Access Management System for Tracking Movement Path of Visitors in a Downtown Building and Movement Managing Method thereof

Abstract

An access control system capable of tracking the movement path of visitors within an urban building and a method for tracking and managing the movement path are disclosed. The access control system of the present invention can perform access control and security surveillance without the need for cooperative actions from visitors by repeatedly performing instant walk-through facial authentication on numerous one-time visitors using access control terminals and cameras such as CCTVs installed within the urban building.

Description

Technology Field

[0001] The present invention relates to an access control system for a building with a large number of one-time visitors, and in particular, to an access control system capable of monitoring entry into areas with security levels and tracking movement paths without requesting cooperative actions for visitor authentication every time. Background Technology

[0002] The access control system for downtown buildings performs authentication for regular entrants or temporary registration for one-time visitors, and controls access and manages security by restricting accessible areas within the building according to security levels.

[0003] Visitor access control in typical downtown buildings is performed through terminals installed at main entrances or key security areas within the building. These terminals perform authentication procedures using various authentication methods, including biometric authentication, to allow entry only to those with the appropriate security level. For one-time visitors, terminals that process visit registration through manual entry or facial recognition may be used.

[0004] Regular entrants and visitors must authenticate via a terminal to access key security areas, preventing unauthorized entry into areas with incompatible security levels. The problem is that without this terminal, there is no way to verify and manage where entrants or visitors are and what they are doing after passing through the main entrance of a downtown building. In particular, tracking the activities of registered visitors is a critical security matter. While CCTVs installed within downtown buildings film key areas, administrators are limited to visually monitoring footage recorded on NVRs (Network Video Recorders) or DVRs (Digital Video Recorders). Consequently, managing visitor movement in downtown buildings with thousands of visitors is virtually impossible.

[0005] Among the various authentication methods known in the past, biometric authentication is widely used. Fingerprint recognition, facial recognition, and iris recognition are frequently used for reasons such as their excellent personal identification capabilities, difficulty of duplication, and lack of risk of loss. User authentication using biometric recognition utilizes a method in which feature point data extracted from biometric information is pre-registered, and when authentication is required, newly acquired authentication feature point data is compared with the registered feature point data. If the authentication target is not identified, a 1:N comparison is performed by comparing the authentication data with all N registered data; if there is feature point data similar to a certain level or higher, authentication is successful, and if there is no matching or similar feature point data to a certain level or higher, authentication fails. Prior art literature

[0006] KR 10-2012-0119724 A (Title of Invention: Access Control System and Method) The problem to be solved

[0007] The objective of the present invention is to provide an access control system and an access control method capable of monitoring entry into areas with security levels and tracking movement paths by generating data that enables verification of movement paths without requesting cooperative actions for visitor authentication every time for numerous one-time visitors entering and exiting a building.

[0008] Another objective of the present invention is to provide an access control system and an access control method that can verify movement paths through facial authentication even without cooperative actions from numerous one-time visitors entering and exiting a building, and can manage visitors whose faces cannot be authenticated. means of solving the problem

[0009] To achieve the above objective, the access control system according to the present invention can track and manage the movement paths of visitors in an urban building. The access control method of the present invention includes a shooting step, a face authentication step, a data generation step, and a tracking step. In the shooting step, a first local terminal installed within the urban building captures the front view at a preset interval to generate an image, and uploads at least one face image, in which the face portion of at least one visitor captured in the image is cropped, to a management server. The face authentication step is performed by the management server. In the face authentication step, the management server performs face authentication by comparing the at least one face image provided by the local terminal with a plurality of pre-registered registrant information lists to identify the at least one visitor and assigning a subject identification number to each. For the subject identification number, the registrant identification number of the authenticated registrant is assigned to the face image that succeeds in authentication, and a newly generated surveillance subject identification number is assigned to the face image that fails authentication, thereby setting the person as a surveillance subject. The above management server generates at least one history data including the location information of the local terminal that performed the upload and the subject identification number during the data generation stage, and stores the face images by matching them respectively in the data server.

