JP7419061B2 - Goods sorting system - Google Patents

Description

The present disclosure relates to an article sorting system for identifying articles.

Conventionally, article sorting systems that sort articles using RF tags have been considered (for example, see Patent Document 1).

The article sorting system attaches an RF tag to an article, reads the tag ID stored in the RF tag with an RFID reader, and sorts the articles based on the tag ID.

Unexamined Japanese Patent Publication No. 2016-3091

By the way, there are cases where various products are combined into a set. Such articles are required to be sorted according to their combinations, and it may be difficult to attach different RF tags to each combination. Therefore, it becomes difficult for the above article sorting system to sort such articles.

The present disclosure has been made in view of the above-mentioned circumstances, and an object of the present disclosure is to provide an article sorting system that can sort articles made up of various products into sets using RF tags.

In order to achieve the above-mentioned object, an article sorting system of the present disclosure includes a conveyance unit that conveys articles provided with a plurality of RF tags, and a transfer unit that conveys articles provided with a plurality of RF tags, and a An RFID reader that acquires a response signal, and a sorting determination unit that acquires a tag ID indicated by the response signal, and the sorting determination unit determines the number of acquired tag IDs, the combination of the tag IDs, The method is characterized in that the sorting of the articles is determined based on the following.

The article sorting system of the present disclosure configured in this manner can sort articles made up of various products into sets using RF tags.

FIG. 1 is an explanatory diagram schematically showing the configuration of an article sorting system according to the present disclosure. FIG. 2 is an explanatory diagram schematically showing the configuration of a receiving area in the article sorting system. FIG. 3 is an explanatory diagram similar to FIG. 2 illustrating how articles are transported through a reception area. It is a graph showing a temporal change in the strength of a received response signal, in which the vertical axis shows the strength of the response signal, and the horizontal axis shows the time at which it was received. 5 is a graph similar to FIG. 4 showing how a plurality of response signals are received and the maximum value of each is detected. It is a flowchart which shows the sorting process (sorting method) performed by the control part of an article sorting system. FIG. 2 is an explanatory diagram showing an example of shipping schedule data. It is an explanatory view showing an example of tag ID which each RF tag of a plurality of transported articles has. FIG. 9 is an explanatory diagram showing how the plurality of articles shown in FIG. 8 are sorted.

An article sorting system 10 according to a first embodiment as an example of an article sorting system according to the present disclosure will be described below with reference to FIGS. 1 to 9.

The article sorting system 10 sorts articles 51 using RFID (Radio Frequency Identification). For this reason, the articles 51 to be sorted by the article sorting system 10 are provided with a plurality of RF tags 52 that use RFID. The article 51 of Example 1 is a package of a plurality of products, and an RF tag 52 is individually attached to each product. In the first embodiment, the RF tag 52 is of a passive type, and includes an antenna and an IC chip. The antenna can receive a search radio wave Rs from an RFID reader 32 of the identification control mechanism 12, which will be described later, and can also transmit a response signal Sr. The IC chip includes a power supply circuit that generates power from the received search radio wave Rs, a storage circuit for writing the tag ID53, a wireless processing circuit for transmitting the response signal Sr, a control circuit that handles the tag ID53 as data, and the like.

The tag ID 53 indicates the type of product to which it is attached, and includes product information and the like. Therefore, the tag ID 53 will be the same if the product is the same, regardless of which product 51 it is, that is, which product it is combined with. Further, the response signal Sr is a signal of the tag ID 53, and can be received by the RFID reader 32.

The article sorting system 10 includes a conveyance sorting device 11 and an identification control mechanism 12, as shown in FIG. In the article sorting system 10, the identification control mechanism 12 identifies the sorting destination of the articles 51 conveyed by the conveying and sorting device 11, and the conveying and sorting device 11 sorts the articles 51 according to the identification. The conveying and sorting device 11 includes a conveying section 21 and a sorting section 22.

The conveyance section 21 conveys the articles 51 to the sorting section 22, and has a conveyance path 23 on which the articles 51 to be conveyed are placed. As shown in FIG. 2, this conveyance path 23 includes a roller conveyor in which a plurality of rollers are arranged side by side in the conveyance direction, a belt conveyor in which an annular belt is rotatably provided in the conveyance direction, or a conveyor chain with continuous plates. It can be constructed of a slat conveyor or the like to which shaped members (slats) are attached, and in the first embodiment, a belt conveyor is used. The transport unit 21 is provided with a reception area 24 for the identification control mechanism 12 to identify the article 51 on the transport path 23 (see FIGS. 1 and 2).

The receiving area 24 is configured by covering the conveying path 23 of the conveying section 21 with a radio wave absorbing frame 25. The radio wave absorption frame 25 is formed of a member that absorbs the search radio wave Rs from the RFID reader 32 and the response signal Sr from the RF tag 52 of the identification control mechanism 12, which will be described later, and suppresses the propagation of these waves to the surrounding area. . The radio wave absorbing frame 25 covers the transport path 23 over a predetermined range in the transport direction Dt while preventing the transport of the article 51 through the transport path 23. The conveyance path 23 is assumed to be covered with a length of 1700 (mm).

