Unit vehicle entry and exit management system based on semi-active RFID technology
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1 Introduction
1.1 Document construction instructions
The purpose of this program is to allow integrators, engineering companies and users to understand the design concepts, principles, overall planning and how to play its huge role in the field of Internet of Things RFID technology in school communication, home-school communication and campus safety management, and explain in detail the relevant Information such as the working principle and installation location of the Internet of Things equipment, so that integrators, engineers, and users can correctly understand the revolutionary changes brought about by the Internet of Things in the field of intelligent transportation, and establish a correct understanding of the Internet of Things in the field of campus safety management.
1.2 Explanation of terms and abbreviations
RFIDRadio frequency identification is a communication technology that can identify specific targets and read and write related data through radio signals without the need to establish mechanical or optical contact between the identification system and specific targets
The RFID active radio frequency card is composed of an embedded processor and its software, a transmitting and receiving antenna in the card, a transceiver circuit and a high-energy battery. The special number is pre-stored in the microcontroller, and a unique encrypted identification code radio signal is transmitted intermittently. The high-energy battery in the card provides energy for the normal operation of the active card, and the battery in the card can be replaced.
The directional reader/industrial-grade omnidirectional reader is composed of information collection, processing, information transmission, and embedded software. Its main function is to complete the real-time collection and processing of the vehicle identification code output signal.
Low-frequency activator 125KHZ low-frequency signal transmitter device, used to transmit 125KHZ low-frequency signal to activate, trigger, and wake up the electronic tag working at 2.4GHZ frequency, so that the electronic tag sends a signal.
Vehicle sensors are used to detect metal objects such as vehicles and bicycles, and are suitable for parking lots, highway vehicle toll stations, and signal light control systems. Adopting the most advanced microprocessor technology, it can meet the application in various use environments. When a metal object passes through a coil buried under the road, because the metal conductor changes the inductance of the coil, the vehicle sensor detects the metal object by detecting the change in the inductance of the coil.
2. Project background
2.1 Status analysis
As people’s living standards continue to improve, the total number of cars owned has also begun to grow rapidly. How to carry out efficient, high-quality and intelligent management of the in and out of vehicles within a unit has become more and more important to various administrative departments, enterprises and institutions. The Active RFID-based remote vehicle access control system is at the forefront of the market and has high technical content. Through non-contact information collection and processing of long-distance fast-moving targets, it can realize rapid automatic identification and automatic management of in and out vehicles, which is the most traditional management method. Best upgrade option. Generally speaking, the system will significantly improve service quality and service level for users from the following aspects:
1. Establish a brand new image of property management. The use of modern high-tech products will surely greatly improve the image and popularity of the company’s property management. Adopting intelligent parking lot management system, no matter from the aspect of product styling, or the advancement and scientificity brought by automatic management, it will establish a good image for property management and make the enterprise a model of scientific management.
2. Strict charge management. For the current manual cash charging method, on the one hand, the labor intensity is high and the efficiency is low, and the other main drawback is that the financial loopholes are easy to cause the loss of cash. After using the radio frequency intelligent parking lot management system, all vehicle charges are confirmed and calculated by the computer, which eliminates errors and cheating and protects the rights and interests of parking lot investors.
3. Enhanced safety management. One card for one vehicle, data archiving, to ensure the safety of vehicles parked in the parking lot. When card issuance and card collection are performed manually, it is inevitable that there are omissions because there is no record to check at any time. Lost cars or false reports of lost cars happen from time to time, causing many troubles and economic losses to the parking lot. After adopting the intelligent parking lot management system, consumers of monthly rental cards and stored-value cards have recorded corresponding information in the computer, and the cards can be reissued in time if they are lost.
4. Good anti-counterfeiting performance. Because of the extremely high confidentiality of the RFID card, its encryption function can not be solved by the general computer after ten years, so it is not easy to forge.
5. Durable and reliable, and the operation process is fully automated. The active radio frequency identification card used in this system is maintenance-free, has a long service life, is fully sealed, contact-free, dust-proof and waterproof, and does not need to open the gate manually. The system automatically reads and verifies the card and opens the gate, which saves manpower and time.
This system also solves the vehicle management problems faced by various units. It can be applied to the tracking control management of internal vehicles entering and exiting the unit gate, and it can also be applied to the fully automatic and unattended management of internal parking lots. , It is especially suitable for occasions such as the entrance and exit gates of military vehicles, school gates, and power company gates.