[0010] As other local terminals installed at different locations within the city building repeat a cycle of sequentially performing the shooting step, face authentication step, and data generation step according to the movement of at least one entrant, the management server performs a tracking step in which it tracks the movement of the monitored person using the historical data stored in the data server.

[0011] According to an embodiment, in the step of performing the monitoring event, the local terminal that performed the upload may output a message requesting the monitored subject to perform authentication through a built-in or external speaker in response to a request from the management server.

[0012] Tracking of surveillance subjects

[0013] According to an embodiment, the access control method of the present invention may further include a surveillance subject registration step in which, in the event of authentication failure, the management server registers surveillance subject registration information, including feature information of the face image and the surveillance subject identification number, in the registrant information list. Subsequently, the movement path of the surveillance subject can be tracked while tracking the face image confirmed as the surveillance subject registered in the face authentication step performed thereafter.

[0014] Untracking of surveillance subjects

[0015] According to another embodiment, the access control method of the present invention may further include the step of the management server deleting the registration information of the monitored person from the registrant information list if, during a cycle in which the location of the monitored person is maintained after the registration of the monitored person, there is a cycle in which a registrant who was not in the previous cycle successfully authenticates and the monitored person disappears.

[0016] Historical data management

[0017] According to another embodiment, the access control method of the present invention may further include, during the tracking step, a step in which the management server deletes the history data of successful authentication among the history data stored in the data server after a preset retention time, thereby preventing the data server from running out of capacity or overflowing.

[0018] Example of a local terminal

[0019] According to another embodiment, the present invention may use an access control terminal as the local terminal, which is installed on the outside of the entrance door of an individual space within the urban building and performs an 'access control mode' that authenticates the visitor and opens / closes the door when there is operation or approach by the visitor, and operates in a 'security mode' to perform the shooting step when there is no operation, request, or cooperation by the visitor. Additionally, a CCTV camera may be used as the local terminal, which is installed in a corridor within the urban building or in the individual space to generate video, and operates in a security mode to perform the shooting step when the visitor is recognized in the image of the video.

[0020] Visitor registration on the registration terminal

[0021] According to another embodiment, the access control method of the present invention may further include the step of a registration terminal performing facial authentication on a visitor at the stage where the visitor enters a downtown building, generating registrant information, and registering it in the registrant information list.

[0022] Access control system

[0023] The present invention also extends to an access control system that performs visitor movement path tracking management or security management in urban buildings.

[0024] The access control system of the present invention comprises a plurality of local terminals, a management server, and a data server. A plurality of local terminals perform a shooting step of capturing the front view at a preset interval to generate an image, and uploading at least one face image to the management server by cropping the face portion of at least one person entering the area captured in the image. The management server performs face authentication by comparing the at least one face image provided by the plurality of local terminals with a list of previously registered registrant information to identify the at least one person entering the area and assigning a subject identification number to each, and generates at least one history data for the at least one face image and stores it in the data server. The data server stores the at least one history data by matching each of the face images.

[0025] The above multiple While repeating the operation cycle by the local terminal and the management server, the management server can track the movement of the monitored person using the history data stored in the data server. Effects of the invention

[0026] The access control system of the present invention utilizes access control terminals and cameras, such as CCTVs, installed within urban buildings to perform access control and security surveillance for numerous one-time visitors without requiring cooperative actions from the visitors. Therefore, according to the present invention, since it uses instant walk-through facial authentication, there is no need to issue physical means, such as contactless recognition cards, for temporary visitors to use when passing through a gate.

[0027] When an entrant accesses a key secure space within an urban building, the system can recognize and respond to the entrant's access rights without requesting authentication, and track the movements of visitors.

