JP2008271379A - Radio authentication system and its sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To add a sensor without stopping a system in operation when each sensor communicates with a radio tag by time-division multiple access in a radio authentication system wherein a plurality of sensors are disposed along the movement space of an object to be detected so that their detection object areas overlap those of adjacent sensors and the radio tag carried by the object to be detected communicates with one of sensors to detect movement of the object to be detected. <P>SOLUTION: When a sensor S5 is added to the system of existent sensors S1 to S4, the sensor S5 in an addition mode notifies an operator that there is no free slot available in such a case so as to have the ID of the sensor S3 as a sharing destination set, transmits a slot sharing request to the sensor S3, and uses the slot No.3 that the sensor S3 uses alternately for the next and succeeding frames on condition that there is a response. Consequently, the sensor can be added without stopping operations of the respective sensors S1 to S4. <P>COPYRIGHT: (C)2009,JPO&INPIT

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, if you intend to use this wireless tag to manage people and objects on the surface, such as occupancy management and location detection in the office, if you try to detect the wireless tag without any gaps, It is necessary to arrange a plurality of sensors along the target movement space so that a part of each detection target area overlaps between adjacent sensors. 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

  The above prior art cannot cope with the case of using a method having no frequency CH such as UWB as a communication method with a wireless tag. Therefore, as a method for preventing interference between sensors without dividing the frequency CH, a predetermined period (period) is divided into a plurality of slots, and communication is performed by a TDMA-TDD system in which each sensor uses different slots. It is possible.

  However, in the TDMA-TDD system, it is necessary to perform slot assignment so that the same slot is not used between adjacent sensors. In this respect, it is possible to some extent determines that assign which slots into which sensor beforehand on paper at the time of new, especially once after starting the operation, when expansion and relocation of the sensor, the empty slots to be allocated to the sensor to be added There may be situations where there is no. In this case, it is necessary to stop the entire system and perform slot allocation again.

  The objective of this invention is providing the radio | wireless authentication system which can add a sensor, and its sensor, without stopping the system in operation.

  The wireless authentication system and its sensor according to the present invention are arranged such that a plurality of sensors are adjacent to each other along a moving space of a detection target so that a part of each detection target area overlaps and is carried by the detection target. In the wireless authentication system and its sensor, the wireless tag detects the movement of the detection target by communicating with one of the sensors, and each sensor is time-division multiplexed with a common wireless communication band. The wireless communication unit used in communication with the wireless tag and capable of communicating between adjacent sensors, and at the time of initial setting, performs wireless communication with each other via the wireless communication unit, and the wireless communication A slot allocation processing unit for selecting a slot to be used between adjacent sensors in a band so as not to overlap, and an operation for communicating with the wireless tag. When adding a sensor for adding the own device to the internal system, the slot allocation processing unit searches for an empty slot, and if an empty slot cannot be detected, the wireless communication unit transmits a slot sharing request, and the wireless communication And a sensor addition processing unit that causes the wireless communication unit to use the same slot in different frames between the transmission and reception sensors of the slot sharing request.

  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. Sensors are arranged so that a part of each detection target area overlaps between adjacent sensors, and a wireless tag carried by the detection target communicates with any one of the sensors to detect the detection target. In a wireless authentication system configured to detect movement, when performing communication with the wireless tag by time division multiple access (TDMA) using a wireless communication band common to the sensors, wireless communication is performed with the wireless tag. It is possible to communicate between adjacent sensors using the communication unit, and not simply communicate with the wireless tag in the detection target area of the own device in an empty slot, In setting mode, the slot allocation unit of each sensor performs wireless communication between a sensor adjacent to each other, make adjustments to slot to be used do not overlap.

  Thus, after starting actual operation to communicate with the wireless tag, when it becomes necessary to add a sensor to the operating system by adding or moving the sensor, the sensor addition processing unit If an empty slot is detected, the slot is used as it is, but if it cannot be detected, it cannot be incorporated into the system as it is. Send a slot sharing request. On the other hand, the sensor addition processing unit of the sensor that has received the slot sharing request in the wireless communication unit among the sensors in operation has the same slot in the wireless communication unit with the sensor that has transmitted the slot sharing request. For example, it is possible to add sensors by using different frames such as alternating or a ratio of the added side being small.

  Therefore, when adding a sensor, even when there is no empty slot, it is possible to add a sensor without stopping the entire system by sharing the same slot with an adjacent sensor.

  Further, in the wireless authentication system of the present invention, each sensor has a slot sharing priority set in advance and is included in a synchronization signal transmitted from the wireless communication unit to the wireless tag. The processing unit analyzes the synchronization signal received by the wireless communication unit, and transmits the slot sharing request to the sensor having the lowest priority.

  According to the above configuration, the priority order is set in advance from the expected number of access to the wireless tag for each sensor, and the priority order information is transmitted in the synchronization signal transmitted to the wireless tag. The sensor addition processing unit of the sensor to be added cannot detect the empty slot as described above, and considers the priority when transmitting the slot sharing request as described above. The slot sharing request is transmitted to the sensor having the lowest value.

  Therefore, for example, a sensor that is considered to have the least influence such as a shortage of slots allocated to wireless tags due to slot sharing, such as a sensor that is expected to have a small number of wireless tags present in the detection target area, is designated for slot sharing. Can be done.

  Furthermore, in the wireless authentication system of the present invention, when the sensor is added, the sensor addition processing unit causes the wireless communication unit to receive a response to each sensor of the wireless tag, and for the sensor with the smallest number of responses, A slot sharing request is transmitted.

  According to the above configuration, as described above, an empty slot cannot be detected, and when transmitting a slot sharing request, the response of the wireless tag to the synchronization signal (question signal) from each sensor is monitored, and the maximum access of the wireless tag The slot sharing request is transmitted to the sensor having the smallest number of responses such as the number and the average number of accesses.

  Therefore, it is possible to cause a sensor that is considered to have the least influence by slot sharing to perform slot sharing.

