JP6672037B2 - Target object detection device - Google Patents

Description

  The present invention relates to a target object detection device that detects a target object (for example, a flying object such as a drone) existing in 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 transporting dangerous goods, are also becoming a concern, and systems that detect such drones entering the surveillance area at an early stage are beginning to appear.

  Conventionally, as disclosed in, for example, Patent Documents 1 and 2 described below, a radar and a radar for compensating parts that are mutually weak for the purpose of monitoring a flying object flying while emitting sound or preventing erroneous detection are provided. There is known a sensor that attempts to make a composite determination by combining the sensors.

JP-A-60-174970 JP 2003-98254 A

  Patent Document 1 describes that an early warning can be performed by adding an acoustic array to a radar apparatus and capturing a flying object approaching from a blind spot of the radar with the acoustic array. Patent Document 2 describes that it is determined whether the radar signal processing or the acoustic signal processing is the most suitable information source for specifying a target object in accordance with the type of the target object.

  The above Patent Literatures 1 and 2 perform determination using an output result of either a radar or an acoustic array. However, when determining a detection object by integrating the results of both, a high-speed flying object or the like is used. Even if the directivity of the acoustic array is controlled in the detection direction after the radar detects an object, correct determination cannot be made unless the object detected by the radar already exists at the detection position.

  In addition, when a plurality of objects are detected, if the radar determines whether or not the object is a target object and controls the directivity in the direction of the object to determine whether the object is the target object, a delay occurs in processing. there's a possibility that.

  An object of the present invention is to solve the above-described problems, and to accurately detect the position of a target object without losing a target object existing in the monitoring region and without detecting a noise source in the monitoring region as a false report. It is an object of the present invention to provide a target object detection device that can be obtained well.

In order to achieve the above object, the target object detection device according to the present invention transmits a predetermined transmission wave, and an object detection unit capable of detecting at least a distance and a direction to an object from a reflected wave with respect to the transmission wave,
Sound signal input means arranged in a plurality of spaces,
Storage means for predetermined past time period storage going back from the current with time information a plurality of acoustic signals input to the plurality of acoustic signal input means,
Sound signal processing means for processing the plurality of sound signals to identify a sound source direction,
An object detection device comprising:
Said sound signal processing means, when said object detecting means detects the object, obtains the detection time, and processes the acoustic signal in said stored detection time in the storage means to identify the sound source direction, and the detection When the direction of the object substantially matches the specified sound source direction, it is determined that there is a target object.

Further, the object detecting device according to the present invention may be configured such that the object detecting means includes an antenna for transmitting and receiving a radio wave having a narrow beam width in an azimuth direction and a wide beam width in an elevation direction, and a rotation mechanism for rotating the antenna at a predetermined cycle. With the distance and azimuth from the reflected wave to the detection object for the transmitted wave transmitted from the antenna, and the elevation range can be specified,
The sound signal processing means determines that the target object is present when the delay sum signal is equal to or larger than a threshold value at an elevation angle at which the delay sum signal generated by performing the delay sum process on the audio signal is within the elevation angle range. You may.

  Furthermore, in the target object detection device according to the present invention, the object detection means may include a plurality of antennas having different elevation ranges, and set the elevation range based on the antenna that has detected the object.

Further, the target object detection device according to the present invention, the value of the threshold is set to be smaller the further away,
The sound signal processing means may acquire distance information from the object detection means, and may determine the presence or absence of the target object by comparing a threshold set at the distance with the delay sum signal.

  Furthermore, the target object detection device according to the present invention further includes an imaging unit capable of changing the imaging direction, and when a plurality of target objects to be detected are detected, a monitoring priority is determined for each of the target objects, The current position information of the target object having a high monitoring priority may be acquired from the object detection unit to control the imaging direction of the imaging unit.

