JP5171881B2 - Method for supporting landing of unmanned air vehicle and unmanned air vehicle - Google Patents

Description

  The present invention relates to a method for supporting landing of an unmanned air vehicle and an unmanned air vehicle, and more particularly to a technique for reliably and safely landing an unmanned air vehicle at a landing target point by autonomous flight.

  As a mechanism for safely landing an aircraft on a runway, for example, in Patent Document 1, a marker is provided on the fuselage of a vertical take-off and landing aircraft, while on the ground, the elevation angle of the optical axis is set to coincide with the descent angle. A first image sensor, a speedometer set so that the measurement direction coincides with its optical axis, a second image sensor with a fisheye lens whose optical axis is set vertically upward, and image and speed information of each image sensor are given. It is described that an image processing / guidance calculation device is provided to control an image of a first image sensor so that a marker coincides with the center of the screen and a speed coincides with a target speed.

  In Patent Document 2, a reference station having a function as a GPS receiver is installed at a known position on the ground, and the position measurement data is transmitted to the aircraft via a wireless line, and the aircraft has a GPS reception function. On the other hand, set the index point where the precise position is known on the axis of the runway RWY, find the absolute coordinates of the aircraft based on the GPS measurement position of the reference station and the aircraft and the reference station installation position, and this index It is described that a guidance route that an aircraft should follow is calculated based on position information of a point, and a deviation between the flight route of the aircraft and the guidance route is obtained and displayed on a display.

JP-A-5-24589 JP-A-11-345399

  In recent years, research and development of unmanned aerial vehicles (helicopters, etc.) that fly autonomously along high-voltage lines and power transmission lines have been carried out by electric power companies, etc., in order to enable automatic inspection of high-voltage lines and transmission lines. It has been broken. Here, an attempt is made to realize autonomous flight of an unmanned air vehicle using, for example, GPS (Grobal Positioning System), but the position information that can be acquired by GPS is not necessarily sufficiently accurate, and the position information that is high at the time of landing is high. In situations where accuracy is required, it is difficult to achieve complete autonomous flight by GPS.

  The present invention has been made in view of such problems, and a method for supporting landing of an unmanned air vehicle capable of reliably and safely landing an unmanned air vehicle at a landing target point by autonomous flight, and an unmanned air vehicle The purpose is to provide.

  A main invention for achieving the above object is a method for supporting landing of an unmanned air vehicle, wherein a plurality of first antennas arranged adjacent to each other with an interval are provided adjacent to a landing target point, and each of the first antennas is provided. A plurality of first radio signals having different phases from each other, the unmanned air vehicle transmits a second radio signal, and transmits a third radio signal synchronized with the second radio signal to the landing target point. An antenna is also provided, and the unmanned air vehicle receives the first radio signal transmitted from each of the first antennas, and determines the phase difference between the first radio signals transmitted from the different first antennas. Based on the phase difference between the second radio signal and the third radio signal, the distance from the landing target point to itself is obtained based on the phase difference between the second radio signal and the third radio signal. Acquired and acquired Serial direction acquires its current location on the basis of said distance, and to perform autonomous flight towards the landing target point in the first flight mode to fly based on the acquired current position.

  In this way, the unmanned air vehicle of the present invention acquires its direction with respect to the landing target point based on the phase difference of the first radio signal, and from the landing target point based on the phase difference between the second radio signal and the third radio signal. The distance to the unmanned air vehicle is acquired, the current position of itself is acquired based on the acquired direction and distance, and autonomous flight is performed toward the landing target point in the first flight mode in which the flight is performed based on the acquired current position. According to this, the helicopter can be landed at the landing target point with high accuracy, reliably and safely by autonomous flight.

  In another aspect of the present invention, when the unmanned air vehicle determines whether or not landing is necessary during the autonomous flight based on a predetermined condition, and determines that landing is necessary The landing target point is automatically set, and it is determined at any time whether the received electric field strength of at least one of the first radio signal and the third radio signal is equal to or higher than a preset threshold value, and the received electric field When it is determined that the strength is greater than or equal to the threshold, autonomous flight toward the landing target point in the first flight mode is started.

  According to the present invention, the unmanned air vehicle determines at any time whether or not landing is necessary during autonomous flight based on a predetermined condition, and if it is determined that landing is necessary, the landing target point is automatically set. Therefore, the unmanned air vehicle can be automatically landed when landing is necessary.

  The predetermined condition is, for example, whether or not the flight is completed for a preset scheduled flight route, whether or not the remaining amount of the mounted storage battery is less than or equal to a preset threshold, Whether the amount is equal to or less than a preset threshold value, whether the remaining capacity of the recording medium for recording data to be collected during the flight is equal to or less than a preset threshold value, and the like.

  In another aspect of the present invention, the unmanned air vehicle obtains its current position from a GPS receiver and performs autonomous flight in a second flight mode, and the first radio signal or the first It is determined at any time whether the received electric field strength of at least one of the three radio signals is greater than or equal to a preset threshold value, and when it is determined that the received electric field strength is greater than or equal to the threshold value, Start autonomous flight to the landing target point.

  According to the present invention, the unmanned aerial vehicle performs autonomous flight in the second flight mode in which, for example, in the over flight, the current position is acquired based on the information from the GPS receiver, the first radio signal or the third radio If it is determined that the received electric field strength of at least one of the signals is greater than or equal to the threshold value, autonomous flight is started toward the landing target point in the first flight mode. According to this, when the received electric field strength of the first radio signal or the third radio signal is not sufficient, autonomous flight is performed in the second flight mode based on the GPS receiver, and only when the received electric field strength is greater than or equal to the threshold value. Since autonomous flight is performed in the 1 flight mode, it is possible to reliably prevent the autonomous flight from being performed in the first flight mode when the received electric field strength is insufficient. According to this, the helicopter can safely fly autonomously.

