JP6093596B2 - Moving object monitoring system - Google Patents

Description

  The present invention relates to a moving object monitoring system that monitors whether or not a moving body is accompanied by a portable device in a monitoring area.

  Conventionally, a person who has entered a monitoring area is detected by a security sensor, and a portable device such as an IC tag possessed by a legitimate user is read by a reader, and the detected person is a legitimate user or a suspicious person. A system to identify this is proposed. For example, in Patent Literature 1, when a heat ray sensor detects a moving object in a warning area, an operation for reading an identification number of a mobile card possessed by an employee is performed, and this is performed when a registered identification number cannot be read. A security system that judges a moving object as an intruder and gives an alarm is disclosed.

  Further, an IC tag driven by a built-in battery needs to prevent useless transmission operation in order to suppress battery consumption. As a countermeasure, the IC tag operates in a power saving mode in which communication with the reader is not performed while the IC tag is not moving. Technology is known. For example, Patent Document 2 discloses a technology related to an IC tag that has a built-in vibration sensor and shifts to a low power consumption mode that does not perform a response operation to a reader (master unit) when vibration is no longer detected.

Japanese Patent Laid-Open No. 11-144160 JP 2003-346107 A

  The security system described in Patent Document 1 can recognize whether or not an IC tag exists within the detection range when a certain heat ray sensor detects a person, but does the detected person truly have an IC tag? It is not possible to determine whether or not. If the detection range of the person and the IC tag is narrow enough for one person to enter, it can be said that the detected person possesses the IC tag. However, if the detection range covers a wide area, the IC tag is located away from the person. Even if exists, the person is mistakenly recognized as a regular user. In addition, even when a person who does not have an IC tag is mixed among a plurality of persons, a situation that cannot be extracted as a suspicious person may occur.

Further, when the IC tag has a power saving function for transmitting only when it vibrates, the IC tag is not detected while the person is stopped, and even if the detected person possesses the IC tag, the IC tag is mistaken as a suspicious person. There is a possibility of judging.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a moving object monitoring system capable of accurately determining whether or not a detected moving body is associated with a portable device.

  In order to achieve the above object, a moving object monitoring system of the present invention is a moving object monitoring system that monitors whether a moving object is associated with a portable device by associating the moving object with the portable device. The portable device includes a communication unit that emits a radio signal including unique identification information, a motion detection unit that detects a motion of the mobile device, a communication control unit that suppresses transmission of the radio signal when there is no motion, The monitoring device includes: object detection means for detecting position information of a moving object in a monitoring area by sensing; and a portable device that receives a radio signal emitted from the portable device and detects position information of the portable device Detection means; and correspondence determination means for associating the moving object with the portable device when the position information of the moving object and the position information of the portable device satisfy a predetermined matching criterion. It means, when the moving object and the correspondence already portable device is not detected, maintaining the association between the portable device on condition that the moving object is a specific moving state, characterized in that.

  According to such a configuration, the moving object is associated with the portable device based on the coincidence between the position information where the moving object is detected and the position information where the portable device is detected. Can be accurately determined. In addition, even if the associated portable device is not detected, the association maintenance determination is performed in consideration of the moving state of the moving object. Therefore, the portable device cannot be detected due to the action of the moving object, or the detection takes time. Correspondence is maintained even in a situation where detection is difficult, and it is possible to suppress erroneous determination that the portable device is not associated.

In the above configuration, the correspondence determining unit determines that the specific moving state is present when a change in position information of the moving object is small. For example, the correspondence determining unit determines that the specific moving state is present when the moving speed of the moving object is equal to or lower than a predetermined value. Alternatively, when the difference between the position information of the moving object and the position information of the moving object is within a predetermined time when the moving object shifts to the specific moving state or when the associated portable device is not detected. , It is determined that the specific movement state.
If the moving object is in a stopped state in which the moving object is hardly moving, it is highly likely that the wireless tag is in a power-saving operation and difficult to detect. In addition, if the moving object is in a stopped state, the threat of safety such as further intrusion into the building is relatively low. Therefore, by performing the above-described maintenance determination on the condition that the moving object is in a stopped state, it is possible to realize high-safety monitoring while suppressing erroneous determination that the moving object does not have a portable device. .

Furthermore, in the above-described configuration, there is an authority determination unit that obtains an accuracy of association between the moving object and the portable device, and performs authority determination of the moving object based on the accuracy, and the authority determination unit includes the movement When the association is maintained with the portable device in which an object is not detected, the accuracy of the moving object is lowered.
When the association with the non-detected wireless tag is maintained, the reliability of the association is low compared to the normal determination for confirming the consistency of the position information. According to such a configuration, it is possible to perform an operation with improved safety, such as not allowing entry into a building in a state in which the association is maintained and simulated.

