JP5027271B2 - Object detection sensor - Google Patents

Description

  The present invention relates to an object detection sensor that detects a distance to an object to be detected in a monitoring area by projecting and receiving light, and more particularly to an object detection sensor that detects a change that affects monitoring performance.

  Conventionally, in order to monitor a wide monitoring range, such as outdoors, a variety of survey signals such as laser light, visible light, ultrasonic waves, infrared rays, etc. are irradiated within the monitoring range and a reflected regression signal from the object is received. An object detection sensor for detecting an object in a monitoring range is known.

  For example, Patent Document 1 discloses a security system using a laser sensor that projects laser light while rotating and scanning a predetermined angle range and determines the presence of an intruder based on a distance value calculated when receiving reflected light. Has been.

Japanese Patent Laid-Open No. 10-244102

  The laser sensor of Patent Document 1 detects the presence of an intruder when there is a change in the distance data acquired by the laser sensor in an arbitrarily set two-dimensional monitoring area, and the amount of movement of the intruder is determined. Based on this, it is determined whether or not it is an intruder. As described above, the laser sensor of Patent Document 1 prevents misjudgment due to planting or installation by adding the movement amount to the determination condition when detecting an intruder. No consideration is given to the fact that the monitoring field of view of the sensor is blocked by the installation object.

  When monitoring such a setting range, in order to ensure security, the laser sensor must be able to irradiate laser light over the entire monitoring area. However, in the outdoor environment, there are many moving objects such as small animals compared to the indoor environment, and there are installations such as plant growth and buds, wind shaking and flying objects, and fences installed by users. It is difficult to keep this state constant.

In other words, when an object to be measured such as planting growth or buds or a new installation is detected in the monitoring area where the laser sensor measures distance, the other side of the object to be measured (sensor) The object in the back direction) cannot be detected, and a blind spot for security is born.
The laser sensor disclosed in Patent Document 1 cannot detect when the effective monitoring field of view is impaired due to such an environmental change in the monitoring area, and cannot maintain security. It was.

  Therefore, an object of the present invention is to propose an object detection sensor that can detect a change that affects monitoring performance even in an environment that changes sequentially, such as outdoors.

  In order to achieve the above object, an object detection sensor according to the present invention is an object detection sensor that monitors an inside of a warning area and detects an object in the warning area, and a storage unit that stores the warning area in advance, A detection unit that periodically scans the inside of the alert area and generates distance measurement data indicating the distance to the object to be measured in each direction in the alert area, and is measured with the current distance measurement data in the alert area And a disturbance determination unit that determines whether or not visual field disturbance has occurred based on the range.

  In such a configuration, the object detection sensor compares the current distance measurement data obtained by scanning in the warning area with the warning area stored in advance, and within the range measured by the current distance measurement data in the warning area. Acts to determine visual field disturbances based on

  According to such a configuration, even in an outdoor environment where the position and movement of an object can change day by day, the current warning area and the current range are set as warning ranges for security planning from the sensor characteristics and detection range. By detecting a relative deviation from the measurement result, it is possible to maintain and ensure security.

  Further, in the object detection sensor of the present invention, the disturbance determination unit compares the warning area with the current distance measurement data, and the range measured with the current distance measurement data in the warning area is the warning value. It may be determined that visual field disturbance has occurred if the ratio is equal to or less than a predetermined ratio with respect to the area.

  This makes it possible to determine the proportion of the range measured by the current measurement results in the warning area that is set in advance as a warning area for security planning, and to monitor the effectiveness of the monitoring field of view. Security can be improved by detecting the obstruction of the sensor and the presence of blind spots.

  In the object detection sensor of the present invention, the disturbance determination unit calculates an area of a range measured in the alert area from a distance to the object to be measured in each direction obtained from the current distance measurement data. If the area of the measured range is not more than a predetermined ratio with respect to the area of the alert area, it may be determined that the visual field disturbance has occurred.

  As a result, the area of the current detection range with respect to the area of the warning area set in advance as a warning area in the security planning is obtained, and the area of the monitoring field of view is determined using the area difference between the area of the warning area and the current detection range. The effectiveness can be monitored, and the security can be improved by detecting the obstruction to the object detection sensor and the presence of blind spots.

