JP4964658B2 - Wireless authentication system and sensor - Google Patents

Description

  In the present invention, a detection target such as a user carrying a wireless tag (slave station) or a product to which the wireless tag is attached is detected by the wireless tag communicating with a sensor (parent station, reader). In particular, the wireless authentication system and the sensor thereof, in particular, a plurality of sensors adjacent to each other along the moving space of the detection target so that the location of the wireless tag and the trajectory passed can be detected. The present invention relates to a configuration in which parts are arranged so as to overlap each other and are detected without omission.

  Conventionally, there is a wireless authentication system that performs appropriate services by detecting a wireless tag (slave station) carried by a user or pasted on a product with a sensor (master station, reader) for use in entrance / exit management, etc. in use. For example, it is an entry / exit control system that performs authentication processing with a wireless tag carried by the user and controls opening and closing of a nearby automatic door, or a wireless tag attached to an asset such as a portable computer An asset management system that manages the taking out of assets by detecting with sensors installed at the doorway, or a logistics management system that manages the location of luggage by detecting wireless tags attached to luggage pallets etc. at each logistics base It is.

However, these systems manage moving wireless tags in terms of points, and usually the sensors are spatially separated. However, when using this wireless tag to manage people and objects on the surface, for example, in-office management or position detection, a plurality of sensors along the movement space to be detected Need to be placed. In this case, in order to prevent interference of communication with the wireless tag between the sensors, it is conceivable to change the frequency CH to be used for each sensor as in Patent Document 1, for example. In Patent Document 1, when a slave station (wireless tag) detects interference, interference is avoided by causing the master station (sensor) to channel hop.
Japanese Patent No. 3405322

  In the above-described prior art, it is possible to automatically set the frequency CH to be used for each sensor, and it is possible to omit the work of newly installing or adding a sensor to some extent, but time division multiple access (TDMA) When strict synchronization is required between sensors as in (), interference occurs if the synchronization is not achieved. Therefore, before starting system operation, it is necessary to perform complicated work such as setting the mode and connecting the sensors with a wired connection to synchronize them. When the deviation from the synchronization signal of the sensor is detected and the timing is adjusted, if the deviation of the sensor used as the reference for adjustment is large, the error will increase.

  An object of the present invention is to provide a wireless authentication system and its sensor capable of automatically obtaining the synchronization of all sensors and starting the system operation without using wired synchronization.

In the wireless authentication system and the sensor of the present invention, a plurality of sensors are arranged along a movement space of a detection target, and a wireless tag carried by the detection target communicates with any of the sensors to detect the detection. In the wireless authentication system and its sensor configured to detect movement of an object, each sensor is obtained by a synchronization signal detection processing unit that receives a frame synchronization signal transmitted from another sensor, and the synchronization signal detection processing unit. A synchronization timing adjustment processing unit that adjusts the synchronization timing within the own device from the received frame synchronization signal, and the frame synchronization signal is retransmitted to the next transmission frame at the synchronization timing of the own device obtained by the synchronization timing adjustment processing unit. look including a synchronization signal output processing unit which, in the synchronization signal detection processing unit receives a plurality of frame sync signals in one frame , The synchronization timing adjustment processing unit is characterized by synchronizing the slowest frame sync signal.

  According to the above configuration, a plurality of detection targets such as a user carrying the wireless tag or a product attached with the wireless tag can be detected along the movement space of the detection target so that the location and the trajectory passed can be detected. In a wireless authentication system in which a sensor is arranged and a wireless tag carried by the detection target detects the movement of the detection target by communicating with one of the sensors, When communicating with the wireless tag using time division multiple access (TDMA) or frequency division multiple access (FDMA) using a wireless communication band, slot selection (TDMA) or When performing frequency hopping (FDMA), a frame synchronization signal is sent from a certain sensor to select the slot and frame synchronization to be used for frequency hopping. And, that the subsequent sensors has received the Yuku repeatedly retransmitting the frame synchronization signal in synchronization of its own, to arrive at the sensor end.