2.2 Design basis
“Interim Provisions on the Management of Engineering Design of Intelligent Building Systems” Ministry of Construction 1997
“Code for Electrical Design of Civil Buildings” (JGJ/T16-92) Ministry of Construction
“Smart Building Design Standard” (DBJ08-4-95) Shanghai Construction Commission 1996
“Code for Design of Integrated Wiring Engineering for Buildings and Building Groups” China Engineering Construction Standards Association 1997
“Code for Construction and Acceptance of Integrated Wiring Engineering for Buildings and Building Groups” China Engineering Construction Standards Association 1997
“Building Communication Integrated Wiring System” (UD/T926) Ministry of Posts and Telecommunications 1997
“Code for Design of Automatic Fire Alarm System” State Planning Commission 1988
2.3 Construction goals and principles
1. Goal
The safety function of the vehicle custody;
Economical and reasonable operating costs;
Convenient and quick way of passage, better service to owners;
Improve the grade of the community;
2. Principle
Advanced and mature technology and equipment ensure the safe, reliable and stable operation of the system;
A complete management system can prevent vehicle loss to the greatest extent and provide better convenience for owners;
Reasonable layout, improve the service quality of the system, shorten the service time, and increase the efficiency of vehicle traffic;
Principles of practicability, real-time and completeness;
Principles of scalability and ease of maintenance;
3. Management system
The general idea of the management system is that the scene is unattended and fully intelligent. Managers can exercise complete control of the parking lot at any fixed location outside the parking lot environment, complete various statistics, monitoring, alarms, guidance and other functions, greatly reducing management The amount of labor of the personnel, and can provide a brand-new modern atmosphere for the owner.
3. Overall system construction plan
3.1 The working principle of the system
The tag is placed in the car. When the car is near the door of the unit, the tag will be activated by the 125K signal from the ground line of the low-frequency activator.
After activation, the 2.4G signal of the tag is in the working state at this time, and the 2.4G signal (ID number) is sent out. After receiving the 2.4G signal (ID number) of the tag from the long-distance omnidirectional reader next to it, the relay in the 2.4G long-distance omnidirectional reader device will work and give a switch signal for the control of opening the door. After the control board receives the switch signal from the 2.4G long-distance omnidirectional reader device, it will actively send voltage to the door opening motor. At this time, the door opening motor works to open the entrance and exit unit doors.
After the vehicle leaves the unit door and leaves the 125K low-frequency activation area, the 2.4G signal of the 2.4G electronic tag stops working. After the 2.4G long-distance omnidirectional reader cannot read the 2.4G electronic tag, the 2.4G remote reader The relay will stop sending the switch signal to the control board. At this time, the door opening control board will stop sending the door opening voltage to the unit door motor. The door opening control board will automatically give a door closing voltage, and the unit door will automatically close.
3.2 System topology
The vehicle entry and exit management system can adopt various network topologies. The server and the management workstation are connected in the form of a local area network (LAN), and the computer is connected to the lower computer by RS485 bus type; it is simple, quick to put into use, and the system is stable. The highest rate of return on investment. The block diagram of its topology is as follows:
3.3 Network topology diagram
Effect picture
Schematic diagram
【Note:】
For the entrance and exit control system, the server is responsible for the important task of the entire system. The rapid access of data is an issue worthy of concern, but the safety of data cannot be ignored. Once the hard disk fails or the data is lost or damaged due to improper operation, it will The entire system enterprise will have a huge impact on the system. It can be seen that the value of the data stored by the server far exceeds the value of the machine itself, and the SQL server selection cannot be ignored. The vehicle management system with the entrances and exits together only needs a computer to manage it. If the entrances and exits are separated and there are many temporary vehicles, it is best to place a computer at each entrance and have a security guard on duty. In order to deal with emergencies.
The first level network is distributed by RS485 bus system, which mainly provides communication for each entrance and exit control machine, and the card reading data is taken; the second level network is LAN Ethernet star connection, computer and computer communication and data storage, SQL server is responsible for Data query and processing, distribution of network resources, and classification review of the authority of each workstation.
3.4 Principles of Use and Installation of System Products
1. Installation location of the electronic label
Electronic tags are placed in the car;
The application of the electronic tag in the vehicle management system is to install the tag on the front windshield of the car cockpit, as shown in Figure 3.
