Abstract:
The present invention is directed to an access control apparatus and method. Enrollment is conducted at a centralized server and enrollment data, such as identification data is downloaded to plural local access units at respective entrances to a restricted area. The local access units then collect data of a person upon an attempted entry in to the area and compare the data with downloaded enrollment data to determine if the person is authorized for access. If the person is authorized, an access control device is operated to open a door, gate, or the like of the entrance. The enrollment data can be primary biometric data or primary and secondary biometric data, said secondary biometric data can be collected at the local access units. If a secondary type of biometric data is collected at the local access units and is correlated to data stored on the local access unit, data of the same type is compared to the downloaded data for access control. The primary enrollment data can be non-environmentally affected data, such as fingerprint parameter data and the secondary type of data can be environmentally affected data, such as facial parameter data. In cases where the primary biometric data does not correspond to stored primary biometric data, secondary biometric data can be collected and authenticated and new primary biometric data collected for potential addition to a user&#39;s primary biometric enrollments.

Description:
RELATED APPLICATION DATA  
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 10/215,950, filed Aug. 12, 2002 which is a continuation-in-part application of Ser. No. 09/574,001 filed May 19, 2000, the entire disclosure of which are hereby incorporated by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to automated systems for permitting authorized persons to access secured buildings or other areas while preventing such access by unauthorized persons. More particularly, the invention relates to an access control system that uses biometric parameters to identify authorized persons and to permit access by the authorized persons.  
           [0004]    2. Description of the Related Art  
           [0005]    The invention relates to restricting access into a restricted area and thus the term “access”, as used herein, refers to physical entry into a building, or other restricted area. However, the restricted area can be the exterior of a building or the like and thus the invention can be applied to controlling entry or exit out of a building or other area. There have always been situations in which it was desirable to restrict access to certain physical areas to a select person or group of people. Such restricted access has been accomplished by fences, walls, locks and other barriers. However, even the use of barriers has not prevented unauthorized access. Accordingly, it has been necessary in many instances to provide human surveillance in the form of a security guard at an entrance to an area or through the use of video cameras or the like to transmit images to a security guard at a remote or centralized location. Of course, the use of security guards and video cameras can become expensive and is only as reliable as the particular guard and his state of alertness at any particular time.  
           [0006]    The complexities of modern society have only served to increase the need for access control. For example, many government agencies and contractors work on matters that are of a confidential or even “top secret” nature. In fact, most workplaces, such as offices, warehouses, and even retail stores in some instances, have a need to implement access control to prevent the theft of intellectual property and/or goods.  
           [0007]    In response to the need for access control, many government agencies and businesses have issued identification cards to their employees and other authorized personnel. Often, the identification card includes a picture of the authorized person. However, such an identification card still requires a security guard or other personnel for verification. Also, such cards are easily forged by replacing the picture with that of an unauthorized person. To overcome these limitations, it is known to provide the employee with a personal identification number (PIN) or other identifying code. The identifying code can be encoded in a magnetic strip or the like in a security card and read by an automated reader at an entrance to grant access only to persons having the card. Alternatively, the code can be entered by the user on a keypad to gain access. However, the use of identifying codes also has drawbacks in access control applications. In particular, the identification card can be stolen or the user can be forced under duress to reveal their code. In such cases, unauthorized possessors of the card or code can gain access to a restricted area.  
           [0008]    The use of biometrics has been proposed as a solution to the limitations noted above. Generally, the term “biometrics” refers to the study of measurable biological characteristics, i.e. biometric parameters, of a living being. In the context of security, “biometrics” refers to techniques that rely on a unique, measurable characteristic of a living being for automatically recognizing or verifying identity. Examples of biometric parameters are facial data, retinal data, fingerprint data, speech data, and the like.  
           [0009]    Generally, biometric systems operate in the following manner. First, a system captures a sample of at least one biometric parameter during an “enrollment” process. The parameters are then converted by the system into a mathematical code, i.e., data, that is stored as the biometric template representing measured biometric parameters for that person. There may also be a way to correlate the template to the person. For example, a personal identification number (PIN) can be given to an enrolled user, which is entered to access the template. A new biometric sample is then taken and compared to the template or to a group of templates. If one of the templates and the new sample match, the person is recognized as authorized. Central to a biometric system is the “engine” which processes the biometric data in accordance with various algorithms or artificial neural networks.  