  In order to achieve the above object, the moving object monitoring system of the present invention is a moving object monitoring system that monitors whether a moving object is associated with a portable device by associating the moving object with the portable device. An object detection means for detecting position information of a moving object in a monitoring area by sensing; a portable device detection means for detecting position information of the portable device by receiving a radio signal emitted by the portable device; and the movement Correspondence determining means for associating the moving object with the portable device when the position information of the object and the position information of the portable device satisfy a predetermined matching criterion, and the correspondence determining means includes the moving object When a portable device associated with the mobile device is not detected, the association with the portable device is maintained on condition that the moving object is in a specific moving state.

  According to the present invention, it is possible to accurately determine whether or not the detected moving body is associated with the portable device by performing the association between the moving object and the portable device in consideration of the moving state of the moving object.

It is a schematic whole block diagram of the suspicious person monitoring system of this embodiment. It is a schematic diagram for demonstrating the example of a matching process. It is a flowchart which shows a matching process. It is a flowchart which shows a matching process.

  As an embodiment of the moving object monitoring system of the present invention, a suspicious person monitoring system that detects a suspicious person who has illegally entered a building site and issues an abnormal alarm will be described below as an example.

  The suspicious person monitoring system according to the present embodiment is applied to, for example, monitoring of a service user's house, and detects an intrusion of a suspicious person into a garden corresponding to the house's premises to give an abnormality alarm. The user is given a portable device in advance, and possesses the portable device when entering and leaving the house. The suspicious person monitoring system detects a person who enters the garden from outside the site by sensing, and specifies the position information. In addition, the presence of the portable device is detected by receiving a wireless signal from the portable device with a reader, and the position information of the portable device is specified by analyzing the received wireless signal. The position information is a position in the monitoring area or an orientation based on a certain point in the monitoring area. Then, the position information of the person is compared with the position information of the portable device, and when the degree of coincidence satisfies a predetermined standard, the person is regarded as possessing the portable device and is recognized as an authorized user. . On the other hand, if the degree of coincidence does not meet a predetermined standard or the portable device is not detected, the detected person is recognized as a suspicious person who does not have the portable device, and for example, staying in the garden or entering the building An abnormal warning is output for the entrance act.

In order to specify the position information of a portable device held by a person in the monitoring area, it is necessary for the reader to be able to receive a radio signal emitted from the portable device from anywhere in the site. Therefore, the portable device is required to have an output level with a communication distance of several meters to several tens of meters, and performs a transmission operation using the built-in battery as a drive source.
Further, when the built-in battery is used as a drive source, a power saving function is provided that limits the transmission operation while the portable device is operating in order to suppress battery consumption. The portable device has a sensor for detecting the movement of the portable device, enables a transmission operation while detecting the movement, and does not perform a transmission operation while the movement is not detected.

  The portable device having the power saving function cannot be detected on the system side while it is not moving even in the monitoring area. Therefore, if the person who possesses the portable device stops in the monitoring area, the portable device is not detected and the association between the position of the person and the portable device is not established, so that the person is not recognized as an authorized user. For example, if a legitimate user possessing a portable device is working at an arbitrary position in the site, an abnormal determination may be made as a staying action by a suspicious person and a false alarm may occur.

Therefore, in the suspicious person monitoring system according to the present embodiment, the portable device is not detected on the condition that the person once associated with the portable device is in a predetermined movement state in which the movement of the portable device is small, such as being stopped. Even if it becomes, the association with the portable device is maintained.
In this way, by associating a person with a portable device in consideration of the movement state of the person, it is possible to accurately determine the tie of the portable device while suppressing the power consumption of the portable device, and regular use with the portable device Misinformation by the person can be suppressed.

FIG. 1 is a schematic overall configuration diagram of the suspicious person monitoring system of the present embodiment.
The suspicious person monitoring system mainly includes a wireless tag 10, a reader 20, a distance measuring sensor 30, and a monitoring device 40, and at least a part of the site around the building is a monitoring area. When a suspicious person who has entered the building site or the building is detected, the remote security center 60 is notified of the occurrence of an abnormality via a communication line 50 such as the Internet network. The security center 60 that has received the abnormality report implements emergency measures such as dispatching security personnel to the site. In addition, if a camera (not shown) is separately provided in the suspicious person monitoring system so that an image at the time of occurrence of an abnormality can be confirmed by the security center 60, the monitor of the security center 60 can accurately check the situation at the site. I can grasp.

