognition step can be performed in some cases. Specifically, in steps <NUM> and <NUM> the facial or other characteristics are retrieved from the verification database <NUM>, for example, and compared to those of the individuals <NUM> possessing the authorized devices <NUM> that have been detected in the threshold area <NUM>. This ensures correspondence between the individuals carrying the user devices and the true owners of those user devices.

If no anomalies are detected in step <NUM>, then the access control system <NUM> provides access through the access point <NUM>. In one example, the door controller <NUM> is signaled to unlock the door, for example.

On the other hand, if anomalies are determined to exist in step <NUM> then a security event is again instantiated, for example, in step <NUM>. Messages are sent to the security workstation <NUM> indicating the possibility of an authorized attempt to access the access point and a stolen user device.

<FIG> illustrates situation where two individuals 104A, 104B are oriented to such that the access control system <NUM> would infer that they are attempting to obtain access through the door <NUM>. Specifically, their shoulders 106A, 106B extend in a direction that is parallel to the plane <NUM> of the door <NUM>. On the other hand, the orientation of a third individual 104C is somewhat ambiguous having shoulders 106C angled in an oblique direction relative to the plane <NUM> of the door <NUM>.

<FIG> illustrates an example where one of the individuals 104A may be merely passing in front of the door <NUM>. Another individual 104B may be trying to gain access through the door <NUM>. In this example, the access control system <NUM> would not unlock the door <NUM> based on the credentials of user 104A, since it appears that this user may be simply walking past the door.

Claim 1:
A security system, comprising:
a positioning unit (<NUM>) configured to determine locations of user devices (<NUM>) in a threshold area (<NUM>) to a doorway with a door (<NUM>);
a surveillance camera (<NUM>) configured to monitor the threshold area (<NUM>);
an access control system (<NUM>) configured to control the door (<NUM>) based on the locations of the user devices (<NUM>) and orientations of individuals carrying the user devices relative to the doorway; and
an analytics system (<NUM>) configured to receive image data from the surveillance camera, determine the orientations of the individuals relative to the doorway by analyzing the image data to determine whether the shoulders of the individuals are parallel to the plane of the doorway, and provides the orientations of the individuals to the access control system
wherein the access control system (<NUM>) is configured to determine that the individuals want to pass through the doorway when their shoulders are parallel to the plane of the doorway and to determine that the individuals are passing by the doorway when their shoulders are not parallel to the plane of the doorway.