           [0010]    Some biometric systems use “identification” methods and some use “verification” methods. In identification systems, a sample is presented to the biometric system and the system then attempts to find out who the sample belongs to by comparing the sample with a plurality of templates obtained through enrollment. Verification systems on the other hand perform a one-to-one process where the biometric system is seeking to verify identity. A single biometric sample is matched against a single template obtained during enrollment. If the two match, the system effectively confirms that the person actually is who he presents himself to be. The key difference between these two approaches centers on the logic addressed by the biometric system and how these fit within a given application. Identification systems decide who the person is and can check whether more than one matching biometric template exists. Accordingly, identification systems can deny access to an individual who is attempting to pass himself off with more than one identity. Verification, on the other hand only decides if the person is who he says he is. Accordingly, identification systems are more versatile and powerful. However, verification systems generally require less processing horsepower and thus are commonly used.  
           [0011]    In typical biometric access control systems, biometric sensors are placed, proximate entrances and are linked to a central computer having biometric “enrollment” data, i.e., templates, representing biometric parameters of authorized users collected from a central enrollment station. If the biometric parameter collected at the entrance matches a template stored in the central computer, access is granted. However, conventional biometric systems have several limitations. In particular, the sensing accuracy of biometric parameters, such as facial parameters, retinal parameters, and the like is highly dependent on the environment in which the parameters are sensed. For example, the lighting intensity, angle and color will affect sensing of biometric parameters. Accordingly, the ability to reliably match data representing parameters collected at an entrance with data of templates collected during enrollment is limited, especially when the entrance is an external entrance where the weather, season, and time of day will affect lighting significantly. Also, sensing biometric parameters, converting the parameters to data, communicating the data to a central computer, and comparing the data parameters with templates of enrollment data in the central computer is relatively time consuming, even with modern high speed computers and communication links. Accordingly, such systems present significant inconveniences to the authorized persons through improperly rejected access and time delays prior to granting access.  
           [0012]    The use of less environmentally affected biometric parameters, such as fingerprint parameters can alleviate some of the problems noted above. However, sensing such parameters requires that the person desiring access make physical contact with a sensor, such as a fingerprint scanner, upon each entry request. Also, such parameters are easily affected by skin debris, and skin blemishes. Therefore, the person desiring access may have to wipe off their finger, not to mention remove any gloves, prior to submitting to the physical contact with the sensor. The match tolerance between a template and data corresponding to a measured parameter can be increased to minimize lockout of authorized users. However, such an approach inherently reduces the accuracy and effectiveness of the system by increasing the likelihood of allowing access to unauthorized users.  
           [0013]    U.S. Pat. No. 5,802,199 attempts to solve the issue of slow response in biometric identification systems by transmitting a subset of templates obtained through enrollment from a central computer to one of plural “local” computers. If the user attempts to use an ATM terminal that corresponds to the “local” computer, identification is accomplished by collection of biometric data and a PIN number and by comparison with templates in the “local” computer. If a matching template and PIN number is not in the “local” computer, biometric identification is accomplished in the central computer by transmitting collected data over a remote communication link.  
           [0014]    U.S. Pat. No. 5,802,199 relates to identification for allowing use of ATM terminals and not for access control as defined herein. The practical communications of access control and ATM use control are quite different. For example, the “local” computers disclosed in U.S. Pat. No. 5,802,199 are apparently not at the location of biometric sampling, i.e. the ATM terminal. It appears that plural ATM terminals are assigned to each local computer because of the inherent geographic distribution of ATM terminals. The “local” computers are actually centralized computers. Accordingly, the system disclosed in U.S. Pat. No. 5,802,199 is not suitable for high speed access control which generally requires high speed identification within a relatively small geographic area, such as a single building or campus. Also, since enrollment is conducted centrally, i.e. not at the site of the ATM terminal, environmental variables will affect the accuracy of identification. Finally, this system requires that two separate things be recognized, the biometric sample parameters and a PIN number entered by the user.  