  Moreover, the object detection sensor of this invention WHEREIN: The said memory | storage part may memorize | store the said alert area as two-dimensional information which consists of the distance and direction from the said detection part.

  Thereby, the comparison with the distance measurement data acquired by scanning by the detection unit is facilitated, and the processing speed can be increased.

  According to the present invention, even in an outdoor environment where the position, movement, etc. of an object can be changed daily, a warning area that is preset as a range that should be warned in terms of security planning from the sensor characteristics, detection range, and the like. By detecting a relative deviation from the measurement result, it is possible to maintain and ensure security.

It is the schematic which shows the whole structure of the security system of this invention. It is a block diagram which shows the structure of the object detection sensor of this invention. It is a figure which shows the detection method of the measurable range by the object detection sensor of this invention. It is a flowchart which shows operation | movement of the object detection sensor of this invention. It is a flowchart which shows the visual field disturbance determination process by the object detection sensor of this invention. It is a flowchart which shows the intruder determination process by the object detection sensor of this invention.

Embodiments of the present invention will be specifically described below with reference to the drawings.
In the present embodiment, a security system that performs outdoor monitoring using an object detection sensor in a monitoring building is illustrated, but the scope of the present invention is not limited to this.

FIG. 1 is a configuration diagram showing a security system 1 using an object detection sensor 2 of the present invention.
FIG. 1 is a schematic plan view showing the relationship between an object detection sensor 2 installed on an outdoor wall surface of a monitoring building 3, a warning area 4 of the object detection sensor 2, and a security device 5 installed in the monitoring building 3. It is shown on the figure. In the example of FIG. 1, three object detection sensors 2 are installed around the monitoring building 3. The object detection sensors 2 are each connected to the security device 5 via a communication line, and the security device 5 is connected to a remote monitoring center 6 via a communication line network 7. Although not particularly illustrated, security sensors such as a heat ray sensor and an open / close sensor are also installed inside the monitoring building 3 and connected to the security device 5.

  The object detection sensor 2 is present in the area by performing spatial scanning at a predetermined cycle while irradiating a laser beam in a preset warning area 4 and receiving reflected light reflected by an object on the optical path. The position of an object as an object to be measured is detected. In this way, the object detection sensor 2 monitors an object appearing in the alert area 4 and outputs a detection signal indicating the type of abnormality that has occurred and its own address information to the security device 5 when it is determined that an abnormality has occurred.

  Here, the types of abnormalities detected by the object detection sensor 2 include visual field obstruction abnormality due to an obstructing object and invasion abnormality due to an intruding object into the alert area 4 such as a suspicious person. The visual field disturbance abnormality is impaired by the object (including a person) existing in the warning area 4 so that the field of view of the object detection sensor 2 to be originally secured, that is, the state where the laser light irradiation can be performed on the entire warning area 4 is performed. This is an abnormality that is determined when a blind spot of a certain level or more occurs in the alert area 4 due to the obstruction of the laser beam by the object. The intrusion abnormality is an abnormality that is determined when a moving object intrudes into the alert area 4 and the maintenance of the surveillance area including the surveillance building 3 can be impaired.

  The security device 5 monitors the inside and outside of the monitoring building 3 serving as a monitoring area. The operation mode of the security device 5 is set when the monitoring area including the monitoring building 3 becomes unattended, such as at night or on holidays, and when the various sensors detect a change in the event, the remote monitoring center 6 is connected via the communication unit. There is a security set mode in which an abnormality notification is performed and a security release mode that is set when the monitoring area is manned and does not perform an abnormality notification by detection of various sensors. When the security device 5 receives the detection signal from the object detection sensor 2 or the security sensor while being set to the security set mode, the security device 5 determines the abnormality of the monitoring area and outputs the abnormality signal to the monitoring center 6.

