Entrance guard control system based on single chip microcomputer

Abstract

The invention discloses an access control system based on a single-chip microcomputer, and relates to the technical field of access control, the access control system comprises an access control system, when a user sends a door opening request through card swiping, password input and fingerprint identification modes, the control system sends a control signal to open a door, and the access control system is started; the system has the advantages that dangerous behaviors are recognized through the environment perception and dangerous behavior recognition module, an access control program is rapidly triggered, access control points for personnel evacuation around a dangerous area are started, personnel in a threatened area can be rapidly and orderly evacuated, the time for people to be trapped in the dangerous area is shortened, the casualty risk is reduced, and when a fire occurs, the safety of the personnel is improved. The system responds quickly, opens an evacuation channel door in time, strives for precious time for people to escape, and sends an opening prohibition instruction to an access control point leading to a dangerous area, so that people are prevented from entering the dangerous area without knowing the situation, more people are prevented from being hurt, and the expansion of a dangerous range is effectively controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of access control, in particular to an access control system based on a single chip microcomputer. Background Art

[0002] Access control system is in the field of intelligent buildings, which means Access Control System, referred to as ACS, which refers to the prohibition of "doors" and is a precaution against "doors". Here, "doors" in a broad sense include various passages that can be passed, including doors for people and vehicles. Therefore, access control includes vehicle access control. In parking lot management applications, vehicle access control is an important means of vehicle management. It is not for the purpose of collecting parking fees, but mainly for managing vehicle access rights.

[0003] The entrance and exit security management system is a new modern security management system, which integrates microcomputer automatic identification technology and modern security management measures. It involves many new technologies such as electronics, machinery, optics, computer technology, communication technology, biotechnology, etc. It is an effective measure to solve the security management of the entrances and exits of important departments, and is suitable for various confidential departments, such as banks, hotels, parking lot management, computer rooms, armories, confidential rooms, offices, intelligent communities, factories, etc.

[0004] The existing access control system only focuses on controlling the entry and exit of personnel, and does not have the ability to perceive the environment in real time and identify dangerous behaviors. The existing access control system cannot detect dangerous behaviors such as fire, fighting, illegal intrusion, etc. When a danger occurs, it cannot control the status of the access control point in time to ensure the safety of personnel. For this reason, we propose an access control system based on a single-chip microcomputer. Summary of the invention

[0005] The purpose of the present invention is to provide a door access control system based on a single chip microcomputer.

[0006] To achieve the above object, the present invention provides the following technical solutions: an access control system based on a single-chip microcomputer, including an access control system, when a user issues a door opening request by swiping a card, inputting a password, or fingerprint recognition, the control system sends a control signal to open the door, and the access control system based on a single-chip microcomputer also includes the following modules:

[0007] Identity verification module: The access control point uses a single-chip microcomputer as the core and integrates identity verification hardware. The single-chip microcomputer receives signals from the sensor and uses dynamic power management technology. The identity verification hardware also supports NFC, fingerprint recognition, face recognition and password input.

[0008] Environmental perception and dangerous behavior recognition module: A camera equipped with an image recognition chip is selected. Infrared sensors, sound sensors, gas sensors, and vibration sensors are deployed in different areas, and corresponding area numbers are assigned to each sensor. Based on the feedback from area sensors, dangerous areas are determined. After a dangerous behavior is recognized, access control is triggered to open the surrounding evacuation access control and prohibit opening the access control to the dangerous area.

[0009] Communication module: The switch signal of the electronic lock at each access control point is fed back to the single-chip microcomputer through an independent line, and the sensors are connected to the access control system through an Ethernet module.

[0010] Door lock control and power supply module: An electromagnetic lock is used for the opening and closing of the access control point. The single-chip microcomputer sends a signal to the electromagnetic lock drive circuit to control the opening and closing of the electromagnetic lock. An ordinary power supply is used to provide the basic power supply for the entire access control system. At the same time, a standby power supply is used as an emergency power supply, which automatically switches to supply power to the system when there is a power outage.