  According to the target object detection device of the present invention, the object detection means transmits a predetermined transmission wave and detects at least a distance and a direction from the reflected wave to the transmission wave to the object. A plurality of sound signal input units are arranged in the space, and acquire sound signals from the monitoring area. The storage unit stores the sound signals input to the plurality of sound signal input units together with the time information for a predetermined past time that is retroactive from the present. The sound signal processing means is for processing a plurality of sound signals to specify a sound source direction, and when the object detection means detects an object, acquires the detection time and outputs the sound signal at the detection time stored in the storage means. The sound source direction is specified by the processing, and when the direction of the detected object substantially matches the specified sound source direction, it is determined that the target object is present. With such a configuration, a plurality of acoustic signals acquired from the monitoring area are stored in the storage unit together with time information for a predetermined past time that is retroactive from the present, and when the object is detected by the object detection unit, the object is detected. The sound source direction at the detection time is specified by processing the acoustic signal of the storage means corresponding to the detected detection time, and it is determined that the target object is present when the direction in which the object is detected substantially matches the specified sound source direction. The position of the target object can be obtained with high accuracy without losing the object and without detecting the noise source in the monitoring area as a false report.

  Further, according to the target object detection device of the present invention, the object detection means includes an antenna for transmitting and receiving radio waves having a narrow beam width in the azimuth direction and a wide beam width in the elevation direction, and a rotation mechanism for rotating the antenna at a predetermined cycle. The distance, the azimuth, and the elevation angle range from the reflected wave to the detection object with respect to the transmission wave transmitted from the antenna are specified. The sound signal processing means, within the elevation angle range specified by the object detection means, at the elevation angle where the delay sum signal generated by the delay sum processing of the sound signal is the largest, and when the delay sum signal is equal to or greater than the threshold, the target object is present judge. With this configuration, the distance, the azimuth, and the elevation angle range from the reflected wave to the detection object with respect to the transmission wave transmitted from the antenna are specified, and the delay sum signal is thresholded at the elevation angle at which the delay sum signal within the specified elevation angle range becomes the maximum. At this time, it can be determined that the target object exists in the monitoring area.

  Further, according to the target object detection device of the present invention, the object detection means includes a plurality of antennas having different elevation ranges, and sets the elevation range based on the antenna that has detected the object. With this configuration, the elevation angle search range can be limited by forming the antennas having different elevation angle ranges in a multi-stage configuration.

  Further, according to the target object detection device of the present invention, the threshold value is set so as to decrease as the distance increases. Then, the sound signal processing unit acquires the distance information from the object detection unit, and compares the threshold set at the acquired distance with the delay sum signal to determine the presence or absence of the target object. With such a configuration, a threshold value is set so as to become smaller as the distance increases, distance information is acquired from the object detection means, and the threshold value corresponding to the distance of the acquired distance information is compared with the delay sum signal to obtain the target object. The presence or absence can be determined.

  Further, according to the target object detection device of the present invention, the image pickup unit is provided with a variable imaging direction, and when a plurality of target objects to be detected are detected, a monitoring priority is set for each target object. The current position information of the high-priority target object is acquired from the object detection means, and the imaging direction of the imaging unit is controlled. With this configuration, when a plurality of target objects are detected, the current position information of the target objects having a high monitoring priority can be acquired from the object detection unit and the imaging direction of the imaging unit can be controlled.

It is a block diagram showing the whole object object detecting device composition concerning the present invention. FIG. 3 is a schematic perspective view of a monitoring range in the target object detection device according to the present invention. It is a figure showing the schematic structure of the surveillance radar in the object detection device concerning the present invention. It is the schematic which shows an example of the microphone array in the target object detection apparatus concerning this invention. 5 is an operation flowchart of the target object detection device according to the present invention.

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

[Overview of the present invention]
The present invention relates to a target object detection device that detects an object that is present in a predetermined monitoring area and moves while emitting an acoustic signal of a predetermined level or higher as a target object (for example, a flying object such as a drone).

  The target object detection device is equipped with a radar and a microphone array, and when an object is detected by both of them, an alarm is output when a target object (a moving object that emits sound) is detected, and the detected object is detected by the radar. Later, even if an attempt is made to determine the presence or absence of an object by controlling the directivity of the microphone array in the detection direction, if the detected object has already moved to another location, it may not be possible to determine the target object.

