JP2014089772A - Monitoring sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitoring sensor which can detect an obstructing action by which a direction of the monitoring sensor is changed.SOLUTION: A monitoring sensor 2 comprises: a detection part 21 for creating distance measurement data which correlates multiple scanning directions over a whole monitoring area and distances to an object corresponding to the respective scanning directions; a storing part 23 for storing past distance measurement data as reference data; a direction variation detection part 243 which compares the present distance measurement data with the reference data while displacing them in an angle direction of the scanning direction and detects angle displacement amount with which the present distance measurement data and the reference data are coincided with each other the best as a displacement angle of the monitoring sensor 2; and a direction variation abnormality detection part 244 for detecting whether abnormality of direction variation with which at least one part of the monitoring area cannot be monitored is generated or not according to the displacement angle.

Description

  The present invention relates to a monitoring sensor that detects an object that has entered a monitoring area by irradiating a search signal into the monitoring area and receiving a reflection signal thereof.

Conventionally, in order to detect an object that has entered a wide monitoring area such as outdoors, a search signal such as infrared ray, visible light, or ultrasonic wave is irradiated into the monitoring area and reflected from the object in the monitoring area. A monitoring sensor has been developed that detects an object in a monitoring area by receiving a signal.
An example of such a monitoring sensor is to set a monitoring area according to a scan angle for two-dimensionally scanning light from an optical distance meter, and when detecting an intruder in the monitoring area, distance data and angle data to the intruder are obtained. The position of the intruder is calculated from the distance data and the angle data (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-244102

The monitoring sensor must prevent the monitoring function from being invalidated in order to ensure security. In particular, when such a monitoring sensor is used in a security system that detects a suspicious object such as a suspicious person or a suspicious vehicle that has entered the monitoring area and reports an abnormality, the monitoring function is invalidated. Since the security system fails to detect suspicious objects, it is very important to prevent such a situation.
For example, if a suspicious person performs an obstructing action such as physically rotating the monitoring sensor and changing the direction, the exploration signal is not irradiated to at least a part of the monitoring area. It becomes a blind spot on security.
Further, even if the monitoring sensor has not detected a suspicious object that has entered the monitoring area, the event itself that an obstructing action has been performed on the monitoring sensor is an abnormal situation to be detected. However, since the conventional monitoring sensor disclosed in Patent Document 1 does not have a means for detecting the above-described disturbing action, the use of the monitoring sensor requires the detection of such disturbing action. It was limited to those requiring a limited monitoring function.

  Therefore, an object of the present invention is to provide a monitoring sensor capable of detecting an obstructing action that changes the direction of the monitoring sensor.

  As one aspect of the present invention, a monitoring sensor for monitoring a monitoring area is provided. The monitoring sensor scans a scanning range including one end to the other end of the monitoring region with a search signal, and receives a search signal reflected by an object existing in the scan range, so that a plurality of scan directions and A detection unit that generates distance measurement data in which distances to objects corresponding to each of a plurality of scanning directions are associated, a storage unit that stores past distance measurement data as reference data, a current distance measurement data, and a reference A direction change amount detection unit that compares the data with shifting along the angular direction of the scanning direction, and detects the amount of angular deviation where the current distance measurement data and the reference data most closely match as the displacement angle of the monitoring sensor; A direction change abnormality determining unit that determines whether or not a direction change abnormality has occurred in which at least a part of the monitoring region cannot be monitored according to the displacement angle;

  The direction change abnormality determination unit obtains an area of a region where the current scanning range of the monitoring sensor and the monitoring region overlap as the monitorable area from the obtained displacement angle, and the monitorable area is equal to or less than a first predetermined threshold. If it is determined that an orientation change abnormality has occurred, or the area of the area that does not overlap the scanning range included in the monitoring area is determined as an unmonitorable area, and the unmonitorable area is equal to or greater than a second predetermined threshold In some cases, it is preferable to determine that an orientation change abnormality has occurred.

  Further, the monitoring sensor determines whether or not an environmental change has been detected in which the number of scanning directions in which the distance value has changed between the current distance measurement data and the previously stored background data is equal to or greater than a third predetermined threshold. And a direction change amount detection unit that stores distance measurement data acquired a predetermined time before the current time in the storage unit as reference data when an environmental change is detected, and a displacement It is preferable to determine the angle.

  Note that the direction change amount detection unit obtains the difference between the current distance measurement data and the reference data by obtaining the difference between the distance values to be compared while shifting the distance value relative to the angle direction by a predetermined angle. It is preferable to calculate the degree of difference between the distance data and the reference data and detect the amount of angular deviation that minimizes the difference as the displacement angle of the monitoring sensor.

  The monitoring sensor according to the present invention has the effect of being able to detect an obstruction that changes the orientation of the monitoring sensor.

1 is an overall configuration diagram of a security system including a monitoring sensor according to one embodiment of the present invention. It is a schematic block diagram of the monitoring sensor which concerns on one Embodiment of this invention. It is a flowchart which shows the operation | movement of an intrusion determination process. It is a flowchart which shows the operation | movement of an environmental change determination process. It is a flowchart which shows the operation | movement of direction change amount detection processing. It is a figure which shows an example of the relationship between a scanning range and a monitoring area | region when a change arises in the direction of the monitoring sensor. It is a flowchart which shows the operation | movement of a direction change abnormality determination process. It is a figure showing the relationship between the scanning range before and behind the change of direction of a monitoring sensor, and its displacement angle when the monitoring sensor rotates counterclockwise by a predetermined displacement angle. It is a flowchart which shows operation | movement of an object detection process. It is a schematic block diagram of a security device.

  Hereinafter, a monitoring sensor according to an embodiment of the present invention will be described with reference to the drawings. The monitoring sensor scans a scanning range including one end to the other end of the monitoring area at a predetermined cycle with the search signal, and receives the reflected signal that is the search signal reflected by the object, thereby receiving the reflected signal from the monitoring sensor. Ranging data obtained by measuring the distance to the object for each scanning azimuth representing the viewed azimuth is created for each scan. This monitoring sensor compares the distance measurement data created in the current scan with the distance measurement data created in the past scan while shifting the angle, and the angle deviation amount that the distance measurement data most closely matches. Is obtained as the displacement angle of the monitoring sensor. This monitoring sensor detects an obstructive action that changes the direction of the monitoring sensor by examining the area of the monitoring area after the direction of the monitoring sensor changes in the monitoring area according to the obtained displacement angle. To do.

  FIG. 1 is a diagram illustrating an overall system configuration of a security system including a monitoring sensor according to one embodiment. As shown in FIG. 1, the security system 1 monitors the outdoor areas of the building 101 on three surfaces around the building 101 so as to monitor the monitoring areas 102 a to 102 c set in a part of the site of the building 101, respectively. It has three monitoring sensors 2 fixedly installed on a wall surface or a pole, and a security device 3 connected to each monitoring sensor 2 through a communication line 4 and installed in a building 101.

When each monitoring sensor 2 detects a suspicious object such as a suspicious person or a suspicious vehicle that has entered the monitoring areas 102a to 102c, it transmits an intrusion abnormality signal indicating that fact to the security device 3. Each monitoring sensor 2 changes the direction of the monitoring sensor 2 to a direction different from that at the time of setting and, as a result, detects that at least a part of the monitoring area becomes unmonitorable, the direction indicating that fact A change abnormality signal is transmitted to the security device 3. Further, each monitoring sensor 2 may transmit the identification number of the monitoring sensor 2 to the security device 3 together with the intrusion abnormality signal or the direction change abnormality signal.
The security device 3 can communicate with the monitoring center device 6 arranged in the monitoring center via the public communication line 5. When the security device 3 receives the intrusion abnormality signal or the direction change abnormality signal from any of the monitoring sensors 2, the identification number of the security device 3 or the security device 3 is installed. Along with the building identification number, it is transmitted to the monitoring center device 6.