  The wireless tag 10 is a portable device that is given in advance to a user who is permitted to enter or leave the building, and is carried when the building that is the subject of monitoring enters or exits. The wireless tag 10 includes a communication unit 12 that performs wireless communication with the reader 20, a vibration sensor 14 that detects movement generated in the device itself, a battery 16 that serves as an operation power supply, and a communication control unit that controls the operation of the wireless tag 10. The wireless signal including the unique identification information (hereinafter referred to as a tag ID) is transmitted for each wireless tag 10 stored in advance using the battery 16 as a drive source. For the wireless communication system, RF-ID (Radio Frequency IDentification) technology is used. The wireless tag can use various frequency bands depending on the application, and there are various types such as an active type in which a driving method is transmitted by its own control and a passive type in which a response signal is returned with a question signal from the reader 20 as a trigger. is there. Although the usage frequency and the driving method are not limited, in the present embodiment, in order to be used for monitoring in a building site, the UHF band suitable for relatively long-distance communication such as several meters to several tens of meters or 2. A response signal including a tag ID is output in response to an interrogation signal from the reader 20 using a frequency of 4 GHz band. Note that a vibration detection sensor may be provided in the wireless tag 10 so that a wireless signal is transmitted only during vibration detection, that is, during movement.

The vibration sensor 14 has a function of detecting a motion generated in the wireless tag 10, and a known vibration detection technique such as an acceleration sensor or an angular velocity sensor (gyroscope) can be employed.
The communication control unit 18 monitors the presence or absence of movement of the wireless tag 10 based on the detection result of the vibration sensor 14. When the vibration sensor 14 is detecting vibration, the motion flag is recognized and the motion flag is turned on. When the vibration sensor 14 is not detected and a certain time (for example, 3 seconds) elapses, the motion flag is recognized and the motion flag is turned off. To do.

  Further, the communication control unit 18 controls the wireless signal transmission operation based on the presence or absence of movement of the wireless tag 10 and suppresses the transmission operation when there is no movement. When the motion flag is ON, the communication control unit 18 operates in the normal mode to allow transmission, and when the motion flag is OFF, the communication control unit 18 operates in the power saving mode and prohibits transmission. In the power saving mode, the transmission may not be completely stopped, but the transmission may be suppressed by thinning out and reducing the number of transmissions. Moreover, it is good also as a structure which notifies that it transferred to the power saving mode by transmitting a radio signal to the reader 20.

  The reader 20 detects the wireless tag 10 existing in a predetermined detection range. The detection range depends on the signal strength of the radio wave transmitted by the wireless tag 10 and the reader 20. The reader 20 receives a response signal issued by the wireless tag 10 in response to the inquiry signal transmitted to the detection range, and extracts a tag ID that identifies the wireless tag 10 included in the response signal. The detection range of the reader 20 needs to include the monitoring area so that the wireless tag 10 possessed by the person in the monitoring area can be detected. Since the reach range of the question signal varies depending on the environment such as the nature of the object existing in the space, the detection range covers a range wider than the monitoring area in advance.

The reader 20 includes an antenna having directivity of a constant angle (for example, 10 °), and transmits a question signal and receives a response signal while electronically switching the directivity angle of the antenna at fixed time intervals. The reader 20 reads the wireless tag 10 over the entire monitoring area at a predetermined cycle (for example, 200 msec), acquires the reception intensity of the response signal for each directivity angle, and outputs it to the monitoring device 40 as tag detection data. Tag detection data is created for each detected tag ID. The angle defining the directivity angle is, for example, one of the horizontal directions around the visual axis of the reader 20 as a positive angle and the other as a negative angle.
As a configuration for obtaining the orientation of the wireless tag 10, a configuration in which a directional antenna is rotated to switch a directional angle, a plurality of directional antennas are mounted, and the weight of each antenna is controlled to control the directional angle. It is possible to substitute a known method such as a configuration for switching between.

  The distance measuring sensor 30 scans the monitoring area with the laser beam and detects the position of the object reflecting the laser beam. The distance measuring sensor 30 sequentially projects near-infrared laser light having a wavelength of, for example, about 890 nm to the entire monitoring area while reflecting it using a scanning mirror that is driven to rotate at a constant speed. Further, the reflected light reflected by the object is received, and distance measurement data is generated as a result of the laser light irradiation. The scanning is performed at a predetermined cycle (for example, 200 msec) with respect to the range of the monitoring area (for example, 180 °). The distance measuring sensor 30 measures the distance to the object to be reflected from the time difference required from the irradiation of the laser light to the reception of the reflected light at every predetermined scanning angle (for example, 0.25 °) (so-called Time of Flight method). The measurement distance for each scanning angle is output to the monitoring device 40 as distance measurement data for one cycle. The distance measurement data is represented by an angle and a distance, and indicates the position of the reflected object with the distance measurement sensor 30 as a viewpoint. For example, one of the horizontal directions around the visual axis of the distance measuring sensor 30 is a positive angle and the other is a negative angle.

