A method and application of sequential reading of radio frequency tags in production line

Abstract

This invention relates to a method and application for sequential reading of RFID tags on a production line. Based on radio frequency detection in the detection area, it analyzes the changes in signal strength between the RFID tag and the radio frequency antenna as the RFID tag moves along the conveyor belt, selecting the time point with the strongest signal strength as the elapsed time of the RFID tag. The order of the RFID tags is then determined by analyzing the elapsed times of each tag. Furthermore, a multi-radio frequency antenna design is introduced, where each antenna independently compares the RFID tag order, using a voting method to determine the order corresponding to the detection area, thus improving the accuracy of the determination. Simultaneously, the invention further introduces multiple detection area settings, and by comparing the orders obtained from different detection areas, it can effectively eliminate misreadings and misjudgments of RFID tags outside the conveyor belt area, further ensuring the accuracy of the obtained RFID tag order.

Description

Technical Field

[0001] The invention relates to a method for sequentially reading a production line radio frequency tag and an application thereof, belonging to the technical field of radio frequency tags. Background Art

[0002] The most difficult problem in using RFID to replace barcodes on the assembly line is cross-reading. The light from the barcode gun is scanned in a straight line, and the electromagnetic waves will scatter, making it difficult to control the reading range very small. Therefore, the distance between the two radio frequency tags must be increased, which will slow down the entire logistics processing speed.

[0003] Moreover, for the transmission of RFID tags on the assembly line, when two RFID tags are too close, even if a highly directional RFID antenna is used, it is impossible to effectively judge the order between the RFID tags. In particular, in actual applications, the placement direction of each RFID tag is random, the height difference of each RFID tag is also random, and there may be metal near the RFID tag, which will reflect or block electromagnetic waves, making communication with the RFID tag more difficult. Therefore, in the existing technology, it becomes troublesome to judge the order between the RFID tags in assembly line applications, and the accuracy is not high. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a pipeline RF tag sequence judgment method, which adopts a new strategy to determine the passing time of the RF tag based on the time point of the strongest signal, accurately completes the RF tag sequence judgment, and improves the working efficiency of RF applications.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: the present invention designs a method for sequentially reading radio frequency tags on an assembly line, based on a main radio frequency reading and writing device whose radio frequency reading range covers a preset detection area on a conveyor belt, for each radio frequency tag transmitted on the conveyor belt, the passing time of the radio frequency tag is obtained according to the following steps A to B; then, the order between the radio frequency tags is determined according to the passing time of each radio frequency tag;

[0006] Step A. The RFID tag moves into the detection area on the conveyor belt, triggering the RFID communication between the main RFID reader and the RFID tag, and proceeding to step B;

[0007] Step B. For the entire process of the RFID tag moving with the conveyor belt in the detection area, determine the time point corresponding to the strongest reply signal of the RFID tag in the RFID communication between the main RFID reader and the RFID tag, which is used as the passing time of the RFID tag.

[0008] As a preferred technical solution of the present invention: it also includes at least one secondary RF reading and writing device, the structure of each secondary RF reading and writing device is the same as that of the main RF reading and writing device, and the RF reading range of each secondary RF reading and writing device covers the detection area on the conveyor belt respectively;

[0009] The main RF reader and each secondary RF reader are respectively executed according to the steps A to B, and the passing time of each RF tag transmitted on the conveyor belt is obtained, and the order between the RF tags is determined according to the passing time of each RF tag, that is, the order between the RF tags transmitted on the conveyor belt under each RF reader is obtained; and then the following operations are performed;

[0010] Operation: Traverse each position in the sort in turn, obtain the RFID tag at the position in the sort corresponding to each frequency reading and writing device, and select the RFID tag with the largest number of occurrences to constitute the target RFID tag at that position; then obtain the target RFID tag at each position in the sort, and complete the sorting of each RFID tag transmitted on the conveyor belt.

[0011] As a preferred technical solution of the present invention: the main radio frequency reading and writing device and each auxiliary radio frequency reading and writing device are arranged in a closed loop around the detection area corresponding to the conveyor belt direction.