           [0015]    U.S. Pat. No. 5,903,225 discloses an access control system in which data is encoded on a card during an enrollment procedure in correspondence to the person&#39;s fingerprint. When attempting to gain access to a restricted area, a transmitter on the card transmits the data to a receiver at the entrance to grant access. This system apparently does not implement biometric recognition or identification and thus has the same limitations as conventional access systems using magnetic cards. In particular, whoever possesses the card is granted access regardless of their identity.  
           [0016]    U.S. Pat. No. 4,993,068 discloses an access system in which the enrollment procedure includes recording biometric data on a card to be carried by the user and comparing the data on the card with data of biometric parameters measured at the entrance. This system is inherently a verification system and thus is not as flexible as an identification system for the reasons discussed above. Also, since enrollment is conducted at a central location, sensing of parameters upon access can be affected by the environment at the entrance. Accordingly, the accuracy of this system is limited.  
         SUMMARY OF THE INVENTION  
         [0017]    It is an object of the invention to overcome the limitations of the known systems described above.  
           [0018]    It is an object of the invention to maximize the speed of biometric identification access control.  
           [0019]    It is another object of the invention to maximize the accuracy of biometric identification access control.  
           [0020]    It is another object of the invention to minimize the inconvenience and obtrusiveness of biometric identification access control.  
           [0021]    It is another object of the invention to minimize the effect of environmental variables in biometric identification access control.  
           [0022]    It is another object of the invention to clearly indicate any security anomaly in a biometric identification access control system.  
           [0023]    A first aspect of this invention is an apparatus for controlling access into an area. The apparatus comprises (1) a server including a server memory and a server data collection device; (2) a local access unit; (3) an access control device and (4) a communication channel. The server data collection device is configured to collect identification data. The local access unit is associated with an entrance to an area and includes a local memory, a local processor, a primary local biometric parameter sending device and at least one secondary biometric parameter sensing device, a local data collection device, and an access control device. The communication channel is used for downloading the identification data from the server to the local access unit.  
           [0024]    The local processor is operative to recognize an authorized user by comparing primary biometric parameter data of a person proximate an entrance with primary biometric parameter data stored in the local memory. Access to the area is granted when the primary biometric parameter data of a person proximate the entrance and the primary biometric parameter data stored in the local memory correspond.  
           [0025]    The local processor is also operative to collect secondary biometric parameter data through the secondary biometric parameter sensing device when the primary biometric parameter data collected by the local primary biometric sensing device and the primary biometric parameter data stored in the local memory do not correspond. In this event, access to the area is granted when the secondary biometric parameter data collected by the local secondary biometric parameter sensing device and the secondary biometric parameter data stored in the local memory correspond.  
           [0026]    When the biometric parameter data collected by the local primary biometric parameter sensing device and the biometric parameter data stored in the local memory do not correspond and the secondary biometric parameter data collected by the local secondary biometric parameter sensing device and the secondary biometric parameter data stored in the local memory correspond, the local processor is operative to prompt the user to provide a new biometric parameter data to the local primary biometric parameter sensing device and to store the new biometric parameter sensing device in correspondence with primary biometric parameter data stored in the local memory.  
           [0027]    A second aspect of the invention is an apparatus for controlling access to an area comprising a local processor that is operative to recognize an authorized user by comparing primary biometric parameter data of a person proximate the entrance with primary biometric parameter data corresponding to a plurality of users stored in the local memory. Access is granted if the primary biometric parameter data collected by the local primary biometric parameter sensing device and the stored primary biometric parameter data corresponding to any one of the plural users correspond.  
           [0028]    A third aspect of the invention is an apparatus for controlling access to an area, comprising a local processor that is operative to recognize an authorized user by prompting a person proximate the entrance to enter identification data into the local data collection device, retrieving a subset of primary biometric parameter data corresponding to the identification data stored in the local memory, and comparing the primary biometric parameter data collected by the local primary biometric parameter sensing device with the subset of primary biometric parameter data. Access to the area is granted when the primary biometric parameter data collected by the local primary biometric parameter sensing device and the subset of primary biometric parameter data correspond.  
           [0029]    A fourth aspect of the invention is an apparatus for controlling access to an area comprising a means for authenticating a secondary biometric parameter data when the primary biometric parameter data collected by the local primary biometric parameter sensing device and the primary biometric parameter data stored in the local access unit do not correspond.  
