RFID management system technical scheme of a school in Guangdong Province
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Correctly understanding the school’s application requirements is the key to product and technology selection. As far as our company’s analysis is concerned, the needs of schools can be broken down into three major parts:
l Remote sensing part
It is necessary to install long-distance sensing devices at key occasions such as school gates, building gates, corridors or corridors at appropriate locations. When personnel with special certificates pass normally, they will be automatically sensed and recorded.
In some occasions, according to the requirements of the school, it is also necessary to provide timely warnings for undocumented traffic.
l Software part
The school has more than 20 long-distance personnel access information collection points, covering teaching and
In various important occasions of life, based on this favorable condition, a set of information analysis software can be made to display and record the movement trajectory accurate to the individual, and the distribution of personnel in a certain area can be checked at any time. As for students’ class attendance and lodging records, it is easier to obtain.
Of course, the design of the software part also needs to take into account the necessary data interface to facilitate the school’s future card application.
l Proximity sensing part
A complete RFID system has the application of proximity sensing. In schools, it is also necessary to install low-cost proximity sensing devices and hand-held sensing devices distributed to inspectors in some occasions where people’s traffic is not very frequent.
This requires that the application core of the solution, the electronic label document itself, must be able to take into account both long-distance and short-distance sensing modes. In the future expansion application of the school, it can realize the one-card function of punching in the dining hall, borrowing in the library and other occasions.
The above is our company’s analysis of RFID applications in schools. Based on our years of experience in the application of RFID technology and unremitting tracking of advanced technologies and products, although the school has high technical requirements and advanced application models, we are fully capable of providing mature products and technical services to meet the above needs. Below we will introduce our technical solutions, as well as the main application of RFID products.
two. RFID technology selection
RFID is the English abbreviation of Radio Frequency Identification, the Chinese literal translation of radio frequency identification, also known as “electronic tag”. RFID has a product classification and standard system that spans multiple frequency bands and has multiple working modes. Combined with the application needs of the school, we briefly compare and analyze the reasons and reasons for the type of technology we choose.
The comparison of related long-distance RFID products is shown in the following table:
standard |
– |
ISO18000-6B/C |
ISO15693 |
working frequency |
VHF band, 2.45GHz |
UHF band, 915MHz |
HF band, 13.56 MHz |
power supply |
Built-in battery |
Passive |
Passive |
Recognition distance |
20~50 meters |
3 to 8 meters |
<2m |
Identify the area |
A spherical sensing area with an omnidirectional antenna as the center Very unclear boundaries |
Starting with a directional antenna, the spindle induction area, the boundary is very unclear |
Taking the rectangular antenna as the symmetry axis, the cubic sensing area has a clear boundary and is accurate to centimeters |
environmental impact |
Sensing performance is not affected by the environment |
Bulk metal environment and rain have a large impact on sensing performance |
Bulky metal has a greater impact on induction performance, but is easy to avoid; rain has no impact on performance |
Human influence |
The human body has no effect on the label |
The label is close to the human body or is blocked by the human body, which is difficult to be recognized |
The human body has little influence on the label |
Recognition speed |
soon |
soon |
soon |
Anti-collision |
very good |
very good |
good |
service life |
Battery life is less than 1 year, but not sure |
10 years |
10 years |
Reader cost |
2000~6000 yuan |
5000~12000 yuan |
500~10000 yuan |
label cost |
more than 30 yuan Weak anti-counterfeiting ability |
More than 3 yuan without anti-counterfeiting ability More than 10 yuan with anti-counterfeiting ability |
8 to 16 yuan, depending on different chips Strong anti-counterfeiting ability |
Highlight the advantages |
Long distance, anti-environmental interference |
Moderate distance, passive |
It is very suitable for personnel management, and the cost of short-range equipment is low, which is convenient for one-card application |
highlight weaknesses |
The sensing distance is too far and difficult to adjust, and the sensing boundary is so blurred that it is impossible to judge whether the sensed card is worth recording; The life of the label is uncertain, which is not conducive to long-term use; Labels cost too much |
When people are crowded and the interval is less than 20cm, the card reading efficiency drops sharply, and there will be an unacceptable missed card rate. Lack of low-cost card readers to apply tags to card applications such as canteens |
The long-distance antenna is a gate channel, too large |
The parameters and descriptions in the above table refer to typical situations. In conclusion, since students tend to pass through the detection area relatively densely and have large height differences, if UHF band equipment is used, there will be many people with shorter stature in the crowd who cannot be identified. Although the size of the HF system personnel identification antenna is large, because the equipment does not need to be moved frequently, it does not affect the use of personnel identification.