As shown in FIG. 1, the sorting section 22 sorts the articles 51 conveyed from the conveying section 21 into a plurality of pieces, and includes a sorting conveyance path 26 for conveying the articles 51 and a plurality of exit ports 27 connected thereto. , has. That is, the sorting section 22 is branched from the sorting conveyance path 26 to each outlet 27 . The sorting conveyance path 26 may be a roller conveyor in which a plurality of rollers are arranged side by side in the transfer direction, a belt conveyor in which an annular belt is rotatably provided in the transfer direction, or a plate-like member (slat) is continuously attached to a conveyor chain. In the first embodiment, a slat conveyor is used. The sorting section 22 is provided with a sorting drive section at a branch point in the sorting conveyance path 26, and is configured to sort articles on the sorting conveyance path 26 under the control of the identification control mechanism 12 (control section 42 via a drive section 44, which will be described later). By driving the sorting drive unit in accordance with the conveyance of the articles 51, the articles 51 are discharged from the outlet 27 according to the sorting destination.

The identification control mechanism 12 drives and controls the transport and sorting device 11 to sort the transported articles 51 based on the RF tags 52 . The identification control mechanism 12 includes an entry detection section 31 and an RFID reader 32 connected to a sorting determination section 33.

The entry detection unit 31 detects that the article 51 being transported by the transport unit 21 of the transport and sorting device 11 enters the reception area 24 , that is, the area covered by the radio wave absorption frame 25 . The entry detection unit 31 of the first embodiment is a non-contact photoelectric sensor that includes a light emitter and a light receiver with the conveyance path 23 in between, and detects that light is blocked by the article 51 conveyed on the conveyance path 23. ing. Further, the entry detection unit 31 of the first embodiment detects whether or not the article 51 has reached a predetermined position (see symbol Pd in FIG. 3) in front of the receiving area 24 in the conveyance direction Dt. Note that the entry detection unit 31 may be a limit switch that detects the entry of the article 51 into the reception area 24 by bringing a hinge lever into contact with the article 51 to be conveyed, or may be used for other purposes. It is not limited to the configuration of the first embodiment.

The RFID reader 32 continuously transmits a search radio wave Rs at a constant period. Further, the RFID reader 32 can receive a response signal Sr from the RF tag 52, and outputs the response signal Sr to the sorting determination section 33 (analysis processing section 41 described later). At this time, the RFID reader 32 can also read the radio field intensity of the response signal Sr, and outputs this radio field intensity as well to the sorting determination section 33 (analysis processing section 41). In the RFID reader 32 of the first embodiment, when the entry detection unit 31 detects that the article 51 enters the reception area 24, it starts transmitting the search radio waves Rs continuously at a constant cycle and starts receiving the response signal Sr. Start. Then, the RFID reader 32 detects that a predetermined time has elapsed since the entry detection unit 31 detected the entry, or that the pulse signal for operating the transport path 23 from the transport unit 21 has not been counted since the detection. When the predetermined value is reached, the transmission of the search radio wave Rs and the reception of the response signal Sr are stopped. Note that while the transport unit 21 is transporting the article 51, the RFID reader 32 may continue to transmit the search radio wave Rs and receive the response signal Sr regardless of the detection by the entry detection unit 31. It is not limited to the configuration of Example 1.

As shown in FIG. 2, the RFID reader 32 of the first embodiment is provided below the transport path 23 at the center of the reception area 24, that is, at the center position in the transport direction Dt of the area covered by the radio wave absorption frame 25. ing. Further, the RFID reader 32 is of a premises radio station type (one that requires application as a premises radio station), and the radio wave output (antenna power) of the search radio wave Rs to be transmitted is 1 (W). Furthermore, the RFID reader 32 sets the directivity angle (half-value angle) of the search radio wave Rs to be so large that the search radio wave Rs does not directly go out from the entrance/exit of the article 51 in the radio wave absorption frame 25. In 1, it is 60 degrees. The RFID reader 32 transmits the search radio wave Rs once every 30 (ms), that is, the sampling period is 30 (ms/times).

In this reception area 24, a search radio wave Rs is transmitted from the RFID reader 32 located at the center in the transport direction Dt. In the RFID reader 32 of the first embodiment, the distance from the transmission point of the search radio wave Rs to the transport path 23 is 230 (mm) in the vertical direction. The search radio wave Rs passes through the transport path 23 and advances upward, and is partially absorbed by the ceiling wall 25a of the radio wave absorption frame 25 covering the transport path 23, and the other part is reflected as a reflected wave Rr. Then, it moves toward the conveyance path 23 again. Therefore, in the receiving area 24, the RF tag 52 can transmit the response signal Sr by receiving the search radio wave Rs and the reflected wave Rr on the transport path 23. Therefore, in the reception area 24, the area where the search radio wave Rs and the reflected wave Rr on the carrier path 23 are irradiated is mainly the area where the RF tag 52 receives the search radio wave Rs (including the reflected wave Rr) from the RFID reader 32. ) and can transmit a sufficiently strong response signal Sr (the area colored in black). In other words, the RFID reader 32 has a directivity angle of 60 degrees, and allows the RF tag 52 to transmit a sufficiently strong response signal Sr even with the reflected wave Rr from the ceiling wall 25a in addition to the search radio wave Rs. The radio wave output of the search radio wave Rs is set. Note that the RF tag 52 may be able to receive the search radio wave Rs (reflected wave Rr) even before and after the receiving area Ar. In the first embodiment, this reception area Ar is set to 1300 (mm) in the transport direction Dt.

The sorting determination unit 33 acquires the tag ID 53 indicated by the response signal Sr from the RF tag 52 provided on the article 51 that has passed through the reception area 24, from among the response signals Sr received by the RFID reader 32. Then, the sorting determination unit 33 enables the conveying and sorting device 11 to sort the articles 51 based on the number of acquired tag IDs 53 and their combinations. The sorting determination section 33 includes an analysis processing section 41 , a control section 42 , a data management section 43 , a driving section 44 , and a display section 45 .