  Therefore, the target object detection device of the present invention performs buffering of data (sound signal) for a predetermined time by the microphones constituting the microphone array, and when the radar detects the object, the microphone array detects the object detection time from the radar. A function that processes the buffered data, specifies the sound source direction at the detection time of the object, and determines that the target object is present if the direction of the object detected by the radar substantially matches the specified sound source direction. Having.

[About configuration of target object detection device]
As shown in FIG. 1, a target object detection device 1 according to the present embodiment is schematically configured including an object detection unit 2, an audio signal input unit 3, an imaging unit 4, a control unit 5, and a display unit 6.

  The target object detection device 1 is installed at the center of a circle a shown by a dotted line in FIG. When the target object detection device 1 determines that the target object W within the monitoring range E is detected by the object detection unit 2, the imaging unit 4 installed near the object detection unit 2 performs imaging including the target object W. . Hereinafter, the target object W will be described as a flying object.

[Object detection unit (monitoring radar)]
The object detection unit 2 is configured by a monitoring radar for detecting a flying object W within the monitoring range E. The monitoring radar 2 is fixedly installed at a predetermined position in a monitoring area, and is configured to monitor a hemispherical monitoring range E by combining a plurality of radars.

  The monitoring radar 2 adopts an FM-CW method for performing distance measurement using a frequency-modulated continuous wave as a transmission / reception wave transmitted from the radar, and has a predetermined cycle (for example, one rotation / 1 second) in the azimuth direction. The azimuth angle 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 every predetermined period (for example, 3 ms).

  Further, the rotation speed of the monitoring radar 2 is set to a speed that is small enough that the antenna can be considered to be stopped, as compared with the reciprocating time of the beam determined according to the maximum detection distance (for example, 100 m) of the radar. .

  Two receiving antennas that radiate a transmission beam (for example, 60 degrees) wider than the horizontal beam width in the diagonally upward direction and the sky direction in the elevation direction, and receive radio waves from a vertically divided area that is transmitted diagonally upward, And a reflected wave from the flying object W that has entered the monitoring area by using two receiving antennas (for example, 30 degrees) that receive a received wave from the sky direction.

  The monitoring radar 2 adopts the FM-CW method as the radar method, and thus, the azimuth of the flying object W centered on the radar, the distance to the object, the speed, the reception intensity, the elevation angle monitored by the detected reception antenna. Range information can be obtained.

  Further, the configuration of the monitoring radar 2 will be described with reference to FIG. The monitoring radar 2 here is configured to monitor a hemispherical monitoring range E 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. As shown in FIG. 3, the FM-CW radar installed at the fixed position emits transmission beams T1 and T2 obliquely upward and in the sky direction, respectively. The reflected beam from the flying object W existing in the monitoring area is received by using two receiving antennas for receiving the radio wave R1 and the two receiving antennas for receiving the radio wave R2 from above.

  Although the detailed description of the principle of the FM-CW radar is omitted here, the FM-CW radar as the monitoring radar 2 is generally described as having a transmitting antenna, a plurality of receiving antennas, a transmitting / receiving device, It is configured to include a D converter and a signal processing device.

  Describing each part, the transmission antenna radiates a transmission beam forward. The plurality of receiving antennas having different elevation ranges receive radio waves from a transmission beam range or a monitoring area obtained by dividing the transmission beam range. 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 velocity of the flying object W in the monitoring area from the intensity of the received beam output from the A / D converter, and the intensity of the reflected beam component from the flying object W in the received beam.

  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 flying object W. Then, the beat frequency is calculated by calculating the difference between the calculated frequency of the reflected beam component from the flying object W and the frequency of the transmission beam, and the relative distance and relative speed of the flying object W are calculated and output from the beat frequency. I do. In addition, the signal processing device outputs an azimuth angle based on at which position the rotating radar has detected the flying object W. Further, the signal processing device outputs which one of the plurality of receiving antennas has received the signal. Thereby, the elevation angle range can be obtained.