[0012] Furthermore, the technical problem to be solved by the present invention is to provide an application of a method for sequentially reading radio frequency tags on an execution line, by designing multiple detection areas and applying comparison between multi-point detection results to improve the detection accuracy of the order of each radio frequency tag on the conveyor belt.

[0013] In order to solve the above technical problems, the present invention adopts the following technical solutions: the present invention designs an application for executing the assembly line RF tag sequence determination method, based on at least two preset detection areas on the conveyor belt, and the RF reading and writing devices corresponding to the detection areas, according to the execution of the assembly line RF tag sequence determination method, the order between the RF tags corresponding to the detection areas is obtained, and then the following steps i to iv are executed;

[0014] Step i for each detection area corresponding to each RFID tag sorting involved in each RFID tag, obtain each RFID tag corresponding to each detection area of ​​the elapsed time, and then proceed to step ii;

[0015] Step ii. For each RF tag involved in step i, execute the following steps ii-1 to ii-2; after completing step ii of each RF tag, determine whether there is a RF tag to be deleted, if so, proceed to step iii, otherwise proceed to iv;

[0016] Step ii-1. According to the elapsed time of each detection area corresponding to each RFID tag, obtain the elapsed time between each group of adjacent detection areas corresponding to each RFID tag, and then proceed to step ii-2;

[0017] Step ii-2. For the RFID tags corresponding to each group of adjacent detection areas, determine whether there is a time that does not meet the preset upper and lower fluctuation range of the conveyor belt movement time between the corresponding adjacent detection areas. If it is defined as a RFID tag to be deleted, otherwise no processing is performed;

[0018] Step iii respectively for each detection area corresponding to each RF tag sorting, delete each of the RF tags to be deleted, update the detection area respectively corresponding to each RF tag sorting, and then proceed to step iv;

[0019] Step iv. Obtain the intersection of the rankings of the radio frequency tags corresponding to each detection area to form a target ranking, which is the ranking of the radio frequency tags transmitted on the conveyor belt.

[0020] The method for sequentially reading radio frequency tags in an assembly line described in the present invention adopts the above technical solution and has the following technical effects compared with the prior art:

[0021] The present invention designs a method for sequentially reading radio frequency tags on an assembly line. The method is based on radio frequency detection in a detection area. The method analyzes the change in signal strength between the radio frequency tag and the radio frequency antenna as the radio frequency tag moves with a conveyor belt, and selects the time point with the strongest signal strength as the passing time of the radio frequency tag. The method thus determines the order of each radio frequency tag through the passing time of each radio frequency tag. The method further introduces a multi-radio frequency antenna design. The order of each radio frequency tag is determined by comparing the order of each radio frequency antenna, and the order corresponding to the detection area is determined by voting, thereby improving the accuracy of the determination. The method also further introduces a multi-detection area setting. The method effectively eliminates the misreading and misjudgment of radio frequency tags outside the conveyor belt area through the comparison between the order obtained in different detection areas, thereby further ensuring the accuracy of the order obtained between each radio frequency tag. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the method for sequentially reading radio frequency tags in a pipeline designed by the present invention;

[0023] Figure 2 It is a schematic diagram of the closed-loop arrangement of the main radio frequency reading and writing device and each auxiliary radio frequency reading and writing device in the design of the present invention. DETAILED DESCRIPTION

[0024] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0025] The present invention designs a method for sequentially reading radio frequency tags on an assembly line, based on a main radio frequency reader / writer whose radio frequency reading range covers a preset detection area on a conveyor belt, for each radio frequency tag transmitted on the conveyor belt, such as Figure 1 As shown, the passing time of the radio frequency tag is obtained according to the following steps A to B.

[0026] Step A. The RFID tag moves into the detection area on the conveyor belt, triggering the RFID communication between the main RFID reader and the RFID tag, and then proceeding to step B.

[0027] Step B. For the entire process of the RFID tag moving with the conveyor belt in the detection area, determine the time point corresponding to the strongest reply signal of the RFID tag in the RFID communication between the main RFID reader and the RFID tag, which is used as the passing time of the RFID tag.

[0028] According to the above method, based on the movement of the RFID tags along the conveyor belt, the strength of the reply signal from the RFID tags obtained by the main RFID reader / writer first increases from small to large, and then decreases from large to small. During this process, a strongest reply signal will appear. The time point corresponding to the strongest reply signal is used as the passing time of the RFID tags, and the order between the RFID tags can be determined.

