JP2017135550A - Flying object monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide information which allows an observer to take proper action using supplementary information other than a radar if an incoming flying object in a monitoring region disappears during monitoring.SOLUTION: A monitoring radar 11 detects an incoming flying object in a monitoring region by scanning detection waves in the monitoring region at a predetermined frequency. An acoustic signal processing device 13 acquires an acoustic signal in the monitoring region. If the flying object pursued by the monitoring radar 11 disappears, the flying object monitoring system determines that the flying object crashed if an acoustic signal is observed over a predetermined time before the flying object disappears, the flying object disappears, and the acoustic signal becomes a reference value or lower almost at the same time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flying object monitoring system that monitors a flying object (for example, a drone) flying in a predetermined monitoring area.

  In recent years, small unmanned multicopters called drones have been put into practical use and are effectively used for various applications such as pesticide spraying and facility inspection. On the other hand, crimes that misuse drones such as voyeurism and dangerous goods transportation are also a concern, and systems for early detection of such drones are beginning to appear.

  Conventionally, as disclosed in, for example, Patent Document 1 below, an intruding object that enters into a specific monitoring area is to be monitored, and when an intruding object is detected by a detection means, it is displayed on a remote monitoring monitor and confirmed by a supervisor Possible monitoring devices are known.

JP 2012-198802 A

  In the conventional monitoring device, when a flying object is detected in the monitoring area, the radar image or the monitoring camera image is displayed on the display device of the monitoring table of the remote center device, and the monitoring person views the radar image or the monitoring camera image. To monitor flying objects. At that time, if the flying object being tracked by the radar can no longer be detected, if there are no other flying objects, the supervisor completes the monitoring work on the monitoring console and returns to the standby state.

  However, the flying object being tracked may temporarily fall outside the radar monitoring range, and the flying object being tracked may return to the radar monitoring range after a while. In addition, unlike a manned helicopter, an unstable flying object such as a drone may crash if it loses control due to motor trouble, radio interference, or strong winds.

  Therefore, it is desirable to construct a system that can provide information so that a monitoring person can take an appropriate action according to the situation when a flying object being tracked cannot be detected by the radar.

  The present invention has been made in view of the above problems, and when monitoring a flying object flying in a monitoring area, if the flying object being monitored by the observer disappears, auxiliary information other than the radar is used. It is an object of the present invention to provide a flying object monitoring system that can provide information so that an observer can take appropriate measures.

In order to achieve the above-described object, a flying object monitoring system according to the present invention includes a detecting unit that detects a flying object in a predetermined monitoring area,
An acoustic signal acquisition means for acquiring an acoustic signal in the monitoring area;
A flying object monitoring system comprising:
When the flying object detected by the detection unit disappears during tracking, a determination is made according to a change in acoustic signal before and after the disappearance of the flying object.

  In the flying object monitoring system according to the present invention, before the disappearance of the flying object, the acoustic signal is observed at a first reference value or more, the flying object disappears, and within a first predetermined time from the disappearance. If the acoustic signal falls below a second reference value, it may be determined that the flying object has crashed.

Furthermore, the flying object monitoring system according to the present invention further includes an anemometer that measures the wind speed and the wind direction,
When the measurement information obtained by the anemometer satisfies a predetermined condition, the flying object may be determined to have crashed.

  In addition, the flying object monitoring system according to the present invention may determine that the flying objects detected again while the acoustic signal continues beyond the first reference value after the flying objects disappear are the same. .

  Furthermore, in the flying object monitoring system according to the present invention, after the flying object disappears, the acoustic signal becomes equal to or lower than the second reference value within a second predetermined time after the first predetermined time elapses. In this case, the position may be set as a monitoring point that needs to be monitored.

