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Chapter 1 Preface
The Internet of Things is the Internet that connects things. This means that the core and foundation of the Internet of Things is still the Internet. It is an extended and expanded network based on the Internet. In addition, its user end extends and expands to anything and everything. Information exchange and communication. The Internet of Things appeared at the end of the 20th century. The definition of the Internet of Things is the use of radio frequency identification (RFID), sensors, positioning systems, scanners, sensors and other information sensing equipment to connect objects to the Internet for information exchange according to an agreed protocol. And communication to realize intelligent identification, positioning, tracking, monitoring and management. The Internet of Things can only be said to be in the initial stage of development. The Internet is the need for communication between people, and the Internet of Things reflects the need for communication between things. That is to say, we can communicate with each other very well through Internet technology, and we will rely on the Internet of Things in the future. promote. The information transmission methods, protocols, information volume, access volume, and communication methods of the Internet of Things are somewhat different from the current way people use the Internet to communicate. More, it connects these devices to each other through sensors and collects them. These equipment data, including real-time response, that is to say how we reverse control these equipment. It is estimated that nearly 500 billion devices will be connected to the Internet in 2025, that is, at the level of the Internet of Things, nearly 5,000 trillion data will be generated every year. This is the arrival of the real big data era.
Our country defined China’s Internet of Things in the 2010 Central Government Work Report: “Through sensor equipment in accordance with the agreed agreement, various networks are connected for information exchange and communication to realize intelligent identification, positioning, and tracking. , Monitoring and management of a network.”
With the development of the Internet of Things technology in China, it has gradually been applied to many fields such as public safety, urban management, energy and environmental protection, transportation, public utilities, agricultural services, medical and health, education and culture, and tourism. Maintain rapid development. With the development of RFID, sensor technology, short-range communication, and computing technology, in recent years, its research and development and applications have begun to expand to the fields of environmental monitoring, biomedicine, and intelligent infrastructure. At the same time, it has a leading edge in the key technologies of the Internet of Things.
In recent years, the standardization of law enforcement has continued to deepen, and higher and more detailed requirements have been placed on the law enforcement hardware facilities in the functional areas of public security agencies in handling cases. In order to curb and prevent the occurrence of incidents such as torture at the source, exclude illegal evidence, and further regulate the law enforcement behavior of public security agencies. It also echoes the requirements of the Fourth Plenary Session of the Eighteenth Central Committee of the Communist Party of China, and through the improvement of the rule of law norms, implementation, supervision, and guarantee system, the law enforcement safety accidents “zero occurrence”. In accordance with the concept of “high-quality products and high standards”, all localities have effectively enhanced the law enforcement image and credibility of law enforcement agencies in the public security industry.
In order to further improve the management and use system of case-handling places, the Public Security Industry Bureau has issued various systems to clarify the management and use standards of law-enforcement case-handling places, strengthen the work responsibilities of the police, and standardize and process the specific law enforcement actions of the police. Regularly organize relevant departments to conduct inspections and comments, special inspections, and regular notifications on the implementation of the rules and regulations of the case-handling premises and the implementation of the “Four Uniforms” to force “tracking” and enhance the system’s execution.
However, these hardware and systems alone cannot fully guarantee the standardized and refined management of the case handling center. For this reason, we have introduced the precise positioning of the Internet of Things to ensure that the refined and standardized case handling center can be implemented. The intelligent management and control platform of the case handling center utilizes the world’s leading IoT RFID precise positioning technology, with a positioning accuracy of up to 30cm, combined with the current problems of overdue custody, single-person interrogation, failure to follow the process, and leaving the post to sleep in the current case handling center business. Prevent the occurrence of abnormal incidents of the persons involved; and standardize the storage of the items involved in the case and the property involved in the case, so as to achieve “the source has a source and a destination”; there is also the standardization of supervision and reporting and law enforcement accounts; the fourth is to prevent involvement in the case The occurrence of over-detention of personnel and the backlog of cases.
Chapter 2 System Introduction
Beijing Haotian Tongtai Technology Case Handling Center’s intelligent office case handling platform indoor positioning technology, mobile computing technology, computer software, and database. Therefore, when designing a scheme, in addition to considering its functions, the stability, reliability, anti-interference ability, fault tolerance and abnormal protection must also be fully considered. The system should use the existing mature wireless and wired communication network as the main transmission platform, and the corresponding terminals, anti-disassembly wristband holding terminals and other equipment should be connected to the system, and the Beijing Haotian Tongtai Intelligent Positioning Control Platform and the main system standard The dedicated database performs background data exchange, so that the positioning platform can be easily connected to other systems.