  The monitoring radar 2 only needs to be able to acquire various information on the flying object W such as the relative distance and relative speed of the flying object W present in the monitoring area and the intensity of the reflected beam component from the flying object W in the reception beam. However, the present invention is not limited to the FM-CW radar shown in FIG. For example, a two-frequency CW and a pulse Doppler radar can be applied as another radar method. Further, as a sensor other than the radar, a scanning laser area sensor can be applied.

[Acoustic signal input section]
The sound signal input unit 3 includes a microphone array including a plurality of microphones, a microphone amplifier, a multi-channel A / D converter, and the like.

  FIG. 4 shows an image diagram of the input section of the microphone array. In order to measure the three-dimensional spatial position of the sound source, the microphones in the microphone array require a minimum of four microphones, three microphones and one microphone that is not flush with these three microphones. . FIG. 4 shows an example in which a plurality of microphones M are arranged at predetermined intervals on each side of the triangulation.

  Note that the number of microphones increases as noise suppression performance and direction detection accuracy improve, and is appropriately set according to the monitoring distance from the monitoring radar 2.

  Further, the input unit of the microphone is not limited to the shape shown in FIG. 4, but may be, for example, a spherical shape, and the microphone may be arranged on this spherical surface.

  An omni-directional condenser microphone can be used as a microphone that is an acoustic signal acquisition unit in the monitoring area.

  In addition, the distance between the microphones is set to a value (a phase difference is likely to occur) in which the direction can be sufficiently estimated in relation to the main frequency band (wavelength) of the acoustic signal generated by the flying object W.

  The sound signal input unit 3 amplifies the sound signal obtained by the microphone with a microphone amplifier, converts the sound signal into a digital signal with an A / D converter, and outputs the digital signal to the control unit 5.

[Imaging unit]
The imaging unit 4 is configured by a high-resolution, high-sensitivity camera having pan, tilt, and zoom functions. The imaging unit 4 is fixedly installed at a position where the monitoring area can be imaged, and can be panned, tilted, and zoomed under the control of the control unit 5, and the imaging range is set so that the target flying object W can be projected at the center of the screen. Variable.

  The imaging unit 4 is linked with the monitoring radar 2 and turns the swivel base so that the flying object W is at the center of the image under the control of the control unit 5 based on the position information of the flying object W detected by the monitoring radar 2. The vertical direction is adjusted, the captured image is transmitted to the display unit 6 via the control unit 5, and is displayed on a monitor.

  The acoustic signal input unit 3 and the imaging unit 4 may be installed above or below the monitoring radar 2 or at another location near the monitoring radar 2. Further, the relative positions of the monitoring radar 2, the acoustic signal input unit 3, and the imaging unit 4 are stored in a storage unit (not shown) different from a storage unit 5b of the target object detection device 1 described later.

[Control unit]
When the control unit 5 performs signal processing on the output of the monitoring radar 2 (each radar output) and the output of the acoustic signal input unit 3 (output of the microphone array) and determines that the object is a flying object W (for example, a drone), the imaging unit 4 It outputs a captured camera image to the display unit 6, and includes a radar signal processing unit 5a, a storage unit 5b, an acoustic signal processing unit 5c, and a determination unit 5d.

  Each of the processing units may be configured to be included in one device, or may be realized by providing a control unit in a plurality of separated devices. For example, a control unit including a monitoring radar 2 and a control unit including a radar signal processing unit 5a for processing signals of the monitoring radar 2, and a control unit including a microphone array and an acoustic signal processing unit 5c for processing signals of the microphone array May be connected via a communication network to implement the target object detection device 1. In this case, even when a transmission delay occurs between the two devices, the flying object W is detected by transmitting detection time information at which the monitoring object 2 has detected the flying object W together with the detection information to the acoustic signal processing unit 5c. The presence or absence of an acoustic signal at the time can be confirmed.

(Radar signal processing unit)
The radar signal processing unit 5a performs noise removal processing or the like from the information output by the monitoring radar 2, and determines whether there is a possibility that the object is a flying object W based on the intensity, magnitude, speed, and the like of the signal output by the monitoring radar 2. It determines whether or not.