The most typical case where products of ISO15693 standard are suitable for personnel identification is the application of meeting sign-in. At present, most of the provincial party congresses, people’s congresses and some Chinese People’s Political Consultative Conferences in China have used this kind of equipment for automatic registration of delegates entering and leaving the venue. The manufacturer of RFID equipment for this school bidding has provided sign-in equipment for more than 10 provincial conferences in Guangdong, Hunan, Guangxi, Yunnan, Henan, Sichuan, etc., and the user experience is good. In Guangzhou Baiyun Conference Center, the 18 sets of remote sensing systems they provided have been working for 2 years. Therefore, we choose an electronic tag reading and writing system that conforms to the ISO15693 international standard. The main features of the standard are:
l Operating frequency 13.56MHz
l Read and write distance 0~200cm
l 50 labels can be recognized in 1 second
l Label size (diagonal) 1~15cm optional, thickness generally less than 1mm
After the standard is selected, how to select a specific product will be the focus of the discussion below.
three. RFID tags
The electronic tag is an important part of the reading and writing system. In the application of the school, it will be made into a certificate and worn on the student’s chest, and it will be automatically sensed when the student passes through the RFID induction channel. The actual photos of the relevant labels are shown in the following pictures:
The two color-printed cards in the picture above are finished electronic labels, with a size of 85×54mm and a thickness of 0.9mm. They are printed in generic color, and the cardholder information is printed on the other side of the label. There are also two transparent labels in the above picture, which we call Inlay, which are the core of making RFID documents. The picture shows the Inlay imported from the TI (Texas Instruments) brand. The Inlay is flat and packaged inside the finished label. The surface of the label is flat, and no trace of Inlay can be seen. The correspondence on the plane can be seen in the label map to the right of the center.
In the label provided to the school, we will use the materials and production methods in the picture above. The original imported TI-I02-112B label is used, and it is packaged into a 85×54×0.9mm label with PVC material, with color printing on the back, and the content contains the logo of Guangdong Publishing School. The front of the label is blank or pre-printed with generic content in some areas according to the actual situation. With the greatest convenience, the school can use the dye-sublimation printer to print student information including photos at any time.
The reason why the imported TI brand Inlay is selected is that among all the current products, the label it encapsulates has the farthest sensing distance under the same conditions, and at the same time, its consistency and stability can meet the requirements of long-term use by students. There are domestically produced Inlays that use Philips chips (also known as NXP brand I Code 2 chips) on the market, and use this to encapsulate labels. At present, it lacks a successful case of large-scale application in personnel identification, and the distance is also close to TI’s original labels. Although Philips chips have certain advantages in price, our company puts performance and reliability first, and does not use low-cost labeling solutions. (Philips chips are generally used as item identification tags)
We can also provide the overall personalized printing service when making the first batch of labels according to the requirements of the school.
The technical parameters of the radio frequency induction of the RFID card are as follows:
l Working mode: passive, 13.56MHz electromagnetic coupling
l Chip brand: TI
l Size: 85×54×0.9mm, PVC package
l ID number: 64bit fixed, unique, unchangeable and uncopyable
l Rewritable memory: 2Kbit
l Rewritable times: 100,000 times
l Data storage life: 10 years
l Working temperature: -25~+70 degrees Celsius
three.Long-distance RFID reading and writing equipment
According to the above “demand analysis” point of view, we believe that long-distance high-frequency RFID sensing equipment is the core of school applications. After a preliminary site survey, and a detailed understanding of the school’s needs, combined with the written requirements in the tender, we decided to use three long-distance RFID reading and writing devices in the same series to solve the school’s different application needs.