[0011] Permission management module: Different access permissions are set according to the security levels and functional requirements of different areas. When a dangerous behavior occurs, temporary special permissions are set for security personnel and firefighters.

[0012] As a further solution of the present invention: The identity verification module selects a single-chip microcomputer as the core control unit. The single-chip microcomputer is responsible for receiving and processing signals from each module. The module includes identity verification hardware and environmental perception and dangerous behavior recognition sensors. Two sleep modes are set in the single-chip microcomputer. The sleep modes include the stop mode and the standby mode. When no one approaches the access control point for 10 minutes and no abnormal signals are detected by each sensor, the single-chip microcomputer enters the stop mode, and the internal functional modules of the single-chip microcomputer stop working, only retaining the clock source and the wake-up logic circuit. When no one approaches the access control point within 5 - 10 minutes, the single-chip microcomputer enters the standby mode, and the basic peripheral interfaces remain working. By setting external interrupts, the signals of the identity verification hardware and sensors are used as wake-up sources. When a wake-up source signal is detected, the single-chip microcomputer is woken up from the sleep mode through the wake-up logic circuit and enters the normal working state.

[0013] Stop mode: Only the wake-up circuit is retained, and the wake-up sources are sensor signals or identity verification inputs.

[0014] Standby mode: Peripheral interfaces (such as UART, SPI) operate in low power consumption. The wake-up source is an external interrupt signal, and the wake-up delay time is supplemented (for example, the wake-up from the stop mode requires ≤50 ms, and the standby mode requires ≤10 ms).

[0015] As a further solution of the present invention: The authentication hardware integrates an NFC module, a fingerprint recognition module, a face recognition camera, and a password keyboard. The NFC module uses an NFC controller chip, and the NFC controller chip is connected to the single-chip microcomputer through an SPI interface to transmit the read card data to the single-chip microcomputer for processing. The fingerprint recognition module is equipped with a fingerprint sensor, and the fingerprint sensor communicates with the single-chip microcomputer through a UART interface, compares the collected fingerprint features with the pre-stored templates, and feeds back the comparison results to the single-chip microcomputer. The face recognition camera selects a high-definition camera and is equipped with a face recognition chip. After the camera captures the facial image of a person, the face recognition chip performs preliminary feature extraction and analysis, and then transmits the results to the single-chip microcomputer through a USB interface, and the single-chip microcomputer completes the authentication judgment. The password keyboard is a password keyboard composed of membrane keys, and the password keyboard is connected to the single-chip microcomputer through a GPIO interface. After the user enters the password, the single-chip microcomputer reads the password information and verifies it.

[0016] As a further solution of the present invention: The environment perception and dangerous behavior recognition module includes an environment perception module and a dangerous behavior recognition module. The environment perception module selects a camera equipped with an image recognition chip, and infrared sensors, sound sensors, gas sensors, and vibration sensors are deployed in different areas. Each sensor collects environmental data in real time and transmits it to the single-chip microcomputer through the corresponding communication interface. After receiving the data from each sensor, the single-chip microcomputer uses a data fusion algorithm to comprehensively analyze the multi-source data. The data of each sensor carries its corresponding area number, enabling the single-chip microcomputer to identify the data source and the occurrence area.

