JP2016050820A - Time measurement system for competition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure a passage time of a competitor with fewer frequency channels, in a time measurement system for competition configured to measure a passage time of the competitor at a measurement point in a race course, using an RFID tag attached to the competitor.SOLUTION: Antennae not neighbouring with each other are paired. In respective reader/writers connected to the paired antennae, a carrier sense is performed using the same frequency and at the same timing. If the carrier sense succeeds, carrier radio waves indicating this are sequentially transmitted at a different timing from each other via the connected antennae. When carrier radio waves are transmitted from all reader/writers in the same pair, reading of a tag ID from an IC tag 10 is started at the same timing at the frequency.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a competition time measurement system for measuring a passing time of a competitor at a measurement point of a competition course using an RFID tag attached to the athlete.

  In competitions such as marathons, it is considered to use a RFID tag to measure a passing time at a goal point of a competitor.

  As an example, an RFID tag is attached to a competitor's shoes, etc., a low-frequency magnetic field is generated from a mat-shaped antenna placed on the competition course, and written to the RFID tag when the athlete passes the measurement point. A technology is disclosed in which a tag ID is read by a reader / writer via an antenna, and a reception time is recorded as a measurement point passage time on the reader / writer side (see, for example, Patent Document 1). In this technology, two magnetic fields are generated by using two loops, and the inflection point is detected by detecting the inflection point. In some cases, however, the inflection point cannot be detected. The intermediate point between the time when the magnetic field is detected and the time when the magnetic field disappears is estimated as the passage time.

  Recently, a time measuring system using an RFID tag whose tag ID is read by radio waves in the UHF band has been considered.

  In a time measurement system using an RFID tag whose tag ID is read by radio waves in the UHF band, a maximum of about eight antennas connected to one reader / writer are arranged in a row in the direction crossing the competition course at the measurement point. They are arranged side by side, and a strong read radio wave of about 1 W is transmitted from each antenna, and the tag ID is read from the RFID tag attached to the athlete's race bib or shoe at the measurement point. At that time, in order to reduce costs and effectively use limited frequency resources, read radio waves of the same frequency are transmitted from a plurality of antennas. In addition, it may cause radio wave interference between a plurality of antennas, which may make it difficult to read the tag ID. Therefore, the reader / writer sends the read radio waves while switching them between the plurality of antennas in a time-sharing manner. doing.

  By the way, in the reader / writer used in the system using the RFID tag as described above, there are two systems, the FM0 system and the mirror subcarrier system. In the mirror subcarrier system, the frequency channel transmitted by the reader / writer is used. On the other hand, the same frequency channel is not used as a radio wave to which the IC tag responds, but two side-wave charged waves that are shifted up and down by about 200 kHz are used. For this reason, even if radio waves of the same frequency channel are transmitted from two reader / writers that are close to each other, the radio wave responding to a specific reader / writer from the IC tag is shifted by 200 kHz. You can receive response radio waves from. At this time, it is assumed that the radio wave generated from the other reader / writer is sufficiently attenuated. For example, if two antennas are close to each other and face each other, it is difficult to receive radio waves from the IC tag.

JP 2006-47263 A

  In a system for transmitting radio waves as described above, in order to avoid radio wave interference between a plurality of devices, it is used by measuring the magnitude of received power of the frequency channel to be used before transmitting radio waves. The Radio Law requires that so-called carrier sense, which confirms whether a frequency channel is free, be executed. Therefore, transmission of radio waves is stopped while carrier sense is being executed.

  In addition, not only when reading radio waves are output in a time-sharing manner from a plurality of antennas, but in a system that transmits radio waves after carrier sense is executed, after a radio wave is transmitted for a certain time (for example, 4 s), 50 ms), the transmission of radio waves must be stopped. Therefore, there is a timing at which the transmission of the radio wave is stopped, and when the tag ID is read by transmitting the read radio wave, the read radio wave is intermittently transmitted.

  By the way, in the marathon, when the width of the measurement point in the running direction of the athlete is 50 to 60 cm, the passing time of the athlete's measurement point is about 100 ms. Even if the athlete passes the measurement point while being performed, the possibility that the tag ID cannot be read is low.

  However, if carrier sense fails, the transmission of radio waves is stopped for a few seconds until the next carrier sense timing. Therefore, when the tag ID is read using one frequency channel, the reading is performed as described above. If the athlete passes the measurement point while the transmission of radio waves is stopped, the tag ID of the RFID tag attached to the athlete will be missed. In addition, there is a problem that the number of times of reading the tag ID is limited, and there is a high possibility that the passing time of the measurement point cannot be accurately measured.

  The present invention has been made in view of the problems of the prior art as described above, and uses the RFID tag attached to the athlete to determine the passing time of the athlete at the measurement point of the competition course. It is an object of the present invention to provide a competition time measurement system capable of accurately measuring a player's passage time with a small number of frequency channels.

