CN-115455998-B - Vehicle electronic identification recognition method and system

CN115455998BCN 115455998 BCN115455998 BCN 115455998BCN-115455998-B

Abstract

The invention discloses a vehicle electronic identification recognition method and a system, wherein the method comprises the steps that a reader sends a Query instruction to prescribe frame length, a time slot is randomly selected from tags in a reader recognition range within the frame length range to respond to the instruction of the reader and return an information packet, if collision time slots exist, an observed value in a previous frame is obtained, the number of the tags is obtained according to the observed value in the previous frame and a preset tag estimation algorithm, the number of the time slots of a next frame is obtained according to the number of the tags and the number of the antennas, if the number of the antennas is not larger than the number of the tags in the time slots of the next frame, a second preset separation method is adopted to separate tag signals, and vehicle recognition is carried out according to the separated signals. And selecting a proper separation method, separating out signals, and completing identification. The accuracy of identification is improved, the problem of identification errors caused by collision is avoided, and the identification efficiency is improved.

Inventors

HE SHENG
XIONG LI
PI YONGHONG
Zou Qiangyu
LAI JUN
Nie Siyi
FU XIAODONG
CHEN CHANGQING
LUO JIANMIN
GUO TONG
WU LIPING
ZENG JUN
WEN BING
Fan Cunxin

Assignees

华能秦煤瑞金发电有限责任公司

Dates

Publication Date: 20260505
Application Date: 20220805

Claims (6)

1. The vehicle electronic identification recognition method is characterized by being applied to a multi-antenna RFID system, and presetting the number of antennas, and comprises the following steps: The method comprises the steps that firstly, a reader sends a Query instruction to prescribe a frame length, a time slot is randomly selected from tags in a reader identification range in the frame length range to respond to the instruction of the reader, and an information packet is returned; If collision time slots exist, after the previous frame is finished, obtaining an observed value in the previous frame, and obtaining the number of labels according to the observed value in the previous frame and a preset label estimation algorithm; Step three, obtaining the time slot number of the next frame according to the tag number and the antenna number, and judging whether the antenna number is larger than the tag number in the time slot of the next frame or not on the basis of the time slot number of the next frame; If the number of the antennas is not more than the number of the tags in the time slot of the next frame, a second preset separation method is adopted to separate the tag signals, and vehicle identification is carried out according to the separated signals; wherein, the collision time slot is the time slot of two or more tags returning information packets; If the number of the antennas is not greater than the number of the tags in the time slot of the next frame, a second preset separation method is adopted to separate the tag signals, specifically: Setting that N tags exist in a time slot, wherein the return signals of the N tags are S= [ S 1 ,S 2 ,S 3 ......S N ], the reader is provided with M antennas, the M antennas receive M mixed signals of N tags which are mixed irregularly and are X= [ X 1 ,X 2 ,X 3 ......X M ], wherein X=AS, A is an N X M dimension column full rank instantaneous linear mixed matrix, a separation matrix W is obtained through an ICA method, and the separation matrix is substituted into the following model: Y=WX, wherein Y is a signal which is close to the tag signal after the M mixed signals are separated, and W is an M multiplied by N instantaneous linear separation matrix.
2. The method of claim 1, wherein the number of labels is obtained according to the observed value in the previous frame and a preset label estimation algorithm, specifically: The observation value comprises the number of idle time slots, the number of successful time slots and the number of collision time slots, wherein the number of idle time slots is the number of time slots without a tag returning information packet, the number of successful time slots is the number of time slots with only one tag returning information packet, and the number of collision time slots is the number of time slots with two or more tag returning information packets; Calculating the probability of occurrence of collision time slots in an initial frame according to the number of idle time slots, the number of successful time slots and the number of collision time slots, roughly estimating the number of tags according to the probability to obtain the number of first tags, and if the number of first tags does not meet the preset requirement, carrying out fine estimation to obtain the number of tags; And if the first label number meets the preset requirement, taking the first label number as the label number.
3. The method of claim 1, wherein the method further comprises: if the signals separated by adopting the first preset separation method or the second preset separation method do not have unidentified labels, vehicle identification is carried out according to the separated signals; if the signal separated by the first preset separation method or the second preset separation method has unidentified labels, the steps one to four are carried out again.
4. A vehicle electronic identification recognition system, characterized in that it is applied in a multi-antenna RFID system, and the number of antennas is preset, the system includes: The response module is used for sending a Query instruction to prescribe the frame length by the reader, randomly selecting a time slot in the frame length range by the tag in the identification range of the reader to respond to the instruction of the reader and returning an information packet; the estimating module is used for acquiring an observed value in a previous frame after the previous frame is finished if a collision time slot exists, and obtaining the number of labels according to the observed value in the previous frame and a preset label estimating algorithm; The judging module is used for obtaining the time slot number of the next frame according to the tag number and the antenna number, and judging whether the antenna number is larger than the tag number in the time slot of the next frame or not on the basis of the time slot number of the next frame; The separation module is used for separating the tag signals by adopting a first preset separation method if the number of the antennas is larger than the number of the tags in the time slot of the next frame, and carrying out vehicle identification according to the separated signals; wherein, the collision time slot is the time slot of two or more tags returning information packets; The separation module is specifically configured to: Setting that N tags exist in a time slot, wherein the return signals of the N tags are S= [ S 1 ,S 2 ,S 3 ......S N ], the reader is provided with M antennas, the M antennas receive M mixed signals of N tags which are mixed irregularly and are X= [ X 1 ,X 2 ,X 3 ......X M ], wherein X=AS, A is an N X M dimension column full rank instantaneous linear mixed matrix, a separation matrix W is obtained through an ICA method, and the separation matrix is substituted into the following model: Y=WX, wherein Y is a signal which is close to the tag signal after the M mixed signals are separated, and W is an M multiplied by N instantaneous linear separation matrix.
5. The system of claim 4, wherein the estimation module is specifically configured to: The observation value comprises the number of idle time slots, the number of successful time slots and the number of collision time slots, wherein the number of idle time slots is the number of time slots without a tag returning information packet, the number of successful time slots is the number of time slots with only one tag returning information packet, and the number of collision time slots is the number of time slots with two or more tag returning information packets; Calculating the probability of occurrence of collision time slots in an initial frame according to the number of idle time slots, the number of successful time slots and the number of collision time slots, roughly estimating the number of tags according to the probability to obtain the number of first tags, and if the number of first tags does not meet the preset requirement, carrying out fine estimation to obtain the number of tags; And if the first label number meets the preset requirement, taking the first label number as the label number.
6. The system of claim 5, wherein, the system further comprises a verification module for: if the signals separated by adopting the first preset separation method or the second preset separation method do not have unidentified labels, vehicle identification is carried out according to the separated signals; if the signal separated by the first preset separation method or the second preset separation method has unidentified labels, the steps one to four are carried out again.