  The number of monitoring sensors 2 included in the security system 1 is not limited to three. The number of the monitoring sensors 2 is appropriately determined according to the shape and size of the region to be monitored and a shield existing beforehand in the region. The installation position of the monitoring sensor 2 is also set as appropriate according to the shape of the region to be monitored or the position and shape of the building.

  The monitoring sensor 2 detects a suspicious object that has entered the monitoring area. Further, the monitoring sensor 2 indicates that the monitoring sensor 2 is directed in a direction different from the direction at the time of installation, for example, due to a collision between the monitoring sensor 2 and a suspicious person or an object flying in a strong wind. Detect.

  FIG. 2 is a schematic configuration diagram of the monitoring sensor 2. The monitoring sensor 2 includes a detection unit 21, a communication unit 22, a storage unit 23, and a control unit 24. Each of these parts is accommodated in a housing 25 formed of metal or resin. A monitoring window 26 made of a light-transmitting member such as glass or transparent plastic is provided on the front surface of the casing 25, that is, the surface facing the monitoring region. In the present embodiment, the monitoring window 26 is formed in an arc shape with the detection unit 21 as the center, and the distance between each point on the surface of the monitoring window 26 on the horizontal plane passing through the detection unit 21 and the detection unit 21 is It is almost the same. However, in other embodiments, the monitoring window 26 may be formed in a planar shape.

  The detector 21 irradiates the search signal into the monitoring area and receives the reflected signal. And the detection part 21 produces the ranging data containing the measured value of the distance to the object which reflected the search signal from the monitoring sensor 2 for every scanning direction by analyzing a reflected signal. For this purpose, the detection unit 21 includes, for example, a laser oscillation unit 211, a scanning mirror 212, a drive unit 213, a light receiving unit 214, and a distance measurement data generation unit 215.

The laser oscillation unit 211 oscillates, for example, a near-infrared pulse laser having a wavelength of about 890 nm as a search signal. The pulse laser is output toward the scanning mirror 212. Further, the laser oscillation unit 211 outputs the phase information of the pulse laser to the distance measurement data generation unit 215.
The scanning mirror 212 is, for example, a galvano mirror or a polygon mirror, and is driven by the driving unit 213 to change the direction of the reflecting surface thereof, thereby scanning the entire monitoring region with a pulse laser at regular intervals (for example, 30 msec). .

In the present embodiment, the laser oscillation unit 211 and the scanning mirror 212 are arranged so as to horizontally scan a fan-shaped monitoring region having a predetermined center angle centered on the monitoring sensor 2 with a pulse laser. The predetermined center angle is set to 180 °, for example. The pulse laser reflected by the scanning mirror 212 is irradiated toward the outside of the monitoring sensor 2 through the monitoring window 26 provided on the front surface of the housing 25 of the monitoring sensor 2.
The laser oscillating unit 211 and the scanning mirror 212 may be arranged so that the pulse laser that is an exploration signal has a predetermined depression angle with respect to the horizontal plane, and the pulse laser approaches the ground as it moves away from the monitoring sensor 2. .
Further, the monitoring area may be scanned by repeatedly scanning the pulse laser in the same direction from one end of the monitoring area to the other end, or the pulse laser is scanned every scan. The direction may be reversed.

  Furthermore, the scanning range that can be scanned by the laser oscillator 211 and the scanning mirror 212 may be wider than the monitoring region. For example, when the monitoring area is a fan-shaped area having a central angle of 180 ° centered on the monitoring sensor 2, the scanning range is a fan-shaped area having a central angle of 190 ° centering on the monitoring sensor 2. May be. The scanning range is determined by, for example, the structure of the scanning mirror 212 and the arrangement of the laser oscillation unit 211 and the scanning mirror 212.

The drive unit 213 includes, for example, a motor, a mechanism for transmitting the rotational driving force generated by the motor to the rotation shaft of the scanning mirror 212, and a circuit for controlling the motor. It is driven to rotate at a corresponding equal rotation speed.
In addition, the drive unit 213 notifies the distance measurement data generation unit 215 of angle information indicating the direction in which the pulse laser is currently being irradiated.

  The light receiving unit 214 includes a light receiving element such as a CCD, a CMOS, or a photodiode, for example, and is disposed in the vicinity of the laser oscillation unit 211. The light receiving unit 214 receives a reflected signal that arrives along the scanning direction irradiated with the search signal via the monitoring window 26 and the scanning mirror 212. Then, the light receiving unit 214 outputs a light reception signal having a value corresponding to the intensity of the reflected signal to the distance measurement data generation unit 215.

  The distance measurement data generation unit 215 measures the distance from the monitoring sensor 2 to the object that reflects the reflected signal for each scanning direction, and generates distance measurement data representing the relationship between the scanning direction and the distance. For this purpose, the distance measurement data generation unit 215 includes a processor and its peripheral circuits. The distance measurement data generation unit 215 obtains a difference between the phase of the reflected signal obtained from the light reception signal and the phase of the pulse laser output from the laser oscillation unit 211, for example, according to the Time Of Flight method, and based on the difference. Measure distance. When the light receiving unit 214 does not receive the reflected return light within a predetermined time in a certain scanning direction, the distance measurement data generation unit 215 determines that there is no object within the reachable range of the pulse laser in the scanning direction. Judgment is made, and the distance for the scanning direction is set as a preset pseudo value indicating that. This pseudo value is set to an appropriate value, for example, a distance from the monitoring sensor 2 to the outer edge of the monitoring region or an effective measurement distance by the pulse laser beam.

  The distance measurement data generation unit 215 generates one distance measurement data for each scan. One distance measurement data includes, for example, the number of scanning angles obtained by adding 1 to the number obtained by dividing the angular range corresponding to the entire scanning range by a predetermined angular interval, and the distance at the scanning angle. In this embodiment, an angle range corresponding to the entire scanning range is 180 °, and an interval between adjacent scanning angles is 0.25 °, and one distance measurement data includes 721 pairs of scanning angles and distances. . The scanning angle represents an angle formed by a predetermined reference azimuth and a scanning azimuth with the installation position of the monitoring sensor 2 as an origin. The reference azimuth is set in the front direction when facing the monitoring area from the monitoring sensor 2, and the monitoring area is set so that the angle range is 90 ° equally to the left and right with respect to the reference azimuth. Is a value in the range of -90 ° to 90 °. Here, a negative value indicates a left scanning angle with respect to the front direction (reference direction), and a positive value indicates a right scanning angle with respect to the front direction (reference direction).

The detection unit 21 may be configured to scan the search signal two-dimensionally in the horizontal and vertical directions and obtain three-dimensional data including the scanning direction and the measurement distance. As for the distance measuring method, various known methods may be employed. For example, a phase difference method, a triangulation method, or the like can be used.
The detection unit 21 outputs the distance measurement data generated for the scan to the control unit 24 every time one scan is completed.

  The communication unit 22 connects the monitoring sensor 2 via the communication line 4 so as to be communicable with the security device 3. For this purpose, the communication unit 22 has an interface circuit corresponding to the communication line 4 that connects the monitoring sensor 2 and the security device 3. Then, the communication unit 22 transmits the intrusion abnormality signal or the direction change abnormality signal generated by the control unit 24 to the security device 3. In that case, the communication part 22 may transmit the identification number of the sensor 2 for monitoring to the security apparatus 3 with those signals.

  The storage unit 23 includes, for example, a nonvolatile semiconductor memory and stores various information and programs used by the monitoring sensor 2. The information stored in the storage unit 23 includes, for example, monitoring area information, background data, reference data, and current state information. Furthermore, the memory | storage part 23 may memorize | store the ranging data produced | generated within the past fixed period.