  Here, it is necessary to define in advance the relationship between the “position” indicated by the distance measurement data and the “azimuth” indicated by the tag detection data for the association processing in the monitoring device 40 described later. In the present embodiment, the reader 20 and the distance measuring sensor 30 are installed in the vicinity so that the respective visual axes coincide, and the scanning angle of the distance measuring sensor 30 and the directivity angle of the reader 20, that is, the angle in the distance measurement data and the tag detection data. Are preliminarily adjusted so that the angles are expressed in a common coordinate system. Preferably, the reader 20 and the distance measuring sensor 30 are arranged in the same casing.

  The suspicious person monitoring system according to the present embodiment includes a pair of readers 20 and distance measuring sensors 30. However, the suspicious person monitoring system includes a plurality of readers and distance measuring sensors according to the shape of the region to be monitored. . For example, when monitoring the four surroundings of a building, at least two sets of readers and distance measuring sensors are provided on the diagonal of the site. When installed on the wall of a building, a total of four readers and ranging sensors are installed on each surface.

The monitoring device 40 is connected to the reader 20 and the distance measurement sensor 30 wirelessly or by wire, and executes the monitoring process by inputting the tag detection data transmitted from the reader 20 and the distance measurement data transmitted from the distance sensor 30. When an abnormality is detected, the remote security center 60 is notified of the abnormality.
The monitoring device 40 mainly includes a storage unit 42, a notification unit 44, a notification unit 46, and a monitoring processing unit 48.

  The storage unit 42 includes a ROM, a RAM, and the like. In addition to data and programs necessary for various types of processing by the monitoring processing unit 48, a tag ID of a wireless tag previously assigned to a user, reference distance measurement data used for person detection Remember. The reference distance measurement data is distance measurement data obtained by the distance measurement sensor 30 scanning the monitoring area in the absence of a moving body. The storage unit 42 has an area in which the tracking data regarding the detected person is stored in a rewritable manner, and the tracking data is created, updated, and deleted by the monitoring processing unit 48 as needed.

The reporting unit 44 is a communication interface for transmitting an abnormality signal to the security center 60 via the communication line 50.
The notification unit 46 includes a buzzer, a speaker, a warning lamp, and the like, and is a means for notifying the surroundings that an abnormality has occurred and threatening a suspicious person. Note that the notification unit 46 may be provided in the reader 20 and the distance measuring sensor 30.

  The monitoring processing unit 48 receives distance measurement data from the distance measurement sensor 30 and tag detection data from the reader 20, and a person detection means 481 that performs person detection processing in the monitoring area, and a tag detection means that performs wireless tag detection processing. 482, a movement determination unit 483 for performing a movement determination process for a person, an association unit 484 for performing a process for associating a detected person with a wireless tag, and an abnormality determination unit 485 for executing a person tracking and abnormality determination process. Moreover, each part of the monitoring apparatus 40 is controlled. Further, the reader 20 and the distance measuring sensor 30 are controlled, and synchronous control is performed so that the scanning cycle of the distance measuring sensor 30 coincides with the detection cycle of the reader 20.

  The person detection means 481 receives the distance measurement data obtained from the distance measurement sensor 30 and compares the reference distance measurement data stored in the storage unit 42 to extract a difference. The distance is the same as if it shows the same body, and a group of scanning angles (distance change group) in which the distance change from the reference distance measurement data is more than a predetermined value is extracted, and a new object appears at that position. recognize. The size of the appearing object is estimated from the angle range and the distance value of the distance change group, and the presence of a person is recognized when the size of the appearing object is about a person. Subsequently, the person detection unit 481 acquires position information where the person exists. Specifically, the position of the detected person is indicated by taking the central angle of the distance range indicating the person as the azimuth (person azimuth) of the person and the average distance corresponding to the angle range as the distance to the person. Generate human detection data. When a plurality of distance change groups are extracted from the distance measurement data, person determination and position detection are performed for each group.

  The tag detection means 482 receives the tag detection data obtained from the reader 20 and determines whether a pre-registered tag ID is included. When the registered wireless tag 10 is detected, the position information of the wireless tag 10 is detected by analyzing the arrival direction and reception intensity of the received wireless signal. Specifically, azimuth distribution indicating the reception intensity for each directivity angle is analyzed for the tag detection data of each tag ID, and the peak directivity angle with the highest reception intensity is detected as the direction (tag azimuth) where the wireless tag exists. To do. Since the directivity angle has a certain angle range, the central angle of the peak directivity angle is used for the tag orientation.

