WO2018205767A1

WO2018205767A1 - Open-type rfid entrance guard system for access detection and handling method therefor

Info

Publication number: WO2018205767A1
Application number: PCT/CN2018/081261
Authority: WO
Inventors: 刘佳; 陈力军; 张晓聪; 严颖丽; 陈星宇; 黄嘉琪; 李珍珠; 郁裕杰; 荀凯
Original assignee: 南京大学
Priority date: 2017-05-09
Filing date: 2018-03-30
Publication date: 2018-11-15
Also published as: CN107145919A; CN107145919B

Abstract

Disclosed are an open-type RFID entrance guard system for access detection and a handling method therefor. The system mainly comprises an RFID reader, an antenna, a tag and a background server. The operating method thereof is: respectively deploying two antennas having a certain angle included therebetween inside a device at both sides of an entrance guard channel, both of which are connected to the RFID reader, wherein the antenna receives a signal reflected by an RFID tag carried by an object accessing the entrance guard, and time periods during which the antennas at both ends of the entrance guard receive the reflected signal are different, and by using such a characteristic, determining and recording and displaying entering and exiting behaviours of personnel in the entrance guard system in real time. The present invention applies RFID technology to an open-type entrance guard system, which can automatically recognize entering and exiting behaviours when a person accesses the entrance guard, without the need for arranging a wing gate or contact-type recognition, thereby greatly improving the efficiency of entrance guard access of personnel.

Description

Open RFID access control system for access detection and processing method thereof

Technical field

The invention relates to the field of RFID technology, in particular to an open RFID access control system for access detection and a processing method thereof.

Background technique

RFID (Radio Frequency Identification) technology is an automatic identification technology based on wireless communication technology. Its basic principle is to use the RF signal and spatial coupling transmission characteristics to automatically identify the information carried by the identified object. Its biggest advantage is non-contact. Identify and recognize high-speed moving objects and identify multiple targets. RFID technology is now being used more and more widely in all industries, including supply chain management, warehouse inventory, electronic payment, secure access control, target monitoring and tracking.

At present, most access control systems rely on access cards and gates. When personnel pass through the door, they need to go through a series of complicated and time-consuming processes such as staying for cards, swiping cards, waiting for gates to open, gates to open, and fast passage. In addition, the existing access control allows only one object to pass at a time, and the throughput is very limited, especially for access control for a large number of objects (such as: stadium access control, concert access control), this serialized access method will seriously restrict the access efficiency of the access control. Not conducive to personnel experience. UHF RFID system has the distinctive features of batch reading and non-line-of-sight communication, which can effectively overcome the above shortcomings and provide guarantee for improving the automation degree and throughput of the access control system.

Summary of the invention

OBJECT OF THE INVENTION The technical problem to be solved by the present invention is to provide an open RFID access control system for access detection and a processing method thereof, and to automatically read an RFID tag carried by a mobile object by using a device deployed in the access control. And discriminate the direction of the object that carries the RFID tag through the access control.

In order to solve the above technical problem, the present invention discloses an open RFID access control system for access detection, the access control system is installed at the side of the access passage, and includes at least one RFID reader, each of which has two or more external antennas. At least one antenna is inclined toward the channel; at least one antenna is inclined toward the channel;

During the movement of the RFID tag from the direction of the incoming channel to the direction of the outgoing channel, the antenna tilted toward the incoming channel first receives the RFID tag signal, and receives the RFID tag signal after the antenna tilted toward the outgoing channel;

During the movement of the RFID tag from the direction of the exit channel to the direction of the forward channel, the antenna tilted toward the direction of the channel first receives the RFID tag signal, and receives the RFID tag signal after the antenna tilted toward the channel;

The timing of receiving the same RFID tag signal through the antennas at both ends of the access control system confirms the direction of the RFID tag signal entering and exiting the channel.

Further, the present invention includes two RFID readers, centered on the access channel, and symmetrically disposed on both sides of the channel.