  The monitoring center 6 is a facility provided with a center device 61 operated by a security company or the like. The center device 61 is composed of one or a plurality of computers, and realizes the function of the monitoring center 6 related to the present invention. In the monitoring center 6, various devices are controlled by the center device 61, the abnormality signal received from the security device 5 is recorded, information on the abnormality is displayed on the display 62, and a plurality of monitoring areas to be monitored by the monitor are displayed. Monitoring.

<Object detection sensor>
Next, the configuration of the object detection sensor 2 will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of the object detection sensor 2.
The object detection sensor 2 is installed on the outdoor wall surface of the monitoring building 3 with a horizontal or constant depression angle, and operates by receiving power supply from the security device 5.

  The object detection sensor 2 is composed of a communication unit 21 connected to the security device 5 for communication, a detection unit 22 for irradiating and receiving laser light, and a storage unit configured to store various setting information, programs, and the like. 23 and a control unit 24 that is configured by an MPU, a microcomputer, and the like and controls each unit.

  When the communication unit 21 is connected to the security device 5 and the control unit 24 determines that the warning area 4 is abnormal, the communication unit 21 transmits information on the abnormality and a detection signal indicating its own address information to the security device 5.

  The detection unit 22 scans the alert area 4 with a laser beam and detects the position of an object as a measurement object that reflects the laser beam. The detection unit 22 includes, for example, a laser oscillation unit 221 that emits near-infrared light having a wavelength of about 890 nm, a scanning mirror 222 that reflects laser light and irradiates the object detection sensor 2, and scanning that drives the scanning mirror 222 to rotate at a constant speed. A control unit 223, a reflected light detection unit 224 that includes a light receiving element and is provided in the vicinity of the laser oscillation unit 221, and a distance measurement data generation unit 225 that generates distance measurement data as a laser light irradiation result are provided.

  The irradiation direction of the laser light emitted from the laser oscillation unit 221 is controlled by the scanning mirror 222 and the scanning control unit 223 to scan at least the entire warning area 4. This scanning can be performed on a horizontal plane according to the installation angle of the object detection sensor 2 or on a plane that approaches the ground as the distance increases with a depression angle. The scanning is performed at a predetermined cycle interval (for example, 30 msec). For example, the scanning may be repeatedly performed in the same direction, or the backward scanning may be performed after scanning in the forward direction.

  The distance measurement data generation unit 225 determines the distance between the object detection sensor 2 calculated from the time required from the irradiation of the laser light to the detection of the reflected light and the object (measurement point) reflecting the laser light, and the scanning control unit 223. The relative position of the object that reflects the laser beam, that is, the measurement point that reflects the laser beam, is calculated based on the angle of the scanning mirror 222 that is rotationally driven (the direction in the alert area 4). The relative position is the position of the measurement point with reference to the object detection sensor 2, and specifically, the position of the surface that reflects the laser beam on the object. In addition, if the reflected light does not return within a predetermined time, the distance measurement data generation unit 225 determines that there is no object within the distance that can be irradiated with the laser light, and records the predetermined pseudo data as a relative position. To do. The pseudo data may be a predetermined value, for example, a distance value that is an outer periphery of the alert area 4 to be monitored by the object detection sensor 2 or an appropriate value that is equal to or greater than an effective measurement distance by laser light.

The measurement data obtained by the distance measurement data generation unit 225 is referred to as distance measurement data in this embodiment. The distance measurement data is specifically the result of measuring the alert area 4 at a predetermined angular interval (for example, 0.25 °) by one scan by the detection unit 22. For example, when distance measurement data is acquired at intervals of 0.25 ° in a 180 ° range, 721 distance values are obtained. A set of these 721 distance values becomes one distance measurement data. The distance measurement data may be stored as a table of angles (directions) and distances.
The distance measurement data generation unit 225 generates distance measurement data and outputs it to the control unit 24 every time one scan of the detection unit 22 ends at a predetermined cycle interval (for example, 30 msec).

  The storage unit 23 is configured by a ROM, a RAM, or an HDD, stores address information for identifying itself, various programs, and the like, and further stores various information for operating the object detection sensor 2. Specifically, the storage unit 23 stores warning area information indicating the set warning area 4, reference data generated by the control unit 24, and current state information indicating the current state of the warning area 4. ing. The storage unit 23 stores distance measurement data for the past predetermined period output from the detection unit 22.