  In the wireless authentication system of the present invention, the synchronization signal transmitted from the wireless communication unit to the wireless tag includes information indicating the number of sensors adjacent to each sensor, and the sensor addition processing unit includes The synchronization signal received by the wireless communication unit is analyzed, and the slot sharing request is transmitted to the sensor having the largest number of adjacent sensors.

  According to the above configuration, each sensor is adjacent to its own device, such as information on adjacent sensors is set in advance or a synchronization signal transmitted from the adjacent sensor to the wireless tag is monitored. In advance, and the information indicating the number of adjacent sensors is included in the synchronization signal transmitted to the wireless tag and transmitted, and the empty slot cannot be detected as described above. The sensor addition processing unit of the added sensor considers the number of sensors adjacent to each sensor from the synchronization signal received by the wireless communication unit, and issues the slot sharing request to the sensor having the largest number. Send.

  Therefore, even if the frequency of wireless tag detection decreases due to slot sharing, there is a high possibility that it can be covered by other adjacent sensors, and it is possible to specify a sensor that is considered to be least affected by slot sharing and share the slot. Can be done.

  Furthermore, in the wireless authentication system of the present invention, the sensor addition processing unit causes the wireless communication unit to receive a synchronization signal transmitted from the wireless communication unit of each sensor to the wireless tag, and the sensor from which the synchronization signal has been received. In contrast, the slot sharing request is sequentially transmitted.

  According to the above configuration, when an empty slot cannot be detected as described above and a slot sharing request is transmitted, the number of frames or the number of all the sensors in which the own device and the detection target area partially overlap each other are transmitted. The slot sharing request is transmitted by switching sequentially for each frame or the like.

  Therefore, the slot sharing can be performed by distributing the influence of the slot sharing.

  The wireless authentication system of the present invention is arranged such that a plurality of sensors are adjacent to each other along a moving space of a detection target so that a part of each detection target area overlaps and is carried by the detection target. In the wireless authentication system in which the wireless tag detects the movement of the detection target by communicating with one of the sensors, each sensor uses a common wireless communication band by time division multiplexing. In addition to communicating with the wireless tag, a wireless communication unit capable of communicating between adjacent sensors, and performing wireless communication with each other via the wireless communication unit at the time of initial setting, mutually in the wireless communication band Slot assignment processing unit that selects the slots to be used between adjacent sensors so that they do not overlap, and the own device is added to the operating system that communicates with the wireless tag When the sensor add to, radio frequency identification system, characterized in that it comprises together to explore the empty slot to the slot assignment processing unit, and a sensor additional processing unit which vacant slots to inform the operator if it can not detect.

  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. Sensors are arranged so that a part of each detection target area overlaps between adjacent sensors, and a wireless tag carried by the detection target communicates with any one of the sensors to detect the detection target. In a wireless authentication system configured to detect movement, when performing communication with the wireless tag by time division multiple access (TDMA) using a wireless communication band common to the sensors, wireless communication is performed with the wireless tag. It is possible to communicate between adjacent sensors using the communication unit, and not simply communicate with the wireless tag in the detection target area of the own device in an empty slot, In setting mode, the slot allocation unit of each sensor performs wireless communication between a sensor adjacent to each other, make adjustments to slot to be used do not overlap.

  Thus, after starting actual operation to communicate with the wireless tag, when it becomes necessary to add a sensor to the operating system by adding or moving the sensor, the sensor addition processing unit If an empty slot is detected, the slot is used as is, but if it cannot be detected, it cannot be incorporated into the system as it is. The operator is notified of this by lighting or the like.

  Therefore, when adding a sensor, when there is no empty slot, it is possible to add the sensor without stopping the entire system by adjusting the sensor with an adjacent sensor.

  Furthermore, in the wireless authentication system of the present invention, the sensor addition processing unit causes the wireless communication unit to transmit a slot sharing request to the sensor determined by the designation of the worker who responded to the notification, and When the communication unit receives the slot sharing request, the wireless communication unit is allowed to use the same slot with different frames between the transmission / reception sensors of the slot sharing request.

  According to the above configuration, when a sensor is added, an empty slot cannot be detected as described above, and an operator who has been informed of this is specified by setting the ID of a sensor that should share the slot. Then, the sensor addition processing unit transmits / receives a slot sharing request to / from the designated sensor via the wireless communication unit, and causes the wireless communication unit to use the same slot for different frames. Share.

  Therefore, according to the setting of the worker, for example, a sensor that is expected to have a small influence on the slot sharing, such as a sensor that is expected to have a small number of wireless tags present in the detection area, is designated and the slot sharing is performed. be able to.

  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 plurality of sensors are arranged so that a part of each detection target area overlaps between adjacent sensors along the movement space of the target, and the wireless tag carried by the detection target communicates with any one of the sensors. In the wireless authentication system configured to detect the movement of the detection target by performing wireless communication, the wireless tag is communicated with the wireless tag by time division multiple access using a wireless communication band common to the sensors. Using the wireless communication unit that communicates with the tag, it is possible to communicate between adjacent sensors, and in the initial setting mode when newly installed, the slot allocation processing unit of each sensor Adjust the wireless communication between adjacent sensors so that the slots to be used do not overlap, and after starting the actual operation of communicating with the wireless tag, add sensors to the operating system. When it becomes necessary to add a sensor due to relocation, the sensor addition processing unit makes the slot allocation processing unit search for an empty slot, and if it cannot detect an empty slot, it sends a slot sharing request to the wireless communication unit. The sensor addition processing unit of the active sensor that has transmitted and received the slot sharing request has added the same slot to the wireless communication unit, for example, alternately or in addition to the sensor that has transmitted the slot sharing request. It is possible to add sensors by using different frames, such as a small percentage.

  Therefore, when adding a sensor, even when there is no empty slot, it is possible to add a sensor without stopping the entire system by sharing the same slot with an adjacent sensor.