[0017] As a further solution of the present invention: The danger recognition module integrates a data fusion algorithm and a dangerous behavior recognition algorithm. The data fusion algorithm comprehensively analyzes the data from different sensors. The dangerous behavior recognition algorithm is based on image recognition and sound analysis technologies, extracts features and performs pattern matching on the images captured by the camera, and combines the data of the sound sensor and the infrared sensor. At the same time, according to the feedback of sensors in different areas, it determines the area where dangerous behavior occurs. When the danger recognition module recognizes dangerous behavior and determines the danger area, it triggers the access control program, sends an opening instruction to the access points around the danger area that can be used for personnel evacuation, and at the same time sends a prohibition instruction to the access points leading to the danger area;

[0018] When multiple dangerous events are triggered simultaneously, the system executes responses according to the preset priorities (such as fire > illegal intrusion > others). When a fire occurs, all evacuation channels are preferentially opened, covering other low-priority instructions;

[0019] Using the weighted fusion method, the weight of the infrared sensor data is 0.3, the sound sensor is 0.2, and the gas sensor is 0.5 (dynamically adjusted according to the type of danger);

[0020] Data preprocessing includes normalization, noise filtering (such as Kalman filtering), and timestamp synchronization.

[0021] As a further solution of the present invention: The communication module is equipped with an independent feedback line for each access control point. Each access control point communicates with the single-chip microcomputer through the feedback line. The single-chip microcomputer can grasp the on / off state of the electromagnetic lock at each access control point in real time through the interrupt mode. According to the number of sensors, data transmission rate, and communication distance, an Ethernet module with a rate of 100Mbps - 500Mbps is selected. The Ethernet module sends the collected sensor data to the single-chip microcomputer. During the transmission process, a redundant communication line design is adopted. When one communication line fails, the access control system automatically switches to the standby line;

[0022] Fire recognition: Joint determination is carried out through a gas sensor (CO2 concentration > 1000ppm) and an infrared sensor (temperature sudden increase > 10°C / min);

[0023] Fighting recognition: Analysis is carried out by combining the camera image features (physical conflict actions) with a sound sensor (decibel value > 90dB).

[0024] As a further solution of the present invention: The door lock control and power supply module includes a door lock control module and a power supply module. The door lock control module includes an electromagnetic lock and an electromagnetic lock drive circuit. The corresponding electromagnetic lock is selected according to the type of the door at the access control point. When the environmental perception and dangerous behavior recognition module detects the occurrence of a dangerous behavior, the single-chip microcomputer sends an opening signal to the electromagnetic lock drive circuit of the relevant access control point according to the preset rules to open the electromagnetic lock of the evacuation passage;

[0025] When the main line fails, the standby line is automatically enabled within ≤100ms, and the line status is detected through heartbeat packets;

[0026] The Ethernet module supports dual MAC address binding to ensure seamless data switching.

[0027] As a further solution of the present invention: The power supply module includes a normal power supply, a power supply switching circuit, and a backup power supply. The normal power supply is responsible for converting the commercial power into the DC voltage required by each module of the access control system. The backup power supply uses a storage battery as an energy storage device. When the commercial power is normal, the power supply switching circuit connects the output of the normal power supply to the access control system and charges the storage battery at the same time. When the commercial power is cut off, the power supply switching circuit automatically connects the output of the storage battery to the access control system.

[0028] As a further solution of the present invention: The permission management module sets temporary special permissions for special personnel, including security personnel and fire fighters. The temporary special permissions include emergency door opening permissions and equipment operation permissions. In case of danger, after verifying the password and identifying the identity of the special personnel, the corresponding permissions are granted to the special personnel, giving them the permission to temporarily open specific access control doors for rescue work. After the dangerous situation is lifted, the access control system automatically withdraws the temporary special permissions. At the same time, the usage situation of the special permissions is recorded for subsequent auditing and querying;

[0029] Security personnel activate temporary permissions through dual verification (password + fingerprint), and the validity period of the permissions ≤ 30 minutes. The system automatically records the operation logs (time, personnel ID, access control point);

[0030] Fire fighters directly trigger the emergency door opening instruction through a dedicated NFC card (encrypted IC card) without secondary verification.