[0028] To this end, the present invention eliminates the need for a redundant system by utilizing existing access control terminals or CCTVs installed for security surveillance in urban buildings. Furthermore, regardless of how many people enter the urban building, the amount of data required for facial authentication and the data retention time are minimized, thereby eliminating the need to build a large-capacity data server to track and monitor the movements of numerous entrants. Brief explanation of the drawing

[0029] FIG. 1 is a configuration diagram of an access control system for an urban building according to the present invention. FIG. 2 is a flowchart provided for explaining the visitor movement path tracking method of the access control system of the present invention. FIG. 3 is a cross-sectional view illustrating an example of a visitor movement situation to explain a method for generating historical data, and Figure 4 is a flowchart explaining the method of processing registration information of a person under surveillance. Specific details for implementing the invention

[0030] The present invention will be described in detail below with reference to the drawings.

[0031] Referring to FIG. 1, the access control system (100) of the present invention includes a registration terminal (110), a plurality of local terminals (130), a management server (150), a data server (170), and a network (10) connecting them, and is installed in an urban building to manage access personnel including visitors.

[0032] The term "entry-entry" includes "regular entrants" who reside in or enter the downtown building at regular intervals, as well as "visitors" who visit temporarily. The access control system (100) of the present invention performs access control for regular entrants as well as visitors; however, since the present invention relates to the access control of temporary visitors, the following description specifically explains visitor access control and omits the explanation of the method for managing regular entrants.

[0033] The network (10) may be at least one selected from wired and wireless interfaces, and may be any of the various types of communication interfaces known in the past.

[0034] The registration terminal (110) is equipped with a camera (110a) to acquire a face image of a visitor, extracts feature point data from the face image to generate 'visitor registration information', and performs visitor registration by providing it to the management server (150). When the visitor registration information is stored in the 'registrant information list (155)' of the management server (150), a 'registrant identification number' is assigned. The visitor registration information may include the purpose of the visit, the time of the visit, contact information (phone number), etc. The visitor registration information may also include personal information such as the visitor's name, but this is not a mandatory requirement.

[0035] The registration terminal (110) may be a dedicated device as shown in FIG. 1, or a portable terminal carried by the individual visitor may be used. The visitor's portable terminal is a terminal with an application (or software) installed that can connect to the management server (150) to perform visitor registration.

[0036] The local terminal (130) is a terminal fixed in a downtown building and has a built-in or external camera, and performs a 'shooting step' for the characteristic Instant Walk-through face authentication of the present invention by generating a 'face image' for tracking the visitor's movement path of the present invention. Since the walk-through face authentication is performed, the shooting step operation of the local terminal (130) is performed without any operation, request, or cooperation from the visitor. It is preferable that the local terminal (130) be equipped with a built-in speaker (131b, 135b) or an external speaker (133a).

[0037] The local terminal (130) captures the front at a preset interval to generate an image, and performs image processing on the captured image to check if there is a human face. If a person is detected in the image, the recognized face portion is cropped to generate a face image, and then provided to the management server (150). Since there may be no people in the front and thus no people may be present in the image captured by the local terminal (130), even if the local terminal (130) generates an image at a preset frame rate, the event of uploading the face image to the management server (150) may not occur periodically. Conversely, multiple visitors may be captured in a single image, and the local terminal (130) may generate multiple face images from a single image.

[0038] Here, the face image may be a face with the eyes, nose, mouth, and jawline all exposed, as well as a face wearing a mask or a face with a significant portion covered by hands or a hat, but it must fall within a preset size range sufficient to perform face authentication. Therefore, if the size of the face portion of the visitor captured in the image is not within the preset size, the local terminal (130) ignores it and does not crop it as a face image.

[0039] The local terminal (130) may be implemented in the form of a dedicated terminal for the present invention, but may also be implemented in the form of a multi-purpose device installed in an urban building to perform other functions.

