Mobile body detector and method for detecting mobile body

Abstract

To provide a relatively small mobile body detector for monitoring a relatively wide air space, and a method for detecting a mobile body.SOLUTION: The present invention includes: a plurality of non-directional antennas corresponding to a monitor region; and a detector for detecting a mobile body on the basis of reflected waves of transmission waves that the non-directional antennas sent to the monitor device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a moving object detection device and a moving object detection method.

Background Art

[0002] The following Patent Document 1 discloses an anti-drone security system. This anti-drone security system detects and identifies a drone (unmanned aerial vehicle) that intrudes into a predetermined warning airspace using a long-range detection radar, an RF sensor, and a short / medium-range detection radar, and finally captures it by using a net gun.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the above background art targets drones (moving objects) flying to facilities such as airports and power plants, and uses a relatively wide airspace as a monitoring area. Therefore, the background art has a problem that the scale of the system is relatively large.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a relatively small moving object detection device and a moving object detection method that use a relatively wide airspace as a monitoring area.

Means for Solving the Problems

[0006] In order to achieve the above object, in the present invention, as a first solution means for a moving body detection device, there is adopted a means comprising a plurality of omnidirectional antennas provided corresponding to a monitoring area, and a detection device that detects a moving body based on reflected waves of transmission waves radiated by the plurality of omnidirectional antennas into the monitoring area.

[0007] In the present invention, as a second solution means for a moving body detection device, in the above first solution means, the detection device detects the distances between the plurality of omnidirectional antennas and the moving body based on the reflected waves as a plurality of distance measurement values, and detects the moving body based on the plurality of distance measurement values.

[0008] In the present invention, as a third solution means for a moving body detection device, in the above first or second solution means, the monitoring area is a three-dimensional space, the plurality of omnidirectional antennas consist of at least three arranged at three-dimensionally different locations, and the detection device detects the position and movement path of the moving body in the monitoring area based on the plurality of distance measurement values.

[0009] In the present invention, as a fourth solution means for a moving body detection device, in any of the above first to third solution means, among the plurality of omnidirectional antennas, one is a transmission-only antenna that radiates the transmission wave into the monitoring area, and the rest are reception-only antennas that receive the reflected waves.

[0010] In the present invention, as a fifth solution means for a moving body detection device, in any of the above first to fourth solution means, there is further adopted a means comprising an obstruction device that obstructs the movement of the moving body.

[0011] In the present invention, as a sixth solution means for a moving body detection device, in the above fifth solution means, the obstruction device adopts a means of giving a malfunction to the moving function of the moving body by radiating obstructive radio waves toward the moving body.

[0012] In the present invention, as a seventh solution means for the moving body detection device, in any of the first to sixth solution means, the monitoring area is an airspace, and the moving body is an unmanned aircraft flying in the airspace.

[0013] In the present invention, as an eighth solution means for the moving body detection device, in the second or third solution means, the detection device discriminates a plurality of the moving bodies by performing the same target extraction process on the received signal of the reflected wave, and detects the distances between the plurality of the omnidirectional antennas and the plurality of the moving bodies as a plurality of ranging values.

[0014] Further, in the present invention, as a solution means for the moving body detection method, a moving body is detected based on the reflected wave of the transmission wave radiated by a plurality of omnidirectional antennas provided corresponding to a monitoring area into the monitoring area.

Advantages of the Invention

[0015] According to the present invention, it is possible to provide a relatively small moving body detection device and a moving body detection method having a relatively wide airspace as a monitoring area.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [First Embodiment] First, the first embodiment of the present invention will be described.

[0018] As shown in FIG. 1, the moving body detection device A1 according to the first embodiment monitors an unmanned aircraft T flying into a predetermined monitoring area S. That is, the unmanned aircraft T in the first embodiment corresponds to the moving body of the present invention. The monitoring area S is a three-dimensional space within a predetermined range and is also an airspace within a predetermined range set above the ground.

[0019] As shown in FIG. 1, the moving body detection device A1 according to the first embodiment includes three omnidirectional antennas 1a to 1c, three distance detection units 2a to 2c, a calculation unit 3, a threat evaluation unit 4, an interference signal generation unit 5, and an interference antenna 6. Among these components, the three distance detection units 2a to 2c, the calculation unit 3, the threat evaluation unit 4, and the interference signal generation unit 5 constitute a detection device B1 as shown in the figure.

