JP6644561B2 - Flying object monitoring system - Google Patents

Description

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

  In recent years, small and unmanned multicopters called drones have been put to practical use, and are effectively used for various purposes such as spraying pesticides and inspecting facilities. On the other hand, crimes abusing drones, such as voyeurism and transport of dangerous goods, are also becoming a concern, and systems for detecting such drones at an early stage are beginning to appear.

  Conventionally, for example, as disclosed in Patent Document 1 below, an intruding object that intrudes into a specific monitoring area is set as a monitoring target, and when an intruding object is detected by a detection unit, the intruding object is displayed on a remote monitoring monitor and checked by a monitor. Possible monitoring devices are known.

JP 2012-198802 A

  In a conventional monitoring device, when a flying object is detected in a monitoring area, a radar image or a monitoring camera image is displayed on a display device of a monitoring console of a remote center device, and a monitoring person views the radar image or the monitoring camera image. To monitor flying objects. At that time, if the radar cannot detect the flying object being tracked by the radar, if there is no other flying object, the observer completes the monitoring work on the monitoring console and returns to the standby state.

  However, the tracked flying object may temporarily fall outside the radar monitoring range, and after a while, the tracking object may return to the radar monitoring range again. Also, 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 wind.

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

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

In order to achieve the above 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,
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 detecting means disappears during tracking, a determination is made according to a change in an acoustic signal before and after the flying object disappears.

  Further, 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, 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 for measuring a wind speed and a wind direction,
When the information measured by the anemometer satisfies a predetermined condition, the flying object may be determined to have crashed.

  Further, the flying object monitoring system according to the present invention may determine that the flying object detected again while the acoustic signal continues to be equal to or greater than the first reference value is the same after the disappearance of the flying object. .

Furthermore, in the flying object monitoring system according to the present invention, after the flying object has disappeared, the acoustic signal has become equal to or less than the second reference value within a second predetermined time after the first predetermined time has elapsed. In this case, the position where the flying object has disappeared may be set as the monitoring required point.

Further, the flying object monitoring system according to the present invention, a detecting means for detecting a flying object in a predetermined monitoring area,
Imaging means for imaging the flying object detected by the detection means,
Display means for displaying a captured image taken by the imaging means;
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 stop of the capture of the captured image,
A flying object monitoring system comprising:
When the flying object being detected by the detecting means disappears, if the acoustic signal continues before and after the disappearance of the flying object, it is necessary to input from the user input means whether or not imaging has stopped, and the acoustic signal If there is no, the process is forcibly terminated.

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

  Also, according to the flying object monitoring system of 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, the acoustic signal within a first predetermined time from the disappearance Is determined to be lower than the second reference value. With this configuration, the monitor can take appropriate action when it is determined 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 is possible to take measures such as identification.

  Further, according to the flying object monitoring system of the present invention, the anemometer measures the wind speed and the wind direction. Then, when the information measured by the anemometer satisfies a predetermined condition, it is determined that the flying object has crashed. With this configuration, the fall determination of the flying object can be performed with higher accuracy by adding the measurement information of the anemometer to the condition for the fall determination of the flying object.

  According to the flying object monitoring system of the present invention, after the flying object disappears, the flying object whose acoustic signal is detected again while the acoustic signal is equal to or more than the first reference value is determined to be the same. With this configuration, when a flying object that has disappeared during tracking appears again, continuous determination can be performed 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 has disappeared, after the first predetermined time has elapsed, if the sound signal falls below the second reference value within the second predetermined time, The position where the flying object has disappeared is set as a required monitoring point. With such a configuration, for example, it is often difficult to confirm with the owner in case of accidental landing on a building, etc., but by setting it as a monitoring point required, the drone that emerged from the vanishing point again becomes suspicious. Can be estimated.

  Further, according to the flying object monitoring system of the present invention, the detecting means detects the flying object in the predetermined monitoring area. The imaging unit captures an image of the flying object detected by the detection unit. The display unit displays a captured image captured by the imaging unit. The acoustic signal acquiring means acquires an acoustic signal in the monitoring area. The user input unit instructs to stop acquiring the captured image when acquiring the captured image until the flying object disappears. If the flying object being detected by the detection means disappears, it is necessary to input the presence or absence of imaging stop from the user input means if the acoustic signal continues before and after the disappearance of the flying object. To end. With this configuration, if the sound signal cannot be observed like a bird when the detecting means disappears from the flying object, the monitoring is forcibly stopped even if it can be visually recognized by the imaging means, and the monitoring is performed when the sound signal is observed. Convenience can be improved by relying on user judgment.

