JP6853530B2 - Unmanned aerial vehicle current position detection system, unmanned aerial vehicle - Google Patents

Description

The present invention relates to a current location detection system of the non-human aircraft for detecting the direction and the current position of the current unmanned aircraft flying to the arrival point from the start point, to prevent in particular the alteration of the position information by spoofing signal effectively it is safe current position detecting system of the preferred non-human aircraft in achieving operation, and to a unmanned aerial vehicle that is applied thereto.

Recently, unmanned aerial vehicles consisting of small drones (multicopters) and unmanned helicopters capable of unmanned flight are becoming widespread. This unmanned aerial vehicle is used in various industries such as surveying, disaster relief, research on the natural environment, relaying sports, and spraying pesticides. As the technology of this unmanned aerial vehicle continues to advance, it is expected that its usage will expand further.

In particular, this unmanned aerial vehicle has a wide range of cruising range and flight altitude, and can continue to stay in a fixed position in the air, so it has excellent maneuverability. Therefore, in recent years, it is expected to be applied to monitoring of important infrastructure and logistics. In particular, unmanned logistics in depopulated areas such as depopulated areas and remote islands has become an urgent issue for Japan, and technology for safely transporting goods by unmanned aerial vehicles is eagerly desired.

In particular, unmanned aerial vehicles are premised on navigating after grasping their own position information based on, for example, the Global Positioning System (GNSS) including the Global Positioning System (GPS). However, this GNSS signal is often unencrypted or only encrypted to the extent that it can be easily hijacked. For this reason, if the GNSS signal is spoofed by fake position information by irradiating it with a spoofed signal consisting of strong radio waves, the unmanned aerial vehicle will not be able to accurately grasp its position, which is originally planned. In the worst case, it may crash or be recovered by a third party. For this reason, even if a spoofing signal is radiated to the GNSS signal and is disturbed, the unmanned aerial vehicle itself can accurately grasp its position without being affected by this, resulting in a crash or a third party. In recent years, a technique capable of preventing the recovery due to the above has been particularly desired.

Patent Documents 1 and 2 disclose a technique for adjusting the flight path of an unmanned aerial vehicle based on a matching error between a stored image stored in a storage device and a newly captured captured image.

However, in the disclosed technologies of Patent Documents 1 and 2, when a spoofed signal consisting of a strong radio wave is irradiated to the GNSS signal, the unmanned aerial vehicle itself accurately grasps its position without being affected by the signal. There is no particular disclosure about the technology for doing so. In particular, when receiving a signal other than the GNSS signal and grasping its own position, it is necessary to further enhance the navigation safety of the unmanned aerial vehicle by strengthening the security of the received signal itself.

Japanese Unexamined Patent Publication No. 2008-146197 Japanese Unexamined Patent Publication No. 2014-63294

The present invention has been devised in view of the above problems, it is an object free for detecting the direction and the current position of the current unmanned aircraft flying to the arrival point from the start point In the current position detection system of a human aircraft, even if a spoofing signal is irradiated to the GNSS signal and is disturbed, the unmanned aerial vehicle itself can grasp its position more accurately without being affected by this. that is, the current position detection system of non-person aircraft that can be firmly prevent the recovery by the crash and a third party, is to provide an unmanned aircraft.

The unmanned aerial vehicle current position detection system according to the first invention is an unmanned aerial vehicle current position detection system for detecting the current position of an unmanned aerial vehicle flying from a departure point to an arrival point, and includes at least its own position information. Two or more terrestrial transmission sources that transmit signals, a receiving means that acquires position information of each terrestrial transmission source by receiving optical signals transmitted from each terrestrial transmission source, and a receiving means of the optical signal. The current position with respect to the ground source is calculated based on the incident direction identification means for identifying each incident direction, each position information acquired by the receiving means, and each incident direction identified by the incident direction identifying means. The unmanned aerial vehicle includes an unmanned aerial vehicle having a calculation means, and the unmanned aerial vehicle has a GNSS identification means for identifying a current position based on a GNSS (Global Navigation Satellite System) signal received from a satellite and a present identified by the GNSS identification means. It is characterized by having a spoofed signal discriminating means for discriminating the presence or absence of a spoofed signal based on the result of comparing the position with the current position calculated by the calculating means.

The current position detection system for an unmanned aerial vehicle according to the second invention is described in the first invention when the unmanned aerial vehicle acquires map information in advance and determines the existence of a spoofed signal by the spoofed signal discriminating means. It is characterized in that the flight path is corrected based on the current position calculated by the calculation means and the map information.