(Storage unit)
The storage unit 5b is a ring buffer that associates time information when the sound signal was obtained with the sound signal obtained by each microphone of the microphone array of the sound signal input unit 3 and temporarily stores data for a certain period in the past that is retroactive from the present. It consists of functional memory, and when the memory capacity is full, old data is erased.

  Note that the buffer size is set at least based on a processing delay time in the radar signal processing unit 5a and a delay time such as a transmission delay time when the radar signal processing unit 5a and the acoustic signal processing unit 5c are realized by separate devices. . Alternatively, when a plurality of flying objects W are detected in the monitoring area, the tracking of the other flying objects W may be started after tracking from appearance to disappearance of the flying object W based on the priority. Alternatively, the buffer size may be set with some allowance.

(Acoustic signal processing unit)
The sound signal processing unit 5c processes the output signal of the microphone array of the sound signal input unit 3 to specify the sound source direction. As the sound source direction specifying process for specifying the sound source direction, a correlation function, a delay-and-sum array, a high-resolution method, and the like are known (Oga, Yamazaki, Kaneda, "Sound system and digital processing," IEICE, 1995, pp.199-200).

Here, the principle will be described using a case where a delay-and-sum array is used as an example. For the sake of simplicity, when the sound source arrives from the direction of θ _L with respect to the microphones M _{1 to} M _m arranged on a straight line at an interval d, the signal received by the reference microphone M ₁ and another signal A delay of (m−1) (dsin θ _L ) / c occurs between signals received by the microphone.

The addition of each delay received sound signals from the microphones, signals received sound from the microphones are in phase with, adding the in-phase coded signal, the signal arriving from the sound source direction theta _L is emphasized. On the other hand, signals arriving from sources other than θ _L are not in-phased and are not emphasized even when added. Thereby, the directivity can be controlled to be directed to the sound source direction. Also in the case of a microphone array arranged three-dimensionally instead of a straight line, the microphone position is known, so that signals arriving from a specific direction can be geometrically in-phase.

Here, the output signal of the microphone array is monitored by scanning the target direction θ _L , and the angle at which the output signal becomes maximum can be specified as the sound source direction.

  In the present invention, information on the elevation angle range is acquired from the radar signal processing unit 5a as the detection information of the flying object W based on the azimuth and which receiving antenna has detected.

  Then, for the signal of each microphone corresponding to the time information detected by the monitoring radar 2 stored in the storage unit 5b, the azimuth uses the value acquired from the monitoring radar 2, and the elevation angle is determined by the receiving antenna detected. The output signal of the microphone array is monitored by scanning within the monitored angle range, and the angle at which the power becomes maximum is specified as the elevation angle.

  As described above, the acoustic signal processing unit 5c can narrow the scanning range by acquiring the azimuth and elevation range information acquired from the radar signal processing unit 5a, and can speed up the processing. Further, even when there are a plurality of sound sources, it is only necessary to determine the presence or absence of a sound source only in the direction of the target flying object W, so that the processing can be speeded up.

(Judgment unit)
The determination unit 5d determines the target flying object W in the direction of the flying object W detected by the radar signal processing unit 5a if the delay sum signal, which is the output signal of the microphone array of the acoustic signal input unit 3, is equal to or more than a predetermined value. It is determined that it has been detected.

  Specifically, the determination unit 5d determines the presence or absence of an audio signal based on whether the maximum amplitude value of the delay-sum signal subjected to the delay-sum processing or the power average value within a predetermined period exceeds a predetermined threshold.

  Since the sound signal is attenuated according to the distance, it is desirable that the threshold value is set so as to decrease according to the distance from the microarray. Normally, in the delay-and-sum processing by the microphone array, the sound source direction can be specified, but the distance to the sound source cannot be specified. However, by acquiring the distance information from the monitoring radar 2, it can be determined that there is an acoustic signal when the delay sum signal output exceeds a threshold set according to the distance. The threshold value set according to the distance may be set based on a theoretical value of the distance attenuation of the acoustic signal, or may be set based on an experimental value according to a setting environment of the microphone array. .