The analysis processing unit 41 performs identification processing to identify the tag ID 53 indicated by the response signal Sr from the RF tag 52 provided on the article 51 that has passed through the reception area 24, among the response signals Sr received by the RFID reader 32, The identified tag ID 53 is transmitted to the control unit 42. The analysis processing unit 41 receives the response signal Sr and its radio wave intensity from the RFID reader 32 for specific processing. As a specific process, the analysis processing unit 41 determines whether the received response signal Sr is from the RF tag 52 provided on the article 51 that has passed through the reception area 24, based on the temporal change in the strength of the response signal Sr. It is determined whether or not (passage determination processing). Further, as a specific process, when the analysis processing unit 41 determines that the signal is from the RF tag 52 of the passed article 51, the analysis processing unit 41 analyzes the response signal Sr and acquires the tag ID 53 including the tag ID 53 of the product (acquisition process ). In this way, the analysis processing unit 41 acquires the tag ID 53 identified as the article 51 that has passed through the reception area 24 by performing the identification process consisting of the passage determination process and the acquisition process. Since the analysis processing unit 41 of the first embodiment targets articles 51 to which a plurality of RF tags 52 are attached, a plurality of tag IDs 53 are acquired for a single article 51 through specific processing. . The passage determination process and the acquisition process will be explained in detail later.

When the article 51 reaches the analysis point Pa (see FIG. 3), the analysis processing unit 41 starts the process of specifying the tag ID 53 described above. The analysis point Pa is set at a position where the article 51 passes the receiving area 24 in the transporting direction Dt of the transporting section 21, that is, outside the receiving area 24. The analysis point Pa in Example 1 is located 1575 (mm) from the reading point Pr in the transport direction Dt. The reading point Pr is a position where the RFID reader 32 is provided in the conveyance direction Dt, and is a position where the RF tag 52 of the article 51 to be conveyed comes closest to the RFID reader 32. The arrival of the article 51 at the analysis point Pa is determined by the fact that a predetermined time has elapsed since the entry detection section 31 detected the entry of the article 51, or that a pulse signal for operating the conveyance path 23 is sent from the conveyance section 21. This can be determined based on the fact that the count has reached a predetermined value.

The control section 42 is connected to the drive section 44 and controls the operations of the transport section 21 and the sorting section 22 by transmitting a drive control signal to the drive section 44 . Further, the control unit 42 is connected to the analysis processing unit 41 and acquires the plurality of identified tag IDs 53 from the analysis processing unit 41. The control unit 42 is connected to the data management unit 43, and upon acquiring each tag ID 53, the control unit 42 sends each tag ID 53 to the data management unit 43 to inquire about the exit port 27 of the article 51. The control unit 42 can receive the sorting information Is that is the result of the inquiry from the data management unit 43. The control unit 42 drives and controls the drive unit 44 according to the received sorting information Is.

The data management unit 43 manages various data including shipping schedule data. The shipping schedule data is data for sorting various articles 51 by shipping destination D. In the shipping schedule data of Example 1, the number of multiple tag IDs 53 and the combinations of these tag IDs 53 are determined for each shipping destination D (see FIG. 7). When a plurality of tag IDs 53 are sent from the control section 42, the data management section 43 compares the number of the plurality of tag IDs 53 and the combination of the plurality of tag IDs 53 with shipping schedule data, and stores the shipping destination for each article 51. to judge. Then, the data management unit 43 sends the sorting information Is indicating the export port 27 that matches the determined shipping destination D to the control unit 42.

The drive unit 44 receives a drive control signal corresponding to the sorting information Is from the control unit 42 that has received the sorting information Is, and drives the sorting unit 22 in accordance with the drive control signal. That is, the drive section 44 drives the sorting section 22 so as to convey the articles 51 conveyed by the conveying section 21 to the outlet 27 according to the sent sorting information Is. At this time, the drive unit 44 drives the sorting unit 22 in accordance with the timing when the article 51 reaches the corresponding outlet 27 based on the time point when the entry detection unit 31 detects the entry of the article 51 (see reference symbol Pd in FIG. 3). By doing so, each article 51 is carried out to the designated carry-out port 27.

The display unit 45 displays, under the control of the control unit 42, a graph showing temporal changes in the intensity of the response signal Sr used by the analysis processing unit 41 in the passage determination process (see FIG. 5). As a result, it is possible to check how the response signal Sr is received for each RF tag 52, so there is no bias in the reception status depending on the type of article 51 (packaging) or the type of product (tag ID 53). It is possible to recognize trends. For this reason, it is possible to improve the packaging method of each product in the article 51 and the attachment method and arrangement of the RF tag 52 for items that are unevenly distributed.

Here, the control unit 42 may count the history of the sorted articles 51 and the history of the acquired tag IDs 53 and store them as sorting performance data and acquired ID performance data. By storing this sorting performance data together with the number of each article 51 brought into the article sorting system 10, it is possible to determine the sorting success rate as the probability that the articles were properly sorted. Furthermore, by storing the acquisition ID performance data together with the number of each product in each article 51 brought into the article sorting system 10, it is possible to determine the acquisition success rate as the probability that the items were properly acquired.