  Further, as described above, the wireless authentication system of the present invention sets priorities for each sensor in advance, and includes information on the priorities included in a synchronization signal transmitted to the wireless tag, The sensor addition processing unit of the added sensor considers the priority obtained from the received synchronization signal, and transmits the slot sharing request to the sensor with the lowest priority.

  Therefore, for example, a sensor that is considered to have the least influence from the shortage of slots allocated to wireless tags due to slot sharing, such as a sensor that is expected to have a small number of wireless tags present in the detection target area, and slot sharing. Can be performed.

  Furthermore, in the wireless authentication system of the present invention, as described above, the sensor addition processing unit of the added sensor causes the wireless communication unit to monitor the response of the wireless tag to the synchronization signal (question signal) from each sensor, The slot sharing request is transmitted to the sensor with the smallest number of responses of the wireless tag.

  Therefore, it is possible to cause a sensor that is considered to be least affected by slot sharing to perform slot sharing.

  In the wireless authentication system of the present invention, as described above, each sensor grasps in advance what kind of sensor is adjacent to its own device, and information indicating the number of adjacent sensors is transmitted to the wireless tag. The sensor addition processing part of the added sensor is included in the signal, and it is the most in consideration of the number of sensors adjacent to each sensor from the synchronization signal received by the wireless communication part. The slot sharing request is transmitted to the sensor.

  Therefore, even if the frequency of wireless tag detection decreases due to slot sharing, there is a high possibility that it can be covered by other adjacent sensors, and the slot that is considered to have the least influence from slot sharing is specified and slot sharing is specified. Can be performed.

  Furthermore, in the wireless authentication system of the present invention, as described above, the sensor addition processing unit of the added sensor causes the wireless communication unit to receive a synchronization signal transmitted from the wireless communication unit of each sensor to the wireless tag. Then, the slot sharing request is transmitted by sequentially switching to all the sensors that partially overlap the received own device and the detection target area.

  Therefore, the slot sharing can be performed by distributing the influence of the slot sharing.

  In addition, as described above, the wireless authentication system of the present invention can detect the detection target such as the user carrying the wireless tag or the product attached with the wireless tag so that the location and the trajectory passed can be detected. A plurality of sensors are arranged along adjacent moving spaces so that a part of each detection target area overlaps between adjacent sensors, and a wireless tag carried by the detection target communicates with one of the sensors. In the wireless authentication system configured to detect the movement of the detection target by continuing, the wireless tag is used to communicate with the wireless tag by time division multiple access using a wireless communication band common to the sensors. In the initial setting mode when newly installed, the slot allocation processing units of each sensor are adjacent to each other. After making adjustments so that the slots to be used do not overlap with each other by performing wireless communication between the sensors, the actual operation of communicating with the wireless tag is started, and then the sensor is expanded or moved to the system in operation. When it is necessary to add a sensor, the sensor addition processing unit causes the slot allocation processing unit to search for an empty slot, and if an empty slot cannot be detected, for example, by sounding a buzzer or lighting a lamp. To the worker.

  Therefore, when adding a sensor, if there is no empty slot, it is possible to add the sensor without stopping the entire system by adjusting the sensor with an adjacent sensor.

  Furthermore, as described above, in the wireless authentication system of the present invention, an empty slot cannot be detected, and an operator who has been informed of the setting performs designation by setting the ID of a sensor that should share the slot. The sensor addition processing unit transmits / receives a slot sharing request to / from the designated sensor via the wireless communication unit, and causes the wireless communication unit to use the same slot for different frames. Share.

  Therefore, by setting the operator, for example, sensors that are expected to have a small number of wireless tags present in the detection area, the operator designates a sensor that is considered to be less affected by slot sharing, and performs slot sharing. Can be made.

[Embodiment 1]
FIG. 1 is a block diagram showing a configuration of a wireless authentication system according to the first embodiment of the present invention. In this wireless authentication system, a plurality of sensors S1, S2, S3, and S4 (generally referred to as reference sign S) are arranged along a moving space 1 of a user to be detected and carried by the user. The wireless tag TG communicates with one of the sensors S, and the detection result is monitored by the host device 2 so that the host device 2 detects the location of the user and the trajectory passed. Each sensor S is attached to a ceiling or the like, and its detection target areas A1, A2, A3, A4 (when collectively referred to as reference symbol A below) can detect such a user without omission. It arrange | positions so that the part may mutually overlap between adjacent sensors S. FIG. 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 this embodiment, when each sensor S communicates with the wireless tag TG by the TDMA-TDD method using a common wireless communication band, it should be noted that the operation of a setting button, which will be described later, or wireless ( Each sensor S communicates with each other in response to a setting instruction or the like on the remote control), and in the initial setting mode at the time of new installation, the time slots used for communication by each sensor S can be automatically avoided. In addition, when the total number of slots is insufficient, that is, when an empty slot is not found in the additional mode when the sensor S is added or moved, the same slot as any one of the sensors is used by dividing the frame.

  Each sensor S uses a UHF band 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 additional mode, the reception sensitivity is increased, for example, four times, and reached as shown by reference signs A1 ′, A2 ′, A3 ′, A4 ′ (hereinafter collectively referred to as reference sign A ′) in FIG. Even if the range is doubled and the sensors S are spaced apart so that the detection target areas A overlap with each other, the slot setting can be reliably performed with sufficient communication quality.

  FIG. 2 is a timing chart for explaining the slot setting operation in the initial setting mode when each sensor S is newly installed. In setting, as described above, each sensor S is in the setting mode by the operation of the setting button or the setting instruction by wireless, and the operator selects an arbitrary sensor, preferably a sensor located at the end of the sensor array ( In the example of FIGS. 1 and 2, S1) is selected, and the setting operation is started from the sensor S1 in response to an operation of a start button or a start instruction by the wireless (remote control). In the setting operation, first, an empty slot in the wireless communication band is searched, and if it is detected, the slot with the highest priority (No. 1 in the example of FIG. 2) is selected and used by the own device. Assigned to a slot, the slot No. 1 is sent to other sensors as a use slot notification.