Description

Vehicle electronic identification recognition method and system Technical Field The application relates to the technical field of vehicle identification, in particular to a vehicle electronic identification method and a system. Background Radio Frequency Identification (RFID) is an abbreviation for Radio Frequency Identification. The method is one of automatic identification technologies, non-contact two-way data communication is carried out through a wireless radio frequency mode, and a recording medium (an electronic tag or a radio frequency card) is read and written through the wireless radio frequency mode, so that the purposes of identification targets and data exchange are achieved, and the method is considered as one of the information technologies with the most development potential in the 21 st century. RFID radio frequency identification systems generally comprise at least two parts, an electronic Tag (Tag) and a Reader (Reader). Electronic data in a stipulated format is generally stored in the electronic tag, and in practical application, the electronic tag is attached to the surface of an object to be identified. The reader is also called a reading device, and can read and identify the electronic data stored in the electronic tag in a contactless manner, so that the object can be automatically identified. Further realize the management functions such as collection, processing, remote transmission, etc. of the object identification information through the computer and the computer network. The multi-antenna technology is not only an increase of the number of antennas, but also an intelligent antenna with algorithms for tracking signals, positioning signal sources and the like, and has the advantages of large communication capacity, high transmission rate, small signal transmitting power, positioning signal sources, increasing system capacity, improving frequency spectrum efficiency, expanding signal coverage range and the like compared with the single-antenna technology. At present, a plurality of students carry out related researches on a multi-antenna RFID system, a 4-antenna ultrahigh frequency RFID reader-writer is developed, the influence of the orientation of the tag is avoided when the tag is read, a plurality of tags are read in a moment, and the number of the read tags is increased. However, there is still a problem that the identification efficiency is not high when the multi-antenna RFID system is in a scene with a large number of tags, such as logistics management, warehouse management, motor vehicle management, etc. In a multi-antenna RFID system, a large number of tags transmit signals to a plurality of antennas of a reader in the same time, and at this time, the probability of collision of the tag signals at a certain time point is increased, so that the recognition efficiency of the multi-antenna RFID system is affected. The schematic diagram of the collision of the tag is shown in fig. 3, and the collision of the tag refers to that two or more tag signals simultaneously feed back signals to the reader at the same moment, so that the returned signals collide with each other, and the collided tag cannot be identified, so that the identification efficiency of the RFID system is reduced due to the collision of the tag. Therefore, how to improve the tag recognition efficiency is a technical problem to be solved at present. Disclosure of Invention The invention provides a vehicle electronic identification recognition method which is used for solving the technical problem of low label recognition efficiency in the prior art. The method is applied to a multi-antenna RFID system, the number of antennas is preset, and the method comprises the following steps: The method comprises the steps that firstly, a reader sends a Query instruction to prescribe a frame length, a time slot is randomly selected from tags in a reader identification range in the frame length range to respond to the instruction of the reader, and an information packet is returned; If collision time slots exist, after the previous frame is finished, obtaining an observed value in the previous frame, and obtaining the number of labels according to the observed value in the previous frame and a preset label estimation algorithm; Step three, obtaining the time slot number of the next frame according to the tag number and the antenna number, and judging whether the antenna number is larger than the tag number in the time slot of the next frame or not on the basis of the time slot number of the next frame; If the number of the antennas is not more than the number of the tags in the time slot of the next frame, a second preset separation method is adopted to separate the tag signals, and vehicle identification is carried out according to the separated signals; wherein the collision time slot is a time slot of two or more tags returning information packets. In some embodiments of the present application, the number of labels is o