FIG. 1 is a block diagram illustrating 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 showing the schematic structure of the radar for surveillance which constitutes detecting means of the flying object monitoring system concerning the present invention. It is a flowchart which shows the control content of the flying object monitoring system which concerns on this invention.

  Hereinafter, an embodiment for carrying out the present invention will be described in detail with reference to FIGS.

[Overview of the present invention]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flying object monitoring system for monitoring a flying object (for example, a drone or the like) flying in a monitoring area, which is installed at a predetermined height such as a building rooftop and has a monitoring range equal to or higher than the installation height. When the flying object detected by the detecting means (monitoring radar) for monitoring disappears during tracking, it has a function of making a different determination 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 detecting means disappears, if there is a sudden change (or disappearance) in the acoustic signal obtained from the microphone of the acoustic signal processing device, the monitoring of the monitoring radar is performed. If it is determined that the vehicle falls down outside the range, and if the sound signal can be continuously obtained as before the disappearance, it is determined that the flying object has temporarily moved out of the monitoring area, and continuous monitoring is performed. In this case, the flying objects detected within a predetermined range from the point where the acoustic signal disappears during the continuation are determined to be the same object. Alternatively, after the flying object has disappeared from the radar, after the acoustic signal has continued for a certain period of time, and thereafter, when the acoustic signal has disappeared, it is determined that the landing of the surveillance radar has landed downward outside the monitoring range, and the surrounding area is set as a necessary monitoring point. . Alternatively, when a three-dimensional sound array is employed as the sound signal processing device, after the moving direction of the sound source position determined from the sound signal after the flying object has disappeared from the radar descends, if the sound signal is lost, the landing is stopped. judge.

  When it is determined that the flying object has temporarily disappeared, the monitoring is continuously performed. On the other hand, when it is determined that the flying object has crashed, a response person is dispatched to the site to remove the flying object (eg, a drone). The operator who came to recover can be found. Thus, when the flying object being tracked cannot be detected by the monitoring radar, information can be provided so that the observer can take appropriate measures 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 for monitoring a flying object flying in a monitoring area, and a remote center device disposed at a position distant from the monitoring device 2. 3 and roughly.

  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 a monitoring radar 11 of the monitoring device 2 described later. 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, a point (monitoring required point C) which should be monitored intensively, such as an important facility, can be set.

  A monitoring device 2 including a monitoring radar 11 described below 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 described below near the monitoring radar 11 is provided. Is transmitted to the remote center device 3, and the camera image is displayed on the display device 22 of the monitoring console of the center device 3, which will be described later. The observer monitors the flying object W based on the camera image displayed on the display device 22 of the monitoring console.

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

[Monitoring device]
As shown in FIG. 1, the monitoring device 2 is installed at a predetermined position in a monitoring area so as to form a monitoring range E shown in FIG. 2, for example, and a monitoring radar 11 as a detection unit, an imaging device 12, an audio signal processing It comprises a device 13, 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 the monitoring area with a detection wave at a predetermined cycle, and has a certain height so as not to be affected by surrounding buildings and the like. It is fixedly installed at a predetermined position in the monitoring area, and includes a plurality of radars so that the hemisphere above the monitoring radar 11 can be monitored. The monitoring radar 11 adopts an FM-CW method of performing distance measurement using a frequency-modulated continuous wave as a transmission / reception wave transmitted from the radar, and is provided in a azimuth direction at a predetermined cycle (for example, one rotation / 1 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) by 360 degrees and transmitting and receiving radio waves at predetermined intervals (for example, 3 ms). In addition, the rotation speed of the monitoring radar 11 is set to a speed that is so small that the antenna can be regarded as stopped compared to the reciprocation time of the beam determined according to the maximum detection distance (for example, 100 m) of the radar. From the monitoring radar 11, an angle, a distance, a speed, and a reception intensity on a horizontal plane around the radar can be obtained as output information.