Further, the flying object monitoring system according to the present invention includes a detecting means for detecting a flying object in a predetermined monitoring area,
Imaging means for imaging a flying object detected by the detection means;
Display means for displaying a picked-up image picked up by the image pickup means;
An acoustic signal acquisition means for acquiring an acoustic signal in the monitoring area;
In the case of acquiring a captured image until the flying object disappears, user input means for instructing the acquisition stop of the captured image;
A flying object monitoring system comprising:
When the flying object being detected by the detection means disappears, if the acoustic signal continues before and after the disappearance of the flying object, it is necessary to input whether or not to stop imaging from the user input means, and the acoustic signal It is characterized by forcibly terminating when there is no.

  According to the flying object monitoring system of the present invention, the detecting means detects a flying object flying in a predetermined monitoring area. The acoustic signal acquisition unit acquires an acoustic signal in the monitoring area. When the flying object detected by the detecting means disappears during tracking, a determination is made according to the change in the acoustic signal before and after the disappearance of the flying object. With such a configuration, it is possible to accurately determine the cause when the flying object disappears from the detection means by using the acoustic signal, and when the flying object flying in the monitoring area is monitored, the flying object being monitored by the observer is In the case of disappearance, information can be provided so that the monitoring person can take an appropriate action using an acoustic signal as auxiliary information other than the detection information of the flying object.

  Further, according to the flying object monitoring system of the present invention, the acoustic signal is observed at the first reference value or more before the flying object disappears, the flying object disappears, and the acoustic signal falls within the first predetermined time from the disappearance. It is determined that the flying object has crashed when becomes below the second reference value. With this configuration, the monitoring staff can appropriately cope with the determination that the flying object has crashed. For example, there is a high possibility that the operator will come to collect the drone at the crash point, and it will be possible to confirm the identity.

  Furthermore, according to the flying object monitoring system of the present invention, the anemometer measures the wind speed and the wind direction. Then, when the measurement information by the anemometer satisfies a predetermined condition, it is determined that the flying object has crashed. With such a configuration, it is possible to more accurately determine the flying object crash by adding the measurement information of the anemometer to the condition for the flying object crash judgment.

  Further, according to the flying object monitoring system of the present invention, after the flying object disappears, the flying object detected again while the acoustic signal continues for the first reference value or more is determined to be the same. With this configuration, when a flying object that disappears during tracking appears again, it is possible to make a continuous determination by not determining the flying object as a new object.

  Furthermore, according to the flying object monitoring system of the present invention, after the flying object disappears, the acoustic signal becomes equal to or lower than the second reference value within the second predetermined time after the first predetermined time elapses. The position is set as a monitoring point required. With this configuration, for example, when landing on a building, etc., it is often difficult to confirm with the owner, but by setting it as a monitoring point required, a drone that appears again from the vanishing point is considered suspicious. Can be estimated.

  Further, according to the flying object monitoring system of the present invention, the detecting means detects a flying object in a predetermined monitoring area. The imaging means images the flying object detected by the detection means. The display unit displays the captured image captured by the imaging unit. The acoustic signal acquisition unit acquires an acoustic signal in the monitoring area. The user input means instructs the acquisition stop of the captured image when acquiring the captured image until the flying object disappears. When the flying object being detected by the detection means disappears, if the acoustic signal continues before and after the disappearance of the flying object, it is necessary to input whether or not the imaging is stopped from the user input means, and compulsory if there is no acoustic signal To finish. With this configuration, if the detection means cannot observe an acoustic signal like a bird when the flying object disappears, monitoring is forcibly stopped even if it can be visually recognized by the imaging means, and monitoring is performed when the acoustic signal is observed. The convenience can be improved by letting the user decide.

1 is a block diagram showing an overall configuration of a flying object monitoring system according to the present invention. It is the schematic of the monitoring image by the flying object monitoring system which concerns on this invention. It is a figure which shows schematic structure of the radar for monitoring which comprises the detection means of the flying object monitoring system which concerns on this invention. It is a flowchart which shows the control content of the flying object monitoring system which concerns on this invention.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to FIGS. 1 to 4 of the accompanying drawings.

[Outline of the present invention]
The present invention relates to a flying object monitoring system that monitors a flying object (for example, a drone) flying in a monitoring area, and is installed at a predetermined height such as a rooftop of a building and has a monitoring range that is equal to or higher than the installation height. When a flying object detected by a monitoring means (monitoring radar) that is monitored disappears during tracking, it has a function of performing different determinations according to information such as acoustic information being observed at the same time.