[0020] Since the moving body detection device A1 according to the first embodiment is composed only of the detection device B1 including three omnidirectional antennas 1a to 1c, three distance detection units 2a to 2c, a calculation unit 3, a threat evaluation unit 4, and an interference signal generation unit 5, it is extremely small in comparison with the background art. Therefore, the moving body detection device A1 according to the first embodiment can of course be fixedly installed on the ground, and can also be mounted on a moving means such as a vehicle and moved.

[0021] The three omnidirectional antennas 1a to 1c are transceiver antennas with extremely weak radio wave radiation directivity. That is, among the three omnidirectional antennas 1a to 1c, the first omnidirectional antenna 1a radiates a first transmission wave toward the monitoring area S and receives a first reflected wave generated by the first transmission wave being reflected by the unmanned aircraft T that has entered the monitoring area S.

[0022] The second omnidirectional antenna 1b radiates the second transmission wave toward the monitoring area S and receives the second reflected wave generated by the reflection of the second transmission wave by the unmanned aircraft T that has entered the monitoring area S. Further, the third omnidirectional antenna 1c radiates the third transmission wave toward the monitoring area S and receives the third reflected wave generated by the reflection of the third transmission wave by the unmanned aircraft T that has entered the monitoring area S.

[0023] Such first to third omnidirectional antennas 1a to 1c are antennas in which radio waves propagate in a donut shape in the horizontal direction around the antenna, and the radiation pattern (horizontal radiation pattern) of the radio waves (radiated waves) as viewed from above is a perfect circle, that is, uniform at 360°. Further, the three omnidirectional antennas 1a to 1c have a radiation pattern of radiated waves in the vertical direction with a half-value angle of, for example, about 60°.

[0024] The first to third omnidirectional antennas 1a to 1c use the monitoring area S, which is a three-dimensional space composed of three orthogonal axes (x-axis, y-axis, and z-axis), as the radio wave radiation range. That is, the first to third omnidirectional antennas 1a to 1c have the same radio wave radiation range corresponding to the monitoring area S. Such first to third omnidirectional antennas 1a to 1c are a plurality of omnidirectional antennas provided corresponding to the monitoring area S.

[0025] FIG. 2 is a schematic diagram showing an arrangement example of the first to third omnidirectional antennas 1a to 1c. As shown in this FIG. 2, the first to third omnidirectional antennas 1a to 1c are arranged so as to be located at the vertices of a triangle of a predetermined size in the horizontal plane composed of the x-axis and the y-axis among the three-dimensional space composed of the three orthogonal axes (x-axis, y-axis, and z-axis). Further, the first to third omnidirectional antennas 1a to 1c are arranged at different positions (heights) in the vertical plane composed of the x-axis and the z-axis.

[0026] The three distance detection units 2a to 2c are provided corresponding to the first to third omnidirectional antennas 1a to 1c described above. That is, among the three distance detection units 2a to 2c, the first distance detection unit 2a is provided corresponding to the first omnidirectional antenna 1a, the second distance detection unit 2b is provided corresponding to the second omnidirectional antenna 1b, and the third distance detection unit 2c is provided corresponding to the third omnidirectional antenna 1b.

[0027] The first distance detection unit 2a outputs a first transmission signal for causing the first omnidirectional antenna 1a to emit a first transmission wave. Further, the first distance detection unit 2a, based on the first reception signal input from the first omnidirectional antenna 1a when the first omnidirectional antenna 1a receives the first reflected wave, detects the distance between the moving body (radio wave reflector) from which the first transmission signal of the unmanned aircraft T or the like is reflected and the first omnidirectional antenna 1a as the first distance measurement value R1.

[0028] The second distance detection unit 2b outputs a second transmission signal for causing the second omnidirectional antenna 1b to emit a second transmission wave. Further, the second distance detection unit 2b, based on the second reception signal input from the second omnidirectional antenna 1b when the second omnidirectional antenna 1b receives the second reflected wave, detects the distance between the moving body (radio wave reflector) from which the second transmission signal of the unmanned aircraft T or the like is reflected and the second omnidirectional antenna 1b as the second distance measurement value R2.

[0029] The third distance detection unit 2c outputs a third transmission signal for causing the third omnidirectional antenna 1c to emit a third transmission wave. Further, the third distance detection unit 2c, based on the third reception signal input from the third omnidirectional antenna 1c when the third omnidirectional antenna 1c receives the third reflected wave, detects the distance between the moving body (radio wave reflector) from which the third transmission signal of the unmanned aircraft T or the like is reflected and the third omnidirectional antenna 1c as the third distance measurement value R3.