The system further includes a background server, and the RFID reader feeds back the read RFID tag signal to the background server in real time through an external antenna, including an antenna port number, a label EPC number, and a time stamp of the received signal;

The background server calculates the difference between the average values of the time stamp features of the same RFID tag read by the antennas at both ends of the channel according to the tag signal returned by the RFID reader, and then identifies the mapping relationship between the tag EPC number and the identity information of the object carrying the RFID tag. An object carrying an RFID tag through an access control and determining its access direction;

The antenna radiates electromagnetic waves outwardly, receives signals reflected by the RFID tags and transmits them to the RFID reader.

The background server further includes a display interface, and the display interface displays the access situation of the access control in real time according to the information collected by the RFID reader.

The invention also discloses a processing method for an open RFID access control system for access detection, comprising the following steps:

Step 1. Record the two ends of the access control system as the A end and the B end respectively, and use an RFID reader to read the RFID tag signal passing through the access control system;

Step 2: classify the reflected signals of the same tag received by the antennas on one side or both sides of the channel into one class, and sort them to obtain a sequence;

Step 3: Calculate the sequence obtained in step 2, and obtain an average value of the time stamp features of the same RFID tag read by the antennas at both ends of the channel;

Step 4: Determine, according to the average value of the time stamp feature, the entry and exit of the object carrying the RFID tag.

In step 1, the RFID tag signal includes an antenna port number ant, a tag EPC number epc, and a timestamp t, and the above information is represented as a triplet {ant, epc, t}, indicating that the antenna port number of the RFID reader is ant. The EPC number received by the antenna at time t is the label signal of epc.

Step 2 includes the following steps:

Step 2-1: The ternary group obtained in the step 1 is divided according to the antenna port number and the label EPC number, and the data including the same end antenna port number and the same label EPC number is divided into one class;

In step 2-2, in each of the divided classes, each type of data is sorted in order of timestamp t from small to large to obtain a tag signal sequence.

For the tag signal sequence obtained in step 2, the corresponding total time is T; set a time period of size t _d (generally 100 ms), divide the sequence into time segments, and divide the entire sequence into

Segment

If there are triples {ant,epc,t} in the mth time period, they are combined into one feature triplet {end,epc,t _m }, where end represents the position of the antenna in the access control system. , that is, the A end or the B end, the epc is the label EPC number, and t _m is the middle time of the time period;

If there is no triplet {ant, epc, t} in the mth time period, there is no corresponding feature triplet c _m , and f _m represents the state of the characteristic triplet in the mth time period. If c _{m is} present, f _m takes a value of 1; if c _m does not exist, f _m takes a value of 0, and t _m f _m is the time-lapse eigenvalue of the mth time period.

Step 3 includes: calculating, according to the data obtained in step 2, the time stamp feature average value T _end corresponding to the antennas at both ends by using the following formula:

among them,

(According to the value of end, the average of the timestamp features of the antennas at both ends can be calculated by this formula, T _A represents the average value of the time stamp features at the A end, and T _B represents the average value of the time stamp features at the B end).

Step 4 includes: if the average value of the timestamp feature of the RFID tag read by the A-end antenna is smaller than the average of the time-stamp feature of the RFID tag read by the B-end antenna, it is determined that the object carrying the RFID tag passes through A to B. If the average value of the timestamp feature of the RFID tag read by the A-end antenna is greater than the average of the time-stamp feature of the RFID tag read by the B-end antenna, it is determined that the object carrying the RFID tag passes from B to A. Access control.

Further, the method further includes the step 5 of querying the mapping table of the label EPC number and the object carrying the RFID tag, and acquiring specific identity information (such as the name, job number, and the like) of the object carrying the RFID tag through the channel.

The invention utilizes the difference of the time period when the antennas at the two ends of the access control receive the reflected signal of the mobile tag, and detects the direction of the object carrying the RFID tag through the access control, thereby providing a convenient and efficient access control system. Compared with the traditional access control system, the biggest feature of the present invention is that the RFID technology is used to perceive the movement behavior mode of the person. The system does not need the personnel to cooperate with the action of brushing the access card, and the entry prohibition can be determined after the person passes the access control. In addition, the access control facilities do not need to be equipped with wing gates, which saves the time for the opening and closing of the traditional gated gates, and the personnel do not need to pass one by one, but can pass multiple people in a row, greatly improving the access of personnel through the door. effectiveness.