  Specifically, when the flying object being tracked by the monitoring radar as the detection means disappears, if there is a sudden change (or disappearance) in the acoustic signal acquired from the microphone of the acoustic signal processing device, the monitoring radar monitors On the other hand, if it is determined that the fall has fallen out of the range, and if the acoustic signal can be continuously acquired as before the disappearance, it is determined that the flying object has temporarily deviated from the monitoring region, and continuous monitoring is performed. In this case, the flying objects detected within a predetermined range from the point where the acoustic signal disappears while continuing are determined as the same object. Alternatively, after the flying object disappears from the radar, the acoustic signal continues for a certain period of time, and if the acoustic signal disappears after that, it is determined that it is a non-timed landing outside the monitoring range of the monitoring radar, and the periphery is set as a monitoring point required . Alternatively, when a three-dimensional acoustic array is adopted as the acoustic signal processing device, the arrival time of the sound signal disappears after the moving direction of the sound source position determined from the acoustic signal after the flying object disappears from the radar is lowered. judge.

  If it is determined that the flying object has temporarily disappeared, the monitoring is continued. On the other hand, if it is determined that the flying object has crashed, a cooperating person is dispatched to the site and the flying object (such as a drone) is sent. The operator who came to collect can be found. As a result, when the flying object being tracked can no longer be detected by the monitoring radar, information can be provided so that the monitoring staff can take an appropriate action according to the situation.

[Configuration of flying object monitoring system]
As shown in FIG. 1, a flying object monitoring system 1 according to the present embodiment includes a monitoring device 2 that monitors flying objects flying in a monitoring area, and a remote center device that is disposed at a position away from the monitoring device 2. 3 is roughly composed.

  FIG. 2 shows an outline of a monitoring image by the flying object monitoring system 1. In FIG. 2, a circle indicates a monitoring range E of the monitoring radar 11 described later of the monitoring device 2. FIG. 2 shows an example in which the flying object W1 and the flying object W2 are flying within the monitoring range E. In the monitoring range E, it is possible to set points (monitoring points C to be monitored) that should be focused on important facilities and the like.

  A monitoring device 2 including a monitoring radar 11 to be described later is installed in the monitoring area. When the monitoring radar 11 detects a flying object W, a camera image captured by an imaging device 12 to be described later in the vicinity of the monitoring radar 11. Is transmitted to the remote center device 3, and a camera image is displayed on the display device 22 of the monitoring table described later of the center device 3. The monitoring person monitors the flying object W by the camera image displayed on the display device 22 of the monitoring table.

  In the example of FIG. 2, the monitoring range E is set in the monitoring area by one monitoring device 2, but a plurality of monitoring devices 2 are installed in the monitoring area, and a part of the plurality of monitoring ranges E is set. A wide monitoring area is set by overlapping, and when any of the monitoring radars 11 detects a flying object, a camera image from the imaging device 12 near the monitoring radar 11 is transmitted to the remote center device 3. It may be.

[Monitoring device]
As shown in FIG. 1, the monitoring device 2 is installed at a predetermined location in the monitoring area so as to form a monitoring range E shown in FIG. 2, for example. The device 13 includes a radar signal processing device 14 and a data processing device 15.

[Monitoring radar]
The monitoring radar 11 detects a flying object W flying in the monitoring area by scanning a detection wave at a predetermined period, and has a certain height so as not to be affected by surrounding buildings. It is fixedly installed at a predetermined location in the monitoring area, and is composed of a plurality of radars so that the hemisphere above the monitoring radar 11 can be monitored. The monitoring radar 11 employs an FM-CW method that performs distance measurement using a continuous wave that is frequency-modulated as a transmission / reception wave transmitted from the radar, and in the azimuth direction at a predetermined cycle (for example, one rotation / one second). The azimuth direction of the flying object W can be detected by rotating a beam having a predetermined horizontal beam width (for example, 2 degrees) 360 degrees and transmitting and receiving radio waves at a predetermined period (for example, 3 ms). Further, the rotation speed of the monitoring radar 11 is set to a speed that is small enough to be considered that the antenna is stopped, as compared with the round trip time of the beam determined according to the maximum detection distance (for example, 100 m) of the radar. From the monitoring radar 11, the angle, distance, speed, and received intensity on the horizontal plane centering on the radar can be obtained as output information.