[0029] Based on the above-designed assembly line RFID tag sequential reading method, at least one secondary RFID reader / writer is designed to be added to the preset detection area on the conveyor belt. The structure of each secondary RFID reader / writer is the same as that of the main RFID reader / writer, and the RFID reading range of each secondary RFID reader / writer covers the detection area on the conveyor belt.

[0030] In the application, the main RF reader and each secondary RF reader respectively executes the steps A to B to obtain the passing time of each RF tag transmitted on the conveyor belt, and according to the passing time of each RF tag, the order between the RF tags is determined, that is, the order between the RF tags transmitted on the conveyor belt under each RF reader is obtained; then the following operations are performed.

[0031] Operation: Traverse each position in the sort in turn, obtain the RFID tag at the position in the sort corresponding to each frequency reading and writing device, and select the RFID tag with the largest number of occurrences to constitute the target RFID tag at that position; then obtain the target RFID tag at each position in the sort, and complete the sorting of each RFID tag transmitted on the conveyor belt.

[0032] Such a design, that is, based on the ranking determined by each frequency reader / writer, the RF tag at each position in the ranking is determined by voting at each position in the ranking, thereby improving the accuracy of the obtained ranking. In the specific implementation, the number of secondary RF reader / writers is designed to be an even number, which can more efficiently clarify the voting results.

[0033] Further, the main radio frequency reading and writing device corresponding to the detection area and each secondary radio frequency reading and writing device are arranged in a closed loop around the detection area corresponding to the conveyor belt direction, such as Figure 2 As shown, the conveyor belt passes through the closed loop surrounded by the RF reader / writers, that is, they are arranged around a circle of the conveyor belt corresponding to the detection area, and can detect multiple angle positions of the detection area, and can effectively deal with different positions of the RF tag. When the RF tag is at a certain angle, even if there is a metal device blocking it, the RF reader / writers arranged at multiple angles can also communicate with the RF tag from other angles.

[0034] The above-designed assembly line RF tag sequential reading method is applied in practice. For the main RF reader / writer and each secondary RF reader / writer, the specific design is a RF reader / writer including an array RF antenna, which can effectively improve the directivity of the RF signal on each RF reader / writer.

[0035] Based on the above-mentioned design scheme for a single detection area on the conveyor belt, an application based on this is further designed, introducing a multi-detection area design, that is, based on at least two preset detection areas on the conveyor belt, and each RF reading and writing device corresponding to each detection area, the order between the RF tags corresponding to each detection area is obtained according to the execution of the assembly line RF tag sequence judgment method, and then the following steps i to iv are executed.

[0036] Step i. For each RFID tag involved in the sorting between the RFID tags corresponding to each detection area, obtain the elapsed time of each RFID tag corresponding to each detection area, and then proceed to step ii.

[0037] Step ii. For each RFID tag involved in step i, execute the following steps ii-1 to ii-2; after completing step ii for each RFID tag, determine whether there is a RFID tag to be deleted, if yes, proceed to step iii, otherwise proceed to step iv.

[0038] Step ii-1. According to the passing time of each detection area corresponding to the RFID tag, obtain the passing time between each group of adjacent detection areas corresponding to the RFID tag, and then proceed to step ii-2.

[0039] Step ii-2. For the elapsed time between each group of adjacent detection areas corresponding to the RFID tag, determine whether there is an elapsed time that does not meet the preset upper and lower fluctuation range of the conveyor belt moving time between the corresponding adjacent detection areas. If so, define the RFID tag as an RFID tag to be deleted, otherwise do nothing.

[0040] Step iii. Sort the RF tags corresponding to each detection area respectively, delete the RF tags to be deleted, update the sorting between the RF tags corresponding to each detection area respectively, and then proceed to step iv.

[0041] Step iv. Obtain the intersection of the rankings of the radio frequency tags corresponding to each detection area to form a target ranking, which is the ranking of the radio frequency tags transmitted on the conveyor belt.