In addition to the above-mentioned graph, the display unit 45 may also display sorting performance data, which is the history of the discriminated articles 51, and acquisition ID performance data, which is the history of the acquired tag IDs 53. In this case, it can be confirmed that the sorting operation of the articles 51 is being performed appropriately. In addition, the display unit 45 may also display the sorting success rate and the acquisition success rate. In this case, trends such as bias in sortability depending on the type of article 51 (shipping destination D) and bias in readability depending on the product type (tag ID 53) can be recognized. For this reason, it is possible to improve the packaging method of each product in the article 51 and the attachment method and arrangement of the RF tag 52 for items that are unevenly distributed.

Next, the passage determination process in the specific process will be explained. In the receiving area 24, the receiving area Ar is formed as described above. In this reception area Ar, on the transport path 23, the intensity of the search radio wave Rs from the RFID reader 32 is strongest at the reading point Pr where the RFID reader 32 is provided, and becomes weaker as the distance increases. Since the RF tag 52 is of a passive type, the intensity of the response signal Sr to be transmitted also changes in accordance with the change in the intensity of the search radio wave Rs. Therefore, in the reception area 24, the response signal Sr from the RF tag 52 conveyed on the conveyance path 23 is generated (receivable) when it approaches the reception area Ar in the conveyance direction Dt, and approaches the reading point Pr. The strength increases as the temperature increases. In the receiving area 24, the response signal Sr has the highest intensity at the reading point Pr in the transport direction Dt, the intensity decreases as it moves away from the reading point Pr, and becomes unreceivable as it moves away from the receiving area Ar.

This situation is schematically shown in FIGS. 3 and 4. FIG. 3 shows how the article 51 is transported by the transport section 21 on the transport path 23 from a position P1 at time t1 to a position P7 at time t7. Further, FIG. 4 shows how the intensity of the response signal Sr from the RF tag 52 received by the RFID reader 32 changes when the article 51 moves from the position P1 to the position P7. The earlier you go, the earlier you go. That is, in FIG. 4, each time the RFID reader 32 receives a response signal Sr, the intensity is described, and the position of the description changes to the left in accordance with changes in time, with the left end indicating the latest information. . In other words, the display in FIG. 4 is similar to the case where the recording paper is moved to the right and the intensity of the response signal Sr is written down with a pen or the like at the left end.

As shown in FIG. 3, when the article 51 is conveyed by the conveyance unit 21 on the conveyance path 23 from the position P1 to the position P7, the response signal Sr from the RF tag 52 provided there is transmitted to the RFID reader 32. As an example, the intensity when received at 1 changes as shown in FIG. 4. That is, when the article 51 is at position P1, the RFID reader 32 cannot receive the response signal Sr because the RF tag 52 is outside the reception area Ar. The RFID reader 32 becomes capable of receiving the response signal Sr when the article 51 moves near the position P2, and the intensity of the received response signal Sr increases as the article 51 moves from the position P3 to the position P4. In the RFID reader 32, when the article 51 reaches position P4, the strength of the received response signal Sr becomes maximum, and as the article 51 moves from position P5 to position P6, the strength of the received response signal Sr decreases. Then, the RFID reader 32 cannot receive the response signal Sr until the article 51 passes near the position P6 and reaches the position P7 where the article 51 reaches the analysis point Pa.

Here, the RFID reader 32 continuously transmits the search radio wave Rs at a set sampling period while the article 51 passes through the receiving area 24, and receives a response signal transmitted from the RF tag 52. Continuously receive Sr. Therefore, the response signal Sr becomes a graph as shown in FIG. 4 by arranging the changes in received intensity in time series. The analysis processing unit 41 accumulates the plurality of response signals Sr (their respective graphs) sent from the RFID reader 32 as data for a certain period of time until the article 51 reaches the analysis point Pa.

In the passage determination process, the analysis processing unit 41 uses the above-mentioned characteristics to determine whether the response signal Sr whose maximum value can be detected while the article 51 passes through the reception area 24 is provided to the article 51 passing through. The response signal Sr is determined to be the response signal Sr transmitted from the RF tag 52 that received the response. While this article 51 passes through the reception area 24, the period from the time when the entry detection section 31 detects the entry of the article 51 into the reception area 24 until a predetermined time has elapsed, or when the article 51 passes through the reception area 24. The period may be set until the count of pulse signals for operating the transport path 23 reaches a predetermined value.

Here, the identification control mechanism 12 sets an analysis point Pa outside the reception area 24, as shown in FIG. For this reason, the identification control mechanism 12 detects an area (hereinafter referred to as a quiet zone Zq) in which the RFID reader 32 cannot receive the response signal Sr after the RF tag 52 leaves the reception area 24 until it reaches the analysis point Pa. ) can be provided. Therefore, the identification control mechanism 12 can cause the graph showing the temporal change in the intensity of the response signal Sr from the RF tag 52 of the article 51 that has passed through the reception area 24 to be interrupted (terminated) at the quiet zone Zq. As a result, the analysis processing unit 41 can clarify the end point of detection of the maximum value in the passage determination process and can suppress crosstalk with other response signals Sr. It is possible to appropriately judge whether or not it is from the tag 52.

Since the analysis processing unit 41 performs the passage determination process as described above, even if another article 51 is moved near the identification control mechanism 12 due to being carried, etc., the RF tag 52 will not pass through the reception area 24. It can be concluded that it is not. This is because it is considered that it is rare to be able to detect the maximum value of the response signal Sr from another article 51 that is moved near the identification control mechanism 12 at the same time as the target article 51 passes through the reception area 24. It depends.