  Accordingly, in the example of FIGS. 1 and 2, when the subsequent sensors S2 and S3 receive the use slot notification, the sensors S2 and S3 also start the setting operation using the notification as a trigger. 1 is not used for its own slot allocation, and other slots are similarly searched for empty slots, and when detected, the slot with the highest priority (No. 2 in the example of FIG. 2) is selected. Assigned to the slot to be used by the own device. 2 is transmitted to other sensors as a use slot notification. At this time, the used slot notification received from another sensor (S1 in the examples of FIGS. 1 and 2) is also transmitted, so that the history of the slot notification used in the past is sent to the sensor on the terminal side of the sensor array. The sensors S2 and S3 can be stored in slot Nos. 2 is a slot No. used in the upper sensor S1. Send 1 together.

  Here, in the example of FIGS. 1 and 2, the sensor S1 is located at the branch portion of the moving space 1, and the sensors cascaded to the sensor S1 are the two sensors S2 and S3 as described above. In S1, use slot notifications are simultaneously transmitted from two sensors, and data cannot be reproduced due to a collision. The sensor S1 that has detected the collision transmits a collision detection notification to the other sensors S2 and S3. The collision detection notification is made based on only the reception timing so that it can be detected even if it collides with a notification from another sensor. Specifically, within one transmission cycle W1, a window for a predetermined period W2 after transmission of the use slot notification is set is set, and when a signal of a certain length or more is received in the window, a collision detection notification It is determined that During this window, the used slot notification is not transmitted.

  When the collision is detected in this way, the sensors S2 and S3 end the window and when the next transmission cycle W1 is reached, while avoiding a collision with other sensors while performing carrier sensing by a method such as normal CSMA-CA, The used slot notification is transmitted again. In the example of FIG. 2, after the next transmission cycle W1, the sensors S2 and S3 start transmission after waiting for an arbitrary time in the CSMA-CA method, and are used from the sensor S2 having a short standby time. The slot notification (No. 2 + No. 1) is prioritized, and the sensor S2 is given the slot No. for the time being. 2 is assigned to its own slot. At this time, when the sensor S3 having a long standby time detects the use slot notification from the sensor S2 by the carrier sense of the CSMA-CA method, the sensor S3 executes the use slot notification process again. Slot No. 2 and the previously received slot number. 1 is not used for the slot assignment of its own device, and other slots are searched for empty slots in the same manner. If detected, the slot with the highest priority (No. 3 in the example of FIG. 2) is detected. The slot is selected and assigned to the slot to be used by itself, and the use slot notification (No. 3 + No. 1) is transmitted toward another sensor in the next transmission cycle W1.

  As a result, when the transmission of the used slot notification is completed without collision, the used slots of the sensors S2 and S3 are set in the above-mentioned No. 2 and no. 3 and the subsequent sensors (S4 in the example of FIG. 2) start the setting operation. At this time, in the sensor S4, the arrival ranges A1 ′, A2 ′; A4 ′ of the signals related to the sensors S1, S2 do not overlap, that is, the sensor S4 receives the use slot notification transmitted by the sensors S1, S2. Not done. However, from the history shown in the used slot notification from the adjacent sensor S3, the slot No. used by the adjacent sensor S3 is displayed. 3 as well as the slot No. used by the adjacent sensor S1. 1 is also recognized.

  For this reason, it is possible to select an arbitrary slot having a high priority without interfering with the adjacent sensors S1, S2, and S3. For example, in FIG. 2, the slot No. used in the adjacent sensor S3 is simply indicated by a use slot notification indicated by reference numeral SL1. Other than 3, slot No. which is a slot with high priority. 1 or the slot No. used by the adjacent sensor S1. 1 in consideration of the slot No. 1 as in the use slot notification indicated by reference numeral SL2. 4 or the like.

  Here, in the use slot notification SL2, in considering even the adjacent sensor S1, the slot No. 2 is not selected, and the slot number with the lower priority is selected. 4 is selected. This is because the adjacent sensor S1 has a slot No. 1 is selected, the adjacent sensor S3 has its slot No. which is the next rank. This is because it can be estimated that the sensor S3 is not used in relation to another sensor (in this case, S2). With this configuration, even if direct communication is not possible, it is possible to perform slot selection while avoiding slots used by adjacent sensors, and interference can be reliably prevented.

  The number of histories included in the use slot notification includes the number of sensors scheduled to be accommodated in the moving space, the expansion schedule, the number of sensors to be considered, and the required response (the maximum number of slots allowed in one cycle). What is necessary is just to be suitably determined according to etc.

  In this way, the same slot number is set in the sensors S1 and S4 where the detection target areas A1 to A4 do not overlap. 1 can be used, so even if many sensors are installed in a wide area without interference, the number of slots used is minimized (slot allocation is performed efficiently), and the detection cycle It is possible to improve the responsiveness by shortening the (cycle in which the slot makes a round). In addition, considering the selection history included in the used slot notification transmitted from the upper sensor, slot usage by more than 3 sensors can be used for slot selection to avoid the interference. Thus, slot allocation can be automatically performed in consideration of both prevention of interference and improvement of responsiveness.

  On the other hand, the slot setting operation may be terminated by a timeout process when the use slot notification or the collision detection notification is not received for a predetermined time, and may be terminated by operating the setting button again. Alternatively, the setting end notification may be sequentially transferred by the end operation to the sensor (S1 in the example of FIGS. 1 and 2) in which the start button is operated.

  When the initial setting mode ends, each sensor S enters the operation mode and communicates with the wireless tag TG. In the operation mode, as shown in FIG. 3, when each sensor S becomes the slot selected as described above within one frame period F of the predetermined number of slots 3, the first half of the sensor S is automatically used for the predetermined period. In response to this, the wireless tag TG in the detection target area A returns the identification information ID of the received sensor together with the identification information ID of the sensor. Thus, each sensor S can recognize the wireless tag TG present in the detection target area A of the own device.