The warning area information is information indicating the warning area 4 set according to the security planning of the monitoring area by a security company or the like as a range to be monitored by the object detection sensor 2, for example.
The warning area information is input by designating a range on the scanning plane by the detection unit 22 from a setting terminal, an operation unit (not shown), or the like when the object detection sensor 2 is installed or when security planning of the monitoring area is changed. The range of the warning area 4 that is input is associated with an angle (direction) from the detection unit 22 and a distance value for each predetermined angular interval (for example, 0.25 °) scanned by the detection unit 22. It is stored in the storage unit 23 as a table of angles (directions) and distances. In the present embodiment, as shown in FIG. 1, an example in which the alert area 4 is set in a semicircular shape centering on the object detection sensor 2 will be described.
Note that the alert area information is not limited to this, and it is only necessary to store the positional relationship between the information indicating the range of the alert area 4 and the object detection sensor 2 so that the object detection sensor 2 can be identified. It may be set and stored in two-dimensional coordinates indicating a simple positional relationship.

  The reference data is comparison reference information used for extracting an intruding object that has newly appeared in the alert area 4 in comparison with the current distance measurement data in an intrusion determination process described later. Is generated from distance measurement data acquired at any past time from the current to the present. The reference data may be stored as a table of angles (directions) and distances. Further, the reference data may be generated at any past time point, and may be updated using distance measurement data acquired at any time.

  In the current state information, whether the current warning area is normal as a result of determination by the control unit 24, or whether a visual field disturbance abnormality due to an obstructing object or an intrusion abnormality due to an intruding object such as a suspicious person has occurred. Remembered. When the controller 24 determines that such an abnormality has occurred, the state of each abnormality is stored, and when it is determined that the abnormality has disappeared, it is stored that it is normal.

  The control unit 24 includes a microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof, and controls the above-described units. For this purpose, the control unit 24 is acquired from the detection unit 22 and the disturbance determination unit 241 that determines whether there is a visual field disturbance abnormality as a functional module realized by the microcomputer and a computer program executed on the microcomputer. A reference data generation unit 242 that generates reference data from the distance measurement data and an intrusion determination unit 243 that determines whether there is an intrusion abnormality are provided.

  The disturbance determination unit 241 compares the current distance measurement data acquired by the detection unit 22 with the warning area information stored in the storage unit 23 to determine whether or not the visual field disturbance abnormality has occurred. As described above, the warning area 4 is an area set as a range to be monitored by the object detection sensor 2, and the object detection sensor 2 irradiates the entire area of the warning area 4 with laser light in order to ensure security. Must be in a state where However, in the outdoor environment, there is a possibility that installations such as planting growth and buds, flying objects from the wind, and fences installed by users in the monitoring area may appear in the monitoring area. It becomes difficult to keep the state of 4 constant. For this reason, in the present embodiment, the interference determination unit 241 performs the current distance measurement that is a warning area 4 set in advance as a range to be monitored by the object detection sensor 2 and a line-of-sight distance from the object detection sensor 2 in each direction. By comparing with the data, it is determined whether or not a certain blind spot has occurred in the alert area 4, and it is monitored whether an effective monitoring field of view is secured.

Specifically, the disturbance determination unit 241 calculates a range (hereinafter referred to as a measurable range) that can be measured in the alert area 4 using the distance value for each scanning angle obtained from the distance measurement data, and this measurement. When the area of the possible range (the area through which the laser beam has passed without any reflecting object) falls below a predetermined ratio (for example, ½) with respect to the area of the alert area 4 obtained from the angle indicating the range of the alert area 4 and the distance value. Then, it is determined that the visual field obstruction abnormality has occurred because the monitoring visual field of the object detection sensor 2 is obstructed.
When it is determined that the visual field disturbance abnormality has occurred, the visual field disturbance abnormality is stored in the current state information of the storage unit 23, and when it is determined that the visual field disturbance abnormality has not occurred, the information on the abnormality is deleted from the current state information. The