It can be seen from the architecture of the Internet of Things that people use RFID and sensors to obtain a variety of information from the physical world. This information is finally transmitted to the user or server through the network, providing users with a variety of For services, all collected information must be associated with the specific location information of the sensor, otherwise this information has no meaning. It can be said that the positioning technology of the sensor is an important foundation of the Internet of Things. From the Internet of Things, to realize the connection between any time, any thing, and any place, there must be the support of positioning technology, and the connection of any place itself contains the position information between the objects.
In recent years, as national security, public safety and production safety issues have become increasingly prominent, various needs have become increasingly urgent. To use the most obvious analogy, coal mine gas explosions have occurred frequently in our country in recent years, and many companies have gradually begun to adopt positioning systems to monitor the production management of miners in real time. In addition to clocking in and managing it on a daily basis, a real-time positioning system can be used in emergency situations to provide assistance to rescue personnel, which can improve rescue efficiency. Some time ago, since the forced escape of prisoners in Chifeng, Inner Mongolia, many of our country’s case handling centers have strengthened security management. One of the most important measures is to use real-time positioning systems for prisoners, wear anti-tamper wristbands for prisoners, and intelligently locate them through RFID. The method can implement location-based management and control of prisoners, and can also link location information with the prison’s inherent monitoring, access control and other systems, truly achieving the goal of moving from passive monitoring to active monitoring, from extensive management to fine control .
Based on the above-mentioned various positioning application technology requirements, and the targets and application scenarios are various, the accuracy and parameter requirements of the positioning technology are also different. We have done a lot of research and experiments on positioning technology, and developed an indoor precise positioning system based on ZigBee network, using 2.4G wireless communication and RFID technology.
The field of public security industry is one of the fields that have the conditions to provide large-scale applications for the Internet of Things. On the one hand, in the domestic security field, applications such as video surveillance and perimeter intrusion prevention have achieved good results. We can interact with the inherent video surveillance and access control systems through the intelligent positioning technology of the Internet of Things, from the past passive security to active security; On the other hand, the public security industry, as an important government department for city safety management, has established certain conditions for large-scale applications of the Internet of Things through the construction of a series of safe city and social security monitoring systems. At present, we are handling cases at the Xincheng Police Station in Jiaxing. Both the center and the Haining Detention Center have good application demonstrations based on RFID regional positioning and precise positioning.
Chapter 3 System Requirements Analysis
3.1. Business function requirements
3.1.1. Security Management
Sleeping post alarm: the guardian’s time is in a static state, reminding guarding every 15 minutes
Prevent personnel from sleeping while on duty; suspects and personnel on duty wear wristbands, and the software system will prompt when the personnel on duty are sleeping.
Leaving post alarm: The staff on duty leave the post privately and call the police when a suspect is in the interrogation room.
The person involved in the case did not follow the alarm in time when going to the toilet. This is because it is normal if the police are required to accompany you.
Single-person interrogation (interrogation) alarm: The functional requirement is that there must be two police officers together during the interrogation. This requires the software to bind 3 persons.
Warning area alarm: the suspect approaches the fence, top net and other safety warning areas to report to the police. The software will prompt and automatically pop up the camera.
Wristband damage alarm (wristband broken or disconnected).
Wristband low battery warning.
Equipment failure alarm.
3.1.2 Standardized management
1) Early warning of failure to follow the standardized process (you must first wear a tag or wristband, conduct personnel safety inspections, and enter information before proceeding to the next step). Animation requirements: When personnel enter the buffer zone, they go to the personal safety inspection room for personnel information entry.
Take care of the early warning, and arrange the guarding police force in time according to the number and gender.
Personnel diversion warning: When the suspect enters the case handling area and the number of persons set by the warning is reached, an early warning is issued to inform the diversion.
Anti-collusive confession warning, when the suspect in the case appears in the same area, the warning is issued.
When the suspect enters the information, when the case is the same at the same time, at the same place, and at the same case, one suspect is already in an interrogation room, and we have to call the police as soon as the other suspect arrives at the suspect in custody. .
Minors (holding special tags) ensure the presence of guardians or other relevant personnel: ③ Deaf, mute and other disabled persons.
Early warning of overtime detention: When entering the information of the person involved in the case, when entering the information of the person involved, the age, the nature of the case, the entry measures, etc., are stated, and the system will issue different early warnings.
Automatic warning for out-of-office approval.
3.1.3 Other kinetic energy (efficiency improvement)
Real-time counting of the number of people and their correspondence (inspection by the leader).
Electronic registration, statistical inquiry, electronic form registration, reduce duplication of labor, and facilitate statistical inquiry.