Beneficial effect: Through the method, the access control system monitors the access situation of the personnel. The personnel only need to carry the RFID tag containing the identity information with them, and the system can accurately discriminate and record the entry and exit behavior of the personnel without special operations. The physical control of the traditional access control system for people can work well when multiple people pass continuously, optimizing the personnel experience of the access control system and greatly improving the efficiency of personnel passing the access control.

DRAWINGS

The advantages of the above or other aspects of the present invention will become more apparent from the detailed description of the invention.

1 is a block diagram showing the structure of an access control system of the present invention.

2 is a schematic diagram of deployment of an embodiment.

3 is a flow chart of Embodiment 1.

4 is a flow chart of an access control direction determination algorithm.

Fig. 5 is a schematic view of the second embodiment.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

The invention discloses an open RFID access control system for access detection, characterized in that the access control system is installed on the side of the access passage, and includes at least one RFID reader, each of which is externally connected with two or more antennas; There is an antenna that is inclined toward the channel; at least one antenna is tilted toward the channel;

Step 2 includes the following steps:

Segment

among them,

(According to the value of end, the average of the time stamp characteristics of the antennas at both ends can be calculated by this formula).

Example 1

The invention discloses an open RFID access control system for access detection. As shown in FIG. 1 and FIG. 2, the embodiment includes an access control left device, an access control right device 2, an RFID reader, a first antenna 3, and a second. The antenna 4, the third antenna 5, the fourth antenna 6, the RFID tag 7, the first antenna and the third antenna are located at the access terminal A, and the second antenna and the fourth antenna are located at the access terminal B.

The access control system consists of two parts: the RFID signal acquisition device and the back-end server. The RFID signal acquisition device is composed of an RFID reader and an antenna, and the background server is divided into two parts: the access control direction determination algorithm and the display interface. The functions of each part are as follows:

RFID reader: an external antenna that feeds back the read tag signal to the backend server in real time, including the antenna port number, tag EPC number, and timestamp of the received signal, and sends it to the background server.

Antenna: Two antennas with a certain angle are arranged inside the device on one side or both sides of the access control channel, connected with the RFID reader, radiating electromagnetic waves outward, receiving the signal reflected by the RFID tag and transmitting it to the RFID reader.

The access control direction determination algorithm: according to the tag signal returned by the RFID reader, calculates the difference between the average value of the time stamp features of the antennas at both ends of the access control and the same tag, and then combines the mapping relationship between the label EPC number and the object identity information carrying the RFID tag. Identify the object carrying the RFID tag through the access control and determine its access direction.

Display interface: According to the information collected by the RFID device and the access control direction determination algorithm, the access control of the access control is displayed in real time.

This embodiment provides a processing method for an open RFID access control system for access detection. The process is shown in FIG. 3, and the process is as follows:

1. Each object carries an RFID tag, and the identity of the object can be uniquely determined according to the EPC number of the tag.

2. Two antennas with a certain angle are deployed inside the equipment on one side or both sides of the access control channel. In this embodiment, two antennas with a certain angle are disposed inside the devices on both sides of the access control channel to enhance the robustness of the access control system. The antenna is 60cm away from the ground, the center point distance of the two antennas in the device on the access side is 40cm, the antenna tilt angle θ is 20°, and the reader power is 33.5dBm. The top view is shown in Figure 2.

3. The RFID device continuously monitors the tag signal, including the antenna port number ant, the tag EPC number epc, and the time stamp t of the received signal. When a tag is not read for n seconds, the one listening process for the tag signal ends. In the present embodiment, n is set to 800 ms.