The movement determination unit 483 determines whether each person is in a specific movement state based on a change in the position of the person detected by the person detection unit 481. The movement determination unit 483 refers to the tracking data regarding the person being tracked stored in the storage unit 42 and reads the history of the positions of the persons included in the tracking data. Then, the movement speed of the person is calculated using the position of the newly detected person and the past position of the person, and when the movement speed is equal to or lower than a predetermined reference speed, the person is determined to be in a specific movement state. To do. Here, the specific movement state refers to a state where the person is moving at a low speed enough to be regarded as being stopped or stopped, and is hereinafter referred to as a stopped state. Further, the determination criterion for the stop state is preferably based on the moving speed when the person is moving to such an extent that the vibration sensor 14 of the wireless tag 10 cannot detect the movement.
The stop state determination index is not limited to the moving speed, and various determination indexes for determining that the movement of the person is small may be employed. For example, when the amount of change (distance) between the position before a predetermined time and the current position is small, the stop state is recognized. Alternatively, it may be recognized as a stopped state when the accumulated value of the amount of change in position from a predetermined time before to the present is within a reference.

  The association unit 484 determines the presence / absence of association between the person and the wireless tag 10 based on the detected position information of the person and the detected position information of the wireless tag 10. The associating means 484 compares the position of the person obtained from the person detection data with the orientation of the wireless tag 10 obtained from the tag detection data, and the person orientation included in the information indicating the position of the person and the tag orientation of the wireless tag 10. If the degree of coincidence satisfies the predetermined criterion, the person and the wireless tag 10 pair are associated with each other. Thereby, it is recognized that the detected person is carrying the wireless tag 10. If the degree of coincidence between the person orientation and the tag orientation does not satisfy a predetermined standard, it is not recognized that the person has the wireless tag 10 at that time. Note that the predetermined reference used for the association determination is not always constant, and may be variable depending on the position of the person.

  At the time of the association determination, the association unit 484 performs an association process different from the normal matching criterion so that the association between the already associated person and the wireless tag pair is not easily released. When the link target wireless tag 10 already associated with the person to be determined is not detected, the associating means 484 is connected to the wireless tag 10 if the movement determining means 483 determines that the person is in a stopped state. Maintain the association. If it is determined that the wireless tag 10 is not in a stopped state but is moving, there is no justification that the wireless tag 10 is not detected, and the person is likely not to have the wireless tag 10, so the association is released. On the other hand, when the link target wireless tag 10 is detected, the degree of coincidence between the person direction and the tag direction is determined as usual. If the degree of coincidence is high, the association is maintained, and if the degree of coincidence is low, the association is established. To release. Note that the coincidence criterion at this time may be a looser criterion than the first association. Also, the cancellation of the association is not performed once, but may be canceled when the association is not obtained a plurality of times.

  FIG. 2 is a schematic diagram for explaining an actual example of the association processing by the association unit 484. The example of FIG. 2 represents a situation when the person P having the wireless tag T moves from point a to point b and point c. When a person P carrying the wireless tag T appears at a point a in the monitoring area, the person orientation of the person P is compared with the tag orientation of the wireless tag T from the distance measurement data and tag detection data input at this time, An angle deviation amount θa is obtained. If the deviation amount θa is within a reference value (for example, 10 °), the person P is associated with the wireless tag T (link establishment). If the wireless tag is not detected at the point a, or if the shift amount θa between the person orientation and the tag orientation exceeds the threshold, the wireless tag is not associated with the person P.

  Even at the stage where the person P has moved to the point b, similarly to the point a, the angle deviation amount θb between the person direction of the person P and the tag direction of the wireless tag T is obtained and compared with a reference value to determine the presence or absence of association. Here, since the angle deviation amount θb is within the reference value, the association is maintained (link maintenance). Thereafter, when the person P stops at the point b and enters a stop state, the wireless tag T is not detected and the association determination based on the position cannot be performed. However, since the person P has already been associated with the wireless tag T at the point b and is in a stopped state at the point b, the association with the wireless tag T is maintained (link maintenance imitation).

  Then, when the person P starts to move again and moves to the point c, the angle deviation amount θc between the person orientation of the person P and the tag orientation of the wireless tag T is obtained and compared with a reference value to determine whether or not there is an association. Although the association with the wireless tag T is established at the point b, the association with the wireless tag T is not established at the point c at the stage of moving to the point c. For this reason, the association determination based on the position with the wireless tag T is required. If the wireless tag T is not detected, the association is released (link release).

  The abnormality determination unit 485 assigns a person ID to the person who first appears in the monitoring area, and accumulates and records the detected position change of the person in the storage unit 42 for each person ID as tracking data. The tracking data includes a person ID, a person detection position (angle, distance), a movement state of the person, the presence / absence of association, the tag ID and detection direction (angle) of the associated wireless tag, and time stamp information (detection time). It is linked data. The abnormality determination unit 485 determines whether or not the detected person is the same person as the person being tracked based on the degree of similarity with the previously detected person and the positional relationship (for example, the movement distance and elapsed time of the person). This is done by determining the appropriateness of the derived moving speed.