[0040] For example, an access control terminal (131, 135) equipped with a camera (131a, 135a) and installed on the inside or outside of a specific space within a city building can be used as a local terminal (130). The access control terminal (131, 135) operates in an 'access control mode' that performs visitor authentication when there is an operation by a visitor and opens or closes the door according to the result, but operates in a 'security mode' when there is no operation, request, or cooperation from a visitor. During the security mode, the access control terminal (131, 135) can generate an image by capturing the front at a preset frame rate, determine whether there is a person in the image, perform image processing to crop the face image, and provide the face image to the management server (150).

[0041] Additionally, CCTVs (133, 137) installed in corridors or spaces within downtown buildings can also be used as local terminals (130). When a person (visitor) is detected in an image captured while the CCTV (133, 137) is operating in a 'basic operation mode' that captures and stores video, it operates in a 'security mode' to extract a face image and provide it to the management server (150). Thus, the CCTV (133, 137) can perform image processing to recognize a person in an image and cut out a face image.

[0042] Even if dozens of access control terminals and dozens of CCTVs are installed in a large downtown building, not all spaces within the downtown building can be filmed and monitored, as shown in FIG. 3 where the shooting ranges of the first local terminal (131) and the third local terminal (135) do not overlap. All or part of the access control terminals and CCTVs installed within the building can operate as local terminals (130) and be used for walk-through authentication that does not require the cooperation of visitors. A terminal set as a local terminal (130) is registered with the management server (150). FIG. 1 is an example in which an access control terminal equipped with a camera (131a) is set as the first local terminal (131), and a CCTV installed in a hallway is set as the second local terminal (133). Accordingly, the local terminal (130) basically has a fixed installation location and a fixed shooting range, and is individually assigned a 'terminal identification number' and registered with the management server (150).

[0043] The management server (150) manages a list of registrant information (155). The management server (150) tracks the movement path of a visitor by performing face authentication on at least one face image provided by a local terminal (130) and generating history data for tracking movement paths. To this end, the management server (150) includes a registration management unit (151) and an event processing unit (153).

[0044] The registration management department (151) stores and manages visitors in the registrant information list (155) and registers and manages local terminal information. The local terminal information may include terminal location information or the identification number of a surveillance zone that is monitored by the terminal's camera, along with the terminal identification number.

[0045] The event processing unit (153) performs face authentication on a face image provided by the local terminal (130) to identify the visitor and generates and manages the history data. The event processing unit (153) designates visitors who fail face authentication as monitors and tracks them. The operation of the registration management unit (151) and the event processing unit (153) is explained again with reference to FIG. 2 below.

[0046] In the data server (170), history data generated by the management server (150) is stored by matching it with a face image. In addition, history data generated by the local terminal (131, 135), which is an access control terminal, during the access control mode is also stored in the data server (170).

[0047] Example: Visitor management method based on historical data generation

[0048] Hereinafter, with reference to FIG. 2, the access control method of the access control system (100) of the present invention will be explained focusing on the operation of the management server (150).

[0049] <Visitor Registration: S201>

[0050] In order for a visitor to enter the downtown building, visitor registration is required. Visitor registration is performed by the registration terminal (110) and the registration management unit (151) of the management server (150) upon the visitor's request (cooperation).

[0051] First, the registration terminal (110) photographs the visitor with a camera (110a) at the visitor's request and extracts feature point data of the visitor's face to generate 'visitor registration information'.

[0052] When a registration terminal (110) requests visitor registration, the registration management unit (151) of the management server (150) registers the visitor by assigning a 'registrant identification number' to the visitor registration information and storing it in the registrant information list (155). The registrant information list (155) stores not only the 'visitor registration information' but also the 'monitor registration information' to be described below.

[0053] <Shooting steps performed by the local terminal: S203 to S207>

[0054] The local terminal (130) performs a shooting step in which, during a ‘security mode’ in which there is no operation, request, or cooperation from a visitor regarding face shooting, it shoots the front to generate an image, and when it recognizes a person in the generated image, it cuts out the face portion of the recognized person to generate a face image.