According to the monitored data, the access control direction determination algorithm is used to determine the behavior of the object carrying a tag to enter the ban, as shown in Figure 4, the specific process is as follows:

1, data classification

The tag signal of a tag during a listening process is classified according to the antenna port number. In this embodiment, the first antenna and the third antenna are located at the access terminal A, and the second antenna and the fourth antenna are located at the access terminal B. For the same tag, the tag signals read by the No. 1 antenna and the No. 3 antenna are classified into one class, and the tag signals read by the No. 2 antenna and the No. 4 antenna are classified into one class, and the data in each class is time stamped from small to Sort in large order.

2, data preprocessing

The classified data is divided into several time segments, and the characteristic triples of each time segment are calculated. In the present embodiment, the classified data is divided into a plurality of segments in a time period of 100 ms. In the mth time period, if there is tag signal data, they are combined into one feature triplet {side,epc,t _m }, including the position end of the antenna in the access control system, the label EPC number epc, and the time period. Intermediate time t _m . f _m represents the state of the feature triplet in the mth time period. If c _{m is} present, f _m takes a value of 1. If c _m does not exist, f _m takes a value of 0. t _m f _m is the time stamp feature value of the mth time period.

3. Calculate the average of the time stamp characteristics corresponding to the antennas at both ends.

The time stamp feature average value T _end corresponding to the antennas at both ends is:

among them,

4, discriminate the access situation of the object

If the average value of the time stamp feature of the RFID tag read by the A-end antenna is smaller than the average of the time-stamp feature of the RFID tag read by the B-end antenna, it is determined that the object carrying the RFID tag passes the access control from A to B; If the average value of the timestamp feature of the RFID tag read by the A-end antenna is greater than the average of the time-stamp feature of the RFID tag read by the B-end antenna, it is determined that the object carrying the RFID tag passes the access control from B to A.

Example 2

This embodiment describes the access control determination algorithm in conjunction with FIG. 4 and FIG. 5.

5 represents a circle pattern and a triangular pattern signal has been classified according to the tag antenna port number, EPC number of the tag is epc _1. The circle pattern represents the label signal read by the A-end antenna, and the triangle pattern represents the label signal read by the B-end antenna. The total time T corresponding to the tag signal sequence is 590 ms. The classified data is divided into 6 segments in a time period of 100 ms. For the A-end antenna, there are three-tuples in the first, second, third, fourth, and fifth segments, that is, the corresponding feature triplets exist in the first, second, third, fourth, and fifth segments. For the B-end antenna, there are three-tuples in the second, third, fourth, and sixth segments, that is, the corresponding feature triplets exist in the second, third, fourth, and sixth segments. Taking the first segment of the A-end antenna as an example, there is a characteristic triplet c ₁ ={A, epc ₁ , 50}; taking the second segment of the B-end antenna as an example, there is a characteristic triplet c ₂ ={B, Epc ₁ , 150}.

For the A-side antenna, the corresponding timestamp feature average

For the B-end antenna, the corresponding time-stamp feature average

T _A <T _B , it is determined that the object carrying the RFID tag passes through the access control from A to B.

The present invention provides an open RFID access control system for access detection and a processing method thereof. There are many methods and ways for implementing the technical solution. The above description is only a preferred embodiment of the present invention, and it should be noted that it is common to the technical field. The skilled person will be able to make several modifications and refinements without departing from the principles of the invention, and such modifications and refinements are also considered to be within the scope of the invention. The components that are not clear in this embodiment can be implemented by the prior art.

Claims

An open RFID access control system for access detection, characterized in that the access control system is installed at the edge of the access passage, and includes at least one RFID reader, each of which has two or more external antennas; at least one antenna is provided Inclining in the direction of the channel; at least one antenna is inclined toward the channel;

During the movement of the RFID tag from the direction of the incoming channel to the direction of the outgoing channel, the antenna tilted toward the incoming channel first receives the RFID tag signal, and receives the RFID tag signal after the antenna tilted toward the outgoing channel;

During the movement of the RFID tag from the direction of the exit channel to the direction of the forward channel, the antenna tilted toward the direction of the channel first receives the RFID tag signal, and receives the RFID tag signal after the antenna tilted toward the channel;