In order to achieve the above object, the present invention provides:
A competition time measurement system that measures the passing time of a competitor at a measurement point of a competition course using an RFID tag attached to the athlete,
Three or more antennas arranged side by side in the direction across the competition course at the measurement point;
Three or more readers each connected to the antenna and reading the identification information written on the RFID tag via the connected antenna;
Based on the identification information read by the reading device, having a control device that aggregates the passage time,
The antenna is composed of a pair of antennas that are not adjacent to each other,
The reading device performs carrier sensing at the same timing using the same frequency between the reading devices in which the connected antennas are in the same set, and connects the carrier radio wave indicating that when the carrier sensing is successful, When the carrier radio wave is transmitted from all the reading devices in the same group, the identification information is read at the same timing at the same timing.

In addition, a competition time measurement system for measuring the passing time of the athlete at a measurement point of the competition course using an RFID tag attached to the athlete,
Three or more antennas arranged side by side in the direction across the competition course at the measurement point;
Three or more readers each connected to the antenna and reading the identification information written on the RFID tag via the connected antenna;
Based on the identification information read by the reading device, having a control device that aggregates the passage time,
The antenna is composed of a pair of antennas that are not adjacent to each other,
The control device causes the reading device to perform carrier sense at the same timing using the same frequency between the reading devices in which the antennas connected to the reading device are the same set, and the same set is obtained. When carrier sensing is successful in all reading devices, reading of the identification information is started at the same timing at the frequency.

  In the present invention configured as described above, the identification information written on the RFID tag attached to the athlete through three or more antennas arranged side by side in the direction crossing the competition course at the measurement point However, antennas that are not adjacent to each other are paired, and the identification information written on the RFID tag is read at the same frequency between the readers connected to the paired antennas. It is done. At that time, the readers perform carrier sense at the same timing using the same frequency between the readers in which the connected antennas are in the same set, and when the carrier sense is successful, the carrier radio wave indicating that is performed. When the carrier waves are sent from all the reading devices in the same set in sequence at different timings via the connected antenna, reading of the identification information starts at the same timing at that frequency. The identification information is read without interfering with each other at a low frequency. In addition, between the adjacent antennas, the identification information is read without interfering with each other by reading the identification information in a state in which the mutual frequency interval is secured to a degree that can avoid radio wave interference.

  In addition, the control device causes the reading device to perform carrier sense at the same timing using the same frequency between the reading devices in which the antennas connected to the reading device are the same set, and all of the same set When the carrier sense is successfully detected by the reading device, the identification information can be read without interfering with each other at a low frequency, as described above, by starting the reading of the identification information at the same timing at the frequency. Will be done.

  According to the present invention, antennas that are not adjacent to each other are configured as a pair, and carrier sensing is performed at the same timing using the same frequency between readers connected to the antennas that are the pair. When carrier sense is successful, carrier waves indicating that are sent out sequentially at different timings via connected antennas, and identification is made when carrier waves are sent from all readers in the same set Since the reading of information is started at the same timing at that frequency, the identification information is read without interfering with each other at a small frequency, and the mutual frequency interval is set between adjacent antennas. By reading the identification information in a state secured to avoid radio wave interference, So that Rukoto no identification information is read.

  In addition, the control device causes the reading device to perform carrier sense at the same timing using the same frequency between the reading devices in which the antennas connected to the reading device are the same set, and all of the same set In the case where the carrier sense is successfully detected by the reading device, the identification information can be read without interfering with each other at the same frequency even when the identification information is read at the same timing at the same timing. Can do.

It is a figure which shows 1st Embodiment of the time measuring system for competitions of this invention. It is a block diagram which shows the specific structure of the time measuring system for competitions shown in FIG. It is a flowchart for demonstrating the process of the carrier sense performed with the time measuring system for competitions shown in FIG.1 and FIG.2. It is a time chart for demonstrating the process of the carrier sense performed with the time measuring system for competitions shown in FIG.1 and FIG.2, (a) is a figure which shows the process when a carrier sense is successful, (b) ) Is a diagram showing processing when carrier sense fails, and (c) is a diagram showing timing when tag sense is read from the IC tag after successful carrier sense. FIG. 3 is a flowchart for explaining carrier sense processing for an entire group of reader / writers in the competition time measurement system shown in FIGS. 1 and 2. FIG. It is a time chart which shows operation | movement of three reader / writers which became a group in the time measuring system for competitions shown in FIG.1 and FIG.2. It is a figure for demonstrating the aggregation method of the passage time of a player using tag ID read from IC tag in the time measuring system for competition shown in Drawing 1 and Drawing 2, (a), (b) The figure which shows the information transmitted to a personal computer from a reader / writer, (c) is a figure which shows the information aggregated by a personal computer and registered into a passage time database. It is a figure which shows 2nd Embodiment of the time measuring system for competitions of this invention. It is a block diagram which shows the specific structure of the time measuring system for competitions shown in FIG. It is a figure which shows other embodiment of the time measuring system for competitions of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. It is assumed that the reader / writer used in the competition time measuring system of the present invention adopts a mirror subcarrier system.

(First embodiment)
FIG. 1 is a diagram showing a first embodiment of the competition time measurement system of the present invention, and FIG. 2 is a block diagram showing a specific configuration of the competition time measurement system shown in FIG.

  As shown in FIG. 1, the competition time measurement system in the present embodiment is equipped with an IC tag 10 that is an RFID tag attached to the player 1, and a mat-shaped measurement point on the competition course 2 on which the player 1 runs. Six antennas 25-1 to 25-6 are arranged, reader / writers 20-1 to 20-6 serving as a reading device are connected to each of the antennas 25-1 to 25-6, and the reader / writer 20-1 is further connected. ˜20-6, a personal computer 30 serving as a control device is connected.