In addition, the analysis processing unit 41 determines that the response signal Sr transmitted from the RF tag 52 of the article 51 stored near the identification control mechanism 12 indicates that the RF tag 52 has not passed through the reception area 24. can. This is due to the following. Since the distance to the RFID reader 32 does not change in such a response signal Sr, the temporal change in intensity is almost eliminated or reduced. In this case, the analysis processing unit 41 has difficulty detecting the maximum value of the response signal Sr, and therefore can determine that the RF tag 52 has not passed through the reception area 24.

Furthermore, even if the RFID reader 32 receives the response signal Sr transmitted from the RF tag 52 of the article 51 that passed through the reception area 24 first, the analysis processing unit 41 determines that even if the RFID reader 32 receives the response signal Sr, the RF tag 52 is It can be determined that it has not passed 24. An example of the response signal Sr1 is shown in FIG. Since the response signal Sr1 has passed through the reception area 24 first, the maximum value occurs before time t1. In this case, the analysis processing unit 41 determines that the received response signal Sr1 is the RF tag 52 that detected the maximum value in the previous determination and passed through the reception area 24 first, so It is not determined that the RF tag 52 has passed through the RF tag 24.

In addition, even if the RFID reader 32 receives the response signal Sr transmitted from the RF tag 52 of the article 51 that passes through the reception area 24 after the target article 51, the analysis processing section 41 It can be determined that the RF tag 52 has not passed through the reception area 24. An example of the response signal Sr2 is shown in FIG. Since the response signal Sr2 passes through the reception area 24 later, the maximum value occurs after time t7. In this case, the analysis processing unit 41 cannot detect the maximum value of the received response signal Sr2 while the target article 51 passes through the reception area 24, so the analysis processing unit 41 cannot detect the maximum value of the received response signal Sr2. There is no judgment that there is.

Note that the analysis processing unit 41 closes the receiving area 24 when the strength of the response signal Sr received by the RFID reader 32 is less than a predetermined value or when the time interval at which the response signal Sr is received is less than a predetermined value. It may also be excluded from the determination of whether or not the vehicle has passed. That is, the analysis processing unit 41 may set thresholds for the strength and time interval of the response signal Sr, and determine that the response signal Sr has not passed through the reception area 24 if the response signal Sr does not meet these thresholds. In this way, it is considered that the intensity of the response signal Sr from other articles 51 that are moved near the identification control mechanism 12 will be reduced, so the analysis processing unit 41 determines whether such other articles 51 are in the reception area 24. It can be appropriately determined that it has not passed.

Further, the analysis processing unit 41 determines that the response signal Sr has not passed through the reception area 24 when the rate of change (increase/decrease) is small using a threshold value for the degree of change (inclination) in the intensity of the response signal Sr. You can. Such a case where the degree of change in the intensity of the response signal Sr is small is likely to be a disturbance due to reflection of radio waves or the like. Therefore, the analysis processing unit 41 can appropriately perform the passage determination process by excluding the response signal Sr with a small rate of increase/decrease.

In the identification process, the analysis processing unit 41 performs an acquisition process on the response signal Sr that is determined to have been transmitted from the RF tag 52 that has passed through the reception area 24 through the passage determination process. That is, in the acquisition process, the analysis processing unit 41 acquires the tag ID 53 indicated by the response signal Sr by analyzing the response signal Sr determined to have passed through the passage determination process. Obtaining the tag ID 53 by analyzing the response signal Sr is the same as in the conventional case. Thereby, the analysis processing unit 41 can acquire the tag ID 53 of the product included in the product 51 that has passed through the reception area 24.

Here, the article 51 of Example 1 is composed of a plurality of products packaged together as described above, and an RF tag 52 is attached to each product. For this reason, the analysis processing unit 41 performs specific processing consisting of the above-described passage judgment processing and acquisition processing on the plurality of response signals Sr received by the RFID reader 32, thereby identifying the single article 51. A plurality of tag IDs 53 are acquired for the tag ID 53. An example of this is shown in FIG. FIG. 5 shows a graph showing, as an example, five response signals Sr when an article 51 containing five products and having five RF tags 52 attached thereto passes through the reception area 24. The analysis processing unit 41 is able to detect the maximum value Mp in each of the five response signals Sr in the passage determination process, and acquires the five tag IDs 53 by analyzing each response signal Sr in the acquisition process. This allows the control unit 42 to sort the articles 51 based on the five tag IDs 53.

Next, a sorting process (sorting method) as an example of sorting a plurality of articles 51 in the article sorting system 10 will be described using FIG. 6. This sorting process is executed by the control unit 42 based on a program stored in the storage unit or built-in internal memory. Each step (each process) of the flowchart of FIG. 6 will be explained below. The flowchart in FIG. 6 is started when the article sorting system 10 is activated and the transport unit 21 starts moving along the transport path 23 under the control of the control unit 42. The flowchart in FIG. 6 shows the process until the end of identification of one article 51 conveyed by the conveyance section 21, and the process is repeated for each article 51 while the conveyance section 21 is being driven.

In step S1, it is determined whether or not the article 51 enters the receiving area 24. If YES, the process advances to step S2, and if NO, step S1 is repeated. In step S1, it is determined whether the article 51 has been detected by the entry detection unit 31, that is, whether the article 51 has reached a predetermined position (see symbol Pd in FIG. 3) on the conveyance path 23 before the reception area 24. to judge.

In step S2, transmission of the search radio wave Rs is started, and the process proceeds to step S3. In step S2, the RFID reader 32 starts transmitting continuous search radio waves Rs at regular intervals.