[0031] Adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. The present invention identifies dangerous behaviors through the environmental perception and dangerous behavior recognition module, quickly triggers the access control program, and opens the access control points for personnel evacuation around the dangerous area, enabling the people in the threatened area to evacuate quickly and orderly, reducing the time trapped in the dangerous area, and reducing the risk of casualties. In case of a fire, the system reacts quickly, opens the evacuation passage door in time, buys precious time for people to escape, and at the same time sends a prohibition instruction to the access control points leading to the dangerous area to prevent people from entering the dangerous area without knowing it and avoid more people being injured, effectively controlling the expansion of the dangerous range;

[0033] 2. The present invention provides temporary special permissions for security personnel and fire fighters through the permission management module, enabling them to quickly enter the dangerous area for rescue work. Fire fighters can quickly open the relevant access controls with special permissions and approach the fire source to carry out fire extinguishing operations. Security personnel can arrive at the scene in time to maintain order and assist in evacuation, improving the rescue efficiency, ensuring the safety of the trapped people's lives, controlling the status of the access control points in time, restricting the influence range of dangerous behaviors, and reducing the damage of the danger to the property in the surrounding area. Taking a fire as an example, it prevents the fire from spreading to other areas through the passage, protecting more equipment, materials and other properties from the fire. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic flow chart of the access control system based on a single-chip microcomputer in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The following further describes the specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted here that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation to the present invention.

[0036] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] An access control system based on a single-chip microcomputer of the present invention includes an access control system. When a user issues an opening request through methods such as card swiping, password input, and fingerprint recognition, the control system issues a control signal to open the door. The access control system based on a single-chip microcomputer further includes the following modules:

[0038] An identity verification module. A single-chip microcomputer is used as the core at the access point, and identity verification hardware is integrated. The single-chip microcomputer receives signals transmitted by sensors and adopts dynamic power management technology. The identity verification hardware supports NFC, fingerprint recognition, face recognition, and password input at the same time;

[0039] An environmental perception and dangerous behavior recognition module. A camera equipped with an image recognition chip is selected, and infrared sensors, sound sensors, gas sensors, and vibration sensors are deployed in different areas, and corresponding area numbers are assigned to each sensor. Based on the feedback of area sensors, dangerous areas are determined. After a dangerous behavior is recognized, access control is triggered, the surrounding evacuation access is opened, and the access to the dangerous area is prohibited from being opened;

[0040] A communication module. Each access point feeds back the switch signal of the electronic lock to the single-chip microcomputer through an independent line, and the sensors are connected to the access control system through an Ethernet module;

[0041] A door lock control and power supply module. An electromagnetic lock is used for the opening and closing of the access point. The single-chip microcomputer sends a signal to the electromagnetic lock drive circuit to control the opening and closing of the electromagnetic lock. An ordinary power supply is used to provide the basic power supply for the entire access control system. At the same time, a backup power supply is used as an emergency power supply and automatically switches to power the system when there is a power outage;

[0042] A permission management module. Different access permissions are set according to the security levels and functional requirements of different areas. When a dangerous behavior occurs, temporary special permissions are set for security personnel and firefighters.

[0043] In an embodiment of the present invention: The authentication module selects a single-chip microcomputer as the core control unit. The single-chip microcomputer is responsible for receiving and processing signals from each module. The modules include an authentication hardware, an environment perception and dangerous behavior recognition sensor. Two sleep modes are set in the single-chip microcomputer. The sleep modes include a stop mode and a standby mode. When no person approaches the access control point for 10 minutes and no abnormal signals are detected by each sensor, the single-chip microcomputer enters the stop mode. The internal functional modules of the single-chip microcomputer stop working, and only the clock source and the wake-up logic circuit are retained. When no person approaches the access control point within 5 to 10 minutes, the single-chip microcomputer enters the standby mode. The basic peripheral interfaces remain working. By setting an external interrupt and using the signals of the authentication hardware and the sensor as wake-up sources, when a wake-up source signal is detected, the single-chip microcomputer is woken up from the sleep mode through the wake-up logic circuit and enters the normal working state.