This will be described in more detail with reference to FIG. FIG. 3 shows a method for calculating the area of the measurable range by the interference determination unit 241. In the example of the figure, the distance from the object detection sensor 2 to the measurement point (reflection point by the object) at a certain scanning angle is dn, and the distance to the outer periphery of the alert area 4 stored in the alert area information is d. Therefore, when the outer periphery of the alert area 4 is set as an arc as shown in the figure, if the scan angle interval is 0.25 °, the area of the measurable range in one scan angle unit is πdn ² 0. It is calculated as 25/360. At this time, if the measurement point is obtained outside the alert area 4, that is, if the laser beam passes through the alert area 4, the distance dn to the measurement point is simulated as the distance d to the outer periphery of the alert area 4. To calculate the area (if dn> d, dn = d).
In this way, the interference determination unit 241 calculates the area of the measurable range from the distance value dn for each scanning angle, and adds the entire scanning range (for example, 180 °) of the detection unit 22 to measure in the alert area 4. Calculate the area of the possible range. Then, the area of the measurable range and the area of the alert area 4 are compared to determine whether or not the visual field disturbance abnormality has occurred.

The reference data generation unit 242 generates reference data using the distance measurement data acquired from the detection unit 22. In the present embodiment, an example will be described in which reference data is generated and stored every predetermined time after scanning by the detection unit 22 is started. In other words, when the scanning of the detection unit 22 is started, the reference data generation unit 242 stores the distance measurement data output in the first scan in the storage unit 23 as reference data, and thereafter updates the data every predetermined time. When the distance value corresponding to a certain angle is not within the warning area 4 as the position of the measurement point in the distance measurement data, the distance to the outer periphery of the warning area 4 corresponding to the angle may be stored as reference data. Since the distance to the measurement point by the scanning is stored in the reference data, existing objects such as planting and outer walls existing in the alert area 4 at the time of the scanning are taken in as the reference data.
However, the present invention is not limited to this, and the reference data generation unit 242 sets the distance value for each scanning angle in the distance measurement data a predetermined number of times (for example, scanning performed for 5 minutes) after the detection unit 22 starts scanning. The frequency may be obtained, and the distance value with the highest frequency may be adopted as the reference value of the scanning angle to generate reference data.

The intrusion determination unit 243 compares the current distance measurement data with the reference data to determine whether there is an intruding object that has appeared in the alert area 4, and determines whether an intrusion abnormality has occurred based on the movement of the intruding object. As described above, there are many moving objects such as small animals in the outdoor environment compared to indoors, and there may be shaking such as planting and flying objects due to the wind. Therefore, a new object (intruding object) is present in the alert area 4. It can be erroneously determined to be an intrusion abnormality that can immediately impair the maintenance of the monitored area just by the appearance of. Therefore, in this embodiment, when the intrusion determination unit 243 detects an intruding object that has appeared in the alert area 4, the intrusion determining unit 243 determines whether there is an object corresponding to the intruding object in the detection result of the previous cycle, and If there is an object, the movement of this object is tracked. If the moving distance from the position where the intruding object first appears in the alert area 4 to the current position is equal to or longer than a predetermined distance (for example, 1 m), an intrusion abnormality caused by the intruding object is detected. Determined to occur.
When it is determined that an intrusion abnormality has occurred, the intrusion abnormality is stored in the current state information of the storage unit 23, and when it is determined that no intrusion abnormality has occurred, the information on the abnormality is deleted from the current state information.

<Description of operation>
About the security system 1 comprised as mentioned above, the operation | movement is demonstrated with reference to drawings. Here, an operation related to the object detection sensor 2 will be mainly described. FIG. 4 is a flowchart showing the operation of the monitoring program executed by the object detection sensor 2.

  When the power source of the object detection sensor 2 is turned on and driving of each unit is started, the detection unit 22 starts scanning the alert area 4 and outputs distance measurement data (step ST1-Yes). The reference data generation unit 242 generates reference data based on the distance measurement data obtained by the first scan and stores it in the storage unit 23 (step ST2).