[0030] Here, the first to third distance measurement values R1 to R3 correspond to a plurality of distance measurement values in the present invention. Further, the first to third distance detection units 2a to 2c generate first to third transmission signals capable of acquiring the first to third distance measurement values R1 to R3, such as a two-frequency CW method, a multi-frequency CW method, or an FM-CW method, and output them to the first to third omnidirectional antennas 1a to 1c.

[0031] Based on the first to third distance measurement values R1 to R3 input from the first to third distance detection units 2a to 2c, the calculation unit 3 calculates the three-dimensional position (x coordinate, y coordinate, and z coordinate) of a moving body (radio wave reflector) such as an unmanned aircraft T that has entered the monitoring area S (three-dimensional space: airspace).

[0032] For example, when the three-dimensional coordinates of the first omnidirectional antenna 1a are the first antenna coordinates (x1, y1, z1), the three-dimensional coordinates of the second omnidirectional antenna 1b are the second antenna coordinates (x2, y2, z2), and the three-dimensional coordinates of the third omnidirectional antenna 1c are the third antenna coordinates (x3, y3, z3), the following equations (1) to (3) using the first to third distance measurement values R1 to R3 hold between the first to third antenna coordinates (x1, y1, z1), (x2, y2, z2), (x3, y3, z3) and the position of the unmanned aircraft T, that is, the moving body coordinates (xt, yt, zt).

[0033] R1 = {(xt - x1) 2 + (yt - y1) 2 + (zt - z1) 2 )} 1 / 2 (1) R2 = {(xt - x2) 2 + (yt - y2) 2 + (zt - z2) 2 )} 1 / 2 (2) R3 = {(xt - x1) 2 + (yt - y1) 2 + (zt - z1) 2 )} 1 / 2 (3)

[0034] That is, the arithmetic unit 3 obtains the moving body coordinates (xt, yt, zt) by solving the simultaneous equations (1) to (3) using the first to third ranging values R1 to R3 and the first to third antenna coordinates (x1, y1, z1), (x2, y2, z2), (x3, y3, z3). Further, the arithmetic unit 3 obtains the moving body coordinates (xt, yt, zt) as time series data at a predetermined time interval, thereby obtaining the flight path of the unmanned aircraft T.

[0035] Here, since the arithmetic unit 3 only solves the simultaneous equations (1) to (3), the moving body coordinates (xt, yt, zt) can be calculated in an extremely short time. Therefore, for example, when the moving body detection device A1 is mounted on a vehicle or the like and moved, the three-dimensional coordinates of the first to third omnidirectional antennas 1a to 1c are obtained by using a ranging device such as GPS or gyro mounted on the vehicle or the like, and the moving body coordinates (xt, yt, zt) and flight path of the unmanned aircraft T can be easily calculated.

[0036] Also, in the method (positioning method) for obtaining the moving body coordinates (xt, yt, zt) using the above-described first to third antenna coordinates (x1, y1, z1), (x2, y2, z2), (x3, y3, z3) and the first to third ranging values R1 to R3, the detection accuracy of the first to third ranging values R1 to R3 decreases as the separation between the first to third omnidirectional antennas 1a to 1c decreases.

[0037] When the first to third ranging values R1 to R3 are on the order of several hundred meters, in the multi-frequency CW method, it is possible to expect the performance of detecting the first to third ranging values R1 to R3 with an error of about several centimeters by ensuring a separation of several meters between the first to third omnidirectional antennas 1a to 1c. Therefore, even in such a case, it can be calculated with an error of about several centimeters to several meters.

[0038] The threat evaluation unit 4 determines whether or not to interfere with the flight of the unmanned aircraft T based on the moving body coordinates (xt, yt, zt) and flight path of the unmanned aircraft T calculated by the arithmetic unit 3. When the threat evaluation unit 4 determines that it is necessary to interfere with the flight of the unmanned aircraft T, it outputs an interference instruction signal to the interference signal generation unit 5.

[0039] The interference signal generation unit 5 generates an interference signal of a predetermined frequency based on the interference instruction signal and outputs it to the interference antenna 6. The interference antenna 6 is a directional antenna, different from the first to third omnidirectional antennas 1a to 1c. The interference antenna 6 radiates interference radio waves toward the unmanned aircraft T (mobile object) based on the interference signal powered from the interference signal generation unit 5.