The monitoring area information is information indicating the range of the monitoring area to be monitored by each monitoring sensor 2. The monitoring area is a place set as an area that needs to be monitored in the site monitored by the security system 1, and each monitoring sensor 2 is installed at a position where each monitoring area can be monitored. Each monitoring sensor 2 stores monitoring area information as relative position information representing the range of the monitoring area monitored by itself. The monitoring area information includes, for example, an angular range in which the search signal is scanned around the monitoring sensor 2 and an outer edge of the monitoring area from the monitoring sensor 2 for each scanning angle separated by a predetermined angular interval (for example, 0.25 °). The distance to is included. Alternatively, the monitoring area information is an expression representing the position of each sampling point separated by a predetermined distance on the outer edge of the monitoring area, or the coordinates of the outer edge of the monitoring area, in two-dimensional coordinates with the installation position of the monitoring sensor 2 as the origin. A coefficient may be included.
The monitoring area information is, for example, a setting terminal (not shown) or an operation part (not shown) connected via the communication unit 22 when the monitoring sensor 2 is installed, when the monitoring area is defined or changed, for example. )).

The background data is distance measurement data that is used to detect a suspicious object that has entered the monitoring area and is generated when no other object exists in the monitoring area in advance. The background data is also used to detect an environmental change state in which the direction of the monitoring sensor 2 may have changed from the direction of the monitoring sensor 2 at the time of installation.
The background data may be distance measurement data generated when the monitoring sensor 2 is activated or at a timing instructed via the operation unit or the setting terminal. Further, the control unit 24 selects the distance value having the highest appearance frequency within the past fixed period for each scanning angle based on the distance measurement data generated by the detection unit 21 as needed, and rewrites the selected distance value. Thus, the background data may be updated. The background data may be used as the monitoring area information.
The reference data is generated when the orientation of the monitoring sensor 2 is not changed from the time of installation, which is used to detect a displacement angle that is an angle difference between the current orientation of the monitoring sensor 2 and the orientation at the time of installation. Distance measurement data. The reference data can be, for example, distance measurement data acquired a predetermined time before the distance measurement data when the environment change detection unit 242 described later determines that there is an environment change.

  The current state information is information representing the current state of the monitoring area. At this time, if the monitoring area is in an intrusion abnormal state where an intrusion abnormality is detected, or if it is in a direction change abnormal state where it is detected that at least a part of the monitoring area is unmonitorable, the current state information is It has a value that represents each abnormal state. On the other hand, if the monitoring area is in a normal state where no abnormality is detected at the present time, the current state information has a value indicating the normal state. For example, the current state information value is set to '1' for an intrusion abnormal state, the current state information value is set to '2' for a direction change abnormal state, and the current state information value for a normal state. The value of the status information is set to “0”. If the intrusion abnormal state and the direction change abnormal state are detected in duplicate, the value of the current state information is set to '4'. Note that the current state information is set when the control unit 24 detects any abnormality, when it detects that any abnormal state detected before it has been resolved, or when a security guard sets the terminal. Alternatively, it is rewritten by the control unit 24 when an operation indicating that the abnormal state has been resolved is performed via the operation unit.

  Furthermore, the storage unit 23 stores a plurality of flags, such as a change flag and a direction change determination flag, which are used to detect an orientation change abnormality. Details of these flags will be described together with related functions of the control unit 24.

  The control unit 24 has at least one processor, a timer, and its peripheral circuits. The control unit 24 controls each unit of the monitoring sensor 2. In addition, the control unit 24 detects a suspicious object that has entered the monitoring area based on the distance measurement data, or whether the monitoring sensor 2 is directed in a different direction from that at the time of setting, resulting in an unmonitorable area exceeding a certain area. Determine whether or not. For this purpose, the control unit 24 includes an intrusion determination unit 241, an environment change detection unit 242, a direction change amount detection unit 243, and a direction change abnormality determination unit 244. Each of these units is mounted on the monitoring sensor 2 as a function module realized by software executed on a processor included in the control unit 24, for example.

Whenever the latest distance measurement data is received, the intrusion determination unit 241 compares the latest distance measurement data with the background data, and extracts the difference in the distance to the object, so that it is within the monitoring area. Detect suspicious objects that have entered.
FIG. 3 is an operation flowchart of the intrusion determination process executed by the intrusion determination unit 241. The intrusion determination unit 241 executes the following intrusion determination process every time it receives the latest distance measurement data, that is, every time one scan of the monitoring area by the detection unit 21 is completed.
The intrusion determination unit 241 calculates the difference between the distance value included in the distance measurement data and the distance value included in the background data for each scanning angle (step S101). Then, the intrusion determination unit 241 sets the scanning angle at which the distance value indicated in the latest distance measurement data is closer to the monitoring sensor 2 by the predetermined distance or more than the distance value indicated in the background data and is within the monitoring area. Extracted as candidate points (step S102). The predetermined distance is set to, for example, the minimum value of the thickness of the object to be detected, for example, 15 cm.

ただし、d₁は、グループの一方の端の侵入物体候補点における距離値であり、d₂は、他方の端の侵入物体候補点における距離値である。またθは、測距データに含まれる、隣接する走査角度間の間隔である。そしてnは、そのグループに含まれる侵入物体候補点の数である。 The intrusion determination unit 241 determines whether or not an intruding object candidate point exists (step S103). If there is no intruding object candidate point, the intrusion determining unit 241 determines that there is no intruding object in the monitoring area. Then, the intrusion determination unit 241 notifies the control unit 24 that there is no intrusion abnormality, and ends the intrusion object determination process.
On the other hand, if there is an intruding object candidate point, the intrusion determination unit 241 combines the adjacent intruding object candidate points into one group if the difference in distance value between adjacent intruding object candidate points is within a predetermined value. A labeling process is performed (step S104). The predetermined value is set to 10 cm, for example.
Then, the intrusion determination unit 241 obtains a width for each group (step S105). For example, the group width W _g is calculated by the following equation according to the cosine theorem.

Here, d ₁ is a distance value at an intruding object candidate point at one end of the group, and d ₂ is a distance value at an intruding object candidate point at the other end. Θ is an interval between adjacent scanning angles included in the distance measurement data. N is the number of intruding object candidate points included in the group.

The intrusion determination unit 241 selects a group whose group width W _g is equal to or greater than a predetermined width from the groups created by the labeling process as an intruding object candidate group that may be a suspicious object (step S106). This predetermined width is also set to the minimum value of the thickness of the object to be detected, for example, 15 cm.
The intrusion determination unit 241 uses the scanning angle corresponding to the intruder object candidate point at the center of the intruder object candidate group and the distance value at the intruder object candidate point as the position of the intruder object candidate group with the monitoring sensor 2 as the origin, The storage unit 23 stores the position of the intruding object candidate group and the corresponding distance measurement data acquisition time.

  The intrusion determination unit 241 determines a target intrusion object candidate group from groups that have not yet been set as the target intrusion object candidate group among the intrusion object candidate groups obtained from the latest distance measurement data (step S107). . Then, the intrusion determination unit 241 performs a tracking process between the intruding object candidate group of interest and the past candidate group that is the intruding object candidate group obtained for the ranging data one to several times before, and pays attention to it. It is determined whether there is a past candidate group corresponding to the same object as the object corresponding to the intruding object candidate group (step S108). Note that any of various known tracking processes can be employed as the tracking process. For example, the intrusion determination unit 241 obtains the position of the past candidate group that is closest to the position of the target intruding object candidate group, and the difference between the positions indicates the estimated moving speed of the suspicious object to be detected and the two If it is less than the movable distance determined as the product of the difference between the acquisition times of candidate groups, it is determined that the intruding object candidate group of interest and the past candidate group correspond to the same object.