Unmanned aircraft according to a third aspect of the invention is applied to a current position sensing system engaged Ru to the first or second aspect of the invention, said decoding means, the incident direction identification means, and wherein a said calculation means To do.

According to the present invention having the above-described configuration, even if a spoofing signal is emitted by an interfering source in the process of navigation of an unmanned aerial vehicle, which adversely affects the GNSS signal, the optical signal from the ground source is used. Based on this, the current position can be accurately grasped. That is, since the method of grasping the current position from the ground source is completely independent of grasping the current position based on the GNSS signal transmitted from the satellite, the unmanned aerial vehicle is particularly affected by the spoofing signal. It is possible to always grasp accurate position information. As a result, even if a spoofing signal is irradiated to the GNSS signal and is disturbed, the unmanned aerial vehicle itself can more accurately grasp its position without being affected by this, resulting in a crash or a crash. It is possible to firmly prevent collection by a third party. Moreover, since the optical signal transmitted from the ground source is encrypted in advance with a common encryption key with the unmanned aerial vehicle, even if the interference radio wave from the interference source exists, this can be done. It is possible to accurately grasp one's current position without being affected by. Therefore, it is possible to further improve the navigation safety of the unmanned aerial vehicle.

It is a figure which shows the whole structure of the present position detection system of the unmanned aerial vehicle to which this invention is applied. It is a figure which shows the system configuration of an unmanned aerial vehicle. It is a figure for demonstrating the operation method of the present position detection system of the unmanned aerial vehicle to which this invention is applied. It is a figure which shows the frame structure of the optical signal transmitted from the terrestrial source. It is a figure for demonstrating the detail of the calculation method of the present position of an unmanned aerial vehicle. It is a figure which shows the example which an optical signal is transmitted to an unmanned aerial vehicle from one ground source.

Hereinafter, a mode for implementing the current position detection system of an unmanned aerial vehicle to which the present invention is applied will be described in detail with reference to the drawings.

FIG. 1 shows the overall configuration of the current position detection system 1 of an unmanned aerial vehicle to which the present invention is applied. The current position detection system 1 includes a satellite 2, an unmanned aerial vehicle 3 that flies at a lower altitude than the satellite 2, and a plurality of ground transmission sources 4 installed on the ground. The current position detection system 1 detects the current position of the unmanned aerial vehicle 3 flying from the departure point A to the arrival point B.

Satellite 2 orbits in about 24 hours as a geosynchronous orbit with an orbital period that matches the earth's rotation period at an altitude of about 36,000 km, or a quasi-synchronous start at an altitude of 20,000 km above the ground. It is an artificial satellite that orbits in time. The satellite 2 may be launched based on any purpose. Satellite 2 transmits a GNSS signal to the unmanned aerial vehicle 3. Incidentally, the GNSS) signal transmitted from the satellite 2 is not particularly encrypted as in the conventional case.

The unmanned aerial vehicle 3 is a so-called small aircraft capable of unmanned flight, and a typical one is a drone (multicopter), but it is not limited to this and is embodied by an unmanned helicopter or the like. It may be a thing. The unmanned aerial vehicle 3 is basically premised on flying from the departure point A to the arrival point B for a certain purpose. Further, the purpose of the flight from the departure point A to the arrival point B of the unmanned aerial vehicle 3 may be anything, and may be applied to, for example, monitoring of important infrastructure or distribution.

FIG. 2 shows a block configuration of a control unit 45 for controlling an unmanned aerial vehicle 3. The control unit 45 is supplied with power from the connected battery 44, and is connected to the flight controller 50 as the center, and is connected to the coding / decoding unit 52, the wireless communication unit 51, the electric gimbal 72, the camera 53, and the like. It is equipped with an ESC (Electronic Speed Controller) 54. An encryption / decryption unit 58 is provided between the camera 53 and the flight controller 50. A signal incident direction detection unit 59 is connected to the wireless communication unit 51 and the camera 53.

Next, the detailed configuration of the control unit 15 will be described.