[Display]
The display unit 6 is a monitor that is connected to the control unit 5 and installed on a monitoring console, and displays a nearby camera image detected by the monitoring radar 2.

  When the monitoring radar 2 detects the flying object W in the monitoring area, the display unit 6 controls the control unit 5 to display a camera image captured by the imaging unit 4 near the monitoring radar 2. At that time, the control unit 5 performs pan / tilt / zoom control (hereinafter, referred to as PTZ control) of the imaging unit 4 based on the position information of the flying object W acquired from the monitoring radar 2, and the detected flying object W So that it can be projected in the center of the screen.

[Operation of target object detection device]
Next, the operation of the control unit 5 in the target object detection device 1 configured as described above will be described with reference to the flowchart of FIG.

  Here, an artificial flying object that has entered the monitoring area, whether manned or unmanned, is operated autonomously or by a person, and is a flying object that generates an acoustic signal during flight. And Specific examples of the target object W include a multicopter such as a drone, a helicopter, and a radio control airplane.

  First, the control unit 5 determines whether the monitoring radar 2 has detected the flying object W (S101). When the monitoring radar 2 detects a plurality of flying objects W, the processing is performed from the flying object W closer to the important monitoring point existing in the monitoring area.

  When the surveillance radar 2 detects the flying object W from the reflected wave (S101-Y), the radar signal processing unit 5a of the control unit 5 performs noise removal processing on the radar signal from the surveillance radar 2 as radar signal processing. Is performed (S102). Thereafter, a flying object such as a bird or a plastic bag is obviously excluded as a non-target object from the detected flying speed, size, and the like of the flying object W.

  As a result of the processing in S102, the control unit 5 determines whether there is a possibility that the flying object W is the target object (S103), and satisfies the determination condition that the size of the flying object W is equal to or larger than a predetermined value. If there is a possibility that the flying object W is an object, the process proceeds to S104. If the flying object W is a non-target object, the process proceeds to S107.

  When determining that there is a possibility that the flying object W is the target object (S103-Y), the control unit 5 selects any one of the distance information, the azimuth angle, and the plurality of receiving antennas of the flying object W detected from the radar signal processing unit 5a. To acquire information (information for specifying a reception area). The control unit 5 also obtains time information when it is determined that there is a possibility that the flying object W is the target object.

  Subsequently, the control unit 5 reads from the storage unit 5b an input signal of the microphone corresponding to the time information at which the flying object W was detected. Based on the information of the azimuth angle and the elevation angle range obtained from the monitoring radar 2, the angle of the read microphone input signal is scanned by delay-sum processing in the elevation angle range, and the angle at which the output of the microphone array is maximized is fly. It is specified as the elevation angle of the object W (S104).

  The control unit 5 controls the azimuth angle obtained by the monitoring radar 2, the maximum amplitude value of the delay sum signal of the microphone array in the direction specified by the elevation angle obtained by the delay sum processing in S104, or the power average value within a predetermined period. The presence / absence of an acoustic signal is determined based on whether or not a predetermined threshold is exceeded (S105).

  The threshold value is selected based on the distance information acquired from the monitoring radar 2, and is set to be smaller according to the distance from the microphone array as described above.

  When the control unit 5 determines that the detected flying object is the target object based on the determination result by the monitoring radar 2 in S103 and the determination result by the microphone array in S105 (S105-Y), it is determined whether or not to be alerted with priority. Are set (S106). In this example, the priority of the object detected first is set to first. If there is another object with a priority set, it is determined which object should be watched with priority, and the priority is set.

  The priority order is set by comparing the distance to an important monitoring point existing in the monitoring area, the approach speed, and the like.

  If the control unit 5 sets a priority (S106) or determines that there is no possibility of the flying object W being the target object (S103-N), the control unit 5 determines whether there is another flying object W in the monitoring area. Is determined (S107). When the control unit 5 determines that there is another flying object W in the monitoring area and there are a plurality of flying objects W in the monitoring area (S107-Y), the process returns to S102.