In step S3, the response signal Sr is received, and the process proceeds to step S4. In step S3, the RFID reader 32 receives a response signal Sr from the RF tag 52 that has received the search radio wave Rs. The RFID reader 32 outputs the received response signal Sr to the analysis processing section 41.

In step S4, it is determined whether the article 51 has reached the analysis point Pa. If YES, the process advances to step S5; if NO, step S4 is repeated. In step S4, the analysis point Pa is reached because a predetermined time has elapsed or the pulse signal count has reached a predetermined number after the entry detection unit 31 detected the entry (step S1). I judge that.

In step S5, the response signal Sr that has passed through the reception area 24 is selected, and the process proceeds to step S6. In step S5, the analysis processing unit 41 determines whether the received response signal Sr is attached to the RF tag attached to the article 51 that has passed through the reception area 24, based on the temporal change in the intensity of the response signal Sr transmitted from the RFID reader 32. 52 (passage determination process), and only the response signals Sr that have passed are selected.

In step S6, the tag ID 53 of each passed response signal Sr is acquired, and the process proceeds to step S7. In step S6, the analysis processing unit 41 analyzes each response signal Sr determined to be from the RF tag 52 that passed through the reception area 24 in step S5, and acquires the tag ID 53 indicated by each response signal Sr. (acquisition processing). Therefore, in step S6, in cooperation with step S5, the number of tag IDs 53 from the passed RF tags 52 and the tag IDs 53 can be acquired. From this, Step S5 and Step S6 become a specifying process for specifying the tag ID 53 of the article 51 that has passed through the receiving area 24. The analysis processing unit 41 transmits the identified plurality of tag IDs 53 to the control unit 42.

In step S7, the article 51 is verified, and the process proceeds to step S8. In step S7, the number of tag IDs 53 identified in step S6 and each tag ID 53 are transmitted to the data management section 43, and the data management section 43 compares the combination of the number and tag IDs 53 with shipping schedule data.

In step S8, the sorting information Is is received, and the process proceeds to step S9. In step S8, the sorting information Is indicating the shipping destination D of the article 51 based on the number and combination of tag IDs 53 is received from the data management unit 43 by comparison with the shipping schedule data.

In step S9, the sorting section 22 is driven to end this sorting process. In step S9, the entry detection section 31 detects the entry of the article 51 so that the drive section 44 transports the article 51 transported from the transport section 21 to the exit 27 according to the sent sorting information Is. The sorting section 22 is driven at the appropriate timing.

This article sorting system 10 acquires a plurality of response signals Sr when the article 51 is conveyed by the conveyance unit 21, and selects the article 51 that has passed through the receiving area 24 from among the acquired response signals Sr. Only the response signal Sr from the provided RF tag 52 is selected (S1 to S5). The article sorting system 10 also receives the sorting destination (sorting information Is) of the article 51 based on the combination of the number of selected tag IDs 53 (response signal Sr) and the tag ID 53 (S6 to S8). Then, the article sorting system 10 drives the sorting unit 22 according to the received sorting destination (S9), so that the article sorting system 10 can deal with the combination of attached RF tags 52, that is, the combination of products packaged in one. By conveying the articles 51 to the carry-out port 27, the articles 51 are sorted. This sorting process is repeated for each article 51 while the conveyance unit 21 is being driven as described above, so a plurality of articles 51 can be conveyed one after another to the corresponding outlet 27. , a plurality of articles 51 can be successively sorted.

Next, an example of sorting the plurality of articles 51 will be explained using FIGS. 7 to 9. The shipping schedule data collated by the data management unit 43 is sorted by shipping destination D of the article 51, as shown in FIG. This indicates that the export port 27 is supported. In the example of FIG. 7, codes DA to DC are set as the shipping destination D, and the number of tag IDs 53 is three regardless of the shipping destination D. Note that the number of tag IDs 53 may be different for each shipping destination D, and is not limited to the configuration of the first embodiment.

In addition, in the example of FIG. 7, four types of tag IDs 53, 53A to 53D, are prepared using the code of the tag ID 53, the shipping destination DA is a combination of 53A, 53B, and 53C, and the export port 27A is It is supported. Similarly, the shipping destination DB is a combination of 53B, 53C, and 53D, which corresponds to the outlet 27B, and the shipping destination DC is a combination of 53A, 53C, and 53D, which corresponds to the outlet 27C. In the example of FIG. 7, the outlet 27D corresponds to the article 51 that cannot be sorted.

On the other hand, it is assumed that articles 51A to 51F shown in FIG. 8 are conveyed by the conveyance unit 21. Three RF tags 52 having tag IDs 53 of 53A, 53B, and 53C are attached to the article 51A, and three RF tags 52 having tag IDs 53 of 53B, 53C, and 53D are attached to the article 51B. Further, three RF tags 52 having tag IDs 53 of 53A, 53B, and 53C are attached to the article 51C, and three RF tags 52 having tag IDs 53 of 53A, 53C, and 53D are attached to the article 51D. Although three RF tags 52 having tag IDs 53 of 53A, 53B, and 53C are attached to the article 51E, the response signal Sr from the RF tag 52 including the third tag ID 53 of 53C cannot be properly received. Assume it never happened. In addition, two RF tags 52 having tag IDs 53 of 53A and 53B are attached to the article 51F. In other words, the article 51F is one in which only two products are packaged, or the RF tag 52 is not attached to any one of the three packaged products.