The unmanned aerial vehicle 3 can obtain buoyancy by rotating a plurality of rotors. This rotor can be rotated based on the rotation of the rotor motor 42. The rotor motor 42 can rotate based on the electric power supplied from the battery 44. The rotor can be rotated by rotating the rotor motor 42, and the unmanned aerial vehicle 3 can be immediately raised or lowered in the vertical direction, or can be stopped in place. Further, when the unmanned aerial vehicle 3 is moved back and forth and left and right, the rotation speed of the rotor motor 42 in the traveling direction is decreased, and the rotation speed of the rotor motor 42 on the opposite side of the traveling direction is increased. As a result, the unmanned aerial vehicle 3 is in a leaning posture with respect to the traveling direction, and can move in the traveling direction. Further, by adjusting the output according to the rotation direction of the rotor motor 42, it is possible to rotate the unmanned aerial vehicle 3 itself. The rotation speed of the rotor motor 42 is controlled via the ESC 54 under the control of the flight controller 50 in the control unit 45.

The wireless communication unit 51 performs frequency conversion and other various conversion processes necessary for performing wireless communication and optical communication with the terrestrial transmission source 4, and converts an electric signal into a radio wave or a radio wave into an electric signal. Also includes antennas that do. The wireless communication unit 51 also includes a converter that converts infrared light, near-infrared light, laser light, or an optical signal of any wavelength into an electric signal, or converts an electric signal into an optical signal. The wireless communication unit 51 converts a signal superimposed on a radio wave or an optical signal transmitted from the outside into an electric signal and then outputs the signal to the coding / decoding unit 52. Further, the wireless communication unit 51 superimposes the signal transmitted from the coding / decoding unit 52 on the radio wave or the optical signal and transmits the signal to the outside.

The coding / decoding unit 52 decodes the signal transmitted from the wireless communication unit 51 and then transmits the signal to the flight controller 50. Further, the coding / decoding unit 52 performs appropriate coding / encryption processing on the random number string sent from the flight controller 50 to prevent error correction and leakage to an eavesdropper, and performs this with the wireless communication unit 51. Send to.

The flight controller 50 includes a control unit 57, a flight control sensor group 55 connected to the control unit 57, and a GNSS receiving unit 56.

The control unit 57 is a so-called central calculation unit for controlling all the components. The control unit 57 notifies each component of an instruction for reading a program stored in a memory (not shown) and performing various operations. For example, if the program stored in the memory is related to the encryption processing method and the flight method in the unmanned aerial vehicle 40, the encryption processing is performed based on this, or various instructions for flying are stopped and each component is stopped. Send to. Further, in the memory (not shown), map information and the like of the area where the navigation is actually planned may be stored in advance.

The flight control sensor group 55 includes at least an accelerometer, an angular velocity sensor, a pressure sensor (altitude sensor), a geomagnetic sensor (orientation sensor), an altitude meter for detecting flight altitude, and a wind direction and wind speed meter for detecting wind speed and direction. It is composed of various sensors such as an acceleration sensor for detecting the tilt angle and tilt direction of the aircraft, a gyro sensor, and the like. The flight control sensor group 55 transmits each detected data to the control unit 57.

The GNSS receiving unit 56 acquires the current position information of the unmanned aerial vehicle 40 at the time of flight in real time based on the GNSS signal transmitted from the satellite 2. The GNSS receiving unit 56 transmits the acquired position information to the control unit 57.

Among the above-mentioned components, the flight controller 50, the ESC 54, and the like are all connected to the battery 44, and electric power is supplied.

The electric gimbal 72 is a turntable on which the camera 53 is mounted. The electric gimbal 72 is rotatably configured under the control of the control unit 57. By rotating the electric gimbal 72, the shooting direction of the camera 53 can be changed. The electric gimbal 72 may be provided with a vibration absorbing mechanism for preventing the vibration from the unmanned aerial vehicle 3 from being transmitted to the camera 53.

The camera 53 captures a subject in a shooting direction determined based on the rotation of the electric gimbal 72. The imaging timing of the camera 53 is controlled by the control unit 57. The image captured by the camera 53 is transmitted to the control unit 57 via the encryption / decryption unit 58. The image transmitted to the control unit 57 is stored in the memory under the control of the control unit 57, and may be transmitted to the public communication network via the wireless communication unit 51 as needed. In the current position detection system 1 to which the present invention is applied, the camera 53 in the unmanned aerial vehicle 3 mainly captures a signal consisting of visible light transmitted from each ground source 4. The camera 53 may be embodied by, for example, a wide-angle imaging device. This makes it possible to simultaneously image signals in the visible light region transmitted from both the ground transmission sources 4a and 4b.