3.1.4 Caretaker management
The area real-time roll call function regularly rolls names of personnel in different areas of the detention center (track backward check).
Routine alarms: Process timeout alarms, such as timeout in the toilet, timeout for review, and timeout for interviews.
Risk point warning: warning when approaching an unauthorized area.
3.1.5 Other requirements
Alarm and linkage: It can receive a variety of alarms reported by the front end, and perform linkage actions according to various pre-set plans, linkage video recording, notification users, etc.
Video playback: Provide convenient means of video retrieval and query. Images can be retrieved and played back according to information such as time, location and alarm type. During playback, functions such as play, fast play, slow play, single frame play, drag, and pause can be realized. Choose to realize the multi-channel image synchronization playback function.
Built-in lithium battery power supply, the battery is easy to remove and replace.
Historical track playback.
Chapter 4 Solution
4.1 System overall design
1. Achieve effective identification and real-time monitoring of monitoring objectives, so that the management system fully reflects “humanization, informationization and high automation”.
2. Provide managers with real-time tracking of personnel, over-distance alarms, safety monitoring and other management information. Once there is an emergency, the system can immediately know the position of the controlled target or trace back the movement history trajectory to ensure safe management Efficient operation of work.
3. The system design is safe, expandable, easy to maintain and easy to operate.
4. Through the network management platform built by the system, the unified management of the monitoring equipment of the system is realized, and the functions of displaying the operating status and monitoring parameters of the system are realized.
Through the application of indoor positioning technology, the intelligent office case handling platform of Beijing Haotian Tongtai Science and Technology Case Handling Center is used to send the positioning data obtained by the indoor module to the server through the Ethernet network, so as to realize the query, monitoring and management terminal on the information center platform . At work, managers track and locate targets through the networked system platform.
The system should fully integrate high-tech such as RFID indoor positioning, and realize multiple functions such as trajectory positioning, real-time video monitoring, two-way voice command, multi-level information storage, and linkage alarm for the entire process of escorting.
The overall structure of the system is shown in Figure 1:
Figure 1 Overall structure diagram of the case handling center positioning system
4.2 System Design of Case Handling Center
By arranging RFID precise positioning equipment in the case handling center, precise control can be achieved in every process. The process of the system includes: file entry, personal inspection, information collection, guards pending trial, inquiry and interrogation, etc. The system can perform video linkage and record storage according to each person involved in the case, providing a technical guarantee for fast video verification. Once a problem occurs, the entire process can be played back by video, and the recording point of the person involved is currently not reachable by other technologies. It can protect the legitimate rights and interests of the parties, but also protect the police, prevent malicious complaints, and ultimately ensure the standardization of law enforcement. Law enforcement premises have a full-process audio and video recording system, online video surveillance supervision system, and law enforcement case management system. After criminal suspects enter the premises, they can report, enter, security, and store personal belongings, personnel activities, rest, and food. The entire process is monitored and used by the premises Carry out full-process monitoring and real-time supervision. Fully informatized records, process management, and comprehensive supervision of the case handling center for all kinds of law enforcement safety details.
The design hierarchy of the case handling center is shown in Figure 2:
Figure 2 System hierarchy diagram
4.3 System implementation
4.3.1 The composition of the system
The system consists of two parts: software and hardware. The software is the positioning system of Beijing Haotian Tongtai Technology Case Handling Center.
The hardware of the material evidence management system of Beijing Haotian Tongtai Science and Technology Public Security Bureau is mainly composed of communication links, RFID tags, IoT wireless nodes, IoT directional monitors, IoT omnidirectional monitors and IoT network repeaters, and communication links composition.
The communication link is divided into a wireless link and a wired link, and the wireless link does not need to add other hardware. It is between the RFID tag and the IoT wireless node, between the RFID tag and the IoT directional monitor, between the RFID tag and the IoT omnidirectional monitor; the directional monitor or the IoT wireless node and the IoT network repeater Between, the link that exchanges and transmits information through radio frequency signals.
4.3.2 Work process of each layer of the system
4.3.2.1 Acquisition layer:
1) RFID tag: Each or a group of exhibits is bound with an RFID tag, and each RFID has a unique ID identification, which forms a one-to-one identification relationship with one or a group of exhibits through the bound one-dimensional bar code. RFID actively transmits radio frequency signals to the outside in a prescribed protocol every 1s, including valid information such as tag ID number and tag power.
2) Internet of things wireless node: actively monitor the surrounding radio frequency signal, when receiving a valid RFID signal, add its own information to the protocol frame, and then send the information.