[0055] The local terminal (130) may continuously generate images, or it may generate images during a shooting event when an incoming person is recognized by being equipped with a separate sensor (not shown). However, the local terminal (130) periodically generates images by shooting the front at a preset frame rate, whether during a shooting event or during continuous shooting. The local terminal (130) may perform a face image generation operation for all generated images, but it may also perform a face image generation operation by selecting at least one image at regular intervals from among the images of frames continuously generated according to a preset algorithm.

[0056] The local terminal (130) uploads one or more generated face images to the management server (150). The face images uploaded by the local terminal (130) to the management server (150) are merely extracted from images generated at the time of shooting. In other words, the local terminal (130) does not provide the management server (150) with information regarding the temporal / positional connection between the face images, that is, clues or grounds for estimation regarding whether the face image is the same person as someone captured in a previous frame or someone captured by another local terminal (130). Referring to FIG. 3, it is assumed that the first local terminal (131) and the third local terminal (135) take 10 photos per second, and that Visitor A and Visitor B stop in front of the first local terminal (131) to talk, and then walk down the hallway at a normal walking speed following the arrow. Assume that the first local terminal (131) captures Visitor A and Visitor B for 1 minute to generate 600 images, and after 5 seconds, the third local terminal (135) captures passing Visitor A for 2 seconds to generate 20 images. The first local terminal (131) provides 2 face images extracted from the 600 images to the management server (150) 600 times, and the third local terminal (135) provides 1 face image extracted from the 20 images to the management server (150) 20 times. As previously explained, the first local terminal (131) does not provide information regarding connectivity between the face images provided 600 times to the management server (150), and the third local terminal (135) does not provide information regarding connectivity between the face images provided 20 times to the management server (150). However, it can be confirmed that the two face images uploaded by the first local terminal (131) at once were taken at the same time.

[0057] <Face Authentication: S209, S211>

[0058] First, for face authentication, the event processing unit (153) of the management server (150) compares each face image provided by the local terminal (130) with a plurality (N) of registrants registered in the registrant information list (155) to determine if it is a previously registered registrant. The face authentication of the event processing unit (153) is a 1:N authentication that determines whether a face image is a registrant without other information, and a conventionally known face authentication algorithm can be used.

[0059] The list of registrant information (155) includes the registration information of visitors who have registered through the registration terminal (110). Depending on the embodiment, the registration information of the person under surveillance described in step S217 below may be stored. For example, the person may be in a state of being registered as a person under surveillance in step S217 of the method of FIG. 2, which was performed on the face image provided by the second local terminal (133) about 10 minutes ago.

[0060] Face authentication is successful when the face image is determined to be the same person as one of the entrants registered in the registrant information list (155), and face authentication is failed when there is no person among the entrants registered in the registrant information list (155) who is determined to be the same person as the face image.

[0061] <If face authentication was successful: S213>

[0062] The event processing unit (153) generates history data based on the result of face authentication. The history data is data that recognizes visitors in real time and is intended for tracking movement paths. The management server (150) can check the movement path of a visitor by confirming the visitor's location using a face image captured and provided by the local terminal (130).

[0063] The history data includes subject identification numbers, location information, and time information, and other information such as security levels may be added depending on various embodiments.

[0064] The subject identification number is assigned based on face authentication. If face authentication is successful in steps S209 and S211 and the subject is determined to be the same person as one of the visitors registered in the registrant information list (155), the event processing unit (153) designates the 'registrant identification number' confirmed in the 'registration information' of the registrant (visitor) verified by face authentication as the subject identification number.