  When the distance measurement data is acquired after generating the reference data (step ST3-Yes), the disturbance determination unit 241 compares the current distance measurement data with the preset warning area information, and the visual field disturbance determination process. Is performed (step ST4). The visual field disturbance determination process will be described later. Since the visual field disturbance determination process can be executed even with the distance measurement data used for generating the reference data, the visual field disturbance determination process may be executed by skipping step ST3 for the first time.

  In step ST5, the intrusion determination unit 243 compares the current distance measurement data with the reference data to perform intrusion determination processing. The intrusion determination process will be described later. And if the abnormal information which is not output to the security device 5 is memorize | stored in the present state information of the memory | storage part 23 based on the result of a visual field disturbance determination process and an intrusion determination process (step ST6-Yes), it will start from the communication part 21 A detection signal indicating the abnormality information and its own address information is transmitted to the security device 5 (step ST7).

  The object detection sensor 2 repeats the processes of steps ST3 to ST7 to monitor the warning area 4 until a predetermined drive end signal is input from the security device 5 or an operation unit (not shown). Further, the reference data is updated at a predetermined timing. On the other hand, when a predetermined driving end signal is input from the security device 5 or an operation unit (not shown) (step ST8—Yes), the driving of the detection unit 22 is stopped (step ST9) and stored in the current state information of the storage unit 23. The information on the abnormality that has been made is deleted, the state becomes normal (step ST10), and the series of processing ends. In steps ST1 and ST3, if distance measurement data is not acquired even after exceeding a predetermined scanning period (for example, 30 msec), the process may be terminated as an abnormality of the device.

The basic operation of the object detection sensor 2 has been described above.
Next, the visual field disturbance determination process in step ST4 of FIG. 4 will be described with reference to FIG. FIG. 5 is a flowchart of the visual field disturbance determination process.

In FIG. 5, the interference determination unit 241 reads the distance measurement data and the warning area information acquired in the current cycle (step ST21), and the distance value detected from the current distance measurement data for each angle component (direction). From dn, the area of the measurable range from the object detection sensor 2 to the shielded object detected as the measurement point is calculated (step ST22). For example, as shown in FIG. 3, when the scanning angle interval is 0.25 ° and the outer periphery of the alert area 4 is set as an arc, the area of the measurable range for one angle component is πdn ² 0 .25 / 360 (provided that dn = d if dn> d).

Then, the interference determination unit 241 calculates the area of the measurable range of the entire scanning range (for example, 180 °) by adding all the areas of the measurable range calculated for each angle component (direction) (step ST23). . In step ST24, the interference determination unit 241 determines whether or not the calculated area of the measurable range is equal to or less than a predetermined ratio (for example, 1/2) with respect to the area of the alert area 4, and if this is satisfied (Step ST24-Yes), it determines with visual field disturbance abnormality having generate | occur | produced in the alert area 4, and memorize | stores visual field disturbance abnormality in the current state information of the memory | storage part 23 (step ST25). As a result, a detection signal is output to the security device 5 in step ST7 of FIG. 4, and when the abnormality is confirmed by the security device 5, an abnormality is notified to the remote monitoring center 6.
On the other hand, if the calculated area of the measurable range exceeds a predetermined ratio with respect to the area of the alert area (step ST24-No), it is determined that there is no visual field obstruction and the process ends. At this time, if the visual field disturbance abnormality is stored in the current state information, the abnormality information is deleted.

  If it is determined in step ST24 that the area of the measurable range is equal to or less than a predetermined ratio (for example, 1/2) with respect to the area of the alert area 4, the interference determination unit 241 stores this as current cycle information. 23, when it is determined that the area of the measurable range is continuously equal to or less than a predetermined ratio with respect to the area of the alert area 4 for a predetermined time or a plurality of periods, it is determined that the visual field disturbance abnormality of step ST25 has occurred. You may make it perform the process to perform.