In a general multicopter or the like in which the movement of the airframe is realized by the tilt of the airframe, an electric gimbal 72 for correcting the tilt in order to correct the tilt or deviation of the camera image is often installed. The electric gimbal 72 is a device having a movable part so that the shooting range of the camera does not change even if the aircraft is tilted. When such an electric gimbal 72 is used, the direction of the ground source 4 (direction of information incident). May not be detected correctly. In such a case, the incident direction can be correctly detected by using the absolute amount of the electric gimbal 72 rotating with respect to the airframe and the inclination correction amount.

When the optical signal (image) composed of visible light captured by the camera 53 is encrypted, the encryption / decryption unit 58 performs a process for decrypting the optical signal (image).

The signal incident direction detection unit 59 is a device for detecting the incident direction of an optical signal transmitted from the terrestrial source 4 and received by the wireless communication unit 51, and is composed of, for example, a gyro or the like. The signal incident direction detection unit 59 may be configured as a device for detecting the incident direction of visible light captured by the camera 53. In such a case, it may be configured as a shooting angle measuring unit for detecting the shooting direction and the like of visible light from each ground source 4. The signal incident direction detection unit 59 notifies the control unit 57 of the incident direction of the detected optical signal. In detecting the direction of visible light actually incident on the camera 53, the function of the signal incident direction detecting unit 59 may be mounted on the camera 53 itself. That is, the camera 53 may be used as a wide-angle camera to capture the optical signals of the respective visible lights transmitted from the ground transmission sources 4a and 4b, and the incident angle may be determined by using an image processing technique.

The terrestrial transmission source 4 is a signal transmission source that transmits an optical signal such as visible light or infrared light. The terrestrial transmission source 4 may be configured by a lighthouse or the like as long as it transmits a signal based on visible light. From this lighthouse, light having a wavelength in the visible region is emitted from an LD (Laser Diode), an LED (Light Emitting Diode), or the like. Further, as long as it emits a signal based on light of another wavelength such as infrared light, it may be configured by an infrared light source or the like. The terrestrial source 4 may perform an encryption process on transmitting such an optical signal. In the following example, the installation positions of the ground source 4 will be described by taking as an example the case where the distance between the ground source 4 is known to be two locations, the departure point A and the arrival point B. That is, the explanation will be given by taking as an example the case where the ground source 4a installed at the departure point A and the ground source 4b installed at the arrival point B are used, but the explanation is limited to this. It's not a thing. The ground transmission source 4 may be installed at any location other than the departure point A and the arrival point B, as long as the transmitted optical signal can reach the unmanned aerial vehicle 3.

The encryption method applied to the transmitted optical signal may be based on any conventional method. For example, the time 92, the terrestrial source ID 93, the location information 94, and the like may be collectively encrypted by one-time pad.

Next, the operation of the current position detection system 1 having the above-described configuration will be described.

First, as shown in step S11 of FIG. 3, the unmanned aerial vehicle 3 starts at the departure point A, loads, for example, luggage, and then takes off toward the arrival point B. At this time, the unmanned aerial vehicle 3 shares a common encryption key with the ground transmission sources 4a and 4b in advance. The unmanned aerial vehicle 3 holds the encryption key by storing it in the encryption / decryption unit 58, the coding / decryption unit 52, or the like.

Next, the process proceeds to step S12, and the unmanned aerial vehicle 3 that has taken off from the departure point A basically grasps its position based on the received GNSS signal. That is, the control unit 57 acquires the current position information in real time based on the GNSS signal received via the GNSS receiving unit 56. Then, the control unit 57 refers to the acquired current position information and the preset navigation route from the departure point A to the arrival point B, and controls the rotor motor 42 to adjust the flight direction. Aim. The above processing operation is the same as the flight direction control performed in the normal unmanned aerial vehicle 3.

In addition to the above, in the present invention, optical signals such as visible light and infrared light are emitted from the ground transmission sources 4a and 4b at any time, and the unmanned aerial vehicle 3 receives these optical signals at any time. The optical signals from the ground transmission sources 4a and 4b are transmitted in a state of being encrypted by a code shared with the unmanned aerial vehicle 3. If the optical signals transmitted from the ground transmission sources 4a and 4b have infrared wavelengths or the like, the unmanned aerial vehicle 3 receives the optical signals via the wireless communication unit 51. Further, when the optical signals transmitted from the ground transmission sources 4a and 4b are in the visible light region, the unmanned aerial vehicle 3 receives the optical signals by imaging the optical signals via the camera 53.