  For example, the IC tag 10 is attached to the shoe of the player 1. A tag ID serving as identification information unique to the IC tag 10 is written in the IC tag 10, and this tag ID uses the UHF band frequency channel via the antennas 25-1 to 25-6 and the reader / writer 20-. It is read at 1-20-6.

  The antennas 25-1 to 25-6 are arranged side by side in a direction crossing the competition course 2 at measurement points on the competition course 2.

  The reader / writers 20-1 to 20-6 are connected to the antennas 25-1 to 25-6, respectively. Each of the reader / writers 20-1 to 20-6 includes a data memory 21, a program memory 22, a processor 23, and a transmission / reception unit 24, as shown in FIG. The data memory 21 stores a frequency list including a list of frequency channels of radio waves that can be transmitted via the antennas 25-1 to 25-6 in order to read the tag ID from the IC tag 10. The program memory 22 stores a carrier sense operation program and the like performed before transmitting radio waves via the antennas 25-1 to 25-6. The processor 23 refers to the data memory 21 and the program memory 22 to control transmission of radio waves for carrier sense and tag ID reading, and reads the tag ID read from the IC tag 10 and received by the transmission / reception unit 24. It transmits to the personal computer 30 with time. The transmission / reception unit 24 performs carrier sensing, transmission of radio waves via the antennas 25-1 to 25-6, and reception of tag IDs under the control of the processor 23.

  The personal computer 30 is connected to the reader / writers 20-1 to 20-6, and has a passage time aggregation unit 31, a passage time registration unit 32, and a passage time database 33 as shown in FIG. Yes. The passing time aggregating unit 31 aggregates the passing time of the player 1 at the measurement point based on the tag IDs transmitted from the reader / writers 20-1 to 20-6. The passage time registration unit 32 registers the passage times aggregated by the passage time aggregation unit 31 in the passage time database 33.

  Below, the passing time collecting method in the competition time measuring system configured as described above will be described.

  First, carrier sense executed by the above-described competition time measurement system will be described.

  FIG. 3 is a flowchart for explaining carrier sense processing executed in the competition time measuring system shown in FIGS. 1 and 2. FIG. 4 is a time chart for explaining the carrier sense process executed in the competition time measuring system shown in FIGS. 1 and 2, and (a) shows the process when the carrier sense is successful. FIG. 5B is a diagram illustrating processing when carrier sense fails, and FIG. 5C is a diagram illustrating timing for reading the tag ID from the IC tag 10 after successful carrier sense.

  As described above, in a system that sends out radio waves, in order to avoid radio wave interference between multiple devices, it is used by measuring the magnitude of the received power of the frequency channel to be used before sending out the radio waves. The Radio Law requires that so-called carrier sense, which confirms whether or not a frequency channel to be used is free, be performed.

  Therefore, also in the above-described competition time measurement system, it is necessary to perform carrier sense before transmitting radio waves from the antennas 25-1 to 25-6 in order to read the tag ID written in the IC tag 10.

  Therefore, in the reader / writers 20-1 to 20-6, carrier sense is executed. First, it is determined whether or not 50 ms has elapsed since the previous stop of transmission of radio waves (step 1). This is because, as described above, in a system that transmits radio waves, when radio waves are transmitted for a maximum of 4 s, transmission of radio waves must be stopped for a period of 50 ms thereafter. Needless to say, it is not necessary to determine the elapse of 50 ms in the first carrier sense after the power is turned on.

  If 50 ms has elapsed since the previous transmission stop of radio waves, the reader / writer 20-1 to 20-6 receives the frequency channel of the radio waves to be transmitted based on the frequency list stored in the data memory 21. Carrier sense for measuring the magnitude of electric power is started (step 2). The frequency list is allocated in advance by the personal computer 30 and downloaded from the personal computer 30 by the reader / writers 20-1 to 20-6. For example, when the output of the transmitted radio wave is 1 W, the frequency channel of 916.8 MHz as CH1, 918.0 MHz as CH2, 919.2 MHz as CH3, and 920.4 MHz as CH4 is downloaded. When the output of the radio wave to be transmitted is 250 mW, the frequency channel of 921.0 MHz as CH1, 921.4 MHz as CH2, 921.8 MHz as CH3, and 922.2 MHz as CH4 is downloaded. As described above, when the output of the radio wave to be transmitted is 250 mW, the reader / writers 20-1 to 20-6 can download the frequency channels that can be used every other of the 9 CHs so that the reader / writers 20-1 to 20-6 can mirror subcarriers. Even with the system, the tag ID can be read without causing an error. The reader / writers 20-1 to 20-6 select one frequency from the frequency list and measure the magnitude of the reception power of the frequency channel.

  If a radio wave of -74 dBm or more is not received for the selected frequency channel until a fixed time of 5 ms or more has elapsed after the start of carrier sense (step 3), it is determined that the carrier sense is successful (step 4), Transmission of radio waves is started from the antennas 25-1 to 25-6 on the frequency channel (step 5). In addition, as described above, in a system for transmitting radio waves, when radio waves are transmitted for a maximum of 4 s, the transmission of radio waves must be stopped for 50 ms thereafter. Instead of executing 5 ms carrier sense after 50 ms elapses, 10 ms carrier sense may be executed after 40 ms elapses from the previous stop of transmission of radio waves.