[0044] In an embodiment of the present invention: The authentication hardware integrates an NFC module, a fingerprint recognition module, a face recognition camera, and a password keyboard. The NFC module uses an NFC controller chip. The NFC controller chip is connected to the single-chip microcomputer through an SPI interface and transmits the read card data to the single-chip microcomputer for processing. The fingerprint recognition module is equipped with a fingerprint sensor. The fingerprint sensor communicates with the single-chip microcomputer through a UART interface, compares the collected fingerprint features with the pre-stored templates, and feeds back the comparison results to the single-chip microcomputer. The face recognition camera selects a high-definition camera and is equipped with a face recognition chip. After the camera collects the facial images of people, the face recognition chip performs preliminary feature extraction and analysis, and then transmits the results to the single-chip microcomputer through a USB interface. The single-chip microcomputer completes the authentication judgment. The password keyboard is a password keyboard composed of membrane keys. The password keyboard is connected to the single-chip microcomputer through a GPIO interface. After the user inputs a password, the single-chip microcomputer reads the password information and verifies it.

[0045] In an embodiment of the present invention: The environment perception and dangerous behavior recognition module includes an environment perception module and a dangerous behavior recognition module. The environment perception module selects a camera equipped with an image recognition chip, and infrared sensors, sound sensors, gas sensors, and vibration sensors are deployed in different areas. Each sensor collects environmental data in real time and transmits it to the single-chip microcomputer through the corresponding communication interface. After the single-chip microcomputer receives the data from each sensor, it uses a data fusion algorithm to comprehensively analyze the multi-source data. The data of each sensor carries its corresponding area number, enabling the single-chip microcomputer to identify the data source and the occurrence area.

[0046] In an embodiment of the present invention: The danger recognition module integrates a data fusion algorithm and a dangerous behavior recognition algorithm. The data fusion algorithm comprehensively analyzes data from different sensors. The dangerous behavior recognition algorithm, based on image recognition and sound analysis technologies, extracts features and performs pattern matching on the images captured by the camera, combines the data from the sound sensor and the infrared sensor. Meanwhile, according to the feedback from sensors in different areas, it determines the area where the dangerous behavior occurs. When the danger recognition module recognizes a dangerous behavior and determines the danger area, it triggers the access control program, sends an opening instruction to the access control points around the danger area that can be used for personnel evacuation, and at the same time sends a prohibition instruction to the access control points leading to the danger area.

[0047] In an embodiment of the present invention: The communication module equips each access control point with an independent feedback line. Each access control point communicates with the single-chip microcomputer through the feedback line. The single-chip microcomputer real-time masters the on-off state of the electromagnetic locks at each access control point through the interrupt mode. According to the number of sensors, data transmission rate, and communication distance, an Ethernet module with a speed of 100 Mbps - 500 Mbps is selected. The Ethernet module sends the sensor data collected to the single-chip microcomputer. During the transmission process, a redundant communication line design is adopted. When one communication line fails, the access control system automatically switches to the standby line.

[0048] In an embodiment of the present invention: The door lock control and power supply module includes a door lock control module and a power supply module. The door lock control module includes an electromagnetic lock and an electromagnetic lock drive circuit. The corresponding electromagnetic lock is selected according to the type of the door at the access control point. When the environmental perception and dangerous behavior recognition module detects that a dangerous behavior occurs, the single-chip microcomputer sends an opening signal to the electromagnetic lock drive circuit of the relevant access control point according to the preset rules to open the electromagnetic lock of the evacuation passage.

[0049] In an embodiment of the present invention: The power supply module includes a normal power supply, a power supply switching circuit, and a backup power supply. The normal power supply is responsible for converting the commercial power into the DC voltage required by each module of the access control system. The backup power supply uses a storage battery as the energy storage device. When the commercial power is normal, the power supply switching circuit connects the output of the normal power supply to the access control system and charges the storage battery at the same time. When the commercial power is cut off, the power supply switching circuit automatically connects the output of the storage battery to the access control system.