In this way, the interference determination unit 241 compares the warning area 4 set in advance as a range to be monitored by the object detection sensor 2 with the current distance measurement data that is the line-of-sight distance from the object detection sensor 2. By doing so, it is determined whether or not a blind spot of a certain level or more is generated in the alert area 4, and it is monitored whether an effective monitoring field of view is secured. When the range that can be monitored in the alert area 4 becomes a certain value (for example, an area ratio of 1/2) or less, it is determined that the monitoring field of view is obstructed.
As a result, even in an outdoor environment where it is difficult to keep the state of the alert area 4 in a certain state due to the effects of planting growth, new installations, etc., it is set as a range to be alerted for security planning. It becomes possible to evaluate the monitoring range by the object detection sensor 2 based on the relative range that cannot be measured with the current measurement result with respect to the alert area 4, and detect a situation where the monitoring capability is impaired, and security It is possible to ensure maintenance.

Next, the intrusion determination process in step ST5 of FIG. 4 will be described with reference to FIG. FIG. 6 is a flowchart of the intrusion determination process.
In FIG. 6, the intrusion determination unit 243 reads the distance measurement data and reference data acquired in the current cycle (step ST31), and the distance value detected from the current distance measurement data for each angle component (direction). The difference between dn and the distance value stored in the reference data is calculated (step ST32). Then, the intrusion determination unit 243 checks whether there is a change point where the current distance measurement data is closer than the reference data by a predetermined distance or more from the difference result between the current distance measurement data and the reference data (step ST33). ).

  If there is a change point (Yes in step ST33), the intrusion determination unit 243 labels the change points extracted continuously between a plurality of angles and detects them as an intruding object (step ST34). Here, since the angular interval when the detection unit 22 scans is sufficiently close compared to the detection target object (such as a person or a vehicle), the change points (isolation points) that are not continuous or the size of the labeling are not observed. An object that is smaller than a predetermined size (for example, 15 cm) that can be determined as a part of a detection target object (such as a person or a vehicle) may be removed as noise.

  Then, the intrusion determination unit 243 compares the processing results of the previous period and the current period, and determines whether there is a tracking target for each label (step ST35). In the tracking process, the presence / absence of a tracking target is determined based on whether or not there are objects of substantially the same size within a predetermined angle and distance range between the previous cycle and the current cycle. If there is a corresponding object, that object becomes the tracking target. If there is no tracking target (step ST35-No), the label of the current cycle is stored as a newly appearing label, and the intrusion determination process ends. On the other hand, when the tracking target exists (step ST35-Yes), the intrusion determination unit 243 reads the position and size when the corresponding label newly appears in the alert area 4, and newly appears in the alert area 4. The moving distance from the position to the current position is calculated (step ST36). The movement distance is calculated from the straight line distance from the newly appearing position to the current position.

  If the calculated moving distance is less than a predetermined distance (for example, 1 m) (step ST37-No), the label of the previous period and the corresponding label of the current period are stored in association with each other and newly appear in the alert area 4. The position and size at the time and the current position and size are associated with each other, and the intrusion determination process is terminated. On the other hand, if the calculated moving distance is equal to or greater than a predetermined distance (for example, 1 m) (step ST37-Yes), it is determined that an intrusion abnormality has occurred due to the corresponding label (intruding object) and the current state information in the storage unit 23 is intruded. The abnormality is stored (step ST38). As a result, a detection signal is output to the security device 5 in step ST7 of FIG. 4, and when the abnormality is confirmed by the security device 5, an abnormality is notified to the remote monitoring center 6.

  In this manner, the intrusion determination unit 243 determines whether or not there is an intruding object that has appeared in the alert area 4 by comparing the reference data acquired as past distance measurement data with the current distance measurement data.

  The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there.

  For example, in the above-described embodiment, the example in which the visual field disturbance abnormality is determined from the area of the range that can be monitored in the warning area 4 (the range in which the laser beam has passed without the reflection object) has been described. The presence / absence of the visual field obstruction act on the object detection sensor 2 may be determined based on the area in the area 4 that cannot be monitored, that is, the area that cannot be measured because the laser beam is blocked by the blocked object (blocked area).