3) Internet of Things Orientation Monitor: The working principle is the same as that of the Internet of Things wireless node, but the recognition range is relatively small. It is usually placed at the door and in a relatively small space to determine whether there is evidence passing.
4) Internet of things omnidirectional monitor: Actively monitor the surrounding radio frequency signals, and transmit the received information and its own unique ID information to the background application system for analysis through the Ethernet or RS485 interface. It is a device between the collection layer and the communication layer.
5) Handheld terminal: automatic inventory.
4.3.2.2 Transport layer
IOT network repeater: Actively monitor the surrounding radio frequency signals, and when the effective information sent by the wireless node of the Internet of Things or the directional monitor of the Internet of Things is received, it is transmitted to the background application system for analysis through the transmission method such as Ethernet or RS485.
4.3.2.3 Application layer
Complete the processing of the paired collected data and the realization of functions.
4.3.4 Overview of system positioning principle
Room positioning: bind and install an IoT wireless node in the room and bind and install an IoT orientation monitor at the door of the room. Due to the small range of the directional card reader that can receive signals, the RFID signal will only be received when the RFID passes through the door. Therefore, if and only if the RFID signal is received from the card reader bound to the room and the wireless IoT wireless node bound to the room receives the signal strength of the RFID reaches a certain threshold, it is considered to be related to the RFID The bound evidence was brought into the room. Conversely, if and only if the IoT orientation monitor bound to the room receives the RFID signal again and the strength of the RFID signal received by the IoT wireless node bound to the room decreases to a fixed threshold or even cannot be received When the RFID signal arrives, it is considered that the exhibit bound to the RFID has been taken away from the room.
Corridor positioning: install several IoT wireless nodes in the corridor according to the length of the corridor, refer to the received RFID signal strength of each IoT wireless node and use a certain algorithm to locate the approximate location of the RFID-bound exhibit in the corridor .
Stairway: bind and install an IoT directional monitor at the stairway. When the IoT directional monitor receives the tag signal and the IoT wireless node in the corridor adjacent to the stairway cannot receive the RFID signal, it is considered The exhibit bound to the RFID was taken away through this stairway.
Building exit positioning: bind and install an IoT orientation monitor at the building exit. When the IoT orientation monitor reads the RFID signal, it is considered that the evidence bound to the RFID passes through the door.
Chapter 5 System Function
5.1 Real-time positioning of personnel area
It can locate the area of the person wearing the location tag in real time and display it on the map of the monitoring terminal.
5.2 Management and control personnel statistics and electronic roll call
Count the number of attendance and actual attendance in each area, as well as the actual attendance in a specific area, and compare it with the expected attendance to determine whether the attendance is complete. And display the name of the absent person.
5.3 Personnel search
At the monitoring terminal, you can enter the person’s name or tag number to find the current location of the designated person.
5.4 Failure to follow the process
The person involved in the case must follow the established process. If the process is not followed and the previous process is not completed before entering the next process, the system will generate an alarm and the area alarm will give voice prompts.
5.5 Single inquiry and interrogation
The questioning and interrogation of the person involved must be completed by two police officers at the same time. If a police officer conducts the interrogation, the system will report to the police within the specified time.
5.6 Leaving post, sleeping post
It can monitor and remind the staff on duty. From 12:00 in the evening to 7:00 in the morning, the police officers on duty must go for normal inspections every half hour, otherwise the system will generate sound and light alarms.
5.7 Disappearing alarm
It can focus on monitoring certain tags, and the system will find corresponding alarms when these tags leave the designated area or are cleared.
5.8 Out of bounds, leaving the alarm
Some areas are important areas, and an alarm message will be issued if unauthorized persons enter. It can also be set in some areas that certain personnel are not allowed to leave within a set time, if they leave or disappear, the system alarms.
5.9 Track playback
You can query the movement track of a tag during a specified time period, and which areas the tag has been to during this time period.
5.10 Video linkage
A camera can be bound to each positioning device, and the video of the area where the positioning device is located can be called by clicking the map of the positioning device on the map of the monitoring terminal. When there is a specific alarm, the system will automatically call up the video of the area where the alarm occurred.
5. 11 Temporary authorization of personnel
When a person needs to temporarily enter an important area or leave the itinerary area, a temporary authorization can be made in the system to allow him to enter an important area or leave the work area for a certain period of time.
5.12 Electronic label failure alarm
The failure of the electronic tag mainly refers to the low voltage of the tag battery; the wristband worn on the person’s hand is damaged or removed;
As long as the wristband worn on the person’s hand is taken off, the system will give an alarm; whether it is cut or removed with a tool, the system will give an alarm. The system will also prompt when the battery voltage of the label is too low, and the battery needs to be replaced as soon as possible.
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