[0040] This interference radio wave has a frequency and radio wave intensity that interfere with the flight function (mobility function) of the unmanned aircraft T (mobile object). This interference radio wave interferes with, for example, the operation of electronic devices mounted on the unmanned aircraft T (mobile object) and remote control signals.

[0041] Such a threat evaluation unit 4, interference signal generation unit 5, and interference antenna 6 constitute the interference device in the present invention. That is, the threat evaluation unit 4, interference signal generation unit 5, and interference antenna 6 are devices that interfere with the flight (mobility) of the unmanned aircraft T (mobile object).

[0042] Subsequently, the operation of the mobile object detection device A1 according to the first embodiment, that is, the mobile object detection method according to the first embodiment using the mobile object detection device A1, will be described in detail with reference to the flowchart of FIG. 3.

[0043] In the mobile object detection method according to the first embodiment, the first to third distance detection units 2a to 2c generate the first to third transmission signals at a predetermined cycle and output them to the first to third omnidirectional antennas 1a to 1c (step S1). As a result, the first to third omnidirectional antennas 1a to 1c each radiate radio waves (radiated waves) of a radiation pattern over the entire monitoring area S.

[0044] When the unmanned aircraft T enters the monitoring area S, the above radiated waves are reflected by the unmanned aircraft T, and the first to third reflected waves are generated. Then, a part of these first to third reflected waves propagates in the directions of the first to third omnidirectional antennas 1a to 1c, is received by the first to third omnidirectional antennas 1a to 1c, and the first to third received signals are generated (step S2).

[0045] The first to third distance detection units 2a to 2c acquire first to third ranging values R1 to R3 based on the first to third received signals input from the first to third omnidirectional antennas 1a to 1c (step S3).

[0046] Then, the arithmetic unit 3 calculates the moving body coordinates (xt, yt, zt) of the unmanned aircraft T by using the first to third ranging values R1 to R3 input from the first to third distance detection units 2a to 2c, the first to third antenna coordinates (x1, y1, z1), (x2, y2, z2), (x3, y3, z3) stored in the internal memory in advance, and the simultaneous equations (1) to (3) (step S4).

[0047] Then, the moving body detection device A1 repeats the processes of steps S1 to S4 at a predetermined interval. That is, the arithmetic unit 3 sequentially acquires the moving body coordinates (xt, yt, zt) of the unmanned aircraft T at the above time interval, and acquires the flight path of the unmanned aircraft T based on the time series data composed of a plurality of moving body coordinates (xt, yt, zt) (step S5).

[0048] Such a flight path of the unmanned aircraft T is sequentially output from the arithmetic unit 3 to the threat evaluation unit 4. Then, the threat evaluation unit 4 determines whether or not the flight path of the unmanned aircraft T satisfies the threat conditions stored in the internal memory in advance (step S6). When the determination in this step S6 is "Yes", the threat evaluation unit 4 outputs an interference instruction signal to the interference signal generation unit 5 (step S7).

[0049] The interference signal generation unit 5 generates an interference signal based on the above interference instruction signal and outputs it to the interference antenna 6 (step S8). Then, the interference antenna 6 radiates interference radio waves toward the unmanned aircraft T (moving body) based on the interference signal (step S9). As a result, the unmanned aircraft T (moving body) suffers from a flight function failure and becomes in a non-flight state.

[0050] According to such a first embodiment, since it is composed only of the detection device B1 including the first to third omnidirectional antennas 1a to 1c, the first to third distance detection units 2a to 2c, the calculation unit 3, the threat evaluation unit 4, and the interference signal generation unit 5, it is possible to provide a relatively small moving body detection device A1 with a relatively wide airspace as the monitoring area S.

[0051] Also, according to the first embodiment, the detection device B1 detects the distances between the first to third omnidirectional antennas 1a to 1c and the unmanned aircraft T (moving body) as the first to third ranging values R1 to R3 based on the first to third reflected waves generated by the unmanned aircraft T (moving body), and detects the moving body coordinates (xt, yt, zt) of the unmanned aircraft T (moving body) based on these first to third ranging values R1 to R3. Therefore, it is possible to accurately detect the unmanned aircraft T (moving body).