When there is a past candidate group corresponding to the same object as the object corresponding to the target intruding object candidate group, the intrusion determination unit 241 selects the object assigned to the past candidate group with respect to the target intruding object candidate group. The same object identification number as the identification number is assigned, and the object identification number is associated with the position of the target intruding object candidate group and stored in the storage unit 23 (step S109). Then, the intrusion determination unit 241 determines the distance between the position of the target intruding object candidate group to which the same object identification number is assigned and the position of the oldest intruding object candidate group from the object corresponding to the target intruding object candidate group. The travel distance is calculated (step S110).
The intrusion determination unit 241 determines whether the movement distance is equal to or greater than a predetermined value (step S111). If the movement distance is equal to or greater than the predetermined value, the intrusion determination unit 241 determines that the intruding object candidate group of interest is due to a suspicious object that has intruded into the monitoring area and an intrusion abnormality has occurred (step S112). Then, the intrusion determination unit 241 generates an intrusion abnormality signal and notifies the control unit 24 of the intrusion abnormality signal. Then, the intrusion determination unit 241 ends the intrusion determination process.

On the other hand, if there is no past candidate group corresponding to the same object as the object corresponding to the intruding object candidate group of interest in step S108, the intrusion determination unit 241 A new object identification number different from the object identification number assigned to the candidate group is associated and stored in the storage unit 23 (step S113).
After step S113 or when the moving distance is less than the predetermined value in step S111, the intrusion determination unit 241 determines whether or not there is an unfocused intruding object candidate group (step S114). If there is an unfocused intruding object candidate group (step S114—Yes), the intrusion determining unit 241 repeats the processing after step S107.
On the other hand, when all the intruding object candidate groups have already been set as the intruding object candidate group of interest (step S114—No), the intrusion determining unit 241 determines that no intrusion abnormality has occurred. Then, the intrusion determination unit 241 notifies the control unit 24 that there is no intrusion abnormality, and ends the intrusion determination process.

The environment change detection unit 242, the direction change amount detection unit 243, and the direction change abnormality determination unit 244 determine whether or not the direction of the monitoring sensor 2 is directed in a direction different from the direction at the time of setting, and as a result, at least in the monitoring region. It is determined whether or not a direction change abnormality that partially becomes unmonitorable has occurred.
Therefore, the environment change detection unit 242 may compare the latest distance measurement data with the background data, and the direction of the monitoring sensor 2 may be changed when the distance measurement data is significantly different from the background data. It is determined that an environmental change has occurred.

FIG. 4 is a flowchart showing the operation of the environment change detection process executed by the environment change detection unit 242. It should be noted that the environment change detection unit 242 does not detect that the orientation of the monitoring sensor 2 has changed, but each time the latest distance measurement data is received, that is, the detection unit 21 scans the monitoring region once. The environment change detection process is executed every time.
The environment change detection unit 242 sets a focused scan angle from among scan angles that have not yet been focused on, with respect to the latest distance measurement data and the background data read from the storage unit 23 (step S201). Then, the environment change detection unit 242 calculates the absolute value of the difference between the distance value included in the latest distance measurement data and the distance value included in the background data for the focused scanning angle (step S202).

The environment change detection unit 242 determines whether or not the absolute value of the difference is greater than or equal to a predetermined threshold (step S203). The predetermined threshold can be set to, for example, a value that is 20% of the distance value of the scanning angle of interest included in the background data. If the absolute value of the difference is equal to or greater than a predetermined threshold, the environment change detection unit 242 sets a value of the change flag corresponding to the scanning angle of interest as a value indicating that a difference is recognized in the distance value (in this embodiment, For convenience, it is expressed as “ON”) (step S204).
If the absolute value of the difference between the distance values is less than the predetermined threshold value after step S204 or in step S203, all the scanning angles for which distance values are obtained in the background data and the distance measurement data are already focused on. Is determined (step S205). If any one of the scanning angles is not set to the scanning angle of interest, the environment change detection unit 242 repeats the processing from step S201.

On the other hand, when all the scanning angles are already set to the focused scanning angle, the environment change detection unit 242 obtains the number of change flags set to “ON” (step S206). Then, the environment change detection unit 242 determines whether the ratio of the number of change flags set to “ON” with respect to the total number of change flags, that is, the total number of scanning angles for which distance values are obtained in the background data is equal to or greater than a predetermined ratio. Determination is made (step S207). The predetermined ratio is set to 20%, for example.
When the ratio of the number of change flags set to 'ON' with respect to the total number of change flags is equal to or greater than a predetermined ratio, that is, the distance value with respect to the total number of scanning angles for which distance values have been obtained in the distance measurement data has changed. If the ratio of the number of detected scanning angles is greater than or equal to a predetermined ratio, the environment change detection unit 242 determines that an environment change has occurred (step S208). Then, the environment change detection unit 242 writes an environment change flag indicating that an environment change has occurred in the storage unit 23.
After step S208 or when the ratio of the number of change flags set to “ON” with respect to the total number of change flags in step S207 is less than a predetermined ratio (step S207—No), the boundary change detection unit 242 determines that the environment has changed. The detection process ends.

  The direction change amount detection unit 243 scans the search signal when it is determined that the environment has changed, or when it has already been detected that the direction of the monitoring sensor 2 has changed at the time of obtaining the latest distance measurement data. A displacement angle representing an angle amount in which the current orientation of the monitoring sensor 2 and the orientation of the monitoring sensor 2 at the time of installation are shifted is obtained on a plane substantially parallel to the search surface. This displacement angle is used by a direction change abnormality determination unit 244 described later to determine whether there is a direction change abnormality of the monitoring sensor 2.

FIG. 5 is a flowchart showing the operation of the direction change amount detection process executed by the direction change amount detection unit 243. Note that the direction change amount detection unit 243 detects that the orientation of the monitoring sensor 2 has already changed when it is determined that there is an environmental change with respect to the latest distance measurement data or when the latest distance measurement data is acquired. If it is, the direction change detection process is executed based on the latest distance measurement data and reference data.
The direction change amount detection unit 243 indicates that the value of the direction change determination flag indicating whether or not the direction of the monitoring sensor 2 has changed so as to hinder the monitoring of the monitoring area, and the direction of the monitoring sensor 2 has an obstacle to monitoring. It is determined whether or not it is a value (hereinafter, referred to as “ON” for the sake of convenience) indicating that it has been detected that there has been a change since the installation (step S301). If the direction change determination flag is “ON”, the direction change amount detection unit 243 reads the reference data from the storage unit 23 (step S302).
On the other hand, if the direction change determination flag is not “ON”, the direction change amount detection unit 243 sets distance measurement data acquired a predetermined time before the latest distance measurement data as reference data, and the reference data Is stored in the storage unit 23 (step S303). The predetermined time is set to about 10 seconds, for example. This predetermined time is appropriately set in consideration of the time required for performing the obstructing action for changing the direction of the monitoring sensor 2.