[0065] Location information is information about the location of the visitor captured in the face image. Instead of the visitor's location, the location information of the local terminal (130) that uploaded the face image or the 'terminal identification number' can be used, or the identification number of the surveillance zone captured by the camera of the local terminal (130) can be used. Time information may use the time of uploading the face image of the local terminal (130), the time of creating the face image of the local terminal (130), or the time of creating the image of the local terminal (130). The time of creating the face image of the local terminal (130) or the time of creating the image of the local terminal (130) can be provided by the local terminal (130) when uploading the face image in step S207. The security level is assigned to the level given to the temporary visitor. Regular visitors or fixed-term visitors will have their corresponding security level checked.

[0066] The event processing unit (153) stores the generated history data along with the face image in the data server (170).

[0067] <Face authentication failed: S215, S217>

[0068] Authentication failure occurs when there is no face in the registrant information list (155) that matches the face image provided by the local terminal (130) via S207, and therefore the identity cannot be determined. If face authentication fails even though the visitor's face is captured in the face image, it is because the visitor is wearing a mask, covering their face with their hands or a hat, or is a person who is not registered as a visitor. Accordingly, the event processing unit (153) generates a new identification number (hereinafter referred to as the monitored person identification number) for the corresponding face image and designates it as the person identification number, and then generates history data including the person identification number, location information, time information, and security level. The event processing unit (153) stores the generated history data along with the face image in the data server (170).

[0069] The event processing unit (153) sets the face image that failed authentication as a 'monitor' and creates 'monitor registration information' containing feature point data extracted from the face image of the monitor, and registers it by storing it in the registrant information list (155). The event processing unit (153) can request the local terminal (130) that provided the face image in step S207 to output an authentication guidance message through the speakers (131b, 133a, 135b) using the location information included in the history data, and the local terminal (130) outputs the guidance message using the speakers (131b, 133a, 135b). The guidance message may be, for example, 'Please remove your mask'.

[0070] In the above method, the storage of history data using the face image generated by the local terminal (130) is performed.

[0071] Tracking Surveillance Subjects

[0072] History data is real-time data for tracking movement paths. When a visitor moves around various places within the downtown building after registering their visit, different local terminals installed at different locations within the downtown building perform steps S203 to S207 at regular intervals, and the event processing unit (153) performs steps S209 to S217, repeating the cycle, and as a result, history data is accumulated in the data server (170).

[0073] Accordingly, the management server (150) can track the movements of visitors and monitors by extracting historical data containing a specific target identification number from among the historical data accumulated in the data server (170).

[0074] For visitors who have successfully authenticated their faces, the approximate movement path of the user over time can be determined by using the historical data accumulated in the data server (170). Even when face authentication fails, the location where the monitored person was first identified and their subsequent movement path can be determined by using the historical data accumulated in the data server (170).

[0075] Data Server Management

[0076] Meanwhile, the management server (150) can manage the total data volume to a certain level by deleting the history data and face images stored and managed in the data server (170) after a certain maintenance period has elapsed. For example, in the case where thousands of visitors enter and exit a downtown building where dozens of local terminals (130) are installed, hundreds of millions to billions of face images can be generated, and accordingly, hundreds of millions to billions of history data can be generated. The required capacity of the data server (170) must increase, and a problem may arise where system resources become insufficient due to the explosion of data.

[0077] If 100 terminals, including fifty access control terminals and fifty CCTVs, are used as local terminals (130), assuming that all local terminals (130) capture 10 images per second, 3,600,000 images are generated in one hour, and 36 million images are generated in 10 hours. Here, assuming that 2 face images are generated per image, 72 million face images are generated in 10 hours, and assuming that 5 face images are generated per image, 180 million face images are generated and uploaded in 10 hours. As the number of visitors increases, the number of face images increases exponentially.

[0078] The registration management department (151) can prevent a shortage of system resources in the data server (170) by deleting the history data and face images stored in the data server (170) after a certain retention period has elapsed. The history data and face images are deleted when a preset retention period has elapsed since they were stored in the data server (170). The retention period can be set to, for example, as short as 5 minutes, 10 minutes, or 15 minutes, or as long as 24 hours. When the visitor leaves the downtown building, the visitor registration information stored in the registrant information list (155) is also deleted.