The optical signals transmitted from the ground transmission sources 4a and 4b may have a frame structure as shown in FIG. 4, for example. The frame structure may be configured such that the key ID 91, the time 92, the terrestrial source ID 93, the position information 94, and the MAC (Message Authentication Code) frame 95 are sequentially arranged from the beginning. The key ID 91 is an ID based on the encrypted key, and the time 92 describes information about the time at the time of transmission. Further, in the terrestrial source ID 93, an ID assigned to each terrestrial source 4 is described. Further, the position information 94 describes the position information and the like for each terrestrial transmission source 4.

Such a frame structure is encrypted by the above-mentioned common encryption key. When an optical signal consisting of an infrared wavelength or the like is received via the wireless communication unit 51, the optical signal is decoded by the coding / decoding unit 52. When an optical signal in the visible light region is received via the camera 53, it is decrypted by the encryption / decryption unit 58. Both the coding / decoding unit 52 and the encryption / decryption unit 58 have a common encryption key with the terrestrial source 4 in advance. Specifically, it holds an encryption key whose ID matches the key ID 91 in the data frame. In the first place, the key ID of the data frame is encrypted on the terrestrial source 4 side via a common encryption key, so both the encoding / decrypting unit 52 and the encryption / decryption unit 58 are decrypted via the common encryption key. It becomes possible to do. The composited data frame is sent to the control unit 57.

In the present invention, it is not essential to encrypt and send the optical signal, and the ground source 4 may transmit the optical signal to the unmanned aerial vehicle 3 without encrypting it. In such a case, the unmanned aerial vehicle 3 can omit the implementation of the means for decrypting the code.

The control unit 57 can obtain the terrestrial transmission source ID 93 from the decoded data frame, and can also acquire the position information of the terrestrial transmission sources 4a and 4b from the position information 94.

The MAC value is obtained by hashing the terrestrial source ID 93 and the position information of the terrestrial sources 4a and 4b with a hash function such as SHA-2 or a random number (encryption key) shared in advance such as the Wegman-Carter method. I take the. Then, when the control unit 57 compares the MAC value acquired from the optical signal with the MAC value acquired from the ground transmission sources 4a and 4b before takeoff and determines that they match each other, the control unit 57 determines that they match each other. Authenticate as a genuine terrestrial source 4a, 4b. When the control unit 57 authenticates that the authentic terrestrial transmission sources 4a and 4b are used, the control unit 57 returns an authentication signal indicating that the authentication has been performed to the terrestrial transmission sources 4a and 4b. The reply of the authentication signal may be performed under the control of the control unit 57, for example, via the wireless communication unit 51 or the like. On the other hand, if the MAC value acquired from the optical signal and the MAC value acquired from the ground transmission sources 4a and 4b before takeoff are different from each other, the control unit 57 interferes with the navigation of the unmanned aerial vehicle 3. It will be determined that there is a possibility that a spoofing signal has been received.

Further, when the control unit 57 authenticates the reception from the genuine ground transmission sources 4a and 4b, the control unit 57 calculates the current position of the unmanned aerial vehicle 3 itself based on the position information of the ground transmission sources 4a and 4b included in the received optical signal. To do.

As for the calculation method of the current position of the unmanned aerial vehicle 3, for example, as shown in FIG. 5, the positions of the ground transmission sources 4a and 4b are included in the optical signals sent from the ground transmission sources 4a and 4b, respectively. It is identified based on the location information of the sources 4a and 4b. As a result, the distance L between the ground transmission sources 4a and 4b can also be obtained from the respective position information of the ground transmission sources 4a and 4b.

Next, the angles θ1 and θ2 in FIG. 5 are calculated from the incident angle of the optical signal detected by the signal incident direction detecting unit 59. As a result, the distance L and θ1 and θ2 are specified, and the position of the unmanned aerial vehicle 3 is also specified by calculating these numerical values. Since the positions of the ground transmission sources 4a and 4b are known, it is possible to specify the current position of the unmanned aerial vehicle 3 on the coordinate system consisting of latitude and longitude by the same principle as ordinary triangulation. .. At this time, the altitude, speed, acceleration, and other information acquired from the flight control sensor group 55 may also be referred to when determining the current position of the unmanned aerial vehicle 3. Further, the information regarding the current time extracted from the time 92 may also be used to actually correct the current position in the calculation result. As a result, the unmanned aerial vehicle 3 can grasp its current position by using only the optical signals from the ground transmission sources 4a and 4b without using any GNSS signal.