After step S302 or S303, the direction change amount detection unit 243 sets the angle deviation amount for setting a set of scanning angles for obtaining a difference in distance value between the latest distance measurement data and the reference data to 0 °. Setting is made (step S304). When the amount of angular deviation is set to 0 °, a difference in distance value is obtained by combining the same scanning angles in the latest distance measurement data and reference data. If the amount of angular deviation is positive, the scanning angle of interest in the reference data and the scanning angle of the latest distance measurement data that is larger than the noted scanning angle by the amount of angular deviation (for example, clockwise rotation with respect to the reference orientation). If the scanning angle is set so that the direction is positive, the difference in distance value can be obtained from the scanning angle shifted by the amount of angular deviation in the clockwise direction.
The direction change amount detection unit 243 obtains the absolute value of the difference between the distance values of the scanning angle shifted by the above-described angular deviation amount between the latest distance measurement data and the reference data for each set of scanning angles of both data. Then, the average of the absolute values of the differences is calculated as the difference between the two data (step S305). Then, the direction change amount detection unit 243 writes the angle deviation amount and the degree of difference in the storage unit 23 in association with each other. In the present embodiment, with respect to a set of scanning angles for obtaining the absolute value of the difference between the distance values, the scanning angle of the reference data is used as a reference, and the scanning angle of the latest distance measurement data is shifted by the above-described angular deviation amount. However, conversely, the scan angle of the latest distance measurement data may be used as a reference, and the scan angle of the reference data may be shifted by the above-described angular deviation amount. Further, the degree of difference may be an index indicating the degree of difference in distance value between the latest distance measurement data and the reference data. For example, instead of the average value of the absolute values of the above distance value differences, the distance value The mean square of the differences may be used as the degree of difference.

  Thereafter, the direction change amount detection unit 243 increases the angle deviation amount by a predetermined offset angle (step S306). Then, the direction change amount detection unit 243 determines whether or not the absolute value of the angle deviation amount is larger than a predetermined threshold value Thr (step S307). The threshold value Thr is a value that is slightly smaller than an angle corresponding to a difference in scanning direction from one end to the other end of the entire scanning range, for example, a fan shape in which the scanning range has a central angle of 180 ° with the monitoring sensor 2 as the center. If so, it is set to 170 °. The offset angle is set to, for example, an interval between adjacent scanning angles included in the distance measurement data, for example, about 0.25 °, or about 2 to 4 times an interval between adjacent scanning angles.

When the absolute value of the angle deviation amount is equal to or smaller than the threshold value Thr, the direction change amount detection unit 243 repeats the processes after step S305.
On the other hand, when the absolute value of the angle deviation amount is larger than the threshold value Thr, the direction change amount detection unit 243 sets the angle deviation amount to a negative value obtained by subtracting the offset angle from 0 ° (step S308).
The direction change amount detection unit 243 obtains the absolute value of the difference between the distance values of the scanning angle shifted by the above-described angular deviation amount between the latest distance measurement data and the reference data for each set of scanning angles of both data. Then, the average value of the absolute values of the differences is calculated as the dissimilarity (step S309). Then, the direction change amount detection unit 243 writes the angle deviation amount and the degree of difference in the storage unit 23 in association with each other.

Thereafter, the direction change amount detection unit 243 reduces the angle deviation amount by the offset angle (step S310). That is, the amount of angular deviation increases in the negative direction. Then, the direction change amount detection unit 243 determines whether or not the absolute value of the angle deviation amount is larger than the threshold value Thr (step S311).
If the absolute value of the angle deviation amount is equal to or smaller than the threshold value Thr, the direction change amount detection unit 243 repeats the processes after step S309.
On the other hand, when the absolute value of the angle deviation amount is larger than the threshold value Thr, the direction change amount detection unit 243 sets the angle deviation amount corresponding to the minimum value of the differences stored in the storage unit 23 as the displacement angle ( Step S312).
The orientation change amount detection unit 243 writes the displacement angle in the storage unit 23 together with the latest distance measurement data acquisition time, and notifies the orientation change abnormality determination unit 244 that the calculation of the displacement angle has been completed.

  The direction change abnormality determination unit 244 determines whether a direction change abnormality has occurred in the monitoring sensor 2 based on the displacement angle obtained by the direction change amount detection unit 243.

  FIG. 6 is a diagram illustrating an example of the relationship between the scanning range and the monitoring region when a change occurs in the direction of the monitoring sensor. In FIG. 6, a region 600 surrounded by a one-dot chain line represents a monitoring region. In this example, the monitoring area 600 is an area having a central angle of 180 ° with the monitoring sensor 2 as the center. Here, it is assumed that the monitoring sensor 2 is rotated counterclockwise by an angle θ. In this case, a range above the line 601 is a scanning range in which the monitoring sensor 2 can irradiate the search signal. At this time, the area 610 where the monitoring area 600 and the scanning range do not overlap is not monitored, and thus the object cannot be detected despite being within the monitoring area 600. On the other hand, an area 620 where the monitoring area 600 and the scanning area overlap is an area that can be monitored because an exploration signal is emitted even after the orientation of the monitoring sensor 2 changes, and an object existing in the area can be detected. .

As shown in FIG. 6, generally, as the rotation angle of the monitoring sensor 2 increases, the monitorable area decreases and the unmonitorable area increases. Further, the larger the distance from the monitoring sensor 2 to the end of the monitoring region in the unmonitorable region 610, the larger the area of the unmonitorable region.
Furthermore, the center angle of the scanning range centering on the monitoring sensor 2 may be larger than the center angle of the monitoring area. In this case, if the displacement angle is equal to or less than the difference between the center angle of the scanning range and the center angle of the monitoring area, there is a possibility that the unmonitorable area does not exist.
Therefore, the orientation change abnormality determination unit 244 calculates the area of the monitorable region based on the displacement angle, and determines whether or not the orientation change abnormality has occurred based on the ratio of the area of the monitorable region to the area of the entire monitoring region. Thereby, the direction change abnormality determination unit 244 can detect, as a direction change abnormality, that a situation that hinders intrusion monitoring into the monitoring area has occurred due to the change in the direction of the monitoring sensor 2.

FIG. 7 is a flowchart showing the operation of the direction change abnormality determination process executed by the direction change abnormality determination unit 244. The direction change abnormality determination unit 244 changes the direction when it is determined that there is an environmental change with respect to the latest distance measurement data, or when the direction change has already been detected when the latest distance measurement data is acquired. An abnormality determination process is executed.
The orientation change abnormality determination unit 244 corrects the scanning angle included in the monitoring area information and the background data (step S401). This correction will be described in detail with reference to FIG.

  FIG. 8 shows a case where there is a change in direction in which the monitoring sensor 2 is rotated counterclockwise, and a semicircular area 800 surrounded by a solid line represents a scanning range after the change in the direction of the monitoring sensor 2. A semicircular region 810 surrounded by a one-dot chain line represents a scanning range before the change of the direction of the monitoring sensor 2. A region 820 indicated by hatching indicates a monitoring region of the monitoring sensor 2. Here, for the sake of explanation, the case where the monitoring area is set only for a part of the scanning range is illustrated. The angle value described along the arc indicates the scanning angle of the monitoring sensor 2, and the angle value in parentheses indicates the scanning angle of the monitoring sensor 2 before the orientation change (that is, at the time of installation). Yes, the angle value that is not written in parentheses represents the scanning angle of the monitoring sensor 2 after the direction change.

First, since the monitoring area information stored in the storage unit 23 is information specified by the scanning angle of the monitoring sensor 2, the monitoring area that the monitoring sensor 2 recognizes when the orientation of the monitoring sensor 2 changes is also this. It moves with changes. Specifically, -10 ° to + 10 ° is specified as the scanning angle specified in the monitoring area information, and if the monitoring area information is not corrected, the direction of the monitoring sensor 2 changes. As shown in FIG. 8, the monitoring area recognized by the monitoring sensor 2 also moves counterclockwise. For this reason, how much the location of the monitoring area set before the change of the direction of the monitoring sensor 2 is included in the scan range after the change of direction, or whether it is outside the scan range , Cannot be determined as they are, and an abnormal direction change cannot be determined.
Therefore, after changing the orientation of the monitoring sensor 2, the monitoring region information is corrected based on the displacement angle so as to be information for designating the location of the monitoring region set before the orientation change, thereby correcting the orientation change abnormality. Make judgment possible.