[0050] In an embodiment of the present invention: The permission management module sets temporary special permissions for special personnel. Special personnel include security personnel and fire-fighting personnel. The temporary special permissions include emergency door opening permissions and equipment operation permissions. When a danger occurs, after verifying the password and identifying the identity of the special personnel, the corresponding permissions are granted to the special personnel, giving them the temporary permission to open specific access controls for rescue work. After the dangerous situation is lifted, the access control system automatically withdraws the temporary special permissions. At the same time, the usage situation of the special permissions is recorded for subsequent auditing and query.

[0051] Example 1: According to the functions and characteristics of different areas, reasonably select the types and installation positions of sensors. For example, in areas with frequent personnel flow such as entrances, exits, and corridors, cameras and infrared sensors should be key deployed; in areas where gas leakage may occur, such as kitchens and machine rooms, gas sensors should be installed to avoid interference between sensors and affect the monitoring effect. For example, the installation positions of cameras and infrared sensors should avoid mutual occlusion, and sound sensors should be far away from noise sources. According to the structure and function of the building, the entire area is divided into multiple sub-areas, including floors, rooms, corridors, etc. Each sub-area has relatively independent functions and safety requirements. A unified numbering rule is used to number each area to facilitate the system to manage and analyze sensor data. For example, the numbering can be in the form of "building number - floor number - room number", such as "A-3-02" representing Room 02 on the 3rd floor of Building A. The sensors in each area add a suffix based on the area number, such as "A-3-02-C" representing the camera in Room 02 on the 3rd floor of Building A, and "A-3-02-I" representing the infrared sensor in this room.

[0052] Example 2: The single-chip microcomputer receives the fused data and first conducts a preliminary screening to check whether the data of a single sensor exceeds the preset warning threshold. If so, proceed to the next step of detailed judgment; if not, it is determined that there is no dangerous behavior at present and continue to monitor. For the abnormal data situation screened out initially, conduct correlation analysis in combination with the multi-sensor cooperation rules. For example, if the sound sensor detects a high-decibel sound, check whether there are violent movements of people in the camera and whether there are multiple heat sources moving quickly in the infrared sensor, etc. After the multi-sensor data correlation analysis meets certain conditions, check whether this abnormal situation meets the time rule. If it meets, it is determined that there is a dangerous behavior; if it does not meet, it is determined to be a suspected dangerous behavior and continue to monitor for a period of time. If the time condition is still not met subsequently, the dangerous behavior is excluded. Once it is determined that there is a dangerous behavior, determine the specific area where the dangerous behavior occurs according to the area number of the sensor, and classify the dangerous behavior according to the data characteristics, such as fire, fight, etc. According to the type and occurrence area of the dangerous behavior, trigger corresponding emergency response measures. For example, when a fire occurs, open all the access controls to the safe passage, close the access controls to the fire area, and send a fire alarm message to the security personnel; when a fight occurs, open the surrounding evacuation access controls and at the same time notify the security personnel to go to handle it.

[0053] Embodiment 3: When the single-chip microcomputer recognizes a dangerous behavior and determines the dangerous area, it triggers the access control program, sends an opening instruction to the access points around the dangerous area that can be used for personnel evacuation, and at the same time sends a prohibited opening instruction to the access points leading to the dangerous area to prevent people from entering. For example, when a dangerous behavior occurs in Area A of a floor, the access control to the safety passage around Area A is opened, and the access control from other areas to Area A is closed. At the same time, an alarm message including the location of the dangerous area is sent to the security personnel through the SMS module.