  Further, the configuration of the monitoring radar 11 will be described with reference to FIG. Here, the monitoring radar 11 is configured to monitor a hemispherical surface by combining two radar devices including an oblique monitoring radar and a top surface monitoring radar. Hereinafter, a case where FM-CW radar is used for two radar devices will be described as an example.

  FIG. 3 shows an image of a monitoring area composed of two radar devices. FM-CW radar installed at a fixed position emits a transmission beam obliquely upward and upward, and two receiving antennas for receiving radio waves from an area obtained by dividing the area transmitted obliquely upward and downward, and A reflected beam from the flying object W flying in the monitoring area is received using two receiving antennas that receive radio waves from above.

  Here, although the details of the principle of the FM-CW radar are omitted, the outline thereof will be described. The FM-CW radar as the monitoring radar 11 includes a transmission antenna, a first reception antenna, a second reception antenna, A reception antenna changeover switch, a transmission / reception device, an A / D converter, and a signal processing device are included.

  Explaining each part, the transmission antenna radiates a transmission beam forward. The first receiving antenna and the second receiving antenna receive radio waves from a transmission beam range or a monitoring region obtained by dividing the transmission beam range. The reception antenna changeover switch alternately enables one of the first reception antenna and the second reception antenna at regular intervals. The transmission / reception device generates an FM-CW transmission wave and converts the reception beam into a frequency that can be processed by the signal processing device. The A / D converter digitally converts the received beam intensity output from the transmission / reception device. The signal processing device obtains the relative distance and relative speed of the detection target object in the monitoring region and the intensity of the reflected beam component from the detection target object in the reception beam from the reception beam intensity output from the A / D converter.

  More specifically, the signal processing apparatus performs frequency analysis of the reflected beam signal input from the A / D converter, and calculates the signal intensity at each frequency. Next, the frequency at which the signal intensity is equal to or higher than the threshold is obtained, and the frequency is set as the frequency of the reflected beam component from the detection target. Then, the beat frequency is calculated by calculating the difference between the frequency of the reflected beam component from the obtained detection object and the frequency of the transmission beam, and the relative distance and relative speed of the detection object are calculated and output from this beat frequency. To do. Further, the angle can be obtained based on the position where the rotating radar detects the flying object W.

  The monitoring radar 11 scans the detection area with a detection wave at a predetermined cycle to detect a detection target (flying object), and detects the relative distance, the relative speed, and the detection target in the monitoring area. It is only necessary to acquire various types of information related to the detection target such as the intensity of the reflected beam component from the detection target, and the configuration is not limited to that shown in FIG.

[Imaging device]
The imaging device 12 is composed of a high-resolution, high-sensitivity camera having pan, tilt, and zoom functions. The imaging device 12 is fixedly installed at a position where the monitoring area can be photographed, and panning, tilting, and zooming are possible under the control of the control device 21 described later of the center device 3 so that the flying object W can be projected at the center of the screen. The shooting range can be changed. The imaging device 12 is linked to the monitoring radar 11 so that the flying object W becomes the center of the image by the control device 21 described later of the center device 3 based on the position information of the flying object W detected by the monitoring radar 11. The swivel is turned, the vertical direction is adjusted, and the camera image is transmitted to the center device 3 via the data processing device 14.

  Note that the imaging device 12 may be installed above or below the monitoring radar (FM-CW radar) 11 or at another location.

[Acoustic signal processing device]
The acoustic signal processing device 13 includes, for example, a microphone, a microphone amplifier, an A / D converter, and the like. The microphone functions as an acoustic signal acquisition unit in the monitoring area, and an omnidirectional condenser microphone can be employed. Moreover, the direction of the sound source can be specified three-dimensionally by adopting a microphone array composed of a plurality of microphones vertically and horizontally with a predetermined distance.