  When determining that there is no other flying object W in the monitoring area (S107-N), the control unit 5 determines the highest priority of the flying object W to be monitored among the target objects to be detected existing in the monitoring area. The information is sent to the imaging unit 4 (S108). At this time, the information transmitted to the imaging unit 4 is the current position information of the flying object W.

  When acquiring the current position information of the flying object W from the control unit 5, the imaging unit 4 performs PTZ control of the camera in the detection direction of the flying object W according to the position of the flying object W to be watched with priority, and performs imaging. I do. The image taken at this time is displayed on the display unit 6 or stored in the storage unit 5b.

  By the way, in the above-described processing, when a new flying object W is detected, the priority of the flying object W is set as the update processing. In the update processing, it is determined whether the flying object W that has already been detected and continuously detected has not been changed in priority due to disappearance, movement, or the like. Then, when the flying object W of the highest priority is changed, the information (position information and the like) is sent to the imaging unit 4.

  As described above, the target object detection device according to the present embodiment stores the plurality of acoustic signals acquired from the monitoring area in the storage unit 5b together with the time information, and when the monitoring radar 2 detects the object, The sound source direction at the detection time is specified by processing the acoustic signal of the storage unit 5b corresponding to the detection time when the object is detected as the detection target, and the target is detected when the direction in which the object is detected substantially matches the specified sound source direction. It is determined that there is an object. Thereby, the position of the target object can be obtained with high accuracy without losing the target object and without detecting the noise source in the monitoring area as a false report.

  As described above, the best mode of the target object detection device 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.

1 Target object detection device 2 Object detection unit (monitoring radar)
Reference Signs List 3 acoustic signal input unit 4 imaging unit 5 control unit 5a radar signal processing unit 5b storage unit 5c acoustic signal processing unit 5d determination unit 6 display unit E monitoring range M microphone W target object (flying object)

Claims (5)

An object detection unit that transmits a predetermined transmission wave and that can detect a distance and a direction of at least an object from a reflected wave with respect to the transmission wave,
Sound signal input means arranged in a plurality of spaces,
Storage means for predetermined past time period storage going back from the current with time information a plurality of acoustic signals input to the plurality of acoustic signal input means,
Sound signal processing means for processing the plurality of sound signals to identify a sound source direction,
An object detection device comprising:
Said sound signal processing means, when said object detecting means detects the object, obtains the detection time, and processes the acoustic signal in said stored detection time in the storage means to identify the sound source direction, and the detection A target object detection device that determines that there is a target object when the direction of the object and the specified sound source direction substantially match. The object detecting means includes an antenna for transmitting and receiving radio waves having a narrow beam width in the azimuth direction and a wide beam width in the elevation direction, and a rotation mechanism for rotating the antenna at a predetermined cycle, and a transmission wave transmitted from the antenna. It is possible to specify the distance and azimuth angle from the reflected wave to the detection object, and the elevation angle range,
The sound signal processing means determines that there is a target object when the delay sum signal is equal to or larger than a threshold value at an elevation angle at which the delay sum signal generated by performing the delay sum processing on the audio signal is maximum within the elevation angle range. The target object detection device according to claim 1. The target object detection device according to claim 2, wherein the object detection means includes a plurality of antennas having different elevation ranges, and sets the elevation range based on the antenna that has detected the object. The value of the threshold is set to be smaller as the distance increases,
4. The object according to claim 2, wherein the sound signal processing unit acquires distance information from the object detection unit, and determines the presence or absence of the target object by comparing a threshold set at the distance with the delay sum signal. 5. Object detection device. Further, an image pickup unit capable of changing the imaging direction is provided, and when a plurality of target objects to be detected are detected, a monitoring priority is determined for each of the target objects, and the current position information of the target object having a high monitoring priority is set. The target object detection device according to any one of claims 1 to 4, wherein the control unit controls the imaging direction of the imaging unit by acquiring the image data from the object detection unit.

Images