# US 2019/0244459 A1 · Building access control system with spatial modeling > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0244459 A1 - Document ID: US20190244459A1 - Status: Published application - Kind: A1 - Application number: 16/269,384 - Filed: 2019-02-06 - Published: 2019-08-08 - Earliest claimed: 2018-02-07 - Assignees: Johnson Controls Technology Company - Applicants: Johnson Controls Technology Company - Inventors: Donagh S. HORGAN; Jan R. HOLLIDAY; Eamonn O'Toole - Web page: https://patentgrep.com/patent/US20190244459A1 ## CPC - G07C 9/00571: {operated by interacting with a central unit} - G05B 17/02: electric - G06F 16/285: {Clustering or classification} - G06F 30/13: Architectural design, e.g. computer-aided architectural design [CAAD] related to design of buildings, bridges, landscapes, production plants or roads - G07C 9/27: with central registration - G08B 13/08: by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind - G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS ## Abstract A method in an access control system includes maintaining a database of access control event data generated by a plurality of access control devices installed in a building and iterating through the access control event data in order to generate a connectivity model for the building. Generating the connectivity model includes, for each iteration, identifying a user interaction with a first door at a first time and a user interaction with a second door at a second time, determining if a difference between the first time and the second time is less than a threshold period of time, and either creating the connection between the first door and the second door or updating a weight associated with the connection. The connectivity model can be used in the access control system to correlate access control events across locations in a building or building campus. ## Claims ### Claim 1 A method in an access control system, the method comprising: maintaining a database of access control event data generated by a plurality of access control devices installed in a building; iterating through the access control event data in order to generate a connectivity model for the building by, for each iteration: identifying an interaction between a user and an access control device for a first door in the building that occurs at a first time; identifying an interaction between the user and an access control device for a second door in the building that occurs at a second time; determining if a difference between the first time and the second time is less than a threshold period of time; determining if the connectivity model includes a connection between the first door and the second door responsive to a determination that the difference is less than the threshold; creating the connection between the first door and the second door responsive to a determination that the connectivity model does not include the connection; and updating a weight associated with the connection responsive to a determination that the connectivity model does include the connection. ### Claim 2 (depends on 1) The method of claim 1, further comprising removing or disregarding the connection from the connectivity model based on the weight. ### Claim 3 (depends on 2) The method of claim 2, wherein removing or disregarding the connection from the connectivity model based on the weight comprises removing or disregarding the connection from the connectivity model in response to the weight being less than a threshold. ### Claim 4 (depends on 2) The method of claim 2, wherein the connection comprises a first connection and the weight comprises a first weight, and wherein removing or disregarding the first connection from the connectivity model based on the first weight comprises removing or disregarding the first connection from the connectivity model based on a comparison of the first weight to a second weight associated with a second connection. ### Claim 5 (depends on 4) The method of claim 4, further comprising calculating a weight associated with each connection in the connectivity model and removing or disregarding the connection in response to the weight falling below a threshold percentage within a distribution of the weights across the connections in the connectivity model. ### Claim 6 (depends on 4) The method of claim 4, further comprising: calculating a weight associated with each connection in the connectivity model; applying a model to the connections to separate the connections into a plurality of clusters of connections based on similarities of weights; determining a first cluster of the plurality of clusters having smallest weights; and removing or disregarding the connections belonging to the first cluster. ### Claim 7 (depends on 6) The method of claim 6, wherein the model comprises a multi-state Poisson mixture model, and wherein determining the first cluster comprises identifying the first cluster as a cluster of the plurality of clusters having a smallest Poisson rate parameter from among a plurality of Poisson rate parameters of the plurality of clusters. ### Claim 8 (depends on 1) The method of claim 1, further comprising ignoring the interaction between the user and the first door and the interaction between the user and the second door responsive to a determination that the difference is greater than the threshold. ### Claim 9 (depends on 1) The method of claim 1, further comprising identifying an access control zone within the building using the connectivity model. ### Claim 10 (depends on 9) The method of claim 9, further comprising generating an alarm that indicates an intrusion associated with the building responsive to multiple door forced open events occurring within the access control zone within a time period. ### Claim 11 (depends on 1) The method of claim 1, further comprising estimating a probability of a first user coming into contact with a second user or a restricted location using the connectivity model based on a last access control device with which the first user interacted. ### Claim 12 An access control system comprising: one or more processors; and one or more computer-readable storage media having instructions stored thereon that, when executed by the one or more processors, cause the one or more processors to implement operations comprising: maintaining a database of access control event data generated by a plurality of access control devices installed in a building; iterating through the access control event data in order to generate a connectivity model for the building by, for each iteration: identifying an interaction between a user and an access control device for a first door in the building that occurs at a first time; identifying an interaction between the user and an access control device for a second door in the building that occurs at a second time; determining if a difference between the first time and the second time is less than a threshold period of time; determining if the connectivity model includes a connection between the first door and the second door responsive to a determination that the difference is less than the threshold; creating the connection between the first door and the second door responsive to a determination that the connectivity model does not include the connection; and updating a weight associated with the connection responsive to a determination that the connectivity model does include the connection. ### Claim 13 (depends on 12) The system of claim 12, the operations further comprising removing or disregarding the connection from the connectivity model based on the weight. ### Claim 14 (depends on 13) The system of claim 13, wherein removing or disregarding the connection from the connectivity model based on the weight comprises removing or disregarding the connection from the connectivity model in response to the weight being less than a threshold. ### Claim 15 (depends on 13) The system of claim 13, wherein the connection comprises a first connection and the weight comprises a first weight, and wherein removing or disregarding the first connection from the connectivity model based on the first weight comprises removing or disregarding the first connection from the connectivity model based on a comparison of the first weight to a second weight associated with a second connection. ### Claim 16 (depends on 15) The system of claim 15, the operations further comprising calculating a weight associated with each connection in the connectivity model and removing or disregarding the connection in response to the weight falling below a threshold percentage within a distribution of the weights across the connections in the connectivity model. ### Claim 17 (depends on 15) The system of claim 15, the operations further comprising: calculating a weight associated with each connection in the connectivity model; applying a model to the connections to separate the connections into a plurality of clusters of connections based on similarities of weights; determining a first cluster of the plurality of clusters having smallest weights; and removing or disregarding the connections belonging to the first cluster. ### Claim 18 (depends on 17) The system of claim 17, wherein the model comprises a multi-state Poisson mixture model, and wherein determining the first cluster comprises identifying the first cluster as a cluster of the plurality of clusters having a smallest Poisson rate parameter from among a plurality of Poisson rate parameters of the plurality of clusters. ### Claim 19 (depends on 12) The system of claim 12, the operations further comprising ignoring the interaction between the user and the first door and the interaction between the user and the second door responsive to a determination that the difference is greater than the threshold. ### Claim 20 (depends on 12) The system of claim 12, the operations further comprising identifying an access control zone within the building using the connectivity model. ### Claim 21 (depends on 20) The system of claim 20, the operations further comprising generating an alarm that indicates an intrusion associated with the building responsive to multiple door forced open events occurring within the access control zone within a time period. ### Claim 22 (depends on 12) The system of claim 12, the operations further comprising estimating a probability of a first user coming into contact with a second user or a restricted location using the connectivity model based on a last access control device with which the first user interacted.