The best position of the electronic tag: If the card reader is installed on the left side of the road in the forward direction (driver’s side), then the tag should also be installed on the left side of the car’s windshield (position A, E). If the card reader is on the right side of the road in the forward direction (the driving side), then the label should also be affixed to the right side of the car’s windshield (position C, D). If the card reader is directly above the lane, the tag should be installed near the center line of the rearview mirror or windshield of the car (position B, F). For small cars (including ordinary vans), the electronic label should be installed above the front windshield (position A, B, C) as much as possible. For large vehicles (large trucks or buses, etc.), the electronic tags should be installed in the direction below the front windshield (D, E, F positions), generally based on the principle of not blocking the driver’s sight.
2. The long-distance 2.4G omnidirectional reader is installed on either side of the entrance and exit;
3. The 125K low-frequency activator is installed on either side of the entrance and exit door, and the ground line is installed in the middle of the entrance and exit door or a square ring is installed inside and outside (two installation methods are shown in Figure A and B below).
125K ground sense line installation A
4. Hardware introduction
4.1 Semi-active RFID long-distance reader
RW-R 801 industrial grade omnidirectional reader
RW-R800 card issuer
Product technical characteristics
Recognition distance: 0 ~ 20cm
Recognition speed: 300 milliseconds
Recognition ability: Recognize single or multiple labels at the same time
Recognition angle: Focus on the card reading area directly above
Working frequency band: 2.4 GHz ~ 2.483 GHz
Power consumption standard: working power is milliwatt
Communication mechanism: Based on HDLC time division multiple access and synchronous communication mechanism
Anti-interference: channel isolation technology, multiple devices do not interfere with each other
Security: Encrypted calculation and security authentication to prevent link detection
Packaging features: ABS engineering plastic on the front, aluminum alloy cavity on the back
Reliability: Thunderproof, waterproof and shockproof, meeting the requirements of industrial environment
Interface standard: RS232, various software interfaces for development
Power standard: DC 9～12V 500～800mA
Dimensions: 148×175×34mm
Weight: 480g
4.2 Semi-active RFID electronic tags
(front back)
RW-T 700 Dual Frequency Button Electronic Label
Product technical characteristics
Recognition distance: 0 ~ 100 meters adjustable
Recognition speed: 200 km/h
Recognition ability: 200 frames per second anti-collision performance
Recognition method: omnidirectional recognition
Fixed gain: 0～3 levels can be selected on demand
Working frequency band: 2.4 GHz ～ 2.483GHz
Power consumption standard: The average working power is microwatts
Service life: 2 to 3 years for a single battery, prompt to replace the battery when it expires
Voltage detection: wireless and LED prompts when the voltage is lower than the preset value
Communication rate: 250K, 1M, 2M b/s three options
Communication mechanism: Based on HDLC time division multiple access and synchronous communication mechanism
Anti-interference: channel isolation technology, multiple devices do not interfere with each other
Security: Encrypted calculation and security authentication to prevent link detection
Package characteristics: PC material, resistant to high-strength drop and vibration
Environmental characteristics: Working temperature -40℃ ～85℃
Working humidity<95%
Anti-demolition: anti-demolition (alarm) function can be provided as required
Reliability: Waterproof and shockproof, meeting the requirements of industrial environment
Size: 86×54×3.8 mm
Shape: square card type, etc., can be customized according to requirements
Installation method: double-sided adhesive paste or hanging buckle
4.3 Semi-active RFID low-frequency activator
RW-R750/020 (Access Control/Perimeter) Activator
Product technical characteristics
Activation range: 0 ~ 3.5 meters radius
Activation speed: up to 100 km/h
Activation ability: activate more than 300 labels at the same time
Activation angle: omnidirectional
Polarization mode: dual polarization or vertical polarization
Working frequency: 125K Hz
Anti-interference: Using code division multiple access technology, multiple devices do not interfere with each other
Penetration ability: The low-frequency wavelength is longer, which can completely penetrate the human body and the wall
Reliability: Waterproof and shockproof, meeting the requirements of industrial environment
Standard interface: TTL, RS485 interface
Power standard: DC 7.5～18V 1000～3000mA
Dimensions: 85×55×45 mm (built-in or external antenna)
Weight: 200 g
Working temperature: -40～+85℃
Installation method: ceiling, wall or other installation methods
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