  After 4s have elapsed after starting the transmission of radio waves from the antennas 25-1 to 25-6 (step 6), the transmission of radio waves is stopped (step 7).

  Thereafter, when it is time to execute carrier sense, the process returns to step 1, and carrier sense is started if 50 ms has elapsed since the radio wave transmission was stopped.

  As a result, as shown in FIG. 4A, after transmitting the radio wave for 4 s using the frequency channel that has succeeded in the carrier sense, the transmission of the radio wave is stopped for 50 ms, the carrier sense is executed during that time, and the radio wave is again transmitted. Will be sent out.

  On the other hand, if the radio frequency of −74 dBm or more is received for the selected frequency channel after the start of the carrier sense, it is determined that the carrier sense has failed, and the carrier sense is still executed in the frequency list stored in the data memory 21. If there is a frequency channel that has not been performed (step 8), the frequency channel of carrier sense is changed to that frequency channel (step 9), and the processing returns to step 2 at the timing of executing carrier sense, and carrier sense is started.

  If carrier sense is failed and carrier sense is executed for all frequency channels in the frequency list stored in the data memory 21, an error is output to the personal computer 30 (step 10). In this case, as shown in FIG. 4B, the transmission of radio waves stops until the next carrier sense is executed.

  In this way, by sending radio waves from the antennas 25-1 to 25-6, as shown in FIG. 4C, the IC tag is sent at the timing when the radio waves are sent from the antennas 25-1 to 25-6. The tag ID is read from 10.

  Next, an actual aggregation method of passage times in the competition time measurement system shown in FIGS. 1 and 2 will be described.

  As described above, by connecting the antennas 25-1 to 25-6 to the reader / writers 20-1 to 20-6 on a one-to-one basis, the reader / writers 20-1 to 20-6 can read tag IDs. Is 100 to 200 times per second, it is possible to read 6 times as many times (600 to 1200 times per second) as compared with the case of using one reader / writer.

  However, in that case, many of the limited frequency channels are used. Therefore, in this embodiment, the antennas 25-1 to 25-6 and the reader / writers 20-1 to 20-6 are divided into sets, and the antennas 25-1 to 25-6 and the reader / writers 20-1 to 20-6 of the same set are divided. 6 share the same frequency.

  FIG. 5 is a flowchart for explaining carrier sense processing for one group of reader / writers in the competition time measuring system shown in FIGS. 1 and 2, and FIG. 6 is shown in FIGS. It is a time chart which shows operation | movement of the three reader / writers 20-1, 20-3, and 20-5 used as a group in the competition time measurement system.

  In the competition time measurement system of this embodiment, the antennas 25-1 to 25-6 arranged on the competition course 2 are configured as a pair of antennas that are not adjacent to each other. Specifically, the antenna 25-1, the antenna 25-3, and the antenna 25-5 are one set, and the antenna 25-2, the antenna 25-4, and the antenna 25-6 are one set. .

  The reader / writers 20-1 to 20-6 perform carrier sensing at the same timing using the same frequency in the reader / writers in which the connected antennas 25-1 to 25-6 are in the same set. When the sensing is successful, carrier waves indicating that are sequentially transmitted at different timings via the connected antennas, and when the carrier waves are transmitted from all reader / writers in the same group, the IC tag 10 The tag ID is read at the same timing at that frequency. For this reason, the reader / writers that are in the same group must be configured so that the outputs of radio waves transmitted via the connected antennas do not interfere with each other.

  Hereinafter, the operation of the set of the antenna 25-1, the antenna 25-3, and the antenna 25-5 will be described. However, the set of the antenna 25-2, the antenna 25-4, and the antenna 25-6 is also described. 1, the antenna 25-3, and the antenna 25-5 operate in the same manner using different frequencies.

  First, between the reader / writer 20-1 connected to the antenna 25-1, the reader / writer 20-3 connected to the antenna 25-3, and the reader / writer 20-5 connected to the antenna 25-5, When the carrier sense indicating that the carrier sense is successful, the order in which the carrier radio wave is transmitted is determined as follows: the reader / writer 20-1 is first, the reader / writer 20-3 is second, and the reader / writer 20-5 is third. The data is stored in the respective program memories 22 of the reader / writers 20-1, 20-3, and 20-5.

  In this state, the reader / writers 20-1, 20-3, and 20-5 perform carrier sense. First, it is determined whether or not 50 ms has elapsed since the previous stop of transmission of radio waves (step 11). ). This is because, as described above, in a system that transmits radio waves, when radio waves are transmitted for a maximum of 4 s, transmission of radio waves must be stopped for a period of 50 ms thereafter. Needless to say, it is not necessary to determine the elapse of 50 ms in the first carrier sense after the power is turned on.