  Further, the configuration of the monitoring radar 11 will be described with reference to FIG. The monitoring radar 11 here is configured to monitor a hemispheric surface by combining two radar devices, an oblique monitoring radar and a top surface monitoring radar. Hereinafter, a case where the FM-CW radar is used for the 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 transmission beams obliquely upward and in the sky direction, and two reception antennas for receiving radio waves from a vertically divided region vertically transmitted from the region transmitted obliquely upward, and A reflected beam from the flying object W flying in the monitoring area is received by using two receiving antennas for receiving radio waves from above.

  Here, details of the principle of the FM-CW radar are omitted, but the outline will be described. The FM-CW radar as the monitoring radar 11 includes a transmitting antenna, a first receiving antenna, a second receiving antenna, It is configured to include a receiving antenna switch, a transmitting / receiving device, an A / D converter, and a signal processing device.

  Describing each part, the transmission antenna radiates a transmission beam forward. The first receiving antenna and the second receiving antenna receive a radio wave from a range of the transmission beam or a monitoring area obtained by dividing the range of the transmission beam. The receiving antenna changeover switch enables one of the first receiving antenna and the second receiving antenna alternately 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 converts the received beam intensity output from the transmission / reception device into a digital signal. The signal processing device obtains the relative distance and relative speed of the detection target in the monitoring area and the intensity of the reflected beam component from the detection target in the reception beam from the reception beam intensity output from the A / D converter.

  More specifically, the signal processing device analyzes the frequency of the reflected beam signal input from the A / D converter, and calculates the signal strength at each frequency. Next, a 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 calculated frequency of the reflected beam component from the detection target and the frequency of the transmission beam, and the relative distance and relative speed of the detection target are calculated and output from the beat frequency. I 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 monitoring area with a detection wave at a predetermined cycle to detect a detection target (flying object), and detects a relative distance, a relative velocity, and a relative speed of the detection target in the monitoring area. It is sufficient that various types of information regarding the detection target such as the intensity of the reflected beam component from the detection target can be acquired, and the configuration is not limited to the configuration illustrated in FIG.

[Imaging device]
The imaging device 12 is configured by 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 can be panned, tilted, and zoomed under the control of the control device 21 of the center device 3 so that the flying object W can be projected at the center of the screen. The shooting range is changed. The imaging device 12 operates in conjunction with the monitoring radar 11 so that the flying object W becomes the center of the image under the control of a control device 21 of the center device 3 based on the position information of the flying object W detected by the monitoring radar 11. The turn table 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. Further, by adopting a microphone array composed of a plurality of microphones vertically and horizontally at a predetermined distance, the direction of the sound source can be specified three-dimensionally.

  If a microphone array is employed, the judgment condition may be that the direction of the flying object detected by the monitoring radar 11 matches the sound source direction. Further, the number of microphones and the predetermined distance are determined according to a sampling cycle and a monitoring distance. The acoustic signal acquired by the microphone is amplified by a microphone amplifier, converted into a digital signal by an A / D converter, and transmitted to the center device 3 via the data processing device 15.

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

[Data processing device]
The data processing device 15 is connected to the radar signal processing device 14 by wire or wirelessly, performs signal processing on the output of the monitoring radar 11 acquired from the radar signal processing device 14, and determines that the flying object (for example, a drone) W is specified. 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 the monitoring radar 11, the imaging device 12, the acoustic signal processing device 13, the radar signal processing device 14, and the 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 of a monitoring console.

[Control device]
The control device 21 controls the entire system, and determines whether or not the monitoring radar 11 has detected the flying object W in the process of FIG. Whether the sound object has disappeared, whether or not there is an acoustic signal specific to the flying object before the disappearing of the flying object, whether or not the acoustic signal has changed suddenly, a predetermined time from when the flying object disappears (setting Within a predetermined range from the vanishing point of the flying object, and whether the monitoring radar 11 has redetected the flying object within a predetermined range. It performs pan / tilt / zoom control (hereinafter, referred to as PTZ control), display control of the display device 22, and the like.

  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 console 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 within the monitoring range E, the display device 22 displays a camera image captured by the imaging device 12 near the monitoring radar 11. At this 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 projected at the center of the screen.