  Therefore, regardless of the synchronization by wire, etc., the frame synchronization extends like a ripple from the sensor that is one of the starting points to the end sensor, and automatically obtains the synchronization of all the sensors, System operation can be started.

In addition , when a plurality of frame synchronization signals are received by branching or the like, if the frame synchronization signal is synchronized with the previously received frame synchronization signal, the next frame must be synchronized again with respect to the frame synchronization signal received later. By synchronizing with the slowest frame synchronization signal, synchronization of the entire system can be obtained quickly.

Furthermore, in the wireless authentication system and the sensor thereof according to the present invention, the frame synchronization signal output from the synchronization signal output processing unit includes identification information of a source sensor, and the synchronization signal detection processing unit The identification information in the received frame synchronization signal is stored, and when the own frame synchronization signal is transmitted from the synchronization signal output processing unit, the frame synchronization signal from the sensor received before the transmission is The frame timing signal from the sensor that is discarded and received after the transmission is provided to the synchronization timing adjustment processing unit.

  According to the above configuration, the frame synchronization signal output from the synchronization signal output processing unit includes the identification information of the transmission source sensor, thereby receiving the frame received before transmitting the frame synchronization signal of the own device. The transmission source sensor of the synchronization signal can be determined to be higher than the own device, and the transmission source sensor of the frame synchronization signal received after transmission can be determined to be lower than the own device.

  Accordingly, when the received frame synchronization signal is from a higher-order sensor, the synchronization signal detection processing unit performs the second timing adjustment by the synchronization timing adjustment processing unit and the second frame synchronization by the synchronization signal output processing unit. While the signal is not transmitted, the timing adjustment and the transmission of the frame synchronization signal are repeatedly performed when the signal is from a lower sensor. As a result, until the frame synchronization signal is transmitted to the terminal sensor, the synchronization with the frame synchronization signal transmitted by the successive sensors is repeated, but finally the timing of the frame synchronization signal from the terminal sensor Thus, the timings of the upper sensors all coincide with each other, and the accumulation of synchronization errors due to the sequential synchronization of the sensors can be eliminated to prevent interference. In addition, even if the timing of the subsequent sensor is delayed from the own device at the beginning of synchronization, the timing is finally matched with that timing. It is possible to suppress a decrease in responsiveness to the wireless tag due to becoming.

  As described above, the wireless authentication system and the sensor thereof according to the present invention can detect the location and the trajectory passed through a detection target such as a user carrying a wireless tag or a product attached with a wireless tag. A wireless authentication system in which a plurality of sensors are arranged along a movement space of a target, and a wireless tag carried by the detection target communicates with any sensor to detect the movement of the detection target. In order to prevent interference between the sensors when communicating with the wireless tag using time division multiple access or frequency division multiple access using a common wireless communication band between the sensors, When performing frequency hopping, a frame synchronization signal is transmitted from a certain sensor to select the slot and frame hopping for the frequency hopping. Subsequent sensors received by synchronizing the ship by Yuku repeatedly retransmitting the frame synchronization signal, to spread to the sensor terminal.

  Therefore, the frame synchronization extends like a ripple from an arbitrary one sensor to a terminal sensor, regardless of wired synchronization, etc., and all the sensor synchronization is automatically obtained. System operation can be started.

Also, it should when receiving a plurality of frame synchronization signals in minutes岐等and thus in synchronism with the frame sync signal received earlier, unless redone again synchronized to the frame sync signal received after the next frame First, the synchronization of the entire system can be quickly obtained by synchronizing with the slowest frame synchronization signal.

Furthermore, as described above, the wireless authentication system and its sensor according to the present invention include the identification information of the transmission source sensor in the frame synchronization signal, and the received frame synchronization signal is from the upper sensor. However, the timing adjustment and the transmission of the frame synchronization signal are not performed again, while the timing adjustment and the transmission of the frame synchronization signal are performed again when the sensor is from the lower side sensor.