  When the microphone array is adopted, the determination condition can be the coincidence between the direction of the flying object detected by the monitoring radar 11 and the sound source direction. The number of microphones and the predetermined distance are determined according to the sampling period and the monitoring distance. The acoustic signal acquired by the microphone is amplified by a microphone amplifier, converted to a digital signal by an A / D converter, and transmitted to the center device 3 via the data processing device 15.

[Radar signal processor]
The radar signal processing device 14 performs noise removal processing, fixed object removal processing, and the like from output information acquired from the monitoring radar 11 (information such as angle, distance, speed, reception intensity on the horizontal plane centering on the radar). The data is output to the data processing device 15.

[Data processing device]
The data processing device 15 is connected to the radar signal processing device 14 in a wired or wireless manner, and determines the specific flying object (for example, drone) W by performing signal processing on the output of the monitoring radar 11 acquired from the radar signal processing device 14. Then, a determination signal to that effect is output to the center device 3. At this time, the output information from the monitoring radar 11 and the acoustic signal from the acoustic signal processing device 13 that have been subjected to noise removal processing and the like by the radar signal processing device 14 are also output to the center device 3.

  In the configuration of FIG. 1, the monitoring device 2 includes a monitoring radar 11, an imaging device 12, an acoustic signal processing device 13, a radar signal processing device 14, and a data processing device 15. The device 12, the acoustic signal processing device 13, the radar signal processing device 14, and the data processing device 15 may be individually configured and arranged.

[Center equipment]
As shown in FIG. 1, the center device 3 is provided in a monitoring center, and includes a control device 21 and a display device (display means) 22 for a monitoring table.

[Control device]
The control device 21 performs overall control of the whole. In the processing of FIG. 4 described later, the control device 21 determines whether the monitoring radar 11 has detected the flying object W, and the flying object being tracked by the monitoring radar 11. , Whether or not there is an acoustic signal peculiar to the flying object before the disappearance of the flying object, whether or not the acoustic signal has changed suddenly, a predetermined time from the disappearance of the flying object (set Whether or not the acoustic signal has stopped within (time), whether or not the monitoring radar 11 has redetected the flying object within a predetermined range from the vanishing point of the flying object, and the imaging device 12 based on the determination result Pan / tilt / zoom control (hereinafter referred to as PTZ control), display control of the display device 22, and the like are performed.

  The control device 21 includes a storage unit (not shown) in which position information (latitude information, longitude information, altitude information) of the monitoring radar 11 and the imaging device 12 is stored in advance.

[Display device]
The display device 22 of the monitoring table is a monitor that is connected to the control device 21 and displays a radar image and a camera image of the nearby imaging device 12 detected by the monitoring radar 11.

  When the monitoring radar 11 detects the flying object W flying in the monitoring range E, the display device 22 displays a camera image captured by the imaging device 12 near the monitoring radar 11. At that time, the control device 21 performs PTZ control of the imaging device 12 based on the position information of the flying object W acquired from the monitoring radar 11 so that the flying object W can be displayed in the center of the screen.

  On the display screen of the display device 22, when the camera image captured by the imaging device 12 is acquired until the flying object being tracked detected by the monitoring radar 11 disappears, the imaging device 12 is stopped. Then, the user input means 22a for instructing the acquisition stop of the camera image is displayed as a soft key. The user input means 22a may be constituted by buttons, keys, switches, and the like provided on the control device 21 and the main body of the display device 22 in addition to the soft keys displayed on the display screen of the display device 22 in FIG. it can.

  In the flying object monitoring system 1 according to the present embodiment having the above-described configuration, when a flying object flying in the monitoring area E is detected by the monitoring radar 11, the monitoring object is displayed on the monitor screen of the display device 22 of the monitoring table in the center device 3. A camera image taken by the imaging device 12 in the vicinity of the radar 11 is displayed. Thereby, the monitoring person monitors the flying object while looking at the monitor screen of the display device 22 of the monitoring table. When the monitoring radar 11 no longer detects the flying object, it returns to the standby state when no other flying object is detected, but when the flying object disappears from the monitoring radar 11, the presence or absence of an acoustic signal is present. Judgment is different based on.