  The abnormality determination unit 485 analyzes the distance measurement data and tag detection data that are sequentially input and updates the tracking data, while based on the detection position and the tracking elapsed time from the first detection in the tracking data, A predetermined event occurrence is detected. Event detection conditions include, for example, the same person staying in the monitoring area (staying), moving from the monitoring area to the inside of the building (entrance), leaving the monitoring area (exit), etc. It is. The stay event is detected when the same person is detected in the monitoring area for a predetermined time or longer. The entrance event is detected when the person being tracked is not detected and the detection position immediately before the disappearance of the person is near the boundary with the building. The exit event is detected when the person being tracked is no longer detected and the detection position immediately before the disappearance of the person is near the boundary with the outside of the site.

  In the present embodiment, occurrence of a stay event and an entrance event among the above events is recognized as a specific action that requires suspicious person determination. When detecting the specific behavior of the person, the abnormality determination unit 485 determines whether the event occurrence is caused by the behavior of the suspicious person or the authorized user, and performs abnormality determination. Specifically, the association state of the wireless tag 10 is confirmed by referring to the tracking data regarding the person updated at the time of occurrence of the event or immediately before. If the wireless tag 10 is associated, that is, if the tag ID is recorded with respect to the person ID, it is recognized and permitted as an action by an authorized user. If the wireless tag 10 is not associated, it is recognized as an action by a suspicious person, an abnormality is determined, and an alarm process such as an abnormality report to the security center 60 by the report unit 44, an abnormality report or threat by the report unit 46 is performed. In addition, when an entrance event or an exit event occurs, the monitoring processing unit 48 ends the tracking of the person, and erases the tracking data related to the person after a certain time (for example, 10 seconds). When the entrance event is an intrusion abnormality by a suspicious person, the tracking data is retained even after the tracking is completed until a separate abnormality reset signal is input.

Next, the operation of associating a person with a wireless tag will be described in detail.
3 and 4 are flowcharts showing the association processing in the monitoring processing unit. The monitoring processing unit 48 executes association processing every time distance measurement data is input from the distance sensor 30.

The monitoring processing unit 48 analyzes the distance measurement data, performs a person detection process, and determines whether a person has been detected (S400). When a plurality of persons are detected, the subsequent processing is performed for each person. If no person is detected, the association process is terminated. At this time, if the person being tracked is not detected for a certain period of time, the tracking of the person is terminated.
If a person is detected, the presence position is detected for each person (S402), and it is determined by referring to the tracking data whether the person is being tracked (S404). If the person to be processed is not the person being tracked, a new person ID is assigned to the person to be processed (S406), and the process proceeds to the next process S410. In the case of the person being tracked, it is determined whether or not the link has already been established with any of the wireless tags (S408). If the link has not been established, the process proceeds to S410.

  In process S410, the monitoring processor 48 determines whether or not a registered wireless tag is detected based on the input of the tag detection data. If a wireless tag has been detected, it is determined whether there is a wireless tag that has not been established with another person being tracked among the detected wireless tags (S412). If there are wireless tags that have not been established, the tag orientations for those wireless tags are detected (S414). Subsequently, the azimuth deviation amount is calculated by comparing the person azimuth of the person to be processed and the tag azimuth (S416), and it is determined whether the azimuth deviation amount with the wireless tag having the smallest azimuth deviation amount is within the reference value Th. (S418). If the misorientation amount is within the reference value Th, a link is established by associating the person ID of the person to be processed with the tag ID of the wireless tag (S420), and tracking data relating to the person ID is created and recorded. (S422). Then, it is determined whether or not there is an unprocessed person among the detected persons (S424). If there is an unprocessed person, the process returns to process S402. If all the persons have been processed, the input distance measurement data is processed. The association process ends. If there is a person being tracked that has not been detected for a certain period of time, the tracking of the person is terminated.

  On the other hand, when the wireless tag is not detected (No in S410), when all the detected wireless tags have already been linked with another person (Yes in S412), the orientation of the person to be processed and the wireless tag When the deviation amount exceeds the reference value Th (No in S418), tracking data relating to the person ID is created and recorded without being associated with the wireless tag (S422).

Returning to the process S408, if the person to be processed is being tracked and a link has been established with a specific wireless tag (Yes in S408), a link maintenance determination process is performed (S426).
FIG. 4 is a flowchart showing the operation of the link maintenance determination process. The monitoring processor 48 determines whether a wireless tag has been detected based on the input of tag detection data (S500). When the wireless tag is detected, the tag ID of the link target wireless tag associated with reference to the tracking data regarding the person to be processed is extracted, and the link target wireless tag is extracted from the detected wireless tag. It is determined whether there is a tag (S502).