Here, the reference data is distance measurement data before the direction change of the monitoring sensor 2, and the latest distance measurement data can be said to be distance measurement data after the direction change of the monitoring sensor 2. The direction change amount detection unit 243 described above increases (decreases) the angle shift amount by a predetermined offset angle to the scanning angle of the latest distance measurement data, calculates the difference from the reference data, and calculates the latest distance measurement data. The displacement angle is the angle deviation amount with the smallest difference between the reference data and the reference data. Therefore, when this displacement angle takes a positive value, as shown in FIG. 8, if the displacement angle is indicated by using the position of the scanning angle + 90 °, the position of the scanning angle + 90 ° of the latest distance measurement data Is the information indicating the clockwise direction and the amount of angle from the reference data scanning angle to the position of + 90 ° (in the figure, the displacement angle is + 40 °). Therefore, the orientation change abnormality determination unit 244 adds the displacement angle to each scanning angle of the monitoring area information, so that the location of the monitoring area before the orientation change can be determined even after the monitoring sensor 2 changes the orientation. The monitoring area information is corrected so that can be correctly recognized.
Specifically, in the example of FIG. 8, the monitoring area information is specified by a scanning angle of −10 ° to + 10 °, and the displacement angle detected by the direction change amount detection unit 243 is + 40 °. The corrected scanning angle at the left end is + 30 ° obtained by adding the displacement angle + 40 ° to the scanning angle −10 °. The corrected scanning angle at the right end is + 50 ° obtained by adding the displacement angle + 40 ° to the scanning angle + 10 °.
When the scanning angle obtained by adding the displacement angle exceeds the scanning range of the monitoring sensor 2, the orientation change abnormality determination unit 244 determines the value of the exceeding scanning range as the scanning angle of the monitoring area information. To do. Specifically, when the scanning range is -90 ° to + 90 °, the scanning angle of the monitoring area information after correction calculated by the above method has a value of 0 ° to + 120 °. In this case, + 90 ° which is the value at the right end of the scanning range is set as 0 ° to + 90 ° as the scanning angle at the right end of the monitoring area information after correction.
The background data is also corrected by adding a displacement angle to each scanning angle of the background data based on the same concept as described above.
By correcting the monitoring area information and the background data in this way, the control unit 24 can be used for intrusion abnormality determination without re-acquiring the monitoring area information and the background data.

ここでpは、隣接する走査角度間の間隔（角度単位、例えば、0.25°）である。Mは、補正後の監視領域情報に含まれ、かつ、監視領域の角度範囲及び監視用センサ２の走査範囲に相当する角度範囲に含まれる、距離値が求められた走査角度の総数である。例えば、監視領域及び走査範囲の角度範囲が±90°であり、変位角度が+30°であれば、補正後の監視領域情報及び走査範囲に含まれる走査角度の範囲は-60°から+90°の範囲となる。従って、Mは、((90-(-60))/p+1)となる。d_iは、補正後の監視領域情報に含まれるi番目の走査角度についての距離値である。また、監視領域全体の面積Sは、（２）式における各走査角度の距離値d_iの代わりに、補正前の監視領域情報に含まれる各走査角度の距離値を代入することで求められる。 Next, the orientation changes abnormality determination unit 244, based on the monitoring area information and displacement angle of the monitoring sensors 2, determining the area S of the area S _p and monitoring area of the monitoring area (step S402). The area S _p of the monitoring area, for example, is calculated by the following equation.

Here, p is an interval between adjacent scanning angles (angle unit, for example, 0.25 °). M is the total number of scanning angles that are included in the corrected monitoring area information and that are included in the angle range corresponding to the angular range of the monitoring area and the scanning range of the monitoring sensor 2 and for which the distance value is obtained. For example, if the angle range of the monitoring region and the scanning range is ± 90 ° and the displacement angle is + 30 °, the range of the scanning angle included in the corrected monitoring region information and the scanning range is from −60 ° to + 90 ° The range is °. Therefore, M is ((90 − (− 60)) / p + 1). d _i is a distance value for the i-th scanning angle included in the monitored area information after correction. The area S of the entire monitoring area is calculated by substituting the distance value of each scanning angle included in place of, the pre-correction monitoring area information of the distance values d _i of each scan angle in equation (2).

Orientation change abnormality determination unit 244, the area S _p of the monitoring region is a predetermined threshold, in this embodiment, it is not more than the value obtained by multiplying a predetermined ratio to the area S of the whole monitoring area (step S403). The predetermined ratio is set to 1/2, for example. This predetermined ratio is appropriately set according to the required security or the environment where installation is assumed. When the area _Sp of the monitorable area is equal to or less than a predetermined ratio of the area S of the entire monitor area, it is determined that the monitoring is hindered. Then, the orientation change abnormality determination unit 244 determines whether or not the time duration from the first determination that the monitoring is hindered is being measured (step S404). If the duration is not being measured, the orientation change abnormality determination unit 244 activates the timer and starts measuring the duration after it is determined that the monitoring will be hindered (step S405). Further, the direction change abnormality determination unit 244 sets the value of the direction change determination flag stored in the storage unit 23 to a value indicating that the direction of the monitoring sensor 2 has changed so as to hinder monitoring (hereinafter, For convenience).

After step S405, or when the duration has already been measured in step S404 (step S404-Yes), the direction change abnormality determination unit 244 determines whether the duration has reached a predetermined time (step S404). S406). If the continuation time reaches the predetermined time, that is, the direction of the monitoring sensor 2 continues to change from the time of installation for the predetermined time, and the area _Sp of the monitorable area is the monitoring area. When the ratio is equal to or less than the predetermined ratio of the entire area S, the direction change abnormality determination unit 244 determines that a direction change abnormality has occurred (step S407). Then, the direction change abnormality determination unit 244 generates a direction change abnormality signal and passes it to the control unit 24.
After step S407 or when the duration time has not reached the predetermined time in step S406, the direction change abnormality determination unit 244 ends the direction change abnormality determination process.

In step S403, when the area _Sp of the monitorable area is larger than a predetermined ratio of the area S of the entire monitoring area, the orientation change abnormality determination unit 244 causes the monitoring change of the monitoring sensor 2 to hinder monitoring. It is determined that there is no extent. Then, the direction change abnormality determining unit 244 ends the time measurement and resets the timer (step S408). In addition, the direction change abnormality determination unit 244 rewrites the value of the direction change determination flag to a value indicating that there is no change in the direction of the monitoring sensor 2 (hereinafter referred to as “OFF” for convenience). Further, the orientation change abnormality determination unit 244 deletes the environment change flag from the storage unit 23. Then, the orientation change abnormality determination unit 244 notifies the control unit 24 that no orientation change abnormality has been detected. As a result, the orientation change abnormality determination unit 244 detects, for example, a change in distance measurement data caused by a momentary movement of planting in the monitoring area due to a strong wind or a fluctuation of the monitoring sensor 2 itself. It is possible to prevent erroneous recognition that the direction of 2 has changed.
Thereafter, the direction change abnormality determination unit 244 ends the direction change abnormality determination process.

FIG. 9 is a flowchart showing the operation of the object detection process executed by the control unit 24. The control unit 24 executes an object detection process every time one scan of the monitoring area by the detection unit 21 is completed.
The control unit 24 receives distance measurement data from the detection unit 21 (step S501). Then, the control unit 24 stores the distance measurement data in the storage unit 23. In addition, the control unit 24 passes the distance measurement data to the intrusion determination unit 241 and the environment change detection unit 242.
The intrusion determination unit 241 executes intrusion determination processing (step S502). When the intrusion determination unit 241 detects a suspicious object that has entered the monitoring area, the intrusion determination unit 241 generates an intrusion abnormality signal and passes it to the control unit 24. The control unit 24 stores a flag indicating that the intrusion abnormality signal has been received in the storage unit 23. If the intrusion determination unit 241 determines that no intrusion abnormality has occurred, the intrusion determination unit 241 notifies the control unit 24 that there is no intrusion abnormality. And the control part 24 memorize | stores the time which received the notification in the memory | storage part 23 as a normal return time regarding an intrusion abnormality. The details of the intrusion determination process are as described above with reference to FIG.