  If 50 ms has elapsed since the last stop of transmission of radio waves, the reader / writer 20-1, 20-3, 20-5 selects one frequency from the frequency list stored in the data memory 21. Then, carrier sense is started using the frequency channel (step 12). Note that the frequency lists stored in the data memory 21 are the same for the reader / writers that form a pair. In addition, even between reader / writers in which antennas are adjacent to each other, a frequency list composed of combinations of the same frequencies as other groups is stored in the data memory 21, and unused frequencies are stored in the data memory 21. A channel is selected and carrier sense is executed. However, the appearance order of the frequency channels appearing in the frequency list is set so as to be different for each group, and the possibility that the same frequency is simultaneously selected in different groups is reduced.

  Then, until the fixed time of 5 ms or more has elapsed after the start of carrier sense (step 13), if the reader / writer 20-1 does not receive a radio wave of -74 dBm or more for the selected frequency channel, the carrier sense is successful. Since the reader / writer 20-1 transmits the carrier radio wave first, the reader / writer 20-1 sends a 1 ms carrier radio wave indicating that the carrier sense is successful as shown in FIG. Then, it is transmitted through the antenna 25-1 (step 15).

  Further, in the reader / writer 20-3, only the 1 ms carrier wave transmitted from the reader / writer 20-1 via the antenna 25-1 is transmitted to the antenna 25- for the frequency for which carrier sense is executed during the carrier sense period. 3 (steps 16 and 17), the reader / writer 20-3 transmits the carrier radio wave second, and therefore indicates that the carrier sense has been successful as shown in FIG. A 1 ms carrier wave is transmitted through the antenna 25-3 (step 18).

  Further, in the reader / writer 20-5, the reader / writers 20-1 and 20-3 transmit the frequencies for executing the carrier sense through the antennas 25-1 and 25-3, respectively, during the carrier sense period. When only 1 ms carrier radio waves, that is, two 1 ms carrier radio waves are received via the antenna 25-5 (steps 19 and 20), the carrier radio waves are transmitted third, and therefore, as shown in FIG. In this way, a 1 ms carrier wave indicating that the carrier sense is successful is transmitted via the antenna 25-5 (step 21).

  Then, in the reader / writers 20-1, 20-3, and 20-5, the reader / writers 20-1, 20-3, and 20-5 receive the antenna 25 with respect to the frequency at which the carrier sense is executed during the carrier sense period. -When receiving only 1 ms carrier radio waves respectively transmitted through 1, 25-3 and 25-5, that is, three 1 ms carrier radio waves via antennas 25-1, 25-3 and 25-5 ( Step 22) In the reader / writers 20-1, 20-3, 20-5, transmission of radio waves from the antennas 25-1, 25-3, 25-5 is started on the frequency channel in which carrier sense is executed, and the IC Reading of the tag ID from the tag 10 is started (step 23).

  As described above, in the reader / writers 20-1, 20-3, and 20-5 in which the connected antennas 25-1, 25-3, and 25-5 are a set, the same timing is used. When the carrier sense is successful, the carrier radio wave indicating the fact is transmitted sequentially at different timings via the connected antennas 25-1, 25-3, 25-5, and the reader / writer 20 When carrier waves are transmitted from all of -1, 20-3, and 20-5, reading of the tag ID from the IC tag 10 is started at the same timing at that frequency. In addition, when carrier sense is executed almost simultaneously by reader / writers connected to antennas belonging to different groups, and it is attempted to change the frequency channel at the same time, the same frequency channel may be selected by chance between different groups. . However, in that case, in the group that started transmitting radio waves of the same frequency for a moment, the frequency channel is used, and in the group that is delayed for a moment, the frequency channel cannot be used, and carrier sense is executed again. Therefore, the situation where the used frequency collides between the two groups is avoided. On the other hand, after the carrier sense is started, radio waves of -74 dBm or more are transmitted from the reader / writers 20-1, 20-3, and 20-5 to the antennas 25-1, 25-3, and 25-5 for the selected frequency channel. 1 ms carrier radio waves transmitted by the reader / writers 20-1, 20-3, and 20-5 via the antennas 25-1, 20-3, and 20-5 during the carrier sense period, respectively. If not received, it is determined that carrier sense has failed, and if there is a frequency channel in the frequency list stored in the data memory 21 that has not yet been subjected to carrier sense (step 24), Change the frequency channel to that frequency channel (step 25), and return to step 12 at the timing of performing carrier sense, To start the Yariasensu.

  If carrier sense is failed and carrier sense is executed for all frequency channels in the frequency list stored in the data memory 21, an error is output to the personal computer 30 (step 26).