  If a link-target wireless tag is detected, the tag orientation related to the wireless tag is detected (S504), and the orientation deviation amount is calculated by comparing the person orientation with the tag orientation (S506). Then, the azimuth deviation amount is compared with the reference value Th (S508), and if it is within the reference value Th, the association state is maintained and the link maintenance determination process is ended (S510). If the amount of heading deviation exceeds the reference value Th, the person to be processed recognizes that he / she does not have a wireless tag, cancels the association (releases the link), and ends the link maintenance determination process (S516). . After ending the link maintenance determination, the process proceeds to step S422 in FIG. 4 to update the tracking data related to the person ID. Note that if the state in which the association with the link target wireless tag is interrupted has not passed for a certain period of time (for example, 1 sec), the state where the link target wireless tag cannot be detected temporarily or the error in the detection direction becomes large. The association state may be maintained because there is a possibility of a state of being in contact.

  When the link target wireless tag is not detected (No in S500 or No in S502), the movement state of the person to be processed is determined (S512). If the person is in a specific moving state, that is, in a stopped state, the person to be processed is assumed to possess the link target wireless tag and maintains the association (link maintenance), and the link maintenance determination The process ends (S514). If the person is not in the stop state, the person recognizes that the person does not have the wireless tag, cancels the association (releases the link), and ends the link maintenance determination process (S516).

  As described above, according to the suspicious person monitoring system of the present embodiment, the person is associated with the wireless tag based on the coincidence between the direction in which the person detected in the monitoring area exists and the direction in which the wireless tag exists. Therefore, it can be determined with high accuracy that the detected person truly possesses the wireless tag. Therefore, even when a plurality of persons and a plurality of wireless tags are detected, it is possible to accurately grasp whether each person has a wireless tag and which wireless tag each person has. A person who does not have a tag can be reliably identified.

  In addition, even if a wireless tag once associated with a person is no longer detected, the wireless tag is possessed in order to maintain the association with the wireless tag on condition that the person is not moving at that position. Even if the authorized user stops and the wireless tag cannot be detected, the association can be prevented from being inadvertently released and erroneously recognized as a suspicious person.

As mentioned above, although the moving object monitoring system concerning this invention has been demonstrated using the above-mentioned embodiment and modification, the application range of this invention is not limited to this.
For example, in the association processing in the above embodiment, the person and the wireless tag are associated with each other if the person orientation matches the tag orientation. However, in the first association determination, the detected orientation of the person and the wireless tag is The person and the wireless tag may be associated with each other on the condition that the person moves more than a certain amount while maintaining the matching state. By confirming that the movement of the wireless tag is following the movement accompanied by the change in direction of the person and performing the first association, for example, the wireless tag held by the person outside the monitoring area is the person in the monitoring area. Can be prevented from being erroneously associated with each other. As a result, it becomes possible to realize an advanced suspicious person monitoring system that suppresses detection omissions of suspicious persons.

  Further, in the movement determination process in the above-described embodiment, it is configured to determine whether or not the vehicle is in the stopped state based on the moving speed. However, it may be configured to determine whether to resume the movement from the stopped state based on the distance from the stop position. Specifically, if the movement speed falls below the reference value and the person's stop state is detected (stop start point), the person's position is referred to, and if the distance between the position and the current person position is less than the reference value It is recognized that the stop state is continued, and when it exceeds the reference value, it is recognized that the stop state has ended (movement resumed). Alternatively, referring to the position information of the person's link target wireless tag at the time when the person's stop is started, the resumption of movement is determined based on the difference (distance or angle difference) between the position information and the current person's position information. Also good. Alternatively, the timing at which the link target wireless tag is no longer detected can be set as the stop start time, and the resumption of movement can be determined based on the difference from the position information of the person or the wireless tag at this time.

  In the abnormality determination process in the above embodiment, the suspicious person determination is performed based on the presence or absence of the association when the specific action is detected. However, the accuracy is set in the association, and is set in advance according to the type of the specific action. The suspicious person may be determined depending on whether or not the association accuracy is satisfied. Specifically, a relatively low association accuracy is allowed for a staying event, while an admission event has a high association accuracy. The accuracy of association is set to high accuracy in the normal association state in which association is performed based on position matching, and the accuracy is low in a state in which association with a non-detected wireless tag is attempted while the person is stopped. Set to The accuracy of the association may be determined by using other indicators together such as the continuity of the association state, the degree of matching of the positions, and the direction detection accuracy of the wireless tag.