  Therefore, until the frame synchronization signal is transmitted to the end sensor, the synchronization with the frame synchronization signal transmitted by the intermediate sensor is repeated, but finally the timing of the frame synchronization signal from the end sensor Thus, the timings of the upper sensors all coincide with each other, and the accumulation of synchronization errors due to the sequential synchronization of the sensors can be eliminated to prevent interference. In addition, even if the timing of the subsequent sensor is delayed from the own device at the beginning of synchronization, the timing is finally matched with that timing. It is possible to suppress a decrease in responsiveness to the wireless tag due to becoming.

[Embodiment 1]
FIG. 1 is a block diagram showing a configuration of a wireless authentication system according to an embodiment of the present invention. In this wireless authentication system, a plurality of sensors S1, S2, S3, S4, S5,... (When collectively referred to as reference sign S) are arranged along a moving space 1 of a user who is a detection target. The wireless tag TG carried by the user communicates with one of the sensors S, and the detection result is monitored by the host device 2 so that the location of the user and the trajectory passed by the host device 2 can be determined. It is something to detect. Each sensor S is attached to a ceiling or the like, and its detection target areas A1, A2, A3, A4, A5,... (When collectively referred to as reference symbol A below) leak such users. The adjacent sensors S are arranged so that some of them overlap each other so that they can be detected. The wireless tag TG can be detected by the sensor S having the detection target area A as long as it moves within the detection target area A.

  In the present embodiment, when each sensor S communicates with the wireless tag TG by the TDMA-TDD system using a common wireless communication band, each sensor S is mutually connected between adjacent sensors S. Communicate with the wireless tag using different subframes. The subframe is automatically set so that interference can be avoided by communication between the sensors S.

  As shown in FIG. 2, each subframe is configured to include a frame synchronization signal and a plurality of predetermined time slots following the frame synchronization signal, and a wireless tag that newly enters the detection target area A is in the second half of the subframe. When the identification information ID of its own device is transmitted in one or a plurality of arbitrary empty slots and each sensor S receives it, the tag transmission slot number (tag ID) is included in the synchronization signal of the subframe that has been rotated in the next frame. And the slot number) are transmitted including the total number of slots, and it is specified which radio tag should respond in which slot. When each wireless tag responds in a designated slot, the information of the wireless tag is recognized by each sensor S.

  At the time of installation work or addition work of sensors S, first, each sensor S is set as described above in response to an operation of a setting button described later or a setting instruction by wireless (remote control). Subframes that do not interfere with each other are selected. Each of the sensors S uses a UHF band or the like for communication, and its detection target area A is usually about 7 m in diameter in order to prevent interference between adjacent sensors. In the setting mode by addition or the like, by increasing at least one of the transmission power and the reception sensitivity, for example, the transmission power or the reception sensitivity is quadrupled, and in FIG. , A5 ′,... (When collectively referred to as reference symbol A ′ below), the reach is doubled, and the intervals of the sensors S are widened so that the detection target areas A overlap with each other. Even so, the subframe setting can be reliably performed with sufficient communication quality.

  When the sub-frame setting operation is completed, the frame operation between the sensors is then performed and the system operation is started. FIG. 3 is a timing chart for explaining the operation of the synchronization processing. First, the sensor that has started the setting (S1 in the example of FIG. 3) starts transmission of a frame synchronization signal at a frame timing determined by itself. The subsequent sensors S2, S3,... That have received the frame synchronization signal synchronize themselves and repeat the retransmission of the frame synchronization signal every predetermined subframe period W1. Thus, the frame synchronization is extended to the end sensor (S5 in the example of FIG. 3).

  Specifically, the frame synchronization signal includes data of the subframe number and the total number of subframes for communication with the wireless tag TG, and the other sensors that have received the frame synchronization signal The subframe number for which the synchronization signal is output and the total number of subframes are acquired, and counting is started from the acquired subframe number in synchronization with the reception timing. Thus, when the total number of subframes is counted, switching to the next frame is determined. When the selected subframe is reached, transmission / reception is performed at the timing shown in FIG.