  The control unit 24 determines whether or not the value of the direction change determination flag is “ON” (step S503). When the value of the direction change determination flag is “OFF” (step S503—NO), it is not detected that the direction of the monitoring sensor 2 has changed from the time of installation so as to hinder monitoring. Therefore, the environment change detection unit 242 executes environment change detection processing (step S504). The details of the environment change detection process are as described above with reference to FIG. Thereafter, the control unit 24 determines whether an environmental change is detected by the environmental change detection process (step S505). When the environmental change is detected, the direction change amount detection unit 243 executes the direction change amount detection process to obtain the displacement angle of the monitoring sensor 2 (step S506). Further, in step 503, even when the value of the direction change determination flag is “ON”, it has already been detected that the direction of the monitoring sensor 2 has changed from the time of installation so as to hinder monitoring. Therefore, the process of step S506 is performed. The details of the direction change amount detection process are as described above with reference to FIG.

  The direction change abnormality determination unit 244 executes a direction change abnormality determination process based on the displacement angle (step S507). When the direction change abnormality determination unit 244 determines that the direction of the monitoring sensor 2 has changed so as to hinder the monitoring of the monitoring area, the direction change determination flag is set to “ON”. If the change in the direction of 2 does not interfere with monitoring, the direction change determination flag is set to “OFF”. Further, when the direction change abnormality determination unit 244 determines that a direction change abnormality has occurred, the direction change abnormality determination unit 244 generates a direction change abnormality signal and passes it to the control unit 24. The control unit 24 stores a flag indicating that the direction change abnormality signal has been received in the storage unit 23. When the direction change abnormality determination unit 244 determines that no direction change abnormality is detected, the direction change abnormality determination unit 244 notifies the control unit 24 accordingly. And the control part 24 memorize | stores the time which received the notification in the memory | storage part 23 as a normal return time regarding direction change abnormality. The details of the direction change abnormality determination processing are as described above with reference to FIG.

After step S507 or when it is determined in step S505 that there is no environmental change, the control unit 24 outputs an abnormal signal that has not been output among abnormal signals such as an intrusion abnormal signal and a direction change abnormal signal received from each unit. It is determined whether or not there is (step S508). For example, the control unit 24 refers to the previous transmission time and normal return time of the abnormal signal stored in the storage unit 23 for each received abnormal signal. Then, the control unit 24 sets an abnormal signal in which the normal return time is not recorded after the previous transmission time (after the initial time in the initial state) as an unoutput abnormal signal.
When there is a non-output abnormality signal, the control unit 24 outputs the non-output abnormality signal to the security device 3 via the communication unit 22 (step S509). And the control part 24 memorize | stores the output time in the memory | storage part 23 as last transmission time corresponding to the output abnormal signal.
After step S509 or when there is no unoutput abnormal signal in step S508, the control unit 24 ends the object detection process.
Note that the execution order of the processes of steps S502 and S503 to S507 is not limited to the above, and the processes of S503 to S507 may be executed prior to step S502.

  Furthermore, the control unit 24 transmits a sensor status signal including sensor status information indicating whether the monitoring sensor 2 is operating normally or is malfunctioning to the security device 3 via the communication unit 22 periodically or irregularly. May be.

  FIG. 10 is a schematic configuration diagram of the security device 3. The security device 3 includes an operation unit 31, a sensor interface unit 32, a storage unit 33, a control unit 34, and a center communication unit 35.

  The operation unit 31 has, for example, a plurality of operation buttons. When the user presses one of the operation buttons, the operation unit 31 causes the control unit 34 to input a predetermined operation signal assigned to the operation button or various input information such as a user identification number and a password. Output to. And the user can change the security mode showing the security state of a monitoring object building by operating the operation part 31. FIG. Details of the security mode will be described later.

The sensor interface unit 32 connects the security device 3 and the monitoring sensor 2 so that they can communicate with each other. For this purpose, the sensor interface unit 32 includes, for example, an interface circuit corresponding to the communication line 4 that connects the security device 3 and the monitoring sensor 2. The sensor interface unit 32 receives various abnormal signals and the identification code of the monitoring sensor 2 from the monitoring sensor 2 via the communication line 4 and passes them to the control unit 34.
In addition, the security device 3 is connected to the monitored building or other sensors via the sensor interface unit 32, such as an open / close sensor installed at the entrance of the building, a human sensor installed in the building, and the like. It may be connected. In this case, the sensor interface unit 32 may receive an abnormal signal from another sensor and pass it to the control unit 34.
Further, the sensor interface unit 32 periodically or irregularly receives a sensor status signal including sensor status information indicating whether the sensor is operating normally or in failure from the monitoring sensor 2 or another sensor. The sensor state information may be stored in the storage unit 33.

The storage unit 33 includes, for example, a non-volatile semiconductor memory and stores various information and programs used in the security device 3.
For example, the storage unit 33 displays the security mode information indicating the currently set security mode, the identification number of the security device 3 or the identification number of the monitoring target building where the security device 3 is installed, the identification number of the user, and the password. Remember. Further, the storage unit 33 stores an abnormality detection log in which various abnormal signals received from any of the monitoring sensors 2 and the reception time of the abnormal signals are associated with the identification number of the monitoring sensor 2 that has generated the abnormal signal. May be. Further, the storage unit 33 may store current state information indicating the current state of each monitoring sensor 2 connected to the security device 3. This current state information represents, for example, whether the monitoring sensor 2 is in a state where an intrusion abnormality or a direction change abnormality is detected, or a normal state in which no abnormality is detected. Further, the storage unit 33 may store sensor state information.

  The control unit 34 has at least one processor and its peripheral circuits. The control unit 34 controls each unit of the security device 3. The control unit 34 includes an abnormality processing unit 341 and a mode setting unit 342 that sets a security mode according to an operation signal from the operation unit 31.

The abnormality processing unit 341 performs abnormality processing according to the currently set security mode.
In the present embodiment, the security mode includes a security set mode and a security release mode.
The security set mode is set when, for example, a monitoring area including a building where the security system 1 is installed and a monitoring area set around the building is unmanned, such as at night or on holidays.
When the abnormality processing unit 341 indicates that the security mode information stored in the storage unit 33 is the security set mode, when any abnormality signal is received from any of the monitoring sensors 2 or other sensors, An abnormality notification signal including the received abnormality signal and the security device 3 or the identification code of the building where the security device 3 is installed is generated. Then, the abnormality processing unit 341 transmits an abnormality notification signal to the monitoring center device 6 via the center communication unit 35. In addition, the abnormality processing unit 341 writes information regarding the received abnormality signal in the abnormality detection log stored in the storage unit 33. The abnormality processing unit 341 corrects the current state information stored in the storage unit 33 in accordance with the received abnormality signal. Alternatively, when the abnormality processing unit 341 receives an operation signal indicating that the abnormality of any of the monitoring sensors 2 has been eliminated via the operation unit 31, the abnormality processing unit 341 displays the current state information corresponding to the monitoring sensor 2 as follows: You may correct | amend so that it may be in a normal state.