           [0030]    A fifth aspect of the invention is a method of controlling access into an area comprising the steps of (1) recognizing an authorized user by comparing primary biometric parameter data of a person proximate the entrance collected by the local primary biometric parameter sensing device with primary biometric parameter data stored in the local memory, and granting access by operating the access control device if the primary biometric parameter data collected by the local primary biometric parameter sensing device and the primary biometric parameter data stored in the local access unit correspond; (2) prompting the person to enter secondary biometric parameter data through at least one secondary biometric parameter sensing device when the primary biometric parameter data collected by the primary biometric parameter sensing device and the primary biometric parameter data stored in the local access unit do not correspond and granting access by operating the access control device when the secondary biometric parameter data of an authorized person collected by the local secondary biometric parameter sensing device and the secondary biometric parameter data stored in the local memory correspond; and (3) prompting the person to provide additional primary biometric data through the primary biometric parameter sensing device and storing said additional primary biometric parameter data collected by the local primary biometric parameter sensing device in the local access unit when the primary biometric parameter data collected by the local primary biometric parameter sensing device and the primary biometric parameter data stored in the local access unit do not correspond and when the secondary biometric parameter data collected by the at least one local secondary biometric parameter sensing device and the secondary biometric parameter data stored in the local memory correspond.  
           [0031]    A sixth aspect of the invention is a method wherein the recognizing step comprises comparing primary biometric parameter data of a person collected by the local primary biometric parameter sensing device with primary biometric parameter data corresponding to plural users stored in the local memory, and granting access to the area by operating the access control device if the primary biometric parameter data collected by the local primary biometric parameter sensing device and the primary biometric parameter data correspond.  
           [0032]    A seventh aspect of the invention is a method wherein the recognizing step comprises prompting a person prompting a person proximate the entrance to enter identification data into the local data collection device, retrieving a subset of primary biometric parameter data corresponding to the identification data stored in the local memory, comparing the primary biometric parameter data collected by the local primary biometric parameter sensing device with the subset of primary biometric parameter data, and granting access to the area when said primary biometric parameter data collected by said local primary biometric parameter sensing device and said subset of primary biometric parameter data correspond.  
           [0033]    A eighth aspect of the invention is a method including the step of a system administrator authenticating the additional primary biometric parameter data collected by the local primary biometric parameter sensing device when the secondary biometric parameter data collected by the secondary biometric parameter sensing device and the secondary biometric parameter data stored in the local memory correspond, by comparing primary biometric parameter data collected during the primary enrollment procedure with the additional primary biometric parameter data collected by the local primary biometric parameter sensing device.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0034]    The invention is described through a preferred embodiment and the attached drawing in which:  
         [0035]    [0035]FIG. 1 is a block diagram of the architecture of an access control system of the preferred embodiment;  
         [0036]    [0036]FIG. 2 is a flow chart of the primary enrollment procedure of the preferred embodiment;  
         [0037]    [0037]FIG. 3 is a flow chart of the identification and secondary enrollment procedures of the preferred embodiment; and  
         [0038]    [0038]FIG. 4 is a flow chart of the anomaly enunciation procedure. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0039]    [0039]FIG. 1 illustrates the system architecture of a preferred embodiment of the invention. Biometric access control system  20  includes server  40 , plural local access units  60 , and communications channel  80 . Server  40  and local access units  60  can each include microprocessor based digital computers as described in detail below. In the preferred embodiment, communications channel  80  is a local area network (LAN) such as an Ethernet network communicating over a coaxial cable or unshielded twisted pair (UTP). However, communication channel  80  can be any type of communication channel using cables, radio frequency transmission, optical transmission over fibers, infrared transmission, or any other wired or wireless communication mode capable of providing the communication described herein. Any communications protocols and transmission medium can be used. For example, communication channel  80  can be the Internet and each computer can have a separate IP address. Also, communication channel  80  can be accomplished merely by physically moving a removable recording medium, such as a diskette, between server  40  and access terminals  60 ; a channel sometimes referred to as “sneakernet”.  