At this time, the control unit 57 compares the current position calculated based only on the optical signals from the ground transmission sources 4a and 4b with the current position grasped based on the GNSS signal transmitted from the satellite 2. It may be. When the current position based on the optical signal and the current position based on the GNSS signal coincide with each other, it is determined that the GNSS signal is not disturbed by the spoofing signal.

On the other hand, when the current position based on the optical signal from the ground transmission sources 4a and 4b and the current position based on the GNSS signal do not match each other, it is determined that the GNSS signal is disturbed by the spoofing signal. .. In such a case, the unmanned aerial vehicle 3 transmits to the outside via the wireless communication unit 51 that there is an interfering source transmitting such a spoofing signal to alert the unmanned aerial vehicle manager and the like. Alternatively, the existence of the interference source is stored in the memory in the control unit 57 as needed. However, the processing operation that should be performed with the highest priority is to ensure the safety of the unmanned aerial vehicle 3 currently in operation. Therefore, if the current position based on the optical signal and the current position based on the GNSS signal do not match each other, in the subsequent navigation, only the current position based on the optical signal is referred to to correct the flight route. Etc., and the current position acquired based on the GNSS signal shall not be considered at all. In such a case, the control unit 57 refers to the current position calculated based on the optical signal and the map information acquired in advance, determines the flight route toward the destination point B, and is currently based on the flight route. The flight direction from the position will be corrected. When the transmission of the spoofing signal is determined, the navigation mode is shifted to the minimum to prevent a crash, and the current position calculated based on the optical signal and the map information acquired in advance are referred to, and there are few private houses. You may move to the area for the time being.

Finally, as shown in step S13 of FIG. 3, the unmanned aerial vehicle 3 arrives at the destination point B.

That is, according to the current position detection system 1 to which the present invention is applied, when a spoofing signal is tentatively emitted by a disturbing source in the process of navigation of the unmanned aerial vehicle 3, this adversely affects the current position grasp by the GNSS signal. However, the current position can be accurately grasped based on the optical signal from the ground source 4. That is, since the method of grasping the current position from the ground source 4 is completely independent of grasping the current position based on the GNSS signal, the unmanned aerial vehicle 3 is not particularly affected by the spoofing signal. , Accurate position information can be grasped at all times. As a result, even if the unmanned aerial vehicle 3 itself is disturbed by the impersonation signal irradiation, the unmanned aerial vehicle 3 itself can grasp its position more accurately without being affected by the interference, and it can be crashed or recovered by a third party. Can be strongly prevented. Moreover, since the optical signal transmitted from the ground transmission source 4 is encrypted in advance with the common encryption key with the unmanned aerial vehicle 3, even if there is an interference radio wave from the interference source, it is unmanned. The aircraft 3 itself can accurately grasp its current position without being affected by the interfering radio waves. Therefore, it is possible to further improve the navigational safety of the unmanned aerial vehicle 3.

Further, according to the present invention, there is an advantage that the position information can be confirmed only by capturing visible light with the camera 53, and the unmanned aerial vehicle 3 itself can be realized with a very inexpensive configuration.

In addition, when it is determined that the spoofing signal has not been detected, the unmanned aerial vehicle 3 will grasp its current position based only on the GNSS signal transmitted from the satellite 2 as usual for a while. May be good. The method of grasping the current position based on the optical signal from the terrestrial source 4 has a large calculation load and consumes power by that amount, but the current position is grasped only by the GNSS signal. This is because the power consumption can be reduced.

In the present invention, by locating the optical signal from the ground source 4 at substantially the center of the screen of the camera 53, it is possible to process the information in the imaging area having the highest optical detection accuracy. In particular, when the reception spot size of the optical signal from the ground source 4 is small, or when the distance from the ground source 4 to the unmanned aerial vehicle 3 is long, the detection reliability of the detected data can be improved.

The present invention is not limited to the above-described embodiment. It is not limited to grasping the current position of the unmanned aerial vehicle 3 based on the optical signals from two or more ground transmission sources 4a and 4b, and as shown in FIG. 6, the optical signal from one ground transmission source 4c. Is also included when is transmitted to the unmanned aerial vehicle 3. The processing operation itself is the same in the form shown in FIG. The ground source 4c may be installed at any of the departure point A, the arrival point B, or any other point.