The timing of receiving the same RFID tag signal through the antennas at both ends of the access control system confirms the direction of the RFID tag signal entering and exiting the channel.
The open RFID access control system for access detection according to claim 1, comprising two RFID readers, which are symmetrically disposed on both sides of the channel, centered on the access channel.
The open RFID access control system for access detection according to claim 2, further comprising a background server, wherein the RFID reader feeds back the read RFID tag signal to the background server in real time through an external antenna, including receiving the signal. Antenna port number, label EPC number, time stamp;

The background server calculates the difference between the average values of the time stamp features of the same RFID tag read by the antennas at both ends of the channel according to the tag signal returned by the RFID reader, and then combines the mapping relationship between the tag EPC number and the object identity information carrying the RFID tag to identify and pass Accessing an object carrying an RFID tag and determining its access direction;

The antenna radiates electromagnetic waves outward, receives signals reflected by the RFID tags and transmits them to the RFID reader;

The background server further includes a display interface, and the display interface displays the access situation of the access control in real time according to the information collected by the RFID reader.
The processing method of the open RFID access control system for access detection is characterized in that it comprises the following steps:

Step 1. Record the two ends of the access control system as the A end and the B end respectively, and use an RFID reader to read the RFID tag signal passing through the access control system;

Step 2: classify the reflected signals of the same tag received by the antennas on one side or both sides of the channel into one class, and sort them to obtain a sequence;

Step 3: Calculate the sequence obtained in step 2, and obtain an average value of the time stamp features of the same RFID tag read by the antennas at both ends of the channel;

Step 4: Determine, according to the average value of the time stamp feature, the entry and exit of the object carrying the RFID tag.
The processing method of the open RFID access control system for access detection according to claim 4, wherein in step 1, the RFID tag signal comprises an antenna port number ant, a label EPC number epc, a time stamp t, and the above information is represented. It is a triplet {ant,epc,t}, which indicates that the antenna with the antenna port number ant on the RFID reader receives the EPC number as the label signal of epc at time t.
The processing method of the open RFID access control system for access detection according to claim 5, wherein the step 2 comprises the following steps:

Step 2-1: The ternary group obtained in the step 1 is divided according to the antenna port number and the label EPC number, and the data including the same end antenna port number and the same label EPC number is divided into one class;

In step 2-2, in each of the divided classes, each type of data is sorted in order of timestamp t from small to large to obtain a tag signal sequence.
The processing method of the open RFID access control system for access detection according to claim 6, wherein the total time corresponding to the tag signal sequence obtained in step 2 is T; setting a time of size t d Segment, the sequence is divided into time segments, and the entire sequence is divided into
Segment

If there are triples {ant,epc,t} in the mth time period, they are combined into one feature triplet {end,epc,t m }, where end represents the position of the antenna in the access control system. , i.e. terminal a or terminal B, EPC label EPC number, t m for the intermediate time period;

If there is no triplet {ant, epc, t} in the mth time period, there is no corresponding feature triplet c m , and f m represents the state of the characteristic triplet in the mth time period. If c m is present, f m takes a value of 1; if c m does not exist, f m takes a value of 0, and t m f m is the time-lapse eigenvalue of the mth time period.
The processing method of the open RFID access control system for access detection according to claim 7, wherein the step 3 comprises: calculating the average value of the time stamp features corresponding to the antennas at both ends according to the data obtained in step 2 by the following formula T end:

among them,
The method for processing an open RFID access control system for access detection according to claim 4, wherein the step 4 comprises: if the A-end antenna reads an RFID tag, the average time stamp feature is smaller than the B-end antenna read. To the average of the time stamp characteristics of the RFID tag, it is determined that the object carrying the RFID tag passes through the access control from A to B; conversely, if the average time stamp feature of the RFID tag read by the A-end antenna is greater than the B-end antenna read To the average of the time stamp characteristics of the RFID tag, it is determined that the object carrying the RFID tag passes through the access control from B to A.
The processing method of the open RFID access control system for access detection according to claim 9, further comprising the step of: querying the mapping table of the label EPC number and the object carrying the RFID tag, and acquiring the RFID tag carrying the channel through the channel. The specific identity information of the object.