         [0040]    Server  40  is a digital microprocessor based computer, such as a personal computer, a minicomputer, a programmable logic controller, or any other proprietary or non-proprietary device capable of accomplishing the processing and communication functions described below. Server  40  includes central processing unit (CPU)  42 , memory device  44  (such as a magnetic hard drive), random access memory (RAM)  46 , input device  48  (such as a keyboard and mouse), display  50 , microphone  52 , speaker  54 , biometric parameter sensing device  56 , a data bus (not illustrated) for providing communications between the various components and the appropriate interfaces for each component (also not illustrated). Biometric parameter sensing device  56  serves to collect identification data during an enrollment procedure, as described below, and can be of any type, such as a fingerprint scanner, a camera for sensing facial parameters, a retinal scanner, or the like. For the sake of discussion of the preferred embodiment, it is assumed herein that biometric parameter sensing device  56  is a facial recognition camera or a fingerprint scanner capable of sensing parameters relating to a persons fingerprint. Server  40  has a control program stored on memory device  44  that includes instructions for accomplishing the functions described below. The control program of server  40  also includes a biometric engine such as that described in U.S. Pat. No. 5,386,103, the disclosure of which is incorporated herein by reference.  
         [0041]    Local access unit  60  also is a digital microprocessor based computer, such as a personal computer, a minicomputer, a programmable logic controller, or any other proprietary or non-proprietary device capable of accomplishing the processing and communication functions described below. Only one local access unit  60  is illustrated in detail and discussed in detail below. However, each local access unit is similar and thus the description below applies to each local access unit  60 . Local access unit  60  includes central processing unit (CPU)  62 , memory device  64  (such as a magnetic hard drive), random access memory (RAM)  66 , input device  68  (such as a keypad), display  70 , microphone  72 , speaker  74 , biometric parameter sensing device  76  (serving as an auxiliary biometric parameter sensing device), biometric parameter sensing device  77 , access control device  78  (such as a lock solenoid, gate, or the like), a data bus (not illustrated) for providing communications between the various components, and the appropriate interfaces for each component (not illustrated). Biometric parameter sensing device  76  preferably is of the same type, i.e. senses the same biometric parameters, as biometric parameter sensing device  56  of server  40 , a fingerprint scanner or facial recognition camera in the preferred embodiment. Biometric parameter sensing device  77  can be of any type but is preferably of a different type, i.e. senses different biometric parameters, than biometric parameter sensing device  76 . In the preferred embodiment, biometric parameter sensing device  77  is a camera for sensing facial parameters.  
         [0042]    Each local access unit  60  has a control program stored in memory device  64  that includes instructions for accomplishing the functions described below. The control programs of local access units  60  also include a biometric engine, such as that described in U.S. Pat. No. 5,386,103. Each local access unit  60  can include access panel  60   a  (including input device  68 , display  70 , microphone  72 , speaker  74 , biometric parameter sensing device  76 , biometric parameter sensing device  77 , and access control device  78 ) and controller  60   b  (including CPU  62 , memory device  64 , and RAM  66 ). Access panel  60   a  and controller  60   b  can be housed separately. However, it will become apparent below that access panel  60   a  and controller  60   b  preferably are located in close proximity to one another. The number of physical enclosures associated with local access unit  60  can vary as is required by the particular application and entrance.  
         [0043]    Server  40  can be disposed at any location in the building or other area to which access control system  20  is being applied or at a remote location. Also, server  40  can be any one of plural computers coupled to a network or can be embodied by plural computers on the network each conducting a different portion of the function of server  40 . For example, the enrollment procedure disclosed below can be conducted on one computer and the anomaly monitoring functions disclosed below can be conducted by another computer with the two computers together constituting server  40 . Local access units  60  are associated with the respective doors or other entrances of the building or other area to which access control system  20  is applied. Typically, access panels  60   a  are located just outside the doorframe and controllers  60   b  are located inside an entrance to the building or other area to prevent tampering therewith. However, controllers  60   b  are preferably located close enough to respective access panels  60   a  to allow local communications through a serial port, parallel port, Universal Serial Bus (USB) port or the like.  