[0052] Also, according to the first embodiment, for the monitoring area S which is a three-dimensional space, it includes the first to third omnidirectional antennas 1a to 1c arranged at three-dimensionally different locations. The detection device B1 detects the three-dimensional position of the unmanned aircraft T (moving body) in the monitoring area S, that is, the moving body coordinates (xt, yt, zt) and the flight path (moving path) based on the first to third ranging values R1 to R3. Therefore, it is possible to accurately detect the three-dimensional position of the unmanned aircraft T (moving body).

[0053] Also, according to the first embodiment, it includes an interference device that interferes with the flight (movement) of the unmanned aircraft T (moving body). This interference device radiates interference radio waves toward the unmanned aircraft T (moving body) to cause an obstacle to the flight function (movement function) of the unmanned aircraft T (moving body). Therefore, it is possible to prevent damage caused by the intrusion of the unmanned aircraft T (moving body) into the monitoring area S.

[0054] 〔Second Embodiment〕 Next, a second embodiment of the present invention will be described with reference to FIG. 3. In FIG. 4, the interference device in the first embodiment is omitted for convenience. Therefore, the moving body detection device A2 according to the second embodiment may include a threat evaluation unit 4, an interference signal generation unit 5, and an interference antenna 6 as necessary.

[0055] As shown in Fig. 4, the mobile object detection device A2 according to the second embodiment includes three omnidirectional antennas 7a to 7c (first to third omnidirectional antennas 7a to 7c), three distance detection units 8a to 8c (first to third distance detection units 8a to 8c), an arithmetic unit 3, a transmission wave generation unit 9, and a transmission antenna 10.

[0056] Among these components, the three distance detection units 8a to 8c (first to third distance detection units 8a to 8c), the arithmetic unit 3, the transmission wave generation unit 9, the transmission antenna 10, etc. constitute the detection device B2 as shown in the figure.

[0057] Hereinafter, the description of the arithmetic unit 3 similar to that in the first embodiment will be omitted again, and the first to third omnidirectional antennas 7a to 7c, the first to third distance detection units 8a to 8c, the transmission wave generation unit 9, and the transmission antenna 10 different from those in the first embodiment will be described.

[0058] The first to third omnidirectional antennas 7a to 7c are antennas with extremely weak radio wave radiation directivity, similar to the first to third omnidirectional antennas 1a to 1c in the first embodiment. However, the first to third omnidirectional antennas 7a to 7c are dedicated receiving antennas for receiving the first to third reflected waves, different from the first to third omnidirectional antennas 1a to 1c (transceiving antennas) in the first embodiment.

[0059] That is, the first omnidirectional antenna 7a generates a first received signal by receiving the first reflected wave from the unmanned aircraft T and outputs it to the first distance detection unit 8a. The second omnidirectional antenna 7b generates a second received signal by receiving the second reflected wave from the unmanned aircraft T and outputs it to the second distance detection unit 8b. The third omnidirectional antenna 7c generates a third received signal by receiving the third reflected wave from the unmanned aircraft T and outputs it to the third distance detection unit 8c.

[0060] The first to third omnidirectional antennas 7a to 7c have a monitoring area S (three-dimensional space) composed of orthogonal three axes (x-axis, y-axis, and z-axis) as their radio wave radiation range. That is, the first to third omnidirectional antennas 7a to 7c have the same radio wave radiation range corresponding to the monitoring area S. Such first to third omnidirectional antennas 7a to 7c are a plurality of omnidirectional antennas provided corresponding to the monitoring area S.

[0061] The first to third distance detection units 8a to 8c are provided corresponding to the first to third omnidirectional antennas 7a to 7c. That is, the first distance detection unit 8a is provided corresponding to the first omnidirectional antenna 7a. The second distance detection unit 8b is provided corresponding to the second omnidirectional antenna 7b. Also, the third distance detection unit 8c is provided corresponding to the third omnidirectional antenna 7b.

[0062] The first distance detection unit 8a detects a first distance measurement value R1a based on a first received signal input from the first omnidirectional antenna 7a. The second distance detection unit 8b detects a second distance measurement value R2a based on a second received signal input from the second omnidirectional antenna 7b. Also, the third distance detection unit 8c detects a third distance measurement value R3a based on a third received signal input from the third omnidirectional antenna 7c.