  In addition, 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 on the display screen of the display device 22, the imaging device 12 is stopped. Then, the user input means 22a for instructing the stop of the acquisition 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 of the present embodiment having the above configuration, when the monitoring radar 11 detects a flying object flying in the monitoring area E, the monitoring object is displayed on the monitor screen of the display device 22 of the monitoring console in the center device 3. The camera image taken by the imaging device 12 near the radar 11 is displayed. Thus, the observer monitors the flying object while watching the monitor screen of the display device 22 of the monitoring console. When the surveillance radar 11 stops detecting the flying object, it returns to the standby state when no other flying object is detected. When the flying object disappears from the surveillance radar 11, the presence or absence of an acoustic signal is detected. The judgment is made different based on the

  Hereinafter, the 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 or absence of the 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 the flying object W flying in the monitoring area based on the presence or absence of the determination signal from the data processing device 14. (S101).

  When the control device 21 determines that the monitoring radar 11 detects the flying object, the control device 21 turns the imaging device 12 toward 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 display of the camera image captured by the PTZ-controlled imaging device 12 on the display device 22 of the monitoring console (S103). In this way, at the monitoring console, the observer performs the task of monitoring the flying object while watching the monitor of the display device 22.

  Next, the control device 21 determines whether the flying object being tracked by the monitoring radar 11 has disappeared (S104). If the control device 21 determines that the monitoring radar 11 has not lost the flying object being tracked, it performs PTZ control so that the imaging device 12 tracks the flying object following the movement of the flying object. Note that whether or not the detected flying object is being tracked is determined based on a moving distance, a moving direction, and the like from a detection position of the flying object detected immediately before.

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

  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 propeller sound of the drone differs depending on the model, a relatively wide frequency band is used as the monitoring band. If a microphone array is used for the acoustic signal processing device 13, it is determined whether the direction of the flying object that has disappeared in the monitoring radar 11 matches the direction obtained from the output signal of the microphone array. In addition, the present invention can be applied to a flying object having no propeller as described above by detecting a flight sound unique to each flying object.

  When the control device 21 determines that there is an acoustic signal specific to the flying object from the microphone 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. (Including the case where the acoustic signal has disappeared) (S106).

  In the determination of the sudden change of the acoustic signal here, for example, after the acoustic signal obtained from the microphone is processed by a digital filter passing through the specific frequency band, the absolute value (or square value) of the amplitude value is obtained, and Intensity data and frequency spectrum smoothed in the direction are obtained, and this time-series data can be used. A predetermined reference (reference value) is set for the change in the calculated intensity data, and the flying object has an intensity equal to or higher than the predetermined reference value (first reference value) immediately before disappearance, and the flying object has disappeared. Thereafter, when the intensity falls within a predetermined reference value (second reference value) lower than the first reference value within a predetermined time (first predetermined time), it is determined that the acoustic signal has suddenly changed. Alternatively, it is determined that the acoustic signal has suddenly changed if the change in the intensity of the acoustic signal after the disappearance of the flying object has decreased within a first predetermined time by more than a predetermined reference from before the disappearance. Furthermore, when the frequency of the sound signal rises or falls by a certain level or more before and after the disappearance of the flying object, it may be determined that the sound signal has suddenly changed.

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

  In addition, when the flying object crashes as described later, the sound signal is almost lost due to the loss of power and the propeller stops, so the second reference value is set to a low value close to the noise level. You.

  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, the control unit 21 moves the flying object downward outside the monitoring range E of the monitoring radar 11. It is determined that the vehicle has crashed (S112). If it is determined that the flying object has crashed, the observer can instruct the dispatch of a response staff near the crash location. Since the fall of the flying object is presumed to be unintended by the operator, it is assumed that the operator will come to recover the crashed flying object, and it is possible to secure the operator by responding early. Become.

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

  The control device 21 determines that the sound signal has become equal to or less than a predetermined reference value (second reference value) within a first predetermined time for determining the above-mentioned crash from the disappearance of the flying object and within a second predetermined time. If it is determined that the point has disappeared, the vanishing point and its surroundings are registered as monitoring required points (S109). It is assumed that the Service-to-Self lands the flying object outside the monitoring range of the monitoring radar 11 before the event, etc., and executes a crime when the event occurs. However, when a flying object is detected from the point at the time of the event, the flying object can be dealt with as a priority alert target.

  In the above description, the second predetermined time is appropriately set according to the installation height of the monitoring radar 11, the lowest speed at which the target flying object can descend, and the like. In addition, if the sound signal processing device 13 is configured by a microphone array and the three-dimensional movement of the sound source can be detected, it is necessary to determine that the moving direction of the sound source has moved downward in S109, and has become equal to or less than a predetermined value. You may make it register as a monitoring point.