When the articles 51A to 51F shown in FIG. 8 are transported, the article sorting system 10 performs the above-mentioned sorting process (flowchart in FIG. 6) on each of them, thereby sorting them according to the shipping schedule data in FIG. It is transported to the export port 27 (27A to 27D). Specifically, as shown in FIG. 9, articles 51A and 51C are placed at the outlet 27A, articles 51B are placed at the outlet 27B, articles 51D are placed at the outlet 27C, and articles 51E and 51F are placed at the outlet 27D. By being conveyed, the articles 51A to 51F are sorted. Therefore, the article sorting system 10 can appropriately sort the articles 51A to 51D based on the number of tag IDs 53 from the plurality of RF tags 52 and the tag IDs 53.

Then, the article sorting system 10 checks the results of the specific processing of the response signals Sr from each RF tag 52 of the article 51E and article 51F transported to the export exit 27D, the state of attachment of each RF tag 52, etc. This makes it possible to understand the reason why the articles 51E and 51F could not be sorted. This example helps clarify the reason why the response signal Sr from the RF tag 52 including the tag ID 53 of 53C could not be properly received for the article 51E. Further, in this example, it helps to clarify the reason why there were only two RF tags 52 for the article 51F.

Here, problems with the article sorting system of the comparative example will be explained. The article sorting system of the comparative example has the same configuration as the article sorting system 10, but the settings of the RFID reader and reception area are different from the article sorting system 10 of the first embodiment. In the article sorting system of the comparative example, the RFID reader is of a specified low power type (no special license or registration is required), and the radio wave output (antenna power) of the search radio waves to be transmitted is 250 (mW). . Furthermore, in the article sorting system of the comparative example, the directional angle (half-value angle) of the search radio waves transmitted by the RFID reader is 120 degrees, and the sampling period of the search radio waves is 60 (ms/times). In the article sorting system of the comparative example, the reception area 24 is set to 800 (mm) in the transport direction, and the analysis point is located at a position of 1016 (mm) from the reading point in the transport direction. As a result, the article sorting system of the comparative example does not have a quiet zone.

Therefore, in the article sorting system of the comparative example, even if the analysis processing unit performs the same identification processing as in Example 1, response signals from multiple RF tags attached to articles may not be properly received. . This is thought to be due to the fact that in the case of an article, a plurality of RF tags overlap, and the response signals from each RF tag interfere with each other, weakening the response signal. Therefore, it may be possible to appropriately receive each response signal by increasing the radio wave output of the search radio wave from the RFID reader. However, if the radio wave output of the search radio wave is increased, the search radio wave will affect farther than before increasing the radio wave output, resulting in receiving response signals from RF tags that have not passed through the reception area or causing unexpected noise. There is a risk that it may cause

In contrast, in the article sorting system 10 of the present disclosure, the radio wave output of the search radio wave Rs is set to 1 (W), and the directivity angle of the search radio wave Rs is set to 60 degrees. For this reason, the article sorting system 10 increases the radio wave output of the search radio wave Rs to enable appropriate reception of the response signals Sr from the plurality of RF tags 52 while increasing the radio wave output compared to the conventional system. The impact on the surrounding area can be suppressed. In addition, in the article sorting system 10, the transport path 23 of the transport section 21 is covered with the radio wave absorbing frame 25 in the reception area 24, so that the influence of the search radio wave Rs on the surroundings can be appropriately suppressed. In particular, the article sorting system 10 sets the directivity angle (half-value angle) of the emitted search radio wave Rs in the RFID reader 32 to a size such that the search radio wave Rs does not directly go out from the entrance/exit of the article 51 in the radio wave absorption frame 25. (60 degrees), the influence of the search radio wave Rs on the surroundings can be suppressed more appropriately.

Further, the article sorting system 10 sets the sampling period of the search radio wave Rs to 30 (ms/times). For this reason, the article sorting system 10 can improve the resolution of the response signal Sr from each RF tag 52 compared to the conventional system, and can more appropriately understand the state of change in the response signal Sr. The maximum value can be detected more appropriately.

Further, in the article sorting system 10, the reception area 24 is set to 1300 (mm) in the transport direction Dt, the analysis point Pa is located at a position of 1575 (mm) from the reading point Pr in the transport direction Dt, and the RF tag 52 is set in the reception area 24. A quiet zone Zq is provided between the time when the user leaves the room and the time when the user reaches the analysis point Pa. Therefore, the article sorting system 10 can clarify the end point of detection of the maximum value in the graph showing temporal changes in the intensity of the response signal Sr, and can suppress crosstalk with other response signals Sr. It can be appropriately determined whether the received signal is from the RF tag 52 that has passed through the receiving area 24 or not.

Next, the article sorting system 10 sets the radio wave output of the search radio wave Rs so that the RF tag 52 can transmit a sufficiently strong response signal Sr even with the reflected wave Rr from the ceiling wall 25a in addition to the search radio wave Rs. are doing. Therefore, the article sorting system 10 can secure the reception area 24 even if the orientation angle of the RFID reader 32 is 60 degrees, and can increase the possibility of receiving the response signal Sr.

The article sorting system 10, which is an example of the article sorting system according to the present disclosure, can obtain the following effects.

In the article sorting system 10, the sorting determination unit 33 determines the sorting of the articles 51 based on the number of acquired tag IDs 53 and the combination of the tag IDs 53. Therefore, the article sorting system 10 can simply attach an RF tag 52 to each article, without changing the RF tag 52 according to the combination, to the article 51 in which a plurality of articles are packaged. Articles 51 can be sorted.