They include:
3.1. S02 Basic Remote Sensing System
In the 24 sets of long-range RFID equipment requirements, 12 sets are such equipment. It is mainly installed on the rise of the staircase, using one antenna on the left and right, one on the wall and one on the walkway railing. The photo of its single antenna is as follows:
The detailed specifications and electrical parameters of the antenna are as follows:
Introduction to Antennas
HT-S02 is a high-performance 13.56MHz frame antenna with a standard impedance of 50 Ω, with complete intellectual property rights. Built-in proprietary antenna adapter, choose large-section copper cable as antenna, adopt integrated plastic shell and fine manufacturing process, frame preset fixed holes to facilitate installation and height adjustment, can achieve stable induction effect on electronic tags . It is especially suitable for occasions requiring long-distance and large-scale sensing, and is widely used in logistics, production process control, personnel management and other fields.
Features
l Completely designed for application requirements
l Supports RF input power up to 8W
l Coaxial cable SMA interface
l Elegant shape, ABS engineering plastic shell, light gray
Specification
project |
symbol |
Typical value |
unit |
|
Antenna body |
long |
L |
830 |
mm |
width |
W |
612 |
mm |
|
thick |
T |
30 |
mm |
|
Adapter box |
long |
L |
134 |
mm |
width |
W |
106 |
mm |
|
thick |
T |
37 |
mm |
The physical picture of two S02 antennas facing in parallel (with base) is as follows:
The picture above is for reference only; in school applications, the base in the picture above is not required. We will customize plastic or metal fasteners according to the different conditions of each installation occasion for firm installation.
We also promise to optimize the size and installation method of the antenna according to the actual situation of the installation site without affecting the induction performance.
Put two S02 antennas in parallel, with the RR9201T reader with an output power of 4W, the induction performance is as follows:
S02 Antenna RFID Main Induction Performance Parameters Length Unit: cm |
||
project |
Performance parameters |
Remark |
maximum channel width |
140 |
The smaller the width, the stronger the recognition ability Use TI RI-I02-112B label, PVC package, (the test value is applicable to the label and the antenna perpendicular, if parallel, the width of the channel without dead zone can exceed 190cm) |
Minimum channel width |
60 |
|
Standard channel width |
130 |
|
Magnetic Field Rotation Antenna Standard Width |
105 |
For optional function. The magnetic field rotates quickly and smoothly between 90 and 180 degrees, so that the label can be more accurately identified when it is perpendicular to the ground |
Applicable person height |
120~200 |
The label is worn on the chest of the personnel, |
Recognition speed (single label) |
20ms |
|
maximum passing speed |
5 m/s |
Channel is in standard width condition |
anti-collision |
Anti-collision capability |
that allows multiple people to pass through at the same time |
Anti-collision experimental value |
240 tags are placed within the antenna identification range at the same time |
Recognition completed in 6.07 seconds |
Label continuous recognition ability |
unlimited |
|
Communication Interface |
RS485 |
Customizable RS232 or TCP/IP interface |
Support serial cable length |
Up to 1500 meters |
All core components assembled have passed the 7-day aging test, and the finished products meet the needs of 7×24 hours of work. If the antenna needs to be installed outdoors, special waterproof design can be done.
3.2. G02 dual-channel remote sensing system
Among the 24 sets of long-distance RFID equipment requirements, 2 sets of dual-channel equipment need to be installed at the school gate. Each set uses only one RR9202T reader, equipped with 3 antennas similar to the S02 above, which are parallel to form 2 channels.
The reason why this dual-channel device is adopted is that the school gate has a large flow of people, and the basic long-distance channel antenna has only one sensing channel, which is easy to cause pedestrian obstruction. The G02 dual-channel device has two parallel sensing channels, forming a natural left-in and right-out traffic pattern, effectively reducing the speed of large-traffic crowds.
The G02 dual-channel antenna is designed based on the mature technology of S02 above. Because it needs to be installed outdoors, it needs to add a base and an integrated equipment box. The single antenna design diagram we negotiated with the equipment supplier is as follows:
The antenna body and the box are made of ABS engineering plastic as an integrated shell, and the bottom of the box has a customized metal base and structural parts. The metal base is fastened on the ground with expansion bolts to make the antenna firm. The height of the antenna box can be redesigned according to the requirements of the sensing area.