  The above operation is performed in the same manner for the combination of the antenna 25-2, the antenna 25-4, and the antenna 25-6. As described above, the antenna 25-2, the antenna 25-4, the antenna 25-6, For the set of antennas 25-1, antenna 25-3, and antenna 25-5, a frequency list that secures a frequency interval that can avoid radio wave interference is stored in the data memory 21, and this frequency list is stored. Thus, an unused frequency channel is selected and the above-described operation is performed. For example, in the set of antennas 25-1, 25-3, and 25-5, the data memory 21 of the reader / writers 20-1, 20-3, and 20-5 connected to these antennas has 920.4 MHz as CH1, CH2 921.0 MHz, CH3 921.6 MHz, and CH4 922.2 MHz frequency channels are registered as a frequency list, and the antennas 25-2, 25-4, and 25-6 are connected to these channels. The frequency memory of 921.6 MHz as CH1, 922.2 MHz as CH2, 920.4 MHz as CH3, and 921.0 MHz as CH4 is stored in the frequency list in the data memory 21 of the reader / writer 20-2, 20-4, 20-6. It is registered as. When carrier sense fails in each of the set of the antenna 25-1, the antenna 25-3, and the antenna 25-5 and the set of the antenna 25-2, the antenna 25-4, and the antenna 25-6, Carrier sense is executed with the frequency channel of the next channel number as the next candidate in the frequency list. At this time, different frequency channels are used as candidates for the set of the antenna 25-1, the antenna 25-3, and the antenna 25-5, and the set of the antenna 25-2, the antenna 25-4, and the antenna 25-6. By performing sensing, there is no interference between adjacent antennas 25-1 to 25-6, and carrier sense and tag ID reading are performed at different timings between these sets. The length of the antenna 25-1 to 25-6 in the direction in which the player 1 runs the competition course 2 is 50 to 60 cm, so that the player 1 passes over the antennas 25-1 to 25-6. The time to do is about 100 ms. On the other hand, as described above, the time during which the transmission of radio waves from the antennas 25-1 to 25-6 is stopped is about 50 ms, so during the time when the player 1 passes over the antennas 25-1 to 25-6, As described above, a reading time of 50 ms can be secured even if transmission of radio waves is stopped. Since the reading time of the tag ID from the IC tag 10 is generally about 20 ms, the tag ID cannot be read from the IC tag 10.

  The tag ID read from the IC tag 10 by the reader / writers 20-1 to 20-6 in this way is transmitted to the personal computer 30 together with the reading time, and is measured by the player 1 based on the tag ID and the reading time. The passing time at points will be aggregated. Therefore, it is possible to accurately measure the athlete's passing time with a small number of frequency channels. Further, the above-described carrier sense and reading radio waves are transmitted autonomously in cooperation between the paired reader / writers without passing through the personal computer 30, thereby increasing the processing speed of the personal computer 30. Regardless, the number of readings can be increased.

  Next, regarding the method for aggregating the passing time of the player 1 using the tag ID read from the IC tag 10 as described above, the passing time using the reading results of the two reader / writers 20-1 and 20-2. A case where data are aggregated will be described as an example.

  FIG. 7 is a diagram for explaining a method of aggregating the passing time of the player 1 using the tag ID read from the IC tag 10 in the competition time measuring system shown in FIGS. ) Is a diagram showing information transmitted from the reader / writer 20-1 to the personal computer 30, (b) is a diagram showing information transmitted from the reader / writer 20-2 to the personal computer 30, and (c) is a diagram showing information transmitted to the personal computer 30. It is a figure which shows the information aggregated and registered into the passage time database 33. FIG.

  As described above, the tag ID read from the IC tag 10 by the reader / writers 20-1 to 20-6 is transmitted to the personal computer 30 together with the reading time.

  For example, as shown in FIG. 7A, the tag IDs “00123” and “89012” read by the reader / writer 20-1 via the antenna 25-1 are read from the reader / writer 20-1 together with the reading time. It is transmitted to the personal computer 30. In each of the tag IDs “00123” and “89012”, there are a plurality of reading times when the player 1 passes the reading range of the antenna 25-1 and the tag is read / written by the reader / writer 20-1. This is because the ID was read twice.

  Further, as shown in FIG. 7B, the tag IDs “00123” and “45678” read by the reader / writer 20-2 via the antenna 25-1 are read from the reader / writer 20-2 together with the reading time. It is transmitted to the personal computer 30.

  Then, in the passage time registration unit 32 of the personal computer 30, the reading time transmitted from the reader / writers 20-1 and 20-2 is associated with the tag ID transmitted together with the reading time and the measurement point passes. Although the time is registered in the passage time database 33, when the same tag ID exists, the passage time aggregating unit 31 uses the latest reading time transmitted together with the tag ID as the passage time. Is done.

  For example, in the example shown in FIG. 7, two reading times are transmitted from each of the reader / writers 20-1 and 20-2 for the tag ID “00123”. Among them, the reading time transmitted as item 2 of the reader / writer 20-2 is set as the passage time and registered in the passage time database 33.

  In the example shown in FIG. 7, two reading times are transmitted from the reader / writer 20-1 for the tag ID “89012”. Among them, the reading time transmitted as item 4 of the reader / writer 20-1 is set as the passage time and registered in the passage time database 33.

  As described above, in this embodiment, the antennas 25-1, 25-3, 25-5 that are not adjacent to each other are configured as a set, and the antennas 25-1, 25-3, 25 that are set in this set are configured. Carrier writer 20-1, 20-3, 20-5 connected to −5 performs carrier sense at the same timing using the same frequency, and indicates a carrier wave indicating that carrier sense is successful. Are sequentially transmitted at different timings via the connected antennas 25-1, 25-3 and 25-5, and carrier waves are transmitted from all of the reader / writers 20-1, 20-3 and 20-5. In this case, reading of the tag ID from the IC tag 10 is started at the same timing at the frequency, and the antennas 25-2, 25-4, and 25-6 that are not adjacent to each other are used. Are configured as a set, and the reader / writers 20-2, 20-4, and 20-6 connected to the antennas 25-2, 25-4, and 25-6 in this set have the same frequency. Is used to detect carrier waves at the same timing, and when carrier sensing is successful, carrier waves indicating that are sequentially transmitted at different timings via the connected antennas 25-2, 25-4, and 25-6. When the carrier radio wave is transmitted from all of the reader / writers 20-2, 20-4, and 20-6, the reading of the tag ID from the IC tag 10 is started at the same timing at that frequency. Therefore, the tag ID is read without interfering with each other at a small frequency, and the frequency interval between the antennas adjacent to each other is reduced. By reading the tag ID is performed in a state secured enough to avoid, so that the tag ID is read without interfering with each other.