  On the other hand, the security release mode is set when there is a user having a legitimate authority in the monitoring area, for example, during the daytime on weekdays. When the abnormality processing unit 341 receives a certain abnormality signal from any of the monitoring sensors 2 or other sensors when the security mode information stored in the storage unit 33 indicates the security release mode, Information related to the received abnormality signal is written in the abnormality detection log stored in the unit 33. However, the abnormality processing unit 341 does not transmit an abnormality notification signal to the monitoring center device 6. The abnormality processing unit 341 does not correct the current state information stored in the storage unit 33. However, even when the current security mode is the security release mode, the abnormality processing unit 341 receives an abnormality notification signal including the direction change abnormality signal when receiving the direction change abnormality signal from any of the monitoring sensors 2. The abnormality notification signal may be generated and transmitted to the monitoring center device 6. Thereby, even when the monitoring sensor 2 becomes unmonitorable due to an obstruction that changes the direction of the monitoring sensor 2 during the security release mode setting, the security device 3 notifies the monitoring center device 6 of that fact. Since it can report, it becomes possible to make a security guard etc. confirm the cause of the direction change abnormality which occurred in the monitoring sensor 2 during the warning release mode setting.

  The mode setting unit 342 sets the security mode according to the operation signal from the operation unit 31. Specifically, the mode setting unit 342 determines that when the user identification number and password received from the operation unit 31 match the user identification number and password stored in the storage unit 33, Allow change of security mode. When the mode setting unit 342 receives an operation signal for setting the security mode to the security set mode from the operation unit 31 while the change of the security mode is permitted, the mode setting unit 342 sets the security mode information stored in the storage unit 33 to the security set. Rewrite the value to indicate the mode. On the other hand, when the mode setting unit 342 receives an operation signal for setting the security mode to the security release mode from the operation unit 31 with the change of the security mode permitted, the mode setting unit 342 guards the security mode information stored in the storage unit 33. Rewrite the value to indicate the release mode.

  When the storage unit 33 stores sensor state information, the mode setting unit 342 refers to the sensor state information, and sets the security mode to the security set mode only when each sensor is operating normally. It may be set. Further, the mode setting unit 342 may prohibit the change from the security release mode to the security set mode when an orientation change abnormality has occurred for any of the monitoring sensors 2. When the sensor status information indicates that any one of the sensors is out of order, or when a direction change abnormality has occurred, the mode setting unit 342 transmits the security set mode through a monitor or a speaker (not shown). And the monitoring sensor 2 in which a malfunctioning sensor or direction change abnormality has occurred may be notified.

  The center communication unit 35 has an interface circuit for connecting the security device 3 to the public communication line 5. And the center communication part 35 performs the connection process between the security apparatus 3 and the monitoring center apparatus 6 according to control of the control part 34, for example, when reporting abnormality to the monitoring center apparatus 6. FIG. Then, after the connection is established between the security device 3 and the monitoring center device 6, the center communication unit 35 transmits the abnormality notification signal received from the control unit 34 to the monitoring center device 6 through the public communication line 5. When the transmission of the abnormality notification signal is finished, the center communication unit 35 performs processing for releasing the connection between the security device 3 and the monitoring center device 6.

  As described above, the monitoring sensor according to one embodiment of the present invention compares the distance measurement data created in the current scan with the distance measurement data created in the past scan while shifting the angle. Then, the amount of angular deviation where the two distance measurement data most closely matches is obtained as the displacement angle of the monitoring sensor. The monitoring sensor detects a state in which the area of the monitorable area is a predetermined ratio or less with respect to the entire area of the monitoring area according to the obtained displacement angle, and determines whether or not an orientation change abnormality has occurred. Use for judgment. Therefore, this monitoring sensor can detect that the direction of the monitoring sensor has been changed so as to hinder the monitoring of the monitoring area as a disturbing action. In addition, this monitoring sensor determines that the direction of the monitoring sensor has changed in such a way that it interferes with monitoring for a certain period of time. It is possible to accurately discriminate between the movement or shaking of the monitoring sensor and the change of the direction of the monitoring sensor, and to detect a disturbing action in which the direction of the monitoring sensor is changed.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments.
For example, the direction change abnormality determination unit may check the ratio of the unmonitorable area occupied in the entire monitoring area instead of checking the ratio of the monitorable area in the entire monitoring area. The area of the unmonitorable area is obtained as a value obtained by subtracting the area of the monitorable area from the area of the entire monitor area. In this case, the direction change abnormality determining unit determines that the area of the unmonitorable area is equal to or greater than a predetermined threshold, for example, a value obtained by multiplying the total area of the monitor area by a second predetermined ratio (for example, 50%). If it continues for a predetermined period, it will determine with direction change abnormality having arisen.
Alternatively, the orientation change abnormality determining unit may determine the orientation when the displacement angle is equal to or greater than a predetermined value, or when the ratio of the area of the unmonitorable area to the total area of the monitoring area is greater than the third predetermined ratio. It may be determined that a change abnormality has occurred. In this case, the third predetermined ratio is set to a value larger than the above-mentioned second predetermined ratio, for example, 80%, so as not to erroneously detect fluctuations such as planting in the monitoring area due to strong winds or the like as a direction change abnormality. It is preferably set. The predetermined value of the displacement angle is set to a value larger than the displacement angle caused by momentary planting due to strong wind or the like, or the vibration of the monitoring sensor itself, for example, 120 °.
Further, the control unit may not have the environment change detection unit. In this case, every time the distance measurement data is acquired, the direction change amount detection process and the direction change abnormality determination process are performed. Further, the reference data can be, for example, distance measurement data obtained when there is no suspicious object in the monitoring area.
Further, the reference data may be distance measurement data acquired when the monitoring sensor 2 is facing a normal direction. For example, background data or distance measurement data set by a setting terminal may be used. Good.
The detection unit may irradiate an exploration signal other than near-infrared rays, for example, a visible ray, an ultrasonic wave, or a millimeter wave as the exploration signal.
As described above, those skilled in the art can make various modifications in accordance with the embodiment to be implemented within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Security system 2 Monitoring sensor 3 Security apparatus 4 Communication line 5 Public communication line 6 Monitoring center apparatus 21 Detection part 22 Communication part 23 Storage part 24 Control part 25 Housing 26 Monitoring window 211 Laser oscillation part 212 Scan mirror 213 Drive part 214 Light reception Unit 215 distance measurement data generation unit 241 intrusion determination unit 242 environment change detection unit 243 direction change detection unit 244 direction change abnormality determination unit 31 operation unit 32 sensor interface unit 33 storage unit 34 control unit 35 center communication unit 341 abnormality processing unit 342 Mode setting section

Claims (2)

A monitoring sensor for monitoring a monitoring area,
By scanning a scanning range including one end to the other end of the monitoring area with a search signal and receiving a search signal reflected by an object existing in the scan range, a plurality of scan directions and the plurality of scans are received. A detection unit that generates distance measurement data that associates the distance to the object corresponding to each of the orientations;
A storage unit for storing past distance measurement data as reference data;
The current distance measurement data and the reference data are compared while being shifted along the angular direction of the scanning azimuth, and the amount of angular deviation that most closely matches the current distance measurement data and the reference data is determined as the displacement of the monitoring sensor. A direction change amount detection unit that detects an angle;
A direction change abnormality determining unit that determines whether or not a direction change abnormality has occurred in which at least a part of the monitoring region is unmonitorable according to the displacement angle;
A monitoring sensor comprising: An environment change detection unit that determines whether or not an environment change has been detected in which the number of scanning directions in which the distance value has changed between the current distance measurement data and the previously stored background data is equal to or greater than a third predetermined threshold. Further comprising
The direction change amount detection unit stores distance measurement data acquired a predetermined time before the current time in the storage unit as the reference data when the environmental change is detected, and obtains the displacement angle. Item 2. The monitoring sensor according to item 1.

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