  Hereinafter, specific control of the control device 21 of the center device 3 in the flying object monitoring system 1 including the determination based on the presence / absence of an acoustic signal when the flying object disappears will be described with reference to the flowchart of FIG.

  First, the control device 21 determines whether or not the monitoring radar 11 installed at a predetermined height has detected a flying object W flying in the monitoring area based on the presence or absence of a determination signal from the data processing device 14. (S101).

  When determining that the monitoring radar 11 detects a flying object, the control device 21 turns the imaging device 12 in the direction of the flying object based on the position information and performs PTZ control (S102). Thereby, the camera image captured by the PTZ-controlled imaging device 12 is transmitted to the control device 21 of the center device 3 via the data processing device 13.

  Then, the control device 21 controls the display of the camera image captured by the PTZ-controlled imaging device 12 on the display device 22 of the monitoring console (S103). Thereby, in the monitoring table, the monitoring person performs the monitoring operation of the flying object while looking at the monitor of the display device 22.

  Next, the control device 21 determines whether or not the flying object being tracked by the monitoring radar 11 has disappeared (S104). When the control device 21 determines that the flying object being tracked has not disappeared, the control device 21 follows the movement of the flying object and performs PTZ control so that the imaging device 12 tracks the flying object. Whether or not the detected flying object is being tracked is determined from the moving distance, moving direction, and the like of the flying object detected immediately before.

  When the monitoring radar 11 determines that the flying object being tracked has disappeared, the control device 21 determines whether there is an acoustic signal peculiar to the flying object before the flying object disappears (S105). That is, it is determined whether or not an acoustic signal peculiar to the flying object has been acquired from the microphone of the acoustic signal processing device 13 until the flying object disappears. If the control device 21 has not acquired the acoustic signal peculiar to the flying object from the microphone until immediately before the flying object disappears, and determines that there is no acoustic signal peculiar to the flying object before disappearance, the control device 21 returns to the processing of S101.

  Here, the specific acoustic signal is, for example, a continuous sound in a specific frequency band based on a propeller sound such as a multicopter represented by a drone. Since the drone propeller sound varies depending on the model, a wide frequency band is set as the monitoring band. When a microphone array is used for the acoustic signal processing device 13, it is determined whether the direction of the flying object disappeared by the monitoring radar 11 matches the direction obtained from the output signal of the microphone array. Moreover, even if the flying object does not have a propeller as described above, the present invention can be applied by detecting a flying sound peculiar to each flying object.

  If the control device 21 determines that there is an acoustic signal peculiar to the flying object from the microphone until immediately before the flying object disappears, the acoustic signal suddenly changes immediately after the flying object disappears by the monitoring radar 11 (the power of the flying object suddenly stops). It is determined whether or not the sound signal has disappeared (S106).

  For the determination of the sudden change of the acoustic signal here, for example, after the acoustic signal acquired from the microphone is processed by the digital filter that passes the specific frequency band, the absolute value (or square value) of the amplitude value is obtained, and further, the time The intensity data and frequency spectrum smoothed in the direction can be obtained, and this time series data can be used. A fixed reference (reference value) is set for the change in the calculated intensity data, and the flying object has an intensity equal to or greater than the fixed reference value (first reference value) immediately before the flying object disappears, and the flying object disappears Thereafter, it is determined that the acoustic signal has suddenly changed when the intensity falls below a certain reference value (second reference value) lower than the first reference value within a predetermined time (first predetermined time). Alternatively, it is determined that the acoustic signal has suddenly changed when the change in the intensity of the acoustic signal has fallen by a certain standard or more before the disappearance within the first scheduled time after the flying object has disappeared. Furthermore, it may be determined that the acoustic signal has suddenly changed when the frequency of the acoustic signal rises or falls above a certain reference before and after the disappearance of the flying object.