[0063] The transmission wave generation unit 9 generates a transmission signal and supplies power to the dedicated transmission antenna 10. This transmission signal is a signal of a predetermined frequency based on a well-known two-frequency CW method, multi-frequency CW method, or FM-CW method. The transmission antenna 10 is an omnidirectional antenna and a dedicated transmission antenna. This transmission antenna 10 generates a transmission wave based on the transmission signal input from the transmission wave generation unit 9 and radiates it toward the monitoring area S.

[0064] In this way, in the moving object detection device A2, the roles of the four omnidirectional antennas are divided into transmission and reception purposes. That is, among the plurality (four) of omnidirectional antennas, one transmission antenna 10 is a dedicated transmission antenna that radiates a transmission wave to the monitoring area S, and the remaining first to third omnidirectional antennas 7a to 7c are dedicated reception antennas that receive the first to third reflected waves.

[0065] Also, in the moving object detection device A2, the first to third distance detection units 8a to 8c do not have the function of generating a transmission signal, and only have the function of detecting the first to third ranging values R1a to R3a. That is, the transmission signal required for detecting the first to third ranging values R1a to R3a is exclusively generated by a transmission wave generation unit 9 provided separately from the first to third distance detection units 8a to 8c.

[0066] Subsequently, the operation of the moving object detection device A2 according to the second embodiment, that is, the moving object detection method according to the second embodiment using the moving object detection device A2 will be described in detail.

[0067] In the moving object detection method according to the second embodiment, the transmission wave generation unit 9 generates a transmission signal and outputs it to the transmission antenna 10, thereby radiating the transmission wave of the radiation pattern across the entire monitoring area S toward the monitoring area S. And when an unmanned aircraft T intrudes into the monitoring area S, the above transmission wave is reflected by the unmanned aircraft T and the first to third reflected waves are generated.

[0068] Then, a part of these first to third reflected waves is received by the first to third omnidirectional antennas 7a to 7c, thereby generating the first to third received signals. And the first to third distance detection units 8a to 8c acquire the first to third ranging values R1a to R3a based on the first to third received signals.

[0069] Here, the first to third ranging values R1a to R3a are different from the first to third ranging values R1 to R3 in the first embodiment, and are the sum of the distance from the transmission antenna 10 to the unmanned aircraft T and the distance from the unmanned aircraft T to the first to third omnidirectional antennas 7a to 7c.

[0070] That is, the first distance measurement value R1a is the sum of the distance from the transmission antenna 10 to the unmanned aircraft T and the distance from the unmanned aircraft T to the first omnidirectional antenna 7a. The second distance measurement value R2a is the sum of the distance from the transmission antenna 10 to the unmanned aircraft T and the distance from the unmanned aircraft T to the second omnidirectional antenna 7b. Also, the third distance measurement value R3a is the sum of the distance from the transmission antenna 10 to the unmanned aircraft T and the distance from the unmanned aircraft T to the third omnidirectional antenna 7c.

[0071] In addition to the first to third antenna coordinates (x1, y1, z1), (x2, y2, z2), (x3, y3, z3) related to the first to third omnidirectional antennas 7a to 7c, the calculation unit 3 stores in the internal memory in advance the fourth antenna coordinate (x4, y4, z4) related to the transmission antenna 10, and the simultaneous equations (1) to (4) related to the first to fourth antenna coordinates (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), (x4, y4, z4).

[0072] Therefore, the calculation unit 3 calculates the moving body coordinates (xt, yt, zt) of the unmanned aircraft T by using the first to third distance measurement values R1a to R3a, the first to fourth antenna coordinates (x1, y1, z1), (x2, y2, z2), (x3, y3, z3), (x4, y4, z4), and the simultaneous equations (1) to (4).

[0073] Then, the calculation unit 3 detects that the unmanned aircraft T (moving body) has entered the monitoring area S based on the moving body coordinates (xt, yt, zt) of the unmanned aircraft T. And the jamming device (not shown in the figure) takes jamming actions based on the moving body coordinates (xt, yt, zt) and the flight path of the unmanned aircraft T input from the calculation unit 3.

[0074] According to such a second embodiment, since it is composed only of the detection device B2 including the first to third omnidirectional antennas 7a to 7c, the first to third distance detection units 8a to 8c, the calculation unit 3, the transmission wave generation unit 9, the transmission antenna 10, etc., it is possible to provide a relatively small moving object detection device A2 with a relatively wide airspace as the monitoring area S.