         [0044]    [0044]FIG. 2 illustrates the primary enrollment procedure of the preferred embodiment in which persons are authorized for access. A person to be allowed access to the area controlled by system  20  is brought to an enrollment location proximate server  40 . Biometric parameters are sensed by biometric parameter sensing device  56  of server  40  in step A. Preferably, both fingerprint and facial parameters are collected during the primary enrollment procedure. The collection of fingerprint parameters is accomplished by placing the finger of the person on a sensing surface of biometric parameter sensing device  56  and selecting appropriate menu choices displayed on display  50  in accordance with the control program stored in memory device  44  and being executed by CPU  42 . Similarly, facial parameter data is similarly collected by photographing facial parameters of the person being enrolled using biometric parameter sensing device  56  which for this purpose would be in the form of a camera or other device capable of capturing facial parameters. A system administrator or other person with authorized access to the data biometric parameter data can review the collected image data to ensure that there are no irregularities in the biometric parameter data collected that might interfere with the identification of the person whose biometric parameter data is being collected. The reviewed image data corresponding to the sensed parameters is thus collected and recorded in memory device  44 . Using input device  48 , corresponding data, such as the authorized persons name, title, access privileges, assigned PIN number(s) or other known types of conventional identifying data is entered in step B and stored in memory device  44  in correspondence to the data stored in step A.  
         [0045]    In step C, it is determined if all enrollment is finished, i.e. if the operator of server  40  does not wish to enroll other persons at this time. If so, the procedure continues to step D, if not, the procedure returns to step A for collection of biometric parameter data for another person. In step D, enrollment data, including biometric data and corresponding data entered in steps A and B respectively, is downloaded to each local access unit  60 . The enrollment data can be stored in memory device  64  of each local access unit as templates in any format, such as known database formats. Accordingly, the templates are stored in each local access terminal and are constantly or periodically updated with any new enrollment data collected during a primary enrollment procedure. Step D can be conducted immediately after step C or can be delayed to download data in a batch process. The primary enrollment procedure comes to an end in step E. Of course, the primary enrollment procedure can be accomplished at any time and one or more persons can be enrolled during each procedure. Also, enrollment data can be deleted or modified as needed. For example, when an employee leaves a company it may be desirable to delete his template so that he cannot be granted access to the building or other area. Also, when a person is promoted, their access privileges may be increased. Further, a terminated employees template may be left while his access privileges are revoked. In such a situation presence of the terminated employee can be flagged as an anomaly as described below.  
         [0046]    When primary enrollment for one or more authorized persons is finished, system  20  is ready to identify and/or verify authorized persons and control access to a building or other area. FIG. 3 illustrates the procedure for controlling access. As a person approaches an entrance having remote access unit  60 , biometric parameter sensing device  77  begins to sense parameters, e.g. facial image parameters, in an attempt to identify the person as an authorized person. For example, biometric parameter sensing device  77  can be in constant operation and can begin to sense facial parameters when a person is within a prescribed range. Alternatively, biometric parameter sensing device  77  can be turned on by the presence of the person using a proximity sensor or the like. The engine disclosed in U.S. Pat. No. 5,386,103 is capable of sensing parameters while the subject person is several feet away. In any event, as the person approaches remote access unit  60 , facial parameters are sensed and converted to biometric parameter data in step A.  
         [0047]    The method of the preferred embodiment may incorporate an identification process or a verification process. The determination of which process is employed will depend on various factors, including the level of security desired and the operating capacity of the platform on which the system is based. An identification process typically takes longer to complete and requires more operating power than a verification process.  
         [0048]    With an identification system, sensed biometric parameter data is compared with the entire set of templates stored in memory device  64  of local access unit  60  to determine whether the approaching person has been enrolled in the system Step A. If the sensed biometric parameter data corresponds to that of an enrolled user, local operating unit  60  operates access control device  78  to grant access to the user. Otherwise entry is denied.  
         [0049]    If a verification process is employed, the approaching person is, for example, prompted to enter identification data into input device  68 , e.g. additional biometric data, a user ID, PIN number, card swipe or other known identification data. Once this identification information is inputted, server  64  retrieves the subset of templates corresponding the purported identity affiliated with the inputted information. Sensed biometric parameter data collected by local biometric parameter sensing device  77  is then compared to the biometric parameter data stored in the subset of templates. If the biometric parameter data collected by local biometric parameter sensing device corresponds to the biometric parameter data stored in the subset of templates, access is granted. The threshold degree of required likeness between the biometric parameter data in the templates and the biometric parameter data collected by the local biometric parameter sensing device can be adjusted to control the sensitivity of the system. The above-described identification and verification processes are collectively referred to as “recognition” or “recognizing” processes herein.  