  When the number of RFID tags TG accommodated in each detection target area A is large, each slot is set as a subframe, and a frame synchronization signal is transmitted in the first half of the subframe as shown in FIG. Slots TG1, TG2,... May be divided into empty slots. First, the wireless tag that newly enters the detection target area A transmits a transmission request including its own identification information ID in the empty slot, and each sensor S should respond with a frame synchronization signal of the next frame. The identification information ID of the tag and the slot number. And the designated sensor may perform authentication by performing a response in the designated slot.

  In the operation mode, for example, the existing sensors S1 to S4 are arranged as shown in FIG. 5 and configured as slot allocation as shown in FIG. If an attempt is made to add, if one frame period F is composed of four or more slots, the sensor S5 has a slot used in each of the sensors S2, S3, and S4. 2, no. 3, No. 1, slot No. with the highest priority among the empty slots. 4 can be selected and the operation mode can be shifted to.

  However, when one frame period F is composed of three slots as shown in FIG. 4, even if the sensor S5 searches for an empty slot, the empty slot cannot be detected, and the device itself can be incorporated into the system as it is. Can not. For this reason, as shown in FIG. 6, the sensor S5 notifies the operator of this by sounding a buzzer or lighting a lamp. The sensor S5 transmits a slot sharing request to the sensor determined by the operator who responded to the notification (in the example of FIG. 6, the ID of S3 is set), and transmits a slot sharing request. If the slot sharing response is included in the synchronization signal, the sharing of the slot (No. 3 in the example of FIG. 6) is started from the next frame. 3 is used alternately for each frame. The slot sharing is not limited to 1: 1 as shown in FIG. 6, but may be arbitrarily set such as reducing the ratio of the added side.

  FIG. 7 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 the slot as described above between the wireless signal transmission / reception unit 11 which is a wireless communication unit and the other sensor via the wireless signal transmission / reception unit 11. A tag selection unit 12 that performs a setting operation, a user interface 13 that is used for the slot setting operation and the like, and a tag management unit 14 that communicates with and authenticates the wireless tag TG via 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 the control data of the sensor S from the host device 2.

  As shown in FIG. 2, the slot selection unit 12 selects a slot to be used by the own device, transmits a used slot notification, and transmits the used slot notification from the own device. When the detection notification is received, the slot allocation processing unit 21 retransmits the use slot notification. When the use slot notification is received and cannot be reproduced, a collision detection processing unit 22 that transmits the collision detection notification, A slot synchronization unit 23 that synchronizes communication, a setting end detection unit 24 that determines the end of the slot setting operation, a transmission / reception slot management unit 25 that controls the entire slot selection unit 12, and a sensor addition as shown in FIG. And a sensor addition unit 26 that realizes processing.

  The user interface 13 displays, for example, that it is an operation mode in which a normal detection operation of the RFID tag TG is performed, is the initial setting mode or the addition mode, and whether these setting modes have been normally completed. Status display means 31 for notifying the user of a malfunction or the like by a lamp display or the like, and when an abnormality or suspicious wireless tag is detected, an alarm is issued or the wireless tag TG can be recognized normally and the door is unlocked, etc. The alarm / notification sound generating device 32 such as a buzzer for notifying that the operation is performed, and the setting switch 33 such as the setting button, start button, and additional button are configured.

  When a slot setting operation is started by operating the setting button or the start button of the setting switch 33, this is displayed by the status display means 31, and the empty slot detection processing unit 211 of the slot allocation processing unit 21 is empty as described above. When a slot is searched and detected, the slot having the highest priority is selected and assigned to the slot to be used by the own device. The slot number received by the used slot notification reception processing unit 213. The necessary portion of the information is transmitted from the used slot notification transmission processing unit 212 to other sensors via the transmission / reception slot management unit 25 and the wireless signal transmission / reception unit 11. On the other hand, the used slot notification received from the radio signal transmitting / receiving unit 11 via the transmission / reception slot management unit 25 is stored in the used slot notification reception processing unit 213 and used for slot selection by the empty slot detection processing unit 211. . When the use slot notification is received by the use slot notification reception processing unit 213, if the sensor has not started the slot setting operation, the setting operation is started by using the sensor as a trigger, and the empty slot detection processing unit 211 Starts slot selection.

  The use slot notification transmitted in this way is determined to be a collision when the collision detection unit 221 of the collision detection processing unit 22 cannot reproduce the data as described above, but detects the reception of some data. In response to the determination result, the collision notification transmission processing unit 222 transmits the collision detection notification from the transmission / reception slot management unit 25 via the wireless signal transmission / reception unit 11. On the other hand, when the collision detection notification is received by the collision notification reception processing unit 223 from the wireless signal transmission / reception unit 11 via the transmission / reception slot management unit 25, the retransmission control unit 224 searches the slot allocation processing unit 21 for a free slot. Re-send from.

  In the transmission / reception of these used slot notifications and collision detection notifications, the slot synchronization signal detection processing unit 231 of the slot synchronization unit 23 detects the synchronization such as the transmission cycle W1 from the received data in the transmission / reception slot management unit 25. Synchronization is obtained by the synchronization timing adjustment processing unit 232 controlling the transmission / reception slot management unit 25 so that the timing of the own device matches the system timing. The end of the slot setting operation is performed in the setting end detection unit 24 as described above. When the initial setting mode or the sensor addition mode ends, this is displayed by the status display unit 31 and the radio signal transmission / reception unit 11. The operation mode is to return the reception sensitivity to normal and detect the wireless tag.

  On the other hand, in the sensor (S5 in the case of FIG. 5) that is in the sensor addition mode by the operation of the add button of the setting switch 33, this is displayed by the status display means 31, and the slot assignment processing unit 21 vacant slot detection units 211 increase the reception sensitivity of the radio signal transmission / reception unit 11, determine the status of the slot to be used from the one frame period F and the synchronization signal of the adjacent sensor, and based on these results, To determine the slot to be used. When an empty slot is detected, the empty slot detection unit 211 selects a slot with the highest priority among them, assigns it to a slot to be used by itself in the transmission / reception slot management unit 25, and Slot No. Is transmitted from the used slot notification transmission processing unit 212 to other sensors via the transmission / reception slot management unit 25 and the radio signal transmission / reception unit 11 in the selected slot of the next frame, and the normal operation mode is switched.