[0075] Further, according to the second embodiment, since the first to third omnidirectional antennas 7a to 7c are reception-only antennas and the transmission antenna 10 is a transmission-only antenna, it is easy to select the first to third omnidirectional antennas 7a to 7c and the transmission antenna 10.

[0076] Note that the present invention is not limited to the above first and second embodiments, and for example, the following modification examples can be considered. (1) In the above first and second embodiments, the monitoring area S is a three-dimensional airspace, and the unmanned aircraft T flying into the airspace is used as the moving object (detection target), but the present invention is not limited to this. That is, the moving object (detection target) in the present invention is various objects such as a vehicle traveling on the ground, a ship sailing in a predetermined sea area, or a person walking on the road.

[0077] (2) In the above first and second embodiments, three omnidirectional antennas 1a to 1c, 7a to 7c are provided, but the present invention is not limited to this. For example, when the monitoring area S is a two-dimensional plane instead of a three-dimensional space, the number of omnidirectional antennas may be two. Also, in order to improve the detection accuracy of the moving object coordinates (xt, yt, zt), four or more omnidirectional antennas with three-dimensionally different installation locations may be used.

[0078] (3) In the above first and second embodiments, the jamming device using interfering waves has been described, but the present invention is not limited to this. As a jamming device for interfering with the flight (movement) of the unmanned aircraft T (moving object), a flying object may be launched toward the unmanned aircraft T (moving object), or a laser beam may be irradiated on the unmanned aircraft T (moving object).

[0079] (4) In the above-described second embodiment, an omnidirectional antenna is adopted as the transmission antenna 10, but the present invention is not limited thereto. By adopting a directional antenna for the transmission antenna 10, the radiation direction of the transmitted wave may be narrowly limited to detect the unmanned aircraft T (moving body).

[0080] (5) In the above-described first and second embodiments, the case of detecting one unmanned aircraft T (moving body) has been described, but the present invention is not limited thereto. That is, the present invention is also applicable to the detection of a plurality of moving bodies.

[0081] For example, as shown in FIG. 5, a case where two unmanned aircrafts T1 and T2 (moving bodies) enter the monitoring area S may be considered. In this case, the first to third transmitted waves radiated from the first to third omnidirectional antennas 1a to 1c are respectively reflected by the two unmanned aircrafts T1 and T2 and received as the first to third reflected waves by the first to third omnidirectional antennas 1a to 1c.

[0082] Here, as shown in FIG. 5, in the first omnidirectional antenna 1a, the reflected wave flying from the first unmanned aircraft T1 and the reflected wave flying from the second unmanned aircraft T2 are received as the first reflected wave. Also, in the second omnidirectional antenna 1b, the reflected wave flying from the first unmanned aircraft T1 and the reflected wave flying from the second unmanned aircraft T2 are received as the second reflected wave. Further, in the third omnidirectional antenna 1c, the reflected wave flying from the first unmanned aircraft T1 and the reflected wave flying from the second unmanned aircraft T2 are received as the first reflected wave.

[0083] That is, the first received signal input from the first omnidirectional antenna 1a to the first distance detection unit 2a includes the ranging value R11 between the first omnidirectional antenna 1a and the first unmanned aircraft T1 as distance information, and also includes the ranging value R21 between the first omnidirectional antenna 1a and the second unmanned aircraft T2 as distance information.

[0084] In addition, the second received signal input from the second omnidirectional antenna 1b to the second distance detection unit 2b includes the ranging value R12 between the second omnidirectional antenna 1b and the first unmanned aircraft T1 as distance information, and also includes the ranging value R22 between the second omnidirectional antenna 1b and the second unmanned aircraft T2 as distance information.

[0085] Furthermore, the third received signal input from the third omnidirectional antenna 1c to the third distance detection unit 2c includes the ranging value R13 between the third omnidirectional antenna 1c and the first unmanned aircraft T1 as distance information, and also includes the ranging value R23 between the third omnidirectional antenna 1c and the second unmanned aircraft T2 as distance information.

[0086] The first to third distance detection units 2a to 2c perform the same target extraction process on the first to third received signals to identify a plurality of moving objects, that is, the first unmanned aircraft T1 and the second unmanned aircraft T2, and individually obtain six ranging values R11, R21, R12, R22, R13, and R23.

[0087] The same target extraction process separates, for example, the ranging values R11, R12, R13 based on the reflected waves from the first unmanned aircraft T1 and the ranging values R21, R22, R23 based on the reflected waves from the second unmanned aircraft T2 by evaluating the identity of the Doppler frequencies included in the first to third received signals.