  In the above, the first predetermined time is set to a small value that can be regarded as substantially simultaneous with disappearance. The first reference value for the intensity of the acoustic signal may be a constant value, but can be set so as to gradually increase from the distance to the vicinity according to the distance to the flying object measured by the monitoring radar 11. .

  In addition, when the flying object crashes as will be described later, the second reference value is set to a low value that is substantially close to the noise level because the acoustic signal disappears in most cases because it loses power and the propeller stops. The

  When the control device 21 determines that the acoustic signal has suddenly disappeared (below the second reference value) and the acoustic signal has suddenly changed, for example, the flying object moves downward outside the monitoring range E of the monitoring radar 11. It determines with having crashed (S112). If it is determined that the flying object has crashed, the monitoring person can instruct dispatch of a coping person near the crash position. It is presumed that the flight object crash was not intended by the operator, so it is assumed that the operator will come to collect the crashed flight object, and it is possible to secure the operator by responding early. Become.

  If the acoustic signal has not changed suddenly, the control device 21 continuously detects the acoustic signal before the flying object disappears. In this case, the control device 21 flies outside the monitoring range E of the monitoring radar 11. There is a high possibility that the object is temporarily removed, and the monitoring operation is continued as the continuous monitoring process (S107). Then, the control device 21 determines whether or not the acoustic signal has become equal to or less than a predetermined reference value (the second reference value) within a predetermined time (second predetermined time) after the disappearance of the flying object (S108). .

  The control device 21 makes the acoustic signal fall below the predetermined reference value (second reference value) within the second predetermined time and not less than the first predetermined time when the flying object disappears from the time of disappearance of the flying object. If it is determined that the lost point is detected, the disappearance point and its surroundings are registered as a monitoring point required (S109). This is because the Service-to-Self may land a flying object outside the monitoring range of the monitoring radar 11 before an event, etc., and execute a crime when the event occurs. When a flying object is detected at the event from the point, the flying object can be dealt with as a priority alert target.

  In the above, the second predetermined time is appropriately set according to the installation height of the monitoring radar 11, the lowest possible descent speed of the target flying object, and the like. Further, when the acoustic signal processing device 13 is constituted by a microphone array and the movement of the three-dimensional sound source can be detected, it is necessary when the moving direction of the sound source moves downward in S109 and becomes a predetermined value or less. You may make it register as a monitoring point.

  Further, when the control device 21 determines that the acoustic signal has not stopped within the second predetermined time from the disappearance of the flying object, the acoustic signal remains in the continuous state after the monitoring radar 11 disappears the flying object. It is determined whether the monitoring radar 11 redetects the flying object within a predetermined range (S110). When the control device 21 determines that the monitoring radar 11 has re-detected the flying object within a predetermined range from the vanishing point of the flying object, the flying object is the same as the flying object before the disappearance. It determines with it being an object (S111), returns to S102, and monitors a flying object continuously.

  Note that when the monitoring radar 11 determines in S104 that the flying object being tracked has disappeared and the acoustic signal continues and the continuous monitoring process is performed, the monitoring radar 11 is displayed as a soft key on the display screen of the display device 22, for example. The user may instruct to stop imaging of the imaging device 12 by operating the user input means 22a, and forcibly end when there is no acoustic signal. As a result, if the monitoring radar 11 cannot observe an acoustic signal such as a bird when the flying object disappears, the monitoring is forcibly stopped even if it can be visually recognized by the imaging device 12, and monitoring is performed when the acoustic signal is observed. Can be left to the user to improve convenience.

  Moreover, when the acoustic signal is continuously detected in S107 to S110, the continuous monitoring process is performed, but the present invention is not limited to this. For example, when the angle of view captured by the camera image captured by the imaging device 12 is wider than the monitoring range E of the monitoring radar 11, the monitoring person can visually check whether or not the flying object is reflected in the camera image. A user interface (user input means not shown) for instructing whether or not to process may be displayed on the display screen of the display device 22. In other words, when the flying object disappears, a user interface is displayed on the display screen of the display device 22 for instructing whether or not the monitoring person confirms the image and performs the continuous monitoring process, and the continuous monitoring process is performed after waiting for the user input. It may be determined whether or not. In addition, the user interface at that time can be composed of buttons, keys, switches, and the like provided on the control device 21 and the main body of the display device 22 in addition to soft keys on the display screen of the display device 22.