         [0050]    In step C, local access unit  60  determines if the approaching person has been recognized through steps A and B and, if so, operates access control device  78  to grant access to the person in step D. Step D can require that the person press a button and/or turn a door handle to unlock the door. Also, an indication of granted access, such as a green light or a message on display  70  can be enunciated. If the determination in step C is that the person was not recognized, the procedure branches to step E. For example, if it is the first time the person has approached the particular entrance and thus corresponding facial data is not stored in local access unit  60 , if the environment (such as lighting) has changed since the time of the last collected facial data of the person, or if the person is not an authorized (i.e. enrolled) person, the facial parameter data of the person will not correspond to facial parameter data stored as templates on memory device  64 . In step E, the access granted indicator is not enunciated and the person is prompted, through a message on display  70 , to touch biometric parameter sensing device  76  with their finger to obtain a fingerprint scan. Optionally, the person may also be prompted to enter other biometric (e.g. voiceprints, retinal scans, thermal images and the like) or other known types of conventional identifying information (e.g. name, title, access privileges, assigned PIN number(s)) that was collected and stored during the primary enrollment process.  
         [0051]    In step F, the data corresponding to fingerprint parameters (and any other biometric parameter or conventional identifying data) obtained in step E are compared with fingerprint parameters in templates stored in memory device  64  (see step D of the primary enrollment procedure described above with reference to FIG. 2). If the person is authorized for access, i.e. has been enrolled, their fingerprint parameter data will correspond to a stored template in comparison step F. If the fingerprint parameters do not correspond to the template, the person is not identified in step G, is not authorized, and thus is not granted access. Additionally, in step H, an alarm can be sounded, proper personnel can be notified, or the attempted entrance can be recorded for later review in the manner described in detail below. If the person is identified in step G, the procedure continues to Step I.  
         [0052]    In Step I, the person who has been recognized through fingerprint parameter data as being enrolled and thus authorized, but not recognized through facial parameter data, is prompted by a message on display  70 , to look towards local access unit  60  while biometric parameter sensing device  77  senses facial parameters of the person. The newly sensed facial parameter data can then be authenticated by a system administrator, other authorized user, or an automated process by reviewing the newly sensed facial parameter data to ensure that it does not contain any irregularities that might interfere with future recognition of the person whose facial parameters are sensed. This authentication can take place before the newly sensed facial parameters is stored in memory device  64 , in batch mode after the data is stored, or at any other time and in any manner as is deemed necessary. Once authenticated, the newly sensed facial parameters are then converted to data and stored as a template in memory device  64  in step J in correspondence with the existing biometric data and corresponding data downloaded and stored during step D of the primary enrollment process described above. Access is granted to the authorized person in step K. The procedure is then reset and returns to step A to await the next person.  
         [0053]    The template including facial parameter data stored in step J is used (along with other stored templates having facial parameter data) in comparison step B the next time the person approaches local access unit  60 . Therefore, it is more likely that the person will be recognized in steps A-D above upon the person&#39;s next attempted entry and thus the relative inconvenience of steps E-J will not be required. However, steps E-J, i.e. the secondary enrollment procedure, can be accomplished anytime a person is not identified and/or verified by virtue of facial parameters in step C. Eventually, enough facial parameter data is stored in memory device  64  to allow access of the authorized person in a variety of environmental conditions at the particular entrance. A similar procedure can be accomplished at other local access units  60 , i.e. each entrance that the person uses. Of course, if the person alters their face by growing or shaving facial hair, gaining or losing a large amount of weight, having cosmetic surgery, or the like, the secondary enrollment of steps E-J will be accomplished again upon the person&#39;s next entry. Keep in mind that the user is always recognized through at least the first enrollment parameters, i.e fingerprint parameters, or the second enrollment parameters, i.e facial parameters, prior to being granted access.  