[0042] The assembly line RF tag sequence judgment method designed by the above technical scheme is based on the RF detection of the detection area, and analyzes the change in signal strength between the RF tag and the RF antenna as the RF tag moves with the conveyor belt, and selects the time point with the strongest signal strength as the passing time of the RF tag, thereby judging the order of each RF tag through the passing time of each RF tag; and further introduces a multi-RF antenna design, and compares the order of RF tags by each RF antenna, and determines the order corresponding to the detection area by voting, thereby improving the accuracy of judgment; at the same time, further introduces a multi-detection area setting, and through the comparison between the order obtained in different detection areas, it can effectively eliminate the misreading and misjudgment of RF tags outside the conveyor belt area, and further ensure the accuracy of the order between the obtained RF tags.

[0043] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for sequentially reading radio frequency tags on an assembly line, characterized in that: Based on the main RF reading and writing device whose RF reading range covers the preset detection area on the conveyor belt, for each RF tag transmitted on the conveyor belt, the passing time of the RF tag is obtained according to the following steps A to B; then, the order between the RF tags is determined according to the passing time of each RF tag; Step A. The RFID tag moves into the detection area on the conveyor belt, triggering the RFID communication between the main RFID reader and the RFID tag, and then proceeding to step B; Step B. For the entire process of the RFID tag moving with the conveyor belt in the detection area, determine the time point corresponding to the strongest reply signal of the RFID tag in the RFID communication between the main RFID reader and the RFID tag, which is used as the passing time of the RFID tag; It also includes at least one secondary radio frequency reader / writer, the structure of each secondary radio frequency reader / writer is the same as that of the primary radio frequency reader / writer, and the radio frequency reading range of each secondary radio frequency reader / writer covers the detection area on the conveyor belt respectively; The main RF reader and each secondary RF reader are respectively executed according to the steps A to B, and the passing time of each RF tag transmitted on the conveyor belt is obtained, and the order between the RF tags is determined according to the passing time of each RF tag, that is, the order between the RF tags transmitted on the conveyor belt under each RF reader is obtained; and then the following operations are performed; Operation: Traverse each position in the sort in turn, obtain the RFID tag at the position in the sort corresponding to each frequency reading and writing device, and select the RFID tag with the largest number of occurrences to constitute the target RFID tag at that position; then obtain the target RFID tag at each position in the sort, and complete the sorting of each RFID tag transmitted on the conveyor belt.

2. According to claim 1, a method for sequentially reading radio frequency tags in an assembly line, characterized in that: The main radio frequency reading and writing device and each auxiliary radio frequency reading and writing device are arranged in a closed loop around the detection area corresponding to the conveyor belt direction.

3. An application of the method for sequentially reading a pipeline radio frequency tag according to claim 1 or 2, characterized in that: Based on at least two preset detection areas on the conveyor belt and the RF reading and writing devices corresponding to the detection areas, the order between the RF tags corresponding to the detection areas is obtained according to the execution of the assembly line RF tag sequence judgment method, and then the following steps i to iv are executed; Step i. For each RFID tag involved in the sorting between the RFID tags corresponding to each detection area, obtain the elapsed time of each RFID tag corresponding to each detection area, and then proceed to step ii; Step ii. For each RF tag involved in step i, execute the following steps ii-1 to ii-2; after completing step ii for each RF tag, determine whether there is a RF tag to be deleted, if yes, proceed to step iii, otherwise proceed to step iv; Step ii-1. According to the elapsed time of each detection area corresponding to the RFID tag, obtain the elapsed time between each group of adjacent detection areas corresponding to the RFID tag, and then proceed to step ii-2; Step ii-2. For the elapsed time between each group of adjacent detection areas corresponding to the RFID tag, determine whether there is an elapsed time that does not meet the preset upper and lower fluctuation range of the conveyor belt moving time between the corresponding adjacent detection areas. If so, define the RFID tag as an RFID tag to be deleted, otherwise do not do anything; Step iii. sorting the RF tags corresponding to each detection area, deleting each RF tag to be deleted, updating the sorting of the RF tags corresponding to each detection area, and then proceeding to step iv; Step iv. Obtain the intersection of the rankings of the radio frequency tags corresponding to each detection area to form a target ranking, which is the ranking of the radio frequency tags transmitted on the conveyor belt.

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