  Further, if the acoustic signal cannot be detected before disappearance in S105, it is highly possible that the sound signal is not a drone, and the initial state is quickly restored (S101). As a result, it is possible to guard against other flying objects. Further, when the acoustic signal is continuously detected, the monitor can return to the initial state after performing the input operation by performing visual observation with the camera image, so that more reliable monitoring can be performed.

  Moreover, as shown by a dotted line in FIG. 1, it is good also as a structure which provides the anemometer 4 which measures a wind speed and a wind direction. In this case, the anemometer 4 is provided, for example, in the vicinity of the monitoring radar 11 or in the monitoring region, and transmits measurement information (wind speed information, wind direction information) to the control device 21. Then, as the crash determination in S112 described above, a condition that the wind speed measured by the anemometer 4 is equal to or higher than the set value when there is a sudden change in the acoustic signal in S106 is added and the flight is performed when this condition is satisfied. If it is determined that the object has crashed and the wind speed is less than the set value, the process may proceed to S107. As a result, the flying object crash determination can be performed with higher accuracy.

  Further, in S101, the detection condition of the flying object may be added to the condition that the acoustic signal is detected in addition to the detection by the radar. In this case, the process of S105 is omitted.

  The best mode of the flying object monitoring system according to the present invention has been described above, but the present invention is not limited by the description and drawings according to this mode. That is, it is a matter of course that all other forms, examples, operation techniques, and the like made by those skilled in the art based on this form are included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Flying object monitoring system 2 Monitoring apparatus 3 Center apparatus 4 Anemometer 11 Detection means (monitoring radar)
DESCRIPTION OF SYMBOLS 12 Imaging device 13 Acoustic signal processing device 14 Radar signal processing device 15 Data processing device 21 Control device 22 Display device 22a User input means W (W1, W2) Flying object E Monitoring range C Monitoring point required

Claims (6)

Detecting means for detecting a flying object in a predetermined monitoring area;
An acoustic signal acquisition means for acquiring an acoustic signal in the monitoring area;
A flying object monitoring system comprising:
When a flying object detected by the detection unit disappears during tracking, a flying object monitoring system is configured to perform a determination according to a change in an acoustic signal before and after the disappearance of the flying object. Before the disappearance of the flying object, the acoustic signal is observed at a first reference value or more, the flying object disappears, and the acoustic signal falls below a second reference value within a first predetermined time from the disappearance. The flying object monitoring system according to claim 1, wherein it is determined that the flying object has crashed when it becomes. Further equipped with an anemometer that measures the wind speed and direction,
The flying object monitoring system according to claim 2, wherein the flying object is determined to have fallen when the measurement information by the anemometer satisfies a predetermined condition. 2. The flying object monitoring system according to claim 1, wherein after the flying object disappears, the flying object detected again while the acoustic signal continues to be equal to or more than the first reference value is determined to be the same. . After the flying object disappears, if the acoustic signal falls below the second reference value within the second predetermined time after the first predetermined time has elapsed, the position is set as a monitoring point required. The flying object monitoring system according to claim 2. Detecting means for detecting a flying object in a predetermined monitoring area;
Imaging means for imaging a flying object detected by the detection means;
Display means for displaying a picked-up image picked up by the image pickup means;
An acoustic signal acquisition means for acquiring an acoustic signal in the monitoring area;
In the case of acquiring a captured image until the flying object disappears, user input means for instructing the acquisition stop of the captured image;
A flying object monitoring system comprising:
When the flying object being detected by the detection means disappears, if the acoustic signal continues before and after the disappearance of the flying object, it is necessary to input whether or not to stop imaging from the user input means, and the acoustic signal A flying object monitoring system, which is forcibly terminated when there is not.