         [0054]    [0054]FIG. 4 illustrates a procedure for handling anomalies, such as unauthorized persons attempting to gain access, or unauthorized persons gaining access on the coattails of authorized persons. For example, each time access is granted in steps D or K of FIG. 3, local access unit  60  can count the number of persons passing through the entrance. If more than one person enters a “tailgating” anomaly is detected. Counting can be accomplished with biometric parameter collection device  77  or with any appropriate sensor, such as an infrared array, photo sensor, proximity sensor, or the like. Further, an anomaly can be any situation other than the normal granting of access to an authorized person within their access parameters. An anomaly can result from the satisfaction of any predetermined criterion. For example, it may be desirable to know if a particular authorized person or persons, gains access more than a preset number of times. Also, it may be desirable to know if a previously authorized person whose access privileges have been revoked is near an entrance. Local access unit  60  is programmed to detect any anomalies under conditions set forth by a system administrator or other supervisory person and programmed into the control program.  
         [0055]    In step A it is determined if an anomaly is present based on the programmed conditions. If an anomaly is present, local access terminal  60  notifies server  40  over communication channel  80  in step B. Server  40  can be programmed to notify appropriate personnel by one or more of sounding an alarm, sending a message (by email, fax, telephone for example), or the like in step C. As noted above, biometric parameter sensing device  77  collects image data of each approaching person or persons. Ordinarily, the image data is discarded, i.e erased from memory shortly after being recorded in step F. However, in the event of an anomaly, the previous several seconds of image data is saved and sent to server  40  over communication channel  80  for display in substantially real time or for later review in step D. Accordingly, images, i.e. video data, of each anomaly creating approach can be viewed in step E to determine the appropriate action. For example, security personnel can communicate with the unauthorized person or persons causing the anomaly through the microphones  52  and  72  and speakers  54  and  74  to ascertain the person&#39;s status or to warn the person of their violation of security policy.  
         [0056]    If an anomaly is not detected in step A, the image data recorded over the previous time period is, for example, erased in step F and processing returns to step A. Accordingly, a “loop” of video image data is recorded over and over and only saved or played back when an anomaly is detected. Therefore, there is no need to have personnel constantly view surveillance video. The personnel is notified when there has been an anomaly and shown only the relevant video images. The notified person or persons can be anyone coupled to the network of FIG. 1 or otherwise in communication with server  40  through any type of communication channel. The anomaly detection procedure can run constantly in parallel with other processing. Also, instead of automatically enunciating an alarm or the like, the anomaly handling procedure can prompt the person to press a “doorbell” button to notify and communicate with security personnel or other appropriate personnel, such as a receptionist. The button can be integrated with the fingerprint scanner of biometric parameter sensing device  76  to thereby obtain a fingerprint scan of the person attempting entry. The personnel can then normally grant or deny access. All access information, such as time, date and identity of persons granted or denied access (including approach video) can be logged and processed by local access units  60  and server  40  for statistical purposes, asset allocation, or for any other reason.  
         [0057]    It can be seen that the preferred embodiment provides the convenience of reliable biometric access control regardless of environmental variables without sacrificing accuracy. Also, the preferred embodiment processes the biometric parameters at the entrance and thus biometric identification can be accomplished very quickly. The preferred embodiment uses fingerprint parameters for a primary enrollment and facial parameters for a secondary enrollment. However, any biometric or other parameters can be used for each enrollment. The primary enrollment can be accomplished by using a PIN number as identifying data in combination with or in place of biometric parameters. Also, the secondary enrollment can be omitted and identification at the local access unit can be accomplished by the primary enrollment only. For example, enrollment and identification can be accomplished by virtue of sensing of a single biometric parameter with the server downloading templates to the local access units. Access can be granted by sensing the same parameters at the local access units and comparing to the downloaded templates stored in the local access units.  
         [0058]    There can be any number of local access units. Any hardware and/or software can be used in the invention for accomplishing the functions disclosed above. The various data communication and storage can be accomplished using any appropriate formats, protocols, and media. The various disclosed features of the invention can be combined in any manner. The control programs can be programmed in any language by one of skill in the art based on the functions disclosed herein. Any biometric technologies can be used for identification in the invention and any type of sensors or scanners can be used to collect the appropriate data or parameters. The invention can be applied to identification and/or verification systems. The access device can be any device for selectively providing access. The invention can be used to control entry into an area or exit from the area. Accordingly, the term “entrance”, as used herein, refers to a door, gate, passage, or the like through which persons can enter or leave an area.  
         [0059]    The invention has been described through a preferred embodiment. However various modifications can be made without departing from the scope of the invention as defined by the appended claims.