The main RFID performance parameters of the G02 dual-channel antenna with the RR9202T reader are as follows:
G02 dual-channel antenna RFID main induction performance parameters Length unit: cm |
||
project |
Performance parameters |
Remark |
single channel width |
100 |
The smaller the width, the stronger the recognition ability Use TI RI-I02-112B label, PVC encapsulation, (test value applies to label perpendicular to the antenna) |
Sum of two channel widths |
205 |
|
Magnetic Field Rotation Antenna Width |
130 Refers to the sum of the two channel widths |
For optional function. The magnetic field rotates quickly and smoothly between 90 and 180 degrees, so that the label can be more accurately identified when it is perpendicular to the ground |
Applicable person height |
120~200 |
The label is worn on the chest of the personnel, |
Recognition speed (single label) |
20ms |
|
maximum passing speed |
4 m/s |
Channel is in standard width condition |
anti-collision |
Anti-collision capability |
that allows multiple people to pass through at the same time |
Anti-collision experimental value |
240 tags are placed within the antenna identification range at the same time |
Recognition completed in 6.07 seconds |
Label continuous recognition ability |
unlimited |
|
Communication Interface |
RS485 |
Customizable RS232 or TCP/IP interface |
Support serial cable length |
Up to 1500 meters |
All core components assembled have passed the 7-day aging test, and the finished products meet the needs of 7×24 hours of work, and have a waterproof design.
3.3. G11B with infrared long-distance sensing system
According to the requirements of the bidding document, among the 24 sets of long-distance RFID equipment requirements, 10 sets of equipment need to be installed with infrared detection modules to realize the alarm and record of the operation without a card. In fact, the infrared module of this product can not only judge the phenomenon of no-card travel, but also directly determine the travel direction of a person.
In addition to the RFID reader and antenna, the G11B channel antenna is also equipped with 4 pairs of infrared sensor switches and a specially developed embedded controller. The basic principle and working logic of G11B are as follows:
The RFID sensing device is the core part of the system. The top view of its sensing area is as follows:
It can be seen from the above schematic diagram that a normal passage process will enter the RFID area twice, and will also cut the infrared rays twice, which can avoid blind reading to the greatest extent. The meaning of entering or leaving the venue. Of course, the primary significance of setting infrared identification is to warn when the radio frequency identification is not indicated. It can be seen from the schematic diagram that the radio frequency identification capability is the weakest when the personnel stand in the center of the passage, so when the documents need to be checked repeatedly, the personnel must walk again.
A complete RFID identification and infrared judgment process is shown in the flow chart:
The latest product provides 4 pairs of infrared sensing devices, which can more accurately determine the number and direction of people entering and leaving.
According to the above statement, there are two functions of RFID induction and infrared induction in G11B that work independently and coordinate with each other. The system calculates whether the number of cards read by RFID and the number of people judged by infrared induction are consistent at any time. Instantly determine whether the card is missing or multi-band, and integrate the data, save and transmit it to the host computer. When people pass through the channel, the infrared switches arranged in series will be triggered in sequence, and the system will judge the direction of the current passage.
The system has a set of advanced simulation algorithms, which can effectively filter out the interference of personnel swinging arms, shaking and narrow objects. But it is worth noting that when people walk completely side by side, the infrared system’s judgment of the number of people will be less than the actual number of people. Therefore, when using this equipment, in order to ensure the accuracy of the collected data, it is necessary to strengthen the management, so that people can form the habit of not walking side by side when passing through.
Of course, no matter how the infrared system works, the performance of the RFID sensing part is not affected.