However, only the direction (angle) of the unmanned aerial vehicle 3 with respect to the ground source 4c can be determined only from the optical signal received from one ground source 4c, and the current position cannot be accurately grasped. Therefore, the form shown in FIG. 6 is specialized in determining the direction (angle) of the unmanned aerial vehicle 3 with respect to the ground transmission source 4c. However, even if the reliability of the position information from the GNSS signal cannot be maintained due to the spoofing signal, the flight direction can be corrected based on the determined azimuth (angle) information of the ground source 4c. As a result, it is possible to guide to the installation position of the ground transmission source 4c. By installing the ground source 4c at the arrival point B, it is possible to guide the unmanned aerial vehicle 3 toward the ground source 4c and eventually the arrival point B.

At this time, according to the present invention, the inclination of the unmanned aerial vehicle 3 may be further acquired from the flight control sensor group 55. If the tilt of the unmanned aerial vehicle 3 can be detected, it is possible to identify how much the receiving surface of the camera 53 is tilted accordingly. The signal incident direction detection unit 59 may calculate the incident direction of the optical signal in consideration of the inclination of the unmanned aerial vehicle 3 or the inclination of the receiving surface of the camera. Based on the incident direction of the optical signal thus obtained and the position information of the terrestrial transmission source 4, the spatial direction of the unmanned aerial vehicle is calculated in the same manner as described above. At this time, the position information of the terrestrial transmission source 4 may be acquired from the received optical signal, or may be acquired in advance.

At this time, the signal incident direction detection unit 59 may detect both the inclination of the unmanned aerial vehicle 3 and the inclination of the receiving surface of the camera 53, and calculate the incident direction of the optical signal based on both of them. If the electric gimbal 72 is a biaxial gimbal, only the inclination of the front, rear, left and right of the machine can be canceled, and the blur in the rotation direction of the machine cannot be canceled. Therefore, in addition to the inclination of the receiving surface of the camera 53, the inclination of the unmanned aerial vehicle 3 itself is detected, and the incident direction of the optical signal is determined in consideration of these. This makes it possible to further improve the accuracy of determining the incident direction of the optical signal.

Similarly, when transmitting an optical signal from one ground source 4c, it is not essential to encrypt the optical signal and send it, and the ground source 4 transmits the optical signal to the unmanned aerial vehicle 3 without encryption. It may be sent to. In such a case, the unmanned aerial vehicle 3 can omit the implementation of the means for decrypting the code.

1 Current position detection system 2 Satellite 3 Unmanned aerial vehicle 4 Ground source 15 Control unit 40 Unmanned aerial vehicle 42 Rotor motor 44 Battery 45 Control unit 50 Flight controller 51 Wireless communication unit 52 Coding and decoding unit 53 Camera 55 Flight control sensor group 56 Reception Unit 57 Control unit 58 Code decoding unit 59 Signal incident direction detection unit 72 Electric gimbal 92 Time 94 Position information 95 Frame

Claims (3)

In the current position detection system for unmanned aerial vehicles to detect the current position of unmanned aerial vehicles flying from the departure point to the arrival point
At least two or more terrestrial sources that emit optical signals including their location information,
A receiving means for acquiring the position information of each terrestrial source by receiving each optical signal transmitted from each terrestrial source, an incident direction identifying means for identifying each incident direction of the optical signal, and a means for identifying the incident direction. An unmanned aerial vehicle having a calculation means for calculating a current position with respect to the ground source based on each position information acquired by the receiving means and each incident direction identified by the incident direction identification means .
The unmanned aerial vehicle includes a GNSS identification means for identifying the current position based on a GNSS (Global Navigation Satellite System) signal received from a satellite, and a GNSS identification means.
An unmanned aerial vehicle characterized by having a spoofed signal discriminating means for discriminating the presence or absence of a spoofed signal based on the result of comparing the current position identified by the GNSS identifying means with the current position calculated by the calculating means. Current position detection system. When the unmanned aerial vehicle acquires map information in advance and determines the existence of a spoofed signal by the spoofed signal discriminating means, the flight route is based on the current position calculated by the calculating means and the map information. current position detecting system of the unmanned aircraft according to claim 1, characterized in that the modifications. An unmanned aerial vehicle that is applied to the current position detection system for an unmanned aerial vehicle according to claim 1 or 2 , and includes the receiving means, the incident direction identifying means, and the calculating means.

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