[0054] As shown in the Figure 1 appendix, after the environmental perception and dangerous behavior recognition module recognizes the dangerous behavior and determines the dangerous area, the instruction is sent to the door lock control and power module through the communication module to control the access control of the corresponding area to take action;

[0055] The evacuation passage adopts a power-off normally open electromagnetic lock, and the ordinary area adopts a power-off normally closed type to ensure automatic opening in case of emergency;

[0056] The drive circuit supports PWM voltage regulation and adapts to the current requirements of different locks (such as 12V / 24V);

[0057] The battery capacity ≥ 2000 mAh, supporting the full-load operation of the system for ≥ 2 hours;

[0058] The power supply switching time ≤ 20 ms, and the switching circuit adopts a relay + MOSFET hybrid design.

[0059] Although the present invention is disclosed above in a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. An access control system based on a single-chip microcomputer, including an access control system. When a user sends an open door request through methods such as card swiping, password input, and fingerprint recognition, the control system issues a control signal to open the door. It is characterized in that, The single-chip microcomputer-based access control system further includes the following modules: An authentication module. The access point uses a single-chip microcomputer as the core and integrates authentication hardware. The single-chip microcomputer receives the signals transmitted by the sensors and adopts dynamic power management technology. The authentication hardware supports NFC, fingerprint recognition, face recognition, and password input at the same time. An environment perception and dangerous behavior recognition module. A camera equipped with an image recognition chip is selected. Infrared sensors, sound sensors, gas sensors, and vibration sensors are deployed in different areas, and each sensor is assigned a corresponding area number. Based on the feedback of the area sensors, dangerous areas are determined. After a dangerous behavior is recognized, the access control is triggered to open the surrounding evacuation access gates and prohibit the opening of access gates leading to dangerous areas. A communication module. Each access point feeds back the switch signal of the electronic lock to the single-chip microcomputer through an independent line, and the sensors are connected to the access control system through an Ethernet module. A door lock control and power supply module. An electromagnetic lock is used for the opening and closing of the access point. The single-chip microcomputer sends a signal to the electromagnetic lock drive circuit to control the opening and closing of the electromagnetic lock. An ordinary power supply is used to provide the basic power supply for the entire access control system. At the same time, a standby power supply is used as an emergency power supply, which automatically switches to supply power to the system when the power is cut off. A permission management module. Different access permissions are set according to the security levels and functional requirements of different areas. When a dangerous behavior occurs, temporary special permissions are set for security personnel and firefighters.

2. The access control system based on a single-chip microcomputer according to claim 1, characterized in that: The authentication module selects a single-chip microcomputer as the core control unit. The single-chip microcomputer is responsible for receiving and processing signals from each module. The module includes authentication hardware and environment perception and dangerous behavior recognition sensors. Two sleep modes are set in the single-chip microcomputer. The sleep modes include the stop mode and the standby mode. When no one approaches the access point for 10 minutes and no abnormal signals are detected by each sensor, the single-chip microcomputer enters the stop mode, and the internal functional modules of the single-chip microcomputer stop working, only the clock source and the wake-up logic circuit are retained. When no one approaches the access point within 5-10 minutes, the single-chip microcomputer enters the standby mode, and the basic peripheral interfaces remain working. By setting external interrupts, the signals of the authentication hardware and the sensors are used as wake-up sources. When a wake-up source signal is detected, the single-chip microcomputer is woken up from the sleep mode through the wake-up logic circuit and enters the normal working state.

3. The access control system based on a single-chip microcomputer according to claim 2, wherein: The authentication hardware integrates an NFC module, a fingerprint recognition module, a face recognition camera, and a password keyboard. The NFC module uses an NFC controller chip, which is connected to the single-chip microcomputer through an SPI interface to transmit the read card data to the single-chip microcomputer for processing. The fingerprint recognition module is equipped with a fingerprint sensor, which communicates with the single-chip microcomputer through a UART interface, compares the collected fingerprint features with the pre-stored templates, and feeds back the comparison results to the single-chip microcomputer. The face recognition camera selects a high-definition camera and is paired with a face recognition chip. After the camera captures the facial image of a person, the face recognition chip performs preliminary feature extraction and analysis, and then transmits the results to the single-chip microcomputer through a USB interface. The single-chip microcomputer completes the identity verification judgment. The password keyboard is composed of membrane keys and is connected to the single-chip microcomputer through a GPIO interface. After the user enters the password, the single-chip microcomputer reads the password information and verifies it.