  As a result, the frame synchronization extends like a ripple from the sensor (S1), which is the starting point of any one unit, to the end sensor (S5), regardless of wired synchronization, etc. The system operation can be started with the synchronization of the sensors S1 to S5.

  It should be noted that in this embodiment, as indicated by the sensor S5, a plurality of frame synchronization signals (in the example of FIG. 3, S3 and S4 in one subframe (corresponding to the frame of the claims)). To) is synchronized with the latest frame synchronization signal (from S4 in the example of FIG. 3). Accordingly, when the sensor S5 receives a plurality of frame synchronization signals (S3, S4) by branching or the like, if it synchronizes with the previously received frame synchronization signal (S3), the next frame receives the frame synchronization received later. While synchronization with the signal (S4) must be performed again, synchronization with the latest frame synchronization signal (S4) makes it possible to quickly synchronize the entire system.

  In addition, when a frame synchronization signal is received from another sensor (S4) with a delay from the synchronized frame timing (S3), synchronization of the entire system can be quickly obtained by delaying the frame timing accordingly. Can do.

  The sub-frame period W1 is defined in advance as described above, and the timing shift W2 of the frame synchronization signal is caused by a subtle shift in the rise of the wireless communication circuit or the microcomputer in each sensor S. Although there is a delay due to wireless communication, it varies depending on the distance, modulation method, etc., and the description thereof is omitted here. When the sensors S are synchronized in the first frame F1, the system is operated in a synchronized state after the second frame F2.

  Therefore, when a plurality of frame synchronization signals are received at a branching portion, etc., if the frame synchronization signal received earlier is synchronized, the next frame must be synchronized again with respect to the frame synchronization signal received later. Instead, the synchronization of the entire system can be obtained quickly by synchronizing with the slowest frame synchronization signal as described above.

  FIG. 4 is a block diagram illustrating a configuration example of the sensor S that realizes the above-described function. This sensor S communicates with other sensors and the wireless tag TG, and does not interfere with each other via the wireless signal transmitting / receiving unit 11 that is a wireless communication unit and the wireless signal transmitting / receiving unit 11. The subframe selection operation is performed as described above, and the frame management unit 12 that performs the frame synchronization processing as described above, the user interface 13, and the wireless tag TG through the wireless signal transmission / reception unit 11, And a network interface 15 that transmits the authentication data obtained by the tag management unit 14 to the host device 2 and receives control data of the sensor S from the host device 2. It is prepared for.

  The frame management unit 12 first communicates with other sensors and, as described above, selects a subframe to be used by itself so as not to interfere with each other, and a frame as described above. The frame synchronization unit 23 is configured to be synchronized, a setting end detection unit 24 that determines the end of the subframe selection operation, and a transmission / reception management unit 25 that controls the entire frame management unit 12.

  The user interface 13 displays, for example, that a normal wireless tag TG detection operation is being performed, whether the subframe selection operation is being performed, whether the selection operation has been completed normally, or has failed, etc. Status display means 31 that informs the user by a lamp display, etc., and notification that an abnormality is detected or a suspicious wireless tag is detected, an alarm is issued, or the wireless tag TG can be recognized normally and the door is unlocked The alarm / notification sound generating device 32 such as a buzzer and a setting switch 33 such as a setting button and a start button are configured.

  When the sub-frame selection operation is started by operating the setting button or the start button of the setting switch 33, the status display means 31 displays that and the sub-frame allocation processing unit 21 communicates with other sensors as described above. While performing, it selects a free subframe and assigns it to a slot to be used by itself. When the setting end detection unit 24 detects that the subframe selection processing has been completed in this way, it is displayed on the status display means 31. When the selection processing has been completed normally, the frame synchronization unit 23 displays the above-mentioned information. Such a synchronization process is performed, and a normal wireless tag detection mode is set.