In addition, in the article sorting system 10, the RFID reader 32 transmits a search radio wave Rs at a constant cycle, and when the RF tag 52 receives the search radio wave Rs, it transmits a response signal Sr, and the RFID reader 32 also adjusts the radio wave intensity of the response signal Sr. Acquire at the same time. Further, in the article sorting system 10, a receiving area 24 in which the RFID reader 32 receives the response signal Sr is set in the transport unit 21, and the sorting determination unit 33 determines the time of the radio wave intensity of the response signal Sr received by the RFID reader 32. Based on this change, it is determined whether the response signal Sr is from the RF tag 52 attached to the article 51 that has passed through the reception area 24. Therefore, the article sorting system 10 can acquire only the plurality of tag IDs 53 suitable for sorting the target articles 51, and can appropriately sort the articles 51.

Furthermore, the article sorting system 10 causes the RF tag 52 to transmit a response signal Sr in response to the reflected wave Rr in the reception area 24 of the search radio wave Rs transmitted by the RFID reader 32 to the transport path 23 of the transport unit 21. The search radio wave Rs is transmitted with the strength that can be used. Therefore, the article sorting system 10 can secure the reception area 24 even if the pointing angle of the RFID reader 32 is narrowed, and can increase the possibility of receiving the response signal Sr.

In the article sorting system 10, the RFID reader 32 is arranged in a positional relationship in which the receiving area 24 transmits the search radio wave Rs toward the conveyance path 23, and the conveyance path 23 is located on the opposite side of the RFID reader 32 and transmits the search radio wave Rs. It is covered with an absorption frame 25. Therefore, the article sorting system 10 can acquire a plurality of tag IDs 53 while more appropriately suppressing the influence of the search radio wave Rs on the surroundings.

In the article sorting system 10, when the article 51 passes through the receiving area 24 and reaches the analysis point Pa, the sorting determination section 33 determines, in the conveying section 21, that the response signal Sr received by the RFID reader 32 detects the article passing through the receiving area 24. Judgment as to whether or not it is from the RF tag 52 provided in the RF tag 51 is started. For this reason, the article sorting system 10 can provide a quiet zone Zq between when the RF tag 52 leaves the reception area 24 and when it reaches the analysis point Pa, making it clear when the detection of the maximum value ends. At the same time, crosstalk with other response signals Sr can be suppressed.

Therefore, the article sorting system 10 of Example 1 as an article sorting system according to the present disclosure can use the RF tags 52 to sort the articles 51 in which various products are grouped together.

Although the article sorting system of the present disclosure has been described above based on the first embodiment, the specific configuration is not limited to the first embodiment, and departs from the gist of the invention according to each claim. Changes and additions to the design are permitted unless otherwise specified.

For example, in Example 1, the article 51 is a plurality of products packaged together, and an RF tag 52 is individually attached to each product. However, it is sufficient that the articles 51 to be sorted are provided with a plurality of RF tags 52 and can be sorted based on the number of tag IDs 53 and the combination of each tag ID 53. It is not limited to the configuration of Example 1.

Further, in the first embodiment, the RF tag 52 transmits the response signal Sr in response to the reflected wave Rr in the reception area 24 of the search radio wave Rs transmitted by the RFID reader 32 to the transport path 23 of the transport unit 21. The search radio wave Rs is transmitted at a strength that allows for this. However, the RFID reader 32 may set the intensity of the search radio wave Rs to be transmitted as appropriate, and is not limited to the configuration of the first embodiment.

10 Article sorting system 21 Transport unit 23 Transport path 24 Receiving area 25 Radio wave absorption frame 32 RFID reader 33 Sorting judgment unit 51 Article 52 RF tag 53 Tag ID Pa Analysis point Rr Reflected wave Rs Search radio wave Sr Response signal

Claims (3)

a transport unit that transports articles provided with a plurality of RF tags;
an RFID reader that acquires response signals from the plurality of RF tags of the article transported by the transport unit;
a sorting determination unit that acquires the tag ID indicated by the response signal;
The sorting determination unit determines the sorting of the article based on the number of acquired tag IDs and the combination of the tag IDs ,
The RFID reader transmits search radio waves at regular intervals,
The RF tag transmits the response signal when receiving the search radio wave,
In the transport unit, a reception area is set in which the RFID reader receives the response signal,
The RFID reader transmits the search radio wave with an intensity that allows the RF tag to transmit the response signal in response to a reflected wave in the reception area of the search radio wave transmitted to the transport path of the transport unit. death,
The receiving area is configured such that the RFID reader is arranged in a positional relationship that transmits the search radio wave toward the transport path of the transport unit, and the transport path is covered with a radio wave absorption frame,
The radio wave absorption frame is formed of a member that absorbs the search radio wave and the response signal,
The RFID reader has a directional angle of the search radio wave to be emitted such that the search radio wave does not directly go out from the entrance/exit of the article in the radio wave absorption frame,
The article sorting system is characterized in that the radio wave absorption frame is sized inwardly to allow at least the first reflected wave of the search radio wave, which spreads according to the directivity angle, to proceed to the conveyance path . The RFID reader also acquires the radio wave intensity of the response signal ,
The sorting determination unit determines whether the response signal is from the RF tag attached to the article that has passed through the reception area, based on a temporal change in radio field intensity of the response signal received by the RFID reader. The article sorting system according to claim 1, wherein the article sorting system determines whether or not there is. The sorting determination unit is configured to transmit the response signal received by the RFID reader to the RF RFID installed on the article that has passed through the reception area when the article passes through the reception area and reaches an analysis point in the conveyance unit. 3. The article sorting system according to claim 2, wherein the article sorting system starts determining whether the article is from a tag .