  In the competition time measurement system of the present invention, the reader / writer adopts the mirror subcarrier system as described above, but a plurality of antennas connected to the reader / writer are arranged in a line to emit radio waves in the same direction. Since the signal is transmitted, the “radio wave from another antenna” is sufficiently attenuated, and the radio wave from the IC tag can be received.

  In the FM0 system, since the IC tag responds to radio waves using the same frequency channel as the radio waves transmitted from the antenna connected to the reader / writer, radio waves are transmitted from the antennas connected to the two reader / writers using the same frequency channel. Then, even if “the radio wave from another antenna is sufficiently attenuated”, the reader / writer is stronger than the weak radio wave (for example, −74 dBm) responded from the IC tag. Cannot be received properly. That is, the operation as in the present invention cannot be performed.

  In the mirror subcarrier system, for example, a 920.4 MHz radio wave is transmitted from an antenna connected to one reader / writer, and a 920.6 MHz radio wave is transmitted from an antenna connected to another reader / writer. Since the IC tag trying to respond to one of the frequency channels responds with the frequency channel of the other reader / writer, the reader / writer cannot perform the reading operation.

  In the FM0 system, if the performance of the band filter of the reader / writer is excellent, a 920.4 MHz radio wave is transmitted from the antenna connected to one reader / writer, and the antenna connected to the other reader / writer. Should be able to operate normally even if a 920.6 MHz radio wave is transmitted. Actually, the two reader / writers do not work well at a frequency interval of about 200 kHz, and are operated with a sufficiently large frequency interval.

  In the present invention, the reader / writer adopting the mirror subcarrier system operates as described above, so that radio waves from the IC tag can be accurately received.

  In this embodiment, the reader / writers 20-1 to 20-6 are described as being connected to the antennas 25-1 to 25-6, but two antennas are provided to one reader / writer. By connecting and switching the antenna every 25 ms, the reading accuracy is slightly reduced, but the cost can be reduced.

  In the present embodiment, the case where the mat-shaped six antennas 25-1 to 25-6 are arranged at the measurement points on the competition course 2 where the athlete 1 runs is described as an example. A plurality of antennas may be installed. In that case, it is conceivable that the IC tag 10 is attached not to the shoe of the player 1 but to a bib.

  Further, in the present embodiment, the description has been given by taking as an example one having six antennas 25-1 to 25-6 and six reader / writers 20-1 to 20-6 connected thereto, but these numbers are It is not limited to six. However, in order to configure a plurality of sets as described above, it is necessary to have three or more. When there are three antennas and reader / writers connected to them, the antennas arranged in the middle and reader / writers connected to them are arranged at both ends, although there is no pair of antennas and reader / writers connected to them. A set is composed of the antenna and the reader / writer connected thereto.

(Second Embodiment)
FIG. 8 is a diagram showing a second embodiment of the competition time measurement system of the present invention, and FIG. 9 is a block diagram showing a specific configuration of the competition time measurement system shown in FIG.

  As shown in FIGS. 8 and 9, the competition time measurement system in this embodiment is different from that shown in the first embodiment in that reader / writers 120-1 to 120-6 are processors, data memories, programs, and the like. It is different in that it does not have a memory and the personal computer 130 does not have a passage time database.

  In the competition time measurement system in this embodiment, a personal computer 130 is connected to the information aggregation server 140 via the communication line 150.

  In the personal computer 130, the frequency list stored in the data memory and the program memory of the reader / writer shown in the first embodiment and the operation program of the reader / writer are stored in the CPU memory 133, and the passing time aggregating unit 131 is similar to the reader / writer processor by referring to the frequency list and the reader / writer operation program stored in the CPU memory 133 in addition to the operation of the transit time aggregating unit 31 shown in the first embodiment. Also works. In addition, the transit time transmission unit 132 transmits the transit time aggregated by the transit time aggregation unit 131 to the information aggregation server 140 via the communication line 150.

  The information aggregation server 140 registers the passage time received from the personal computer 130 via the communication line 150 and the passage time received by the passage time receiver 141 in the passage time database 143. And a passage time registration unit 142.

  In the competition time measuring system configured as described above, for the carrier sense and tag ID reading performed by the processor 23 of the reader / writer 20-1 to 20-6 shown in the first embodiment. The passage time aggregating unit 131 controls the transmission of the radio waves. The passage time aggregating unit 131 issues a carrier sense instruction to all of the reader / writers 120-1 to 120-6 to execute the carrier sense, and the carrier radio wave transmitted from the reader / writer paired as described above. Is received from the reader / writer, the reading radio wave from the reader / writer is started to be transmitted using the frequency, and the reader / writer is similar to that shown in the first embodiment. The tag IDs read through the antennas 125-1 to 125-6 are collected at 120-1 to 120-6.