  On the other hand, in the sensor addition mode, when the empty slot detecting unit 211 cannot detect an empty slot, the alarm / notification sound generating device 32 notifies the operator of that fact, and via the network interface 15. If the operator inputs the ID of the sensor (S3 in the example of FIG. 6) to which slot sharing is to be requested from the setting switch 33 or the host device 2 in response to the notification to the host device 2, The slot sharing request transmission processing unit 261 of the additional processing unit 26 receives the response period of the sensor S3 from the transmission / reception slot management unit 25 via the wireless signal transmission / reception unit 11 whose transmission power has been increased (the period of the empty slot in FIG. 4). ) Transmits the slot sharing request.

  On the other hand, the slot sharing request reception processing unit 262 of the sensor S3 that has received the slot sharing request from the wireless signal transmission / reception unit 11 via the transmission / reception slot management unit 25 sends the slot sharing response to the slot sharing response transmission processing unit 263. The transmission / reception slot management unit 25 transmits the data via the wireless signal transmission / reception unit 11 with increased transmission power. In the sensor S5 that receives the slot sharing response from the radio signal transmitting / receiving unit 11 via the transmission / reception slot management unit 25 in the slot sharing response reception processing unit 264 and the sensor S3 that transmits the slot sharing response, as described above, In this transmission frame, the same slot is alternately used for each frame to communicate with the wireless tag TG. When adjusting the sharing ratio of the slots, it may be adjusted as appropriate using subsequent synchronization signals.

  With this configuration, wireless communication is performed between sensors S adjacent to each other, adjustment is performed so that slots to be used do not overlap, and when there is no empty slot when adding sensor S5, By adjusting the operator, it becomes possible to add a sensor without stopping the entire system. As a result, even when an expansion is expected in the future, it is not necessary to increase the number of slots in one frame period in order to enable addition of sensors, and the responsiveness can be improved. Also, slot sharing can be performed by designating a sensor that is considered to be less affected by slot sharing, such as a sensor expected to have a small number of RFID tags TG present in the detection area A.

[Embodiment 2]
FIG. 8 is a timing chart for explaining the sensor addition operation in the wireless authentication system according to the second embodiment of the present invention. It should be noted that in this embodiment, the added sensor (S5 in the example of FIG. 8) voluntarily determines a sensor that requests slot sharing. For this reason, the priority of slot sharing is set in advance for each sensor S according to the installation environment and the like, and the sensors S1 to S4 in operation are in synchronization signals for the wireless tag TG as shown in FIG. In addition to the sensor ID, it is transmitted. In the example of FIG. 8, the priority order of the sensor S1 at the start of the moving space 1 and the sensor S2 at the branch point is set to the highest 1, and the next sensor S3 close to the branch has priority 2 and The sensor S4 is set to priority 3. Then, in the sensor addition mode, the reception sensitivity is increased, and the sensor S5 that receives the synchronization signal from the sensors S2 to S4 analyzes the synchronization signal, and the sensor S4 having the lowest priority order Send slot share request.

  FIG. 9 is a block diagram illustrating a configuration example of the sensor S ′ that realizes the above-described function. This sensor S 'is similar to the above-described sensor S, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. In this sensor S ′, when the empty slot detection processing unit 211 cannot detect an empty slot in the sensor addition mode, the sharing destination determination processing unit 265 of the sensor addition processing unit 26 ′ analyzes the synchronization signal and automatically A sharing destination is determined, and the slot sharing request transmission processing unit 261 is caused to transmit a slot sharing request. Further, the priority order information set by the setting switch 33 'of the user interface 13' is given to the radio signal transmitting / receiving unit 11 'and transmitted by being included in the synchronization signal in operation.

  Even with this configuration, it is possible to add a sensor without stopping the entire system. In addition, to the added sensor (S5 in the example of FIG. 8), to the wireless tag TG based on slot sharing, such as a sensor expected to have a small number of wireless tags present in the detection target area A from the priority order, for example. It is possible to automatically determine a sharing destination that is considered to be least affected by a shortage of allocated slots.

[Embodiment 3]
FIG. 10 is a timing chart for explaining the sensor addition operation in the wireless authentication system according to the third embodiment of the present invention. In the present embodiment, in the configuration of the sensors S and S ′ shown in FIG. 7 and FIG. 9, the configuration of the sensor addition processing units 26 and 26 ′ can be partially changed and used. It should be noted that in this embodiment, the added sensor (S5 in the example of FIG. 10) is a wireless tag for the synchronization signal (question signal) from the adjacent sensors (S2 to S4 in the example of FIG. 10). The slot sharing request is transmitted to the sensor (S4 in the example of FIG. 10) that receives the TG response and has the smallest number of responses.

  Specifically, in the example of FIG. 10, first, one frame period F is composed of three subframes SF corresponding to the slots of FIG. 6 and FIG. 8, and the inside of each subframe SF is shown in FIG. (In the example of FIG. 10, two empty slots are set in the eight response slots 1 to 8 following the frame synchronization signal). When the added sensor S5 cannot detect an empty slot, a response of the wireless tag TG to the synchronization signal (question signal) from the adjacent sensors S2 to S4 is received. In the example of FIG. In the example, six wireless tags are responding, four wireless tags are responding in the sensor S3, and only two wireless tags are responding in the sensor S4. Therefore, the sensor S5 is in the empty slot of the sensor S4. The slot sharing request is transmitted.

  In addition, when the response period of the wireless tag TG with respect to the synchronization signal (question signal) from each sensor S is composed of one slot as shown in FIGS. 6 and 8, the added sensor S5 includes a plurality of sensors S5. A response signal may be received over the frame. In addition, the sensor S5 added as described above does not use the current value of the number of wireless tags detected by receiving the response signal by itself, but the sensors S1 to S4 in operation are The maximum value of the tag access number is updated and stored in the synchronization signal, and transmitted by including it in the synchronization signal, so that the added sensor S5 does not actually receive the response signal and the sensor with the smallest number of responses is received. You may make it determine.