Because the infrared sensor module needs to be installed, the external structure of G11B is quite different from the two long-distance channel antennas mentioned above, as shown in the following figure:
As shown in the figure above, the main body of the antenna shell is made of ABS engineering plastic, the base is made of 3mm rear steel plate, a group of 4 pairs of infrared sensor switches in series are installed at 110cm from the ground, and the reader controller and other equipment are installed inside the box. A warning light and a buzzer are installed on one of the antennas. When a card without a card or an illegal card passes through, the warning light flashes red and the buzzer sounds. If it passes normally, the green light is on and the buzzer is silent. How to set the alarm threshold and alarm method can be customized.
G11B channel antenna is equipped with RR9201T reader, its main specifications and performance parameters are as follows:
G11B type RFID channel antenna parameters
Specifications and dimensions Unit: cm |
||
Antenna part |
||
project |
Performance parameters |
Remark |
high |
150.0 (including base) |
ABS engineering plastic material, the main body is sprayed with dark gray metallic paint, with beige side strip painting, and it is resistant to detergent scrubbing |
width |
46.0 |
|
thickness |
4.0 |
|
Equipment box section |
||
Remark |
||
high |
35.0 |
ABS engineering plastic material, the main body is sprayed with dark gray metallic paint; there is an aluminum plate on the back of the equipment box as a heat sink. Type B has no waterproof design, users can also choose G11A type waterproof design, |
width |
35.0 |
|
thickness |
9.5 |
|
base part |
||
Remark |
||
length |
47.0 |
The antenna base is made of 3mm thick steel plate, the surface is dark gray paint, and there are holes in the four corners to facilitate fixing on the ground |
width |
18.0 |
|
thickness |
1.5 |
|
Antenna weight |
||
project |
Performance parameters |
Remark |
Net weight in full condition |
About 25Kg |
|
Antenna performance parameters Length unit: cm |
||
project |
Performance parameters |
Remark |
maximum channel width |
135 |
The smaller the width, the stronger the recognition ability Use TI RI-I02-112B label, PVC encapsulation, (the test value applies to the case where the label is perpendicular to the antenna) It is recommended to use a width of 100cm to avoid people passing side by side and prevent interference with the infrared algorithm |
Minimum channel width |
60 |
|
Standard channel width |
125 |
|
Magnetic Field Rotation Antenna Standard Width |
105 |
For optional function.The magnetic field rotates quickly and smoothly between 90 and 180 degrees, so that the label can be more accurately identified when it is perpendicular to the ground |
Applicable person height |
120~200 |
The label is worn on the chest, Antennas can be customized to accommodate identification of children |
Recognition speed (single label) |
20ms |
|
maximum passing speed |
4 m/s |
Channel is in standard width condition |
anti-collision |
Anti-collision capability |
that allows multiple people to queue through |
Anti-collision experimental value |
240 tags are placed within the antenna identification range at the same time |
Recognition completed in 6.07 seconds |
Label continuous recognition ability |
unlimited |
|
Number of infrared switches |
4 pairs |
Infrared device is optional equipment |
Infrared identification type |
Through-beam |
Through-beam infrared working state is not affected by external factors such as clothing texture and light |
Maximum infrared radiation distance |
15 meters |
|
Infrared switch brand |
Omron |
This type of device can be used in water |
Controller interface |
Standard interface RS485 |
Custom interface RS232 Optional interface TCP/IP |
Data storage performance |
More than 16000 records |
Optional equipment |
Device power consumption |
18W |
Special note: The RR9201T and RR9202T readers mentioned above are high-power high-frequency read-write modules with an output power of 4W, which are components of the channel antenna, and their performance has been fully listed in the relevant parameter table of the overall equipment. In this embodiment, in order to simplify the complexity, no separate detailed introduction is made in this technical solution.
The equipment introduction of long-distance RFID sensing equipment is over. From the above discussion, it can be seen that our company has a good understanding of the application requirements of schools, smooth technical communication, and a good understanding of the required products, which is an important basis for providing good services.