In this case, the disturbance determination unit 241 determines the blocking area in the warning area 4 from the distance value dn for each scanning angle obtained from the current distance measurement data and the distance d to the outer periphery of the warning area 4 stored in the warning area information. Is calculated. When the outer periphery of the alert area 4 is set as an arc as shown in FIG. 3, if the scanning angle interval is 0.25 °, the area of the blocking area in one scanning angle unit is π (d ² −dn ² ) It is obtained as 0.25 / 360 (provided that dn = d if dn> d). Then, the interference determination unit 241 adds this for the entire scanning range (for example, 180 °) to calculate the area of the shielding area in the warning area 4, and the area of the shielding area is a predetermined ratio with respect to the area of the warning area 4. If (for example, 1/2) or more, it is determined that the visual field disturbance abnormality occurs.
This also makes it possible to evaluate the monitoring range by the object detection sensor 2 based on the relative range of the current measurement result with respect to the warning area 4 set as a warning range in the security planning, and the monitoring capability is impaired. It is possible to detect and maintain security and maintain security.

  Moreover, you may make it the detection part 22 drive only while the security apparatus 5 is set to the security set mode. In this case, when the security device 5 receives a security start signal transmitted when the security device 5 is set to the security set mode, the detection unit 22 is driven to start the processing of FIG. 4, and in step ST <b> 10 of FIG. 4. The determination may be made as to whether or not the security release signal transmitted when the security device 5 is set to the security release mode is received.

Further, weight information is stored in the storage unit 23 for each scanning angle (direction in the alert area) of the detection unit 22, and the interference determination unit 241 calculates the area of the measurable range using this weight information. It is also possible. That is, the interference determination unit 241 weights the area of the measurable range calculated from the distance for each scanning angle obtained from the current distance measurement data according to the scanning angle.
Accordingly, the area of the measurable range calculated in the important direction is multiplied by a count of 1 or less as the weight according to the important object or the important section existing in the direction monitored by the object detection sensor 2. Therefore, it is possible to relatively increase the weight with respect to various monitoring directions, to easily detect a situation in which an important monitoring target cannot be monitored, and to improve security.

  Moreover, in this embodiment, although the example which performs tracking processing between the ranging data of 1 period previous (previous period with respect to the present period) was demonstrated in the intrusion determination process shown in FIG. A tracking process may be performed between distance measurement data within a predetermined time (for example, data acquired during one second). In this case, it is determined whether or not association is possible for all the distance measurement data acquired within a predetermined time in the tracking process, and if there is a corresponding label, it is determined that there is a tracking target. Thereby, even if it is a case where detection is missing by instantaneous noise, it is possible to detect the tracking target without erroneous determination.

DESCRIPTION OF SYMBOLS 1 Security system 2 Object detection sensor 21 Communication part 22 Detection part 221 Laser oscillation part 222 Scanning mirror 223 Scanning control part 224 Reflected light detection part 225 Distance measurement data generation part 23 Storage part 24 Control part 241 Interference determination part 242 Reference data generation part 243 Intrusion determination unit 3 Monitoring building 4 Security area 5 Security device 6 Monitoring center 7 Communication network

Claims (2)

An object detection sensor for monitoring an inside of a warning area and detecting an object in the warning area,
A storage unit for storing the warning area in advance;
A detection unit that periodically scans within the alert area and generates distance measurement data indicating a distance to the object to be measured for each direction in the alert area;
If the range measured by the current distance measurement data in the alert area by comparing the alert area with the current distance measurement data is less than a predetermined ratio with respect to the alert area, visual field disturbance has occurred. An interference determination unit for determining,
The interference determination unit is
If the distance to the object indicated by the current distance measurement data passes through the alert area, the distance of the current distance measurement data is replaced with the distance to the outer periphery of the alert area,
The area of the range measured in the warning area is calculated from the distance to the object to be measured in each direction obtained from the current distance measurement data, and the area of the measured range becomes the area of the warning area. An object detection sensor characterized in that a visual field disturbance is determined to occur if the ratio is less than a predetermined ratio .
The storage unit
The object detection sensor according to claim 1, wherein the warning area is stored as two-dimensional information including a distance and a direction from the detection unit.

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