[0079] Example of Implementation: Deletion of Surveillance Subject Registration Information

[0080] The same applies to the registration information of the monitored person. For example, if, while a cycle in which the location of the monitored person is maintained is repeated after the registration of the monitored person, there is a cycle in which a registrant who was not in the previous cycle is successfully authenticated and the monitored person disappears, the registration management unit (151) deletes the registration information of the monitored person from the registrant information list (155).

[0081] In the example of FIG. 3, it is assumed that Visitor A and Visitor B are having a conversation in front of the first local terminal (131) for about 3 minutes before moving in the direction of the arrow, and that Visitor A appears in front of the first local terminal (131) wearing a mask and meets Visitor B. The first local terminal (131) is set to take 10 photos per second.

[0082] Referring to FIG. 4, the first local terminal (131) extracts two face images from one image taken at any time and provides them to the management server (150), and the event processing unit (153) identifies one of the two face images as visitor B, but the other is not identified among the registered visitors and is designated as a monitor (S401 to S405).

[0083] Since visitors A and B maintain their current locations, the first local terminal (131) uploads two face images in the next frame, and the state in which one of the two face images is not identified as a registered visitor continues to repeat. If it is assumed that visitor A removes the mask after about 2 minutes, the cycle in which the first local terminal (131) generates a face image and only visitor B is identified by face authentication continues for 2 minutes (S407, S409).

[0084] When visitor A removes the mask at the current location, the first local terminal (131) continues to generate face images, and in the following cycle, visitor A and visitor B are suddenly authenticated and the monitor disappears. Then, the registration management unit (151) deletes the registration information of the monitor registered during the past 2 minutes from the registrant information list (155) (S411).

[0085] In order for S411 to be performed, the event processing unit (153) may request the first local terminal (131) to output a guidance message after step S405, and the first local terminal (131) may output the guidance message through the built-in speaker (131b).

[0086] Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. Various modifications are possible by those skilled in the art without departing from the essence of the invention as claimed in the claims, and such modifications should not be understood individually from the technical spirit or perspective of the present invention.