Four.Proximity RFID reading and writing equipment
The short-range RFID sensing device is an integral part of a complete RFID application project, and in this tender, we believe it is an important tool to improve the flexibility of system functions. The following is the product selection and function introduction:
4.1.Portable Handheld Reader
Handheld Reader
Specifications
RF communication protocol |
ISO 15693, ISO 14443 |
model |
EH 0318 |
microprocessor |
32-bit super microcontroller |
memory |
Flash Memory: 16 Mbit (expandable to 32 Mbit or 64 Mbit), DRAM: 16 Mbit Enough to store more than 20,000 pieces of data |
display |
1 28*64 dot, EL backlight, 8*4 lines of Chinese characters (16*8 Western characters), one line of icons |
button |
16 keys, with backlight, a jog wheel |
Communication Interface |
1 external serial port, support standard RS-232 serial communication protocol; 1 IrDA infrared interface |
battery system |
850 mAh Li-Ion battery; motherboard also has a spare coin cell battery to save the clock |
Vibration function |
none |
buzzer |
have |
Operating temperature |
-20℃~50℃ |
Relative humidity |
45%RH~85%RH(No condensation) |
Power consumption |
Average power consumption <0.5W, maximum power consumption <3.5W |
1 54 (H) * 67 (W) * 30 (T) mm |
|
net weight |
170g |
Optional wireless communication
(Optional) GPRS module: Working frequency: EGSM: 900/1800MHZ, GSM: 850/190MHZ; Support TCP/IP transmission protocol; with SMS (Short Message Service) function. Schools can choose to upgrade the above modules at any time when they need this function in the future.
How to use
The hand-held reader has a recognition distance of 5-8cm. Because of its own display and keyboard, it can be used as an effective tool for school inspectors to check student certificates. The basic model of the handheld uses serial communication to exchange data with the database server.
4.2.Proximity high frequency reader
This is a small low-power card reader device, generally placed on the desktop to issue cards; or fixed on the wall as a passive card reader device. Its recognition distance for standard cards is 10cm, and the model is RR9036.It has two different interfaces, among which the USB interface is generally used as a card issuer, as shown below
RR9036USB Reader
The device is directly connected to the USB port of the computer without external power supply, and its working mode is customized according to the characteristics of the card issuing operation.
If it is RS485 or RS232 interface, the picture is as follows:
RR9036 serial port reader
Regardless of the communication interface, the RR9036 conforms to the ISO15693 and ISO14443 standards.DLL dynamic library command set with functions such as searching for card, reading, writing, initializing electronic wallet, adding value, depreciating value, querying balance and loading password.
We provide example programs of VC, and DELPHI, as well as communication protocols, which are convenient for schools to carry out secondary development.
In the future possible expansion of the one-card capacity application, we can also provide a full range of proximity sensing devices, such as a dedicated cafeteria consumer machine with dual-interface display, etc., for schools to choose.
five. RFID system application software
After the school installs RFID sensing equipment at the gate, teaching building, dormitory building, etc., and distributes RFID certificates to students, it can record and analyze teaching attendance and dormitory attendance, and assist in student behavior management.
The main functions of the RFID system application software customized by our company for schools are:
1) The number and regional distribution of current personnel can be inquired
2) The area where any designated person is at the current or designated time
3) Traces of activity of any designated person on that day or on a designated date
4) Select an area to get the current personnel information in that area
5) The student information can be downloaded through the handheld reader and the student ID can be checked at any time
6) Support MSSQL and MySQL database extensions
7) Seamless connection with the school’s education management information system
Where there is cash, tickets or identification (including student ID, library card, pass, staff attendance, staff meeting sign-in, canteen consumption, bathroom water management, dormitory electricity management, computer room charges, parking lot, Canteen consumption and other management functions such as small-amount consumption) are all completed by this RFID certificate.
appendix:
Device List Reference Format
Product name |
model |
brand |
quantity |
unit price |
total project price |
Remark |
long distance card reader |
RR-S02 |
Lombrida |
12 |
Basic |
||
long distance card reader |
RR-G02 |
Lombrida |
2 |
Dual channel type |
||
long distance card reader |
RR-G11B |
Lombrida |
10 |
Including infrared module |
||
Handheld Card Reader |
RR-EH0318 |
Lombrida |
Basic |
|||
proximity card reader |
RR9036 |
Lombrida |
Optional USB or RS232/485 interface |
|||
RFID card |
112B |
TI |
5000 |
Reverse generic color printing front blank |
||
RFID software |
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