  Furthermore, in the above embodiment, the central angle of the angle range that forms the distance change group is used as the person orientation, but the angle range itself that forms the distance change group may be the person orientation. In this case, the association is determined based on whether the detected tag direction of the wireless tag is included in the angle range of the person or whether the amount of deviation from the angle range of the person is within the reference value.

In the above embodiment, the center of the directivity angle of the reader when the wireless tag is detected is used as the tag orientation, but the directivity angle range itself may be used as the tag orientation. In this case, the association is determined based on whether the angle indicating the human azimuth is included in the directivity angle at which the wireless tag is detected or whether the amount of deviation from the angular range of the directivity angle is within the reference value.
Furthermore, the angle range itself that forms the distance change group may be the person orientation, and the angle range of the directivity angle itself may be the tag orientation. In this case, the association is determined based on whether the person orientation and the tag orientation overlap by a certain amount or more, or whether the shift amount is within a reference value.

  In the association processing in the above embodiment, the matching of the orientations of the person and the wireless tag is determined. However, the matching may be determined using the matching of the positions of the person and the wireless tag. In this case, since it is necessary to specify the location of the wireless tag, for example, the distance to the wireless tag is calculated using the reception strength of the response signal and the time difference from the transmission of the question signal to the reception of the response signal. The position of the wireless tag is calculated from the azimuth and distance. Alternatively, it is possible to use a plurality of readers whose detection ranges overlap each other, analyze response signals from wireless tags with the same tag ID, and specify the position of the wireless tag using triangulation technology. Even when the association processing is performed based on the position matching, it is obvious that at least the orientation matching is included in the matching determination condition.

In the above embodiment, the distance measuring sensor using laser light is used as means for detecting the position and orientation of a person. However, for example, a sensor using ultrasonic waves, microwaves, or the like may be used. In addition, it is possible to employ a configuration in which an image sensor that detects a person by image analysis is used to convert the position of the person on the image into a position in the real space and determine the position matching. In this case, the position of the person may be detected by specifying the azimuth by the horizontal coordinate on the image, and estimating the distance by inverse perspective transformation of the vertical coordinate.
Further, instead of a configuration in which a change in the position of a person is tracked and an event for determining a suspicious person is extracted, an event may be extracted based on a change in the direction of the person and a suspicious person may be determined. In this case, the sensor for detecting the person may be configured to detect only the direction of the person.

10 wireless tag, 20 reader, 30 ranging sensor, 40 monitoring device, 42 storage unit, 44 reporting unit, 46 reporting unit, 48 monitoring processing unit, 50 communication line, 60 security center

Claims (6)

A moving object monitoring system that monitors whether or not a moving object has a portable device by associating the moving object with the portable device by a monitoring device,
The portable device is
A communication means for emitting a radio signal including unique identification information;
A motion detection means for detecting the motion of the aircraft;
Communication control means for suppressing transmission of the wireless signal when there is no movement,
The monitoring device
Object detection means for detecting position information of the moving object in the monitoring area;
Portable device detection means for receiving a radio signal emitted by the portable device and detecting position information of the portable device;
Correspondence determination means for associating the moving object with the portable device when the position information of the moving object and the position information of the portable device satisfy a predetermined matching criterion;
The correspondence determination unit maintains the association with the portable device on condition that the movable object is in a specific movement state when a portable device associated with the moving object is not detected.
Moving object monitoring system characterized by that.   The moving object monitoring system according to claim 1, wherein the correspondence determining unit determines that the specific moving state is present when a change in position information of the moving object is small.   The moving object monitoring system according to claim 2, wherein the correspondence determination unit determines that the specific moving state is established when a moving speed of the moving object is equal to or lower than a predetermined value.   The correspondence determination unit is configured to determine a difference between the position information of the moving object and the position information of the moving object when the moving object is shifted to the specific moving state or when the associated portable device is not detected. The moving object monitoring system according to claim 2, wherein the moving object monitoring system determines that the specific moving state is within a predetermined range. Furthermore, it has authority determination means for obtaining the accuracy of association between the moving object and the portable device, and performing authority determination of the moving object based on the accuracy,
5. The moving object monitoring system according to claim 1, wherein the authority determination unit reduces the accuracy of the moving object when the association is maintained with the mobile device in which the moving object is not detected. A moving object monitoring system that monitors whether or not a moving object has a portable device by associating the moving object with the portable device,
Object detection means for detecting position information of the moving object in the monitoring area;
Portable device detection means for receiving a radio signal emitted by the portable device and detecting position information of the portable device;
Correspondence determination means for associating the moving object with the portable device when the position information of the moving object and the position information of the portable device satisfy a predetermined matching criterion;
The correspondence determination unit maintains the association with the portable device on condition that the movable object is in a specific movement state when a portable device associated with the moving object is not detected.
Moving object monitoring system characterized by that.

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