  Furthermore, when the response signal is actually received as shown in FIG. 10, the wireless tag TG exists on the side opposite to the added sensor S5 with respect to the adjacent sensors S2 to S4 (the wireless tag TG is adjacent). Although it is within the detection target areas A2 to A4 of the sensors S2 to S4 that are not within the reach range A5 ′ of the added sensor S5), the response signal cannot be received. The wireless tag that enters the detection target area A transmits an outgoing request including its own identification information ID in an empty slot, and in response to this, each sensor S responds with a frame synchronization signal of the next frame. When specifying slot No. In the sensor S5 to be added, the largest slot No. in which the response signal has been received is specified. Therefore, the number of response sensors can be determined with a certain degree of accuracy.

  Thus, when an empty slot cannot be detected and a slot sharing request is transmitted, the slot sharing request is transmitted to the sensor with the smallest number of responses such as the maximum access count and average access count of the wireless tag. It is possible to cause a sensor that is considered to have the least influence by sharing to perform slot sharing.

[Embodiment 4]
FIG. 11 is a timing chart for explaining the sensor addition operation in the wireless authentication system according to the fourth embodiment of the present invention. Also in this embodiment, in the configuration of the sensors S and S ′ shown in FIG. 7 and FIG. 9, the configuration of the sensor addition processing units 26 and 26 ′ can be partially changed and used. This embodiment is similar to the embodiment shown in FIG. 8, and it should be noted that in this embodiment, the sensors in operation (S1 to S4 in the example of FIG. 11) are transmitted to the wireless tag TG. In the synchronization signal to be transmitted, each sensor S1 to S4 includes information indicating the number of adjacent sensors, and the added sensor (S5 in the example of FIG. 11) receives the synchronization signal. Analyzing and transmitting the slot sharing request to the sensor having the largest number of adjacent sensors.

  Specifically, in the example of FIG. 11, the sensor adjacent to the currently operating sensor S1 is only S2, and the information indicating the number of adjacent sensors is “1”. However, the synchronization signal from the sensor S1 cannot be received by the added sensor S5. On the other hand, in the sensors S2 to S4 in which the sensor S5 can receive the synchronization signal, the sensors S2 are adjacent to the sensors S1 and S3, the sensors S3 are adjacent to the sensors S2 and S4, and the information is “2”. Thus, only the sensor S3 is adjacent to the sensor S4, and the information is “1”. Therefore, the sensor S5 transmits the slot sharing request to the sensor S2 or S3 (the sensor S2 using the slot No. 2 having a high priority in the example of FIG. 11). As described above, each of the sensors S1 to S4 in operation has received the use slot notification from the adjacent sensor at the initial setting stage as described above, and it is possible to grasp the number of sensors adjacent to the own device in advance. is there.

  With this configuration, even if the detection frequency of the wireless tag TG decreases due to slot sharing, there is a high possibility that it can be covered by other adjacent sensors, and the sensor that is considered to have the least influence from slot sharing. Can be used to share slots.

[Embodiment 5]
FIG. 12 is a timing chart for explaining the sensor addition operation in the wireless authentication system according to the fifth embodiment of the present invention. Also in this embodiment, in the configuration of the sensors S and S ′ shown in FIG. 7 and FIG. 9, the configuration of the sensor addition processing units 26 and 26 ′ can be partially changed and used. It should be noted that in the present embodiment, the added sensor (S5 in the example of FIG. 12) receives the synchronization signal from the sensor in operation (S1 to S4 in the example of FIG. 12), and the synchronization signal The slot sharing request is sequentially transmitted to the sensors S2 to S4 that have received.

  Specifically, in the example of FIG. 12, the sensor S5 cannot receive the synchronization signal from the sensor S1, and does not react. However, the slot No. in which the synchronization signal can be received first in the frame F1. When the slot sharing request is transmitted to the first sensor S4 and the slot sharing response included in the synchronization signal from the sensor S4 is received in the next frame F2, the sensor S5 is further transmitted in the next frame F3. Slot No. 1 is used to transmit a synchronization signal, that is, to communicate with the wireless tag TG, and the sensor S4 stops transmission of the synchronization signal, that is, communication with the wireless tag TG.

  On the other hand, the sensor S5, in the frame F2 that receives the slot sharing response, receives the next slot No. that has received the synchronization signal. When the slot sharing request is transmitted to the sensor S2 of No. 2 and a slot sharing response is received from the sensor S2 in the frame F3, the sensor S5 further receives the slot No. in the frame F4. 2 is used, the sensor S2 pauses the transmission of the synchronization signal. Therefore, in this frame F4, the sensor S4 has a slot No. 1 is used to resume transmission of the synchronization signal.

  Similarly, in frame F3, slot No. When the slot sharing request is transmitted to the sensor S3 of No. 3 and a slot sharing response is received in the frame F4, the sensor S5 receives the slot No. in the frame F5 (not shown). 3 in the next frame F6, the slot No. shared with the sensor S4 again. 1 is used.

  By sequentially switching the sensors sharing the slot in this way, the slot sharing can be performed while distributing the influence of the slot sharing. Note that the switching of the shared slot may be performed every several frames instead of every frame as described above.