4. The access control system based on a single-chip microcomputer according to claim 3, wherein: The environment perception and dangerous behavior recognition module includes an environment perception module and a dangerous behavior recognition module. The environment perception module selects a camera paired with an image recognition chip, and infrared sensors, sound sensors, gas sensors, and vibration sensors are deployed in different areas. Each sensor collects environmental data in real time and transmits it to the single-chip microcomputer through the corresponding communication interface. After receiving the data from each sensor, the single-chip microcomputer uses a data fusion algorithm to comprehensively analyze the multi-source data. The data of each sensor carries its corresponding area number, enabling the single-chip microcomputer to identify the data source and the occurrence area.

5. The access control system based on a single-chip microcomputer according to claim 4, wherein: The dangerous behavior recognition module integrates a data fusion algorithm and a dangerous behavior recognition algorithm. The data fusion algorithm comprehensively analyzes the data from different sensors. The dangerous behavior recognition algorithm is based on image recognition and sound analysis technologies. It extracts features and performs pattern matching on the images captured by the camera, combines the data of the sound sensor and the infrared sensor. At the same time, according to the feedback of sensors in different areas, it determines the area where the dangerous behavior occurs. When the dangerous behavior recognition module recognizes a dangerous behavior and determines the dangerous area, it triggers the access control program, sends an opening instruction to the access points available for personnel evacuation around the dangerous area, and sends a prohibited opening instruction to the access points leading to the dangerous area.

6. The access control system based on a single-chip microcomputer according to claim 1, wherein: The communication module is equipped with an independent feedback line for each access point. Each access point communicates with the single-chip microcomputer through the feedback line. The single-chip microcomputer uses the interrupt method to real-time monitor the on / off state of the electromagnetic locks of each access point. According to the number of sensors, data transmission rate, and communication distance, an Ethernet module with a speed of 100Mbps - 500Mbps is selected. The Ethernet module sends the collected sensor data to the single-chip microcomputer. During the transmission process, a redundant communication line design is adopted. When one communication line fails, the access control system automatically switches to the backup line.

7. The access control system based on a single-chip microcomputer according to claim 6, characterized in that: The door lock control and power supply module includes a door lock control module and a power supply module. The door lock control module includes an electromagnetic lock and an electromagnetic lock drive circuit. An appropriate electromagnetic lock is selected according to the type of the door at the access control point. When the environment perception and dangerous behavior recognition module detects the occurrence of a dangerous behavior, the single-chip microcomputer sends an open door signal to the electromagnetic lock drive circuit of the relevant access control point according to the preset rules to open the electromagnetic lock of the evacuation passage.

8. The access control system based on a single-chip microcomputer according to claim 7, characterized in that: The power supply module includes a normal power supply, a power supply switching circuit, and a backup power supply. The normal power supply is responsible for converting the commercial power into the DC voltage required by each module of the access control system. The backup power supply uses a storage battery as the energy storage device. When the commercial power is normal, the power supply switching circuit connects the output of the normal power supply to the access control system and charges the storage battery at the same time. When the commercial power is cut off, the power supply switching circuit automatically connects the output of the storage battery to the access control system.

9. The access control system based on a single-chip microcomputer according to claim 8, characterized in that: The permission management module sets temporary special permissions for special personnel. Special personnel include security personnel and fire fighters. The temporary special permissions include emergency door opening permissions and device operation permissions. When a danger occurs, after verifying the password and identifying the identity of the special personnel, the corresponding permissions are granted to the special personnel, giving them the permission to temporarily open a specific access control for rescue work. After the dangerous situation is lifted, the access control system automatically withdraws the temporary special permissions. At the same time, the usage of the special permissions is recorded for subsequent auditing and query.

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