[0088] That is, since the flight speeds and flight directions of the first and second unmanned aircraft T1 and T2 are different, the Doppler shifts applied to the first to third reflected waves are different in the first received signal. Therefore, the first to third received signals have different Doppler frequencies for each of the first and second unmanned aircraft T1 and T2.

[0089] More specifically, since the distance information (ranging values R11, R12, R13) included in the reflected wave from the first unmanned aircraft T1 has the distances (intervals) between the first to third omnidirectional antennas 1a to 1c set to be sufficiently shorter than the ranging values R11, R12, R13, they have the same Doppler frequency (the first Doppler frequency). In contrast, the distance information (ranging values R21, R22, R23) included in the reflected wave from the second unmanned aircraft T2 has a second Doppler frequency different from the first Doppler frequency.

[0090] The first distance detection unit 2a individually acquires two ranging values R11 and R21 by grouping the distance information (ranging values R11, R21, R13) included in the first received signal for each Doppler frequency. Also, the second distance detection unit 2b individually acquires two ranging values R12 and R22 by grouping the distance information (ranging values R12, R22) included in the second received signal for each Doppler frequency.

[0091] Furthermore, the third distance detection unit 2c individually acquires two ranging values R13 and R23 by grouping the distance information (ranging values R13, R23) included in the third received signal for each Doppler frequency.

[0092] By performing such same target extraction processing, even when a plurality of moving bodies have invaded the monitoring area S, the first to third distance detection units 2a to 2c can acquire distance values for each moving body. Also, such same target extraction processing is applicable not only to the first to third distance detection units 2a to 2c in the first embodiment but also to the first to third distance detection units 8a to 8c in the second embodiment.

[0093] Therefore, according to this modification example, it is possible to provide relatively small moving body detection devices A1 and A2 that use a relatively wide airspace as the monitoring area S while detecting a plurality of moving bodies such as two unmanned aircrafts T1 and T2.

Explanation of Reference Numerals

[0094] A1, A2 Mobile Object Detection Device B1, B2 Detection Device S Monitoring Area T Unmanned Aerial Vehicle (Mobile Object) 1a~1c, 7a~7c Omnidirectional Antenna 2a~2c, 8a~8c Distance Detection Unit 3 Calculation Unit 4 Threat Assessment Unit 5 Jamming Signal Generation Unit 6 Jamming Antenna 9 Transmission Wave Generation Unit 10 Transmission Antenna

Claims

1. A plurality of omnidirectional antennas provided corresponding to a monitoring area, and a detection device that detects a moving object based on reflected waves of transmission waves radiated by the plurality of omnidirectional antennas into the monitoring area characterized in that the moving object detection device comprises the same.

2. The detection device is characterized in that it detects the distances between the plurality of omnidirectional antennas and the moving object as a plurality of ranging values based on the reflected waves, and detects the moving object based on the plurality of ranging values, according to the moving object detection device described in Claim 1.

3. The monitoring area is a three-dimensional space, the plurality of omnidirectional antennas consist of at least three arranged at three-dimensionally different locations, and the detection device is characterized in that it detects the position and movement path of the moving object in the monitoring area based on the plurality of ranging values, according to the moving object detection device described in Claim 2.

4. Among the plurality of omnidirectional antennas, one is a transmission-only antenna that radiates the transmission wave into the monitoring area, and the rest are reception-only antennas that receive the reflected waves, according to the moving object detection device described in Claim 1 or 3.

5. The moving object detection device according to Claim 1 or 3, further comprising an interference device that interferes with the movement of the moving object.

6. The interference device is characterized in that it impairs the movement function of the moving object by radiating interference radio waves toward the moving object, according to the moving object detection device described in Claim 5.

7. The monitoring area is an airspace, and the moving object is an unmanned aerial vehicle flying in the airspace, according to the moving object detection device described in Claim 6.

8. The detection device is characterized in that it identifies a plurality of moving objects by performing the same target extraction process on the received signals of the reflected waves, and detects the distances between the plurality of omnidirectional antennas and the plurality of moving objects as a plurality of ranging values, according to the moving object detection device described in Claim 2 or 3.

9. A moving object detection method, characterized in that a moving object is detected based on reflected waves of transmission waves radiated by a plurality of omnidirectional antennas provided corresponding to a monitoring area into the monitoring area.

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