It is a block diagram which shows the structure of the radio | wireless authentication system which concerns on the 1st Embodiment of this invention. It is a timing chart for demonstrating operation | movement in the initial setting mode of each sensor which concerns on the 1st Embodiment of this invention. It is a timing chart for demonstrating operation | movement in the normal operation mode of each sensor which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the structure of a subslot. It is a block diagram which shows the structure of the radio | wireless authentication system at the time of the sensor addition which concerns on the 1st Embodiment of this invention. It is a timing chart for demonstrating operation | movement in the addition mode of each sensor which concerns on the 1st Embodiment of this invention in the structure shown in FIG. It is a block diagram which shows one structural example of the sensor which concerns on the 1st Embodiment of this invention. It is a timing chart for demonstrating operation | movement in the addition mode of each sensor which concerns on the 2nd Embodiment of this invention in the structure shown in FIG. It is a block diagram which shows one structural example of the sensor which concerns on the 2nd Embodiment of this invention. It is a timing chart for demonstrating operation | movement in the addition mode of each sensor which concerns on the 3rd Embodiment of this invention. It is a timing chart for demonstrating operation | movement in the addition mode of each sensor which concerns on the 4th Embodiment of this invention. It is a timing chart for demonstrating operation | movement in the addition mode of each sensor which concerns on the 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mobile space 2 Host apparatus 11, 11 'Radio signal transmission / reception part 12 Slot selection part 13, 13' User interface 14 Tag management part 15 Network interface 21 Slot allocation process part 211 Empty slot detection process part 212 Used slot notification transmission process Unit 213 used slot notification reception processing unit 22 collision detection processing unit 221 collision detection unit 222 collision notification transmission processing unit 223 collision notification reception processing unit 224 retransmission control unit 23 slot synchronization unit 231 slot synchronization signal detection processing unit 232 synchronization timing adjustment processing unit 24 Setting end detection unit 25 Transmission / reception slot management unit 26, 26 'Sensor addition processing unit 261 Slot sharing request transmission processing unit 262 Slot sharing request reception processing unit 263 Slot sharing response transmission processing unit 264 Slot sharing response reception processing unit 265 Sharing destination determination place Management unit 31 Status display means 32 Alarm / notification sound generator 33, 33 'Setting switch A1, A2, A3, A4, A5 Detection target area S, S'; S1, S2, S3, S4, S5 Sensor TG Wireless tag

Claims (8)

A plurality of sensors are arranged so that a part of each detection target area overlaps between adjacent sensors along the movement space of the detection target, and the wireless tag carried by the detection target communicates with any one of the sensors. In the wireless authentication system that detects the movement of the detection target by performing
Each sensor is
A wireless communication unit capable of performing communication with the wireless tag using a common wireless communication band by time division multiplexing, and capable of performing communication between adjacent sensors;
A slot allocation processing unit that performs wireless communication with each other via the wireless communication unit at the time of initial setting, and selects a slot to be used between sensors adjacent to each other in the wireless communication band; and
When adding a sensor that adds its own device to an operating system that is communicating with the wireless tag, the slot assignment processing unit is searched for an empty slot, and if the empty slot cannot be detected, the wireless communication unit A sensor addition processing unit that transmits a slot sharing request and receives the slot sharing request at the wireless communication unit, and causes the wireless communication unit to use the same slot with different frames between the transmission and reception sensors of the slot sharing request. A wireless authentication system comprising: Each sensor has a slot sharing priority set in advance, and is included in a synchronization signal transmitted from the wireless communication unit to the wireless tag.
The sensor addition processing unit analyzes the synchronization signal received by the wireless communication unit, and transmits the slot sharing request to a sensor having the lowest priority. Wireless authentication system.   The sensor addition processing unit, when adding a sensor, causes the wireless communication unit to receive a response to each sensor of the wireless tag, and transmits the slot sharing request to a sensor with the smallest number of responses. The wireless authentication system according to claim 1. The synchronization signal transmitted from the wireless communication unit to the wireless tag includes information indicating the number of sensors adjacent to each sensor,
2. The sensor addition processing unit analyzes the synchronization signal received by the wireless communication unit, and transmits the slot sharing request to a sensor having the largest number of adjacent sensors. Wireless authentication system.   The sensor addition processing unit causes the wireless communication unit to receive a synchronization signal transmitted from the wireless communication unit of each sensor to the wireless tag, and sequentially issues the slot sharing request to the sensor that has received the synchronization signal. The wireless authentication system according to claim 1, wherein the wireless authentication system is transmitted. A plurality of sensors are arranged so that a part of each detection target area overlaps between adjacent sensors along the movement space of the detection target, and the wireless tag carried by the detection target communicates with any one of the sensors. In the wireless authentication system that detects the movement of the detection target by performing
Each sensor is
A wireless communication unit capable of performing communication with the wireless tag using a common wireless communication band by time division multiplexing, and capable of performing communication between adjacent sensors;
A slot allocation processing unit that performs wireless communication with each other via the wireless communication unit at the time of initial setting, and selects a slot to be used between sensors adjacent to each other in the wireless communication band; and
When adding a sensor for adding the own device to an operating system communicating with the wireless tag, the slot allocation processing unit searches for an empty slot and notifies an operator when an empty slot cannot be detected. A wireless authentication system including a sensor addition processing unit.   The sensor addition processing unit causes the wireless communication unit to transmit a slot sharing request to the sensor determined by the designation of the worker who responded to the notification, and when the wireless communication unit receives the slot sharing request, The wireless authentication system according to claim 6, wherein the same slot is used in different frames by the wireless communication unit between the transmission / reception sensors of the slot sharing request. A plurality of adjacent detection objects are arranged along the movement space of the detection target so that a part of each detection target area overlaps each other, and the wireless tag carried by the detection target communicates with any one of them. In the sensor of the wireless authentication system configured to detect the movement of the detection target,
A wireless communication unit capable of performing communication with the wireless tag using a common wireless communication band by time division multiplexing, and capable of performing communication between adjacent sensors;
A slot allocation processing unit that performs wireless communication with each other via the wireless communication unit at the time of initial setting, and selects a slot to be used between sensors adjacent to each other in the wireless communication band; and
When adding a sensor that adds an own device to an operating system that is communicating with the wireless tag, the slot assignment processing unit searches for an empty slot, and if the empty slot cannot be detected, the wireless communication unit A sensor addition processing unit that transmits a slot sharing request and receives the slot sharing request at the wireless communication unit, and causes the wireless communication unit to use the same slot with different frames between the transmission and reception sensors of the slot sharing request. A sensor characterized by comprising.

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