  In a normal wireless tag detection mode, the tag management unit 14 causes the wireless signal transmission / reception unit 11 to transmit the synchronization signal of the subframe selected by the subframe allocation processing unit 21 including a question signal, and the wireless tag TG. When the response signal is received, it is determined whether or not the ID of the wireless tag TG is registered in advance, and an unlocking operation or the like is performed.

  In the synchronization processing, the frame synchronization signal detection processing unit 231 of the frame synchronization unit 23 acquires the data of the subframe number and the total number of subframes from the frame synchronization signal received by the transmission / reception management unit 25 as described above. In addition, in synchronization with the reception timing, counting is started from the acquired subframe number, and when the total number of subframes is counted, switching to the next frame is determined, and the synchronization timing adjustment processing unit 232 Synchronization is obtained by controlling the transmission / reception slot management unit 25 so that the timing of the own device coincides with the timing of the system. At this time, when receiving a plurality of frame synchronization signals within one subframe, the synchronization timing adjustment processing unit 232 synchronizes with the latest frame synchronization signal. Further, when a frame synchronization signal is received from another sensor behind the synchronized frame timing, the frame timing is delayed accordingly. Then, when the frame synchronization signal output processing unit 233 reaches the selected subframe, the frame synchronization signal as shown in FIG. 3 is transmitted, and the wireless tag TG receives a plurality of time slots as shown in FIG. Wait for a response signal.

[Embodiment 2]
FIG. 5 is a timing chart for explaining the operation of the synchronization processing in the wireless authentication system according to another embodiment of the present invention. As the sensor of the present embodiment, the sensor having the configuration shown in FIG. 1 can be used, and the method of the synchronization process is different only in FIG. 3 and FIG. It should be noted that in the present embodiment, the frame synchronization signal output from the frame synchronization signal output processing unit 233 includes the identification information ID of the source sensor, and the frame synchronization signal detection processing unit 231 stores the identification information ID in the received frame synchronization signal, and when the frame synchronization signal of its own device is transmitted from the frame synchronization signal output processing unit 233, from the sensor received before the transmission. The frame synchronization signal is discarded, and the frame synchronization signal from the sensor received after the transmission is given to the synchronization timing adjustment processing unit 232.

  That is, by including the identification information ID of the transmission source sensor in the frame synchronization signal output from the frame synchronization signal output processing unit 233, the frame synchronization signal received before transmitting the frame synchronization signal of the own device The transmission source sensor can be determined to be higher than the own device, and the transmission source sensor of the frame synchronization signal received after transmission can be determined to be lower than the own device. Using this, the frame synchronization signal detection processing unit 231 causes the synchronization timing adjustment processing unit 232 to adjust its own timing when the received frame synchronization signal is from a lower sensor. At the same time, the frame synchronization signal output from the frame synchronization signal output processing unit 233 also matches the timing. Specifically, in FIG. 5, when the sensor S3 that has received the frame synchronization signal (S4) delayed from its own in the same subframe in the frame F1, delays the frame timing in the next frame F2 accordingly. The upper sensor S2 detects this, similarly delays the frame timing in the next frame F3, and further delays the frame timing in the next frame F4 by the sensor S1.

  Here, when the received frame synchronization signal is from the upper sensor, the frame synchronization timing adjustment processing unit 232 performs the timing adjustment again and the frame synchronization signal output processing unit 233 transmits the frame synchronization signal again. Since the upper sensor delays the timing, it is possible to prevent a problem that the lower sensor delays the timing again and thereby the upper sensor delays again.

  As a result, until the frame synchronization signal is transmitted to the terminal sensor S5, the synchronization to the frame synchronization signal transmitted by the intermediate sensor is repeated, but finally, the frame synchronization signal from the terminal sensor S5 is finally obtained. Thus, the timings of the upper sensors S4 to S1 all coincide with this timing, so that accumulation of synchronization errors due to the sequential synchronization of the sensors S can be eliminated to prevent interference. In addition, even if the timing of the subsequent sensor (S4) is delayed from the own device (S2) at the beginning of synchronization, the timing is finally made to coincide with the timing, so the gap (W2) between frames vacated by the delay is reduced. Thus, it is possible to suppress a decrease in responsiveness to the wireless tag TG due to an unnecessarily long one frame period.