  When the control device 21 determines that the sound signal has not stopped within the second predetermined time after the disappearance of the flying object, the sound signal remains in a continuous state after the monitoring radar 11 has lost the flying object. It is determined whether the monitoring radar 11 has re-detected the flying object within the predetermined range (S110). Then, when the control device 21 determines that the monitoring radar 11 has redetected the flying object within a predetermined range from the vanishing point of the flying object while the acoustic signal is continuing, the flying object is the same as the flying object before disappearance. It is determined that the object is an object (S111), and the process returns to S102 to continuously monitor the flying object.

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

  In the case where 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, if 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 personnel can visually check whether or not the flying object is included in the camera image. A user interface (user input means not shown) for instructing whether or not to perform the processing may be displayed on the display screen of the display device 22. That is, when the flying object disappears, the monitor displays a user interface on the display screen of the display device 22 for instructing whether or not to perform the continuous monitoring process by checking the image and wait for a user input to perform the continuous monitoring process. Alternatively, it may be determined. The user interface at this time can be configured 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 on the display screen of the display device 22.

  Further, when the sound signal cannot be detected before disappearance in S105, it is likely that the sound signal is other than a drone, and thus the sound signal is quickly returned to the initial state (S101). As a result, it is possible to watch other flying objects. In addition, when the acoustic signal is continuously detected, the observer can perform visual input using the camera image and return to the initial state after performing an input operation, so that more reliable monitoring can be performed.

  Further, as shown by a dotted line in FIG. 1, an anemometer 4 for measuring a wind speed and a wind direction may be provided. In this case, the anemometer 4 is provided, for example, at several locations near the monitoring radar 11 or in the monitoring area, and transmits measurement information (wind speed information, wind direction information) to the control device 21. Then, as the above-described crash determination in S112, a condition that the wind speed measured by the anemometer 4 is equal to or higher than the set value when the acoustic signal suddenly changes in S106 is added, and when this condition is satisfied, the flight is performed. 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, it is possible to more accurately determine the fall of the flying object.

  In step S101, detection of an acoustic signal may be added to the condition for detecting a flying object in addition to detection by a radar. In this case, the process of S105 is omitted.

  As described above, the best mode of the flying object monitoring system according to the present invention has been described, but the present invention is not limited by the description and the drawings according to this mode. That is, it goes without saying 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.

Reference Signs List 1 flying object monitoring system 2 monitoring device 3 center device 4 anemometer 11 detecting means (monitoring radar)
Reference Signs List 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 required points

Claims (6)

Detecting means for detecting a flying object within a predetermined monitoring area;
Acoustic signal acquisition means for acquiring an acoustic signal in the monitoring area,
A flying object monitoring system comprising:
A flying object monitoring system, characterized in that when a flying object detected by the detection means disappears during tracking, a determination is made according to a change in an acoustic signal before and after the flying object disappears. Before the disappearance of the flying object, the sound signal is observed at a first reference value or more, the flying object disappears, and within a first predetermined time from the disappearance, the sound signal falls below a second reference value. The flying object monitoring system according to claim 1, wherein it is determined that the flying object has crashed when the flying object has fallen. Further equipped with an anemometer to measure wind speed and direction,
The flying object monitoring system according to claim 2, wherein the flying object is determined to have crashed when measurement information obtained by the anemometer satisfies a predetermined condition. 2. The flying object monitoring system according to claim 1, wherein after the disappearing of the flying object, 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. 3. If the sound signal falls below the second reference value within a second predetermined time after the elapse of the first predetermined time after the disappearance of the flying object, the position at which the flying object has disappeared is required. The flying object monitoring system according to claim 2, wherein the system is set as a monitoring point. Detecting means for detecting a flying object within a predetermined monitoring area;
Imaging means for imaging the flying object detected by the detection means,
Display means for displaying a captured image taken by the imaging means;
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 stop of the capture of the captured image,
A flying object monitoring system comprising:
When the flying object being detected by the detecting means disappears, if the acoustic signal continues before and after the disappearance of the flying object, it is necessary to input from the user input means whether or not imaging has stopped, and the acoustic signal A flying object monitoring system forcibly terminating if there is no such object.