  The passage times aggregated by the passage time aggregation unit 131 are transmitted from the passage time transmission unit 132 and received by the passage time reception unit 141 of the information aggregation server 140 via the communication line 150.

  Thereafter, the passage time received by the passage time reception unit 141 is registered in the passage time database 143 by the passage time registration unit 142.

  In this embodiment, the personal computer 130 reports from the reader / writers 120-1 to 120-6 that all the carrier waves transmitted from the reader / writer are detected, that is, the reader / writer of the reader / writer. Since all the reports that the carrier sense has been successful have been received, the reader / writer 120-1 to 120-6 can be configured to be simplified by omitting the transmission of the carrier wave.

  In that case, the passing time aggregating unit 131 of the personal computer 130 causes the reader / writer to be paired to sequentially execute carrier sense, and after a predetermined time elapses, causes the reader / writer to report the result of carrier sense, or polling It is conceivable to confirm the results by themselves. Alternatively, the passing time aggregating unit 131 of the personal computer 130 may sequentially perform the operation of reporting the result when carrier sense is executed for each reader / writer in the set. However, the former control can reduce the total processing time.

  In any case, after the passing time aggregation unit 131 of the personal computer 130 causes the reader / writers to execute carrier sense, the radio waves for reading the tag ID are simultaneously transmitted to the reader / writers. I will let you. This is because, among reader / writers in a pair, when one reader / writer starts transmitting a radio wave for reading a tag ID and another reader / writer executes carrier sense, the same frequency is used. This is because career sense fails.

(Other embodiments)
FIG. 10 is a diagram showing another embodiment of the competition time measuring system of the present invention.

  As shown in FIG. 10, in the competition time measuring system shown in the first embodiment, the player 1 of the competition course 2 runs in the direction in which the six antennas 25-1 to 25-6 run. Further, six antennas 25-7 to 25-12 may be installed in parallel, and the reader / writers 20-7 to 20-12 may be connected to these antennas 25-7 to 25-12 on a one-to-one basis. .

  In the competition time measuring system configured as described above, the antennas 25-1 to 25-6 and the reader / writers 20-1 to 20-6 connected thereto, the antennas 25-7 to 25-12, and these If the priority order of which reading time is adopted when the tag ID is read in any of the reader / writers 20-7 to 20-12 connected to the antenna 25-1, the antennas 25-1 to 25-1 are set. 25-6 and reader / writers 20-1 to 20-6 connected thereto, and antennas 25-7 to 25-12 and reader / writers 20-7 to 20-12 connected thereto are reserved. Reliability can be improved by using as a system.

  In the above-described competitions such as the marathon, it may be difficult to secure a power supply due to the characteristics of outdoor competition. In addition, since multiple reader / writers are used, there is a point of view that you do not want to consume extra power, or there is time that you have to stop sending radio waves for a certain time after sending radio waves for a certain time. From the viewpoint of reducing the measurement point as much as possible, the area in front of the measurement point where the antenna is placed is monitored with a camera, infrared sensor, etc., and carrier sense is detected when the competitor recognizes that the measurement point is likely to be approached. It may be a mechanism such as starting.

DESCRIPTION OF SYMBOLS 1 Athlete 2 Competition course 10 IC tag 20-1 to 20-12, 120-1 to 120-6 Reader / writer 21, 121 Data memory 22, 122 Program memory 23 Processor 24, 124 Transmission / reception part 25-1 to 25-12 Antenna 30, 130 Personal computer 31, 131 Passing time aggregation unit 32, 142 Passing time registration unit 33, 143 Passing time database 132 Passing time transmission unit 133 CPU memory 140 Information aggregation server 141 Passing time reception unit 150 Communication line

Claims (2)

A competition time measurement system that measures the passing time of a competitor at a measurement point of a competition course using an RFID tag attached to the athlete,
Three or more antennas arranged side by side in the direction across the competition course at the measurement point;
Three or more readers each connected to the antenna and reading the identification information written on the RFID tag via the connected antenna;
Based on the identification information read by the reading device, having a control device that aggregates the passage time,
The antenna is composed of a pair of antennas that are not adjacent to each other,
The reading device performs carrier sensing at the same timing using the same frequency between the reading devices in which the connected antennas are in the same set, and connects the carrier radio wave indicating that when the carrier sensing is successful, Sequentially transmitted at different timings via the antennas that are read, and when the carrier radio wave is transmitted from all the reading devices in the same set, the reading of the identification information is started at the same timing at the frequency, Time measurement system for competitions. A competition time measurement system that measures the passing time of a competitor at a measurement point of a competition course using an RFID tag attached to the athlete,
Three or more antennas arranged side by side in the direction across the competition course at the measurement point;
Three or more readers each connected to the antenna and reading the identification information written on the RFID tag via the connected antenna;
Based on the identification information read by the reading device, having a control device that aggregates the passage time,
The antenna is composed of a pair of antennas that are not adjacent to each other,
The control device causes the reading device to perform carrier sense at the same timing using the same frequency between the reading devices in which the antennas connected to the reading device are the same set, and the same set is obtained. A competition time measurement system that starts reading the identification information at the same timing when the carrier sense is successful in all reading devices.

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