It is a block diagram which shows the structure of the radio | wireless authentication system which concerns on one Embodiment of this invention. It is a figure for demonstrating an example of the sub-frame structure in the said radio | wireless authentication system. It is a timing chart for demonstrating the synchronous processing operation | movement of each sensor which concerns on one Embodiment of this invention. It is a block diagram which shows the example of 1 structure of the sensor which concerns on one Embodiment of this invention. It is a timing chart for demonstrating the synchronous processing operation | movement in the radio | wireless authentication system which concerns on the other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mobile space 2 Host apparatus 11 Radio signal transmission / reception part 12 Slot selection part 13 User interface 14 Tag management part 15 Network interface 21 Sub-frame allocation processing part 23 Frame synchronization part 231 Frame synchronization signal detection processing part 232 Synchronization timing adjustment processing part 233 Frame synchronization signal output processing unit 24 Setting end detection unit 25 Transmission / reception management unit 31 Status display means 32 Alarm / notification sound generator 33 Setting switches A1, A2, A3, A4, A5,. S3, S4, S5 ... Sensor TG Wireless tag

Claims (4)

Wireless authentication in which a plurality of sensors are arranged along the movement space of the detection target, and the wireless tag carried by the detection target detects the movement of the detection target by communicating with one of the sensors. In the system,
Each sensor is
A synchronization signal detection processing unit for receiving a frame synchronization signal transmitted from another sensor;
A synchronization timing adjustment processing unit that adjusts the synchronization timing within the device from the frame synchronization signal obtained by the synchronization signal detection processing unit;
Wherein the synchronous timing obtained in the synchronization timing adjustment processing unit, viewed contains a synchronization signal output processing unit to retransmit the frame synchronization signal to the next transmission frame,
In the synchronization signal detection processing unit, when a plurality of frame synchronization signals are received in one frame, the synchronization timing adjustment processing unit synchronizes with the latest frame synchronization signal . The frame synchronization signal output from the synchronization signal output processing unit includes identification information of the transmission source sensor,
The synchronization signal detection processing unit stores identification information in the received frame synchronization signal, and when the own frame synchronization signal is transmitted from the synchronization signal output processing unit, it was received before the transmission frame sync signal from the sensor is discarded, claim 1 Symbol placement of the wireless authentication system to the frame sync signal from the sensor is received after the transmission, characterized in providing the synchronization timing adjustment processing unit. Wireless authentication in which a plurality of sensors are arranged along the movement space of the detection target, and the wireless tag carried by the detection target detects the movement of the detection target by communicating with one of the sensors. In the system sensor,
A synchronization signal detection processing unit for receiving a frame synchronization signal transmitted from another sensor;
A synchronization timing adjustment processing unit that adjusts the synchronization timing within the device from the frame synchronization signal obtained by the synchronization signal detection processing unit;
Wherein the synchronous timing obtained in the synchronization timing adjustment processing unit, viewed contains a synchronization signal output processing unit to retransmit the frame synchronization signal to the next transmission frame,
In the synchronization signal detection processing unit, when a plurality of frame synchronization signals are received within one frame, the synchronization timing adjustment processing unit is synchronized with the latest frame synchronization signal . The frame synchronization signal output from the synchronization signal output processing unit includes identification information of the transmission source sensor,
The synchronization signal detection processing unit stores identification information in the received frame synchronization signal, and when the own frame synchronization signal is transmitted from the synchronization signal output processing unit, it was received before the transmission 4. The sensor according to claim 3, wherein a frame synchronization signal from the sensor is discarded, and a frame synchronization signal received from the sensor is sent to the synchronization timing adjustment processing unit.

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