Claims

Claim 1 A method for tracking and managing the movement path of visitors in an urban building comprises: a shooting step in which a local terminal installed within the urban building captures the front at a preset interval to generate an image, and uploads at least one face image to a management server by cropping out the face portion of at least one visitor captured in the image; a face authentication step in which the management server compares the at least one face image with a registrant in a registrant information list to identify the at least one visitor and assigns a subject identification number to each, wherein the registrant identification number of the verified registrant is assigned to the face image that succeeds in authentication, and the face image that fails authentication is set as a monitored subject and assigned a newly generated monitored subject identification number; a data generation step in which the management server generates at least one history data including the location information of the local terminal that performed the upload and the subject identification number, and matches the face images to each and stores them in a data server; and, in the case of authentication failure, a monitored subject registration step in which the management server registers monitored subject registration information including the feature information of the face image and the monitored subject identification number in the registrant information list. An access control method of an access control system characterized by including a tracking step in which the management server tracks the movement of the monitored person using historical data stored in the data server while repeating a cycle of sequentially performing the shooting step, face authentication step, and data generation step by different local terminals installed at different locations within the city building and the management server according to the movement of at least one accesser. Claim 2 An access control method of an access control system, characterized in that, in claim 1, the local terminal that performed the upload further includes the step of performing a monitoring event in which the local terminal requests the monitored subject to perform authentication in accordance with the request of the management server. Claim 3 An access control method of an access control system according to paragraph 2, characterized in that, while repeating a cycle in which the local terminal that performed the upload and the management server sequentially perform the shooting step, the face authentication step, and the data generation step after the registration of the surveillance subject, if there is a cycle in which a registrant who was not in the previous cycle succeeds in authentication and the surveillance subject disappears, the management server further includes the step of deleting the surveillance subject registration information from the registrant information list. Claim 4 An access control method of an access control system, characterized in that, in the step of performing the monitoring event according to paragraph 2, the local terminal that performed the upload outputs a message requesting the monitored subject to perform authentication through a built-in or external speaker. Claim 5 An access control method of an access control system, characterized in that, in the first aspect, during the tracking step, the management server further includes the step of deleting the history data of successful authentication among the history data stored in the data server after a preset retention time. Claim 6 An access control method of an access control system according to claim 1, wherein the local terminal is installed on the outside of the entrance door of an individual space within the urban building, performs an 'access control mode' that performs access authentication and opens / closes the entrance door when there is operation or approach by an accesser, and operates in a 'security mode' to perform the shooting step when there is no operation, request, or cooperation by an accesser. Claim 7 An access control method of an access control system according to claim 6, wherein the local terminal is installed in a corridor or individual space within the urban building to generate video, and when the person entering is recognized in the image of the video, it includes a CCTV camera that operates in security mode to perform the shooting step. Claim 8 An access control method of an access control system, characterized in that, in claim 1, the registration terminal further includes the step of performing facial authentication on the visitor at the stage where the visitor enters the downtown building, generating registrant information, and registering it in the registrant information list. Claim 9 In an access control system for an urban building, a plurality of devices installed at different locations within the urban building perform a shooting step of capturing the front at a preset interval to generate an image, and uploading at least one face image to a management server in which the face portion of at least one entrant captured in the image is cropped. A local terminal; a management server that performs face authentication by comparing at least one face image provided by the plurality of local terminals with a registrant in a registrant information list to identify the at least one entrant and assign a subject identification number to each, and generates at least one history data for the at least one face image and stores it in a data server; and a data server that stores the at least one history data by matching it with the face image, wherein the history data includes location information of the local terminal that performed the upload and the subject identification number, wherein the registrant identification number of the registrant who succeeded in authentication is assigned as the subject identification number for the face image that succeeded in authentication, and the face image that failed authentication is set as a surveillance target and a newly generated surveillance target identification number is assigned as the subject identification number, and the plurality of An access control system characterized by, while repeating a cycle in which a shooting step by a local terminal and face authentication and history data generation by the management server are sequentially performed, the management server tracks the movement of the monitored person using history data stored in the data server, and in the case of authentication failure, the management server tracks the movement path of the monitored person by registering the monitored person registration information, which includes feature information of the face image and the monitored person identification number, in the registrant information list. Claim 10 delete Claim 11 An access control system according to claim 9, wherein the management server deletes the registration information of the monitored person from the registrant information list if, during the repetition of the cycle while the location of the monitored person is maintained after the registration of the monitored person, there is a cycle in which a registrant who was not in the previous cycle successfully authenticates and the monitored person disappears. Claim 12 An access control system characterized in that, in claim 9, the local terminal that performed the upload outputs a guidance message requesting the monitored subject to perform authentication through a built-in or external speaker in response to a request from the management server. Claim 13 An access control system according to claim 9, wherein the management server deletes the history data of successful authentication among the history data stored in the data server after a preset retention time. Claim 14 An access control system according to claim 9, wherein the local terminal is installed on the outside of the entrance door of an individual space within the urban building, and operates in an 'access control mode' that performs access authentication and opens / closes the entrance door when there is operation or access by an accesser, and operates in a 'security mode' to generate a face image of the shooting step when there is no operation, request, or cooperation by an accesser. Claim 15 An access control system according to claim 14, wherein the local terminal is installed in a corridor or individual space within the city building to generate video, and when the person entering is recognized in the image of the video, it operates in security mode to generate a face image of the shooting step. Claim 16 An access control system according to claim 9, further comprising a registration terminal that performs facial authentication on the visitor at the stage where the visitor enters the downtown building, generates registrant information, and registers it in the registrant information list.

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