  In another aspect of the present invention, whether the unmanned air vehicle has a distance to the landing target point after a start of the autonomous flight in the first flight mode is equal to or less than a preset threshold value. When the distance to the landing target point is determined to be less than or equal to the threshold value, autonomous flight is started immediately above the landing target point in the first flight mode, and immediately above the landing target point. It is determined at any time whether or not the vehicle has reached the landing target point, and when it is determined that the vehicle has reached directly above the landing target point, a landing operation toward the landing target point is started.

  In this way, the unmanned air vehicle of the present invention automatically starts autonomous flight directly above the landing target point in the first flight mode when the distance to the landing target point becomes equal to or less than the threshold value, and immediately above the landing target point. When it reaches, the landing movement toward the landing target point is started. As described above, the unmanned air vehicle of the present invention performs autonomous flight by switching the flight method step by step when approaching the landing target time, so that the unmanned air vehicle can be landed safely and quickly.

  In addition, the subject which this application discloses, and its solution method are clarified by the column of the form for inventing, and drawing.

  According to the present invention, an unmanned air vehicle can be landed reliably and safely at a landing target point by autonomous flight.

1 is a diagram showing a schematic configuration of an unmanned flight system 1. FIG. It is a side view of helicopter 10 in the state where main part cover 9 was equipped. It is a side view of helicopter 10 in the state where body cover 9 was removed. It is a block diagram of the apparatus provided in each of the helicopter 10 and the base station 5. FIG. It is a figure explaining operation | movement at the time of flight of the helicopter 10 in case the flight mode is set to autonomous flight mode. It is a block diagram explaining the function of the mobile body side location apparatus and the base station side location apparatus. It is a figure which shows the hardware constitutions of the direction orientation part. It is a figure which shows the function of the direction orientation part. It is a figure which shows the hardware constitutions of the direction determination signal transmission part 211. It is a figure which shows the function of the direction determination signal transmission part. It is a data structure of the position location signal 800 (1st radio signal). FIG. 3 is a diagram for explaining a relative positional relationship between an antenna group 224 included in a direction determining signal transmission unit 211 of a base station 5 and an antenna 124 included in a direction determining unit 111 of a helicopter 10. FIG. 3 is a diagram showing the configuration of a first transmission / reception unit 151 and a second transmission / reception unit 251. It is a figure which shows the structure of the radio signal 1100 (2nd radio signal). It is a figure which shows the structure of the radio signal 1150 (3rd radio signal). It is a figure which shows the structure of the signal generation part 1011 and the signal processing part 1012. FIG. It is a figure which shows the structure of the synchronous control part 1025. 5 is a diagram showing a detailed configuration of a synchronous oscillation unit 1414. FIG. It is a timing chart explaining the mechanism of distance measurement. 4 is a flowchart for explaining the operation at the time of landing of the helicopter 10. It is a flowchart explaining operation | movement of the helicopter 10 in autonomous flight in position determination autonomous flight mode. 2 is a diagram illustrating an example of autonomous flight of the helicopter 10. FIG.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic configuration of an autonomous flight type unmanned flight system 1 described as an embodiment of the present invention. As shown in FIG. 1, the unmanned flight system 1 includes a helicopter 10 that is an example of an autonomous flight type unmanned air vehicle, and a base station 5 that performs wireless communication with the helicopter 10. The helicopter 10 is used for operations such as patrol inspection of the high-voltage line tower 2 and a power transmission line (not shown in the figure) over the high-voltage line tower 2. The base station 5 performs control and monitoring related to the flight of the helicopter 10 and the above operations.

  2A and 2B show the configuration of the helicopter 10. FIG. 2A is a side view of the helicopter 10 in a state where the main body cover 9 is mounted. 2B is a side view of the helicopter 10 with the main body cover 9 removed.

  The helicopter 10 includes a main body frame 11, a skid 12, and a tail boom 13 as a basic skeleton. A main rotor 14 is provided above the main body frame 11, and a tail rotor 15 is provided at the end of the tail boom 13.

  As shown in FIG. 2B, the main body frame 11 includes a power mechanism 16, a steering mechanism 17, a control mechanism 18, a control circuit 19, a GPS receiver 21 (GPS: Global Positioning System), a GPS antenna 22, various sensors 23, data. A transmitter / receiver 24, a data transmitting / receiving antenna 25, a computer 26, a video camera 27, and a moving object side position locating device 100 are mounted.

  The power mechanism 16 includes an engine 161, a muffler 162, a fuel tank 163, and the like. The steering mechanism 17 includes an aileron mechanism that controls the attitude of the helicopter 10 in the roll axis direction, an elevator mechanism that controls the attitude in the pitch axis direction, a ladder mechanism that controls the attitude of the helicopter 10 in the yaw axis direction, and the angle of attack of the main rotor 14. Including a pitch mechanism for controlling the motor. The control mechanism 18 includes a servo motor and an actuator. The control mechanism 18 controls the power mechanism 16 and the steering mechanism 17 in accordance with a control signal from the control circuit 19.

  The GPS receiver 21 demodulates the signal input from the GPS antenna 22 and supplies a signal indicating the current position to the computer 26 based on the demodulated signal. The mobile-side position locating device 100 communicates with the base station-side position locating device 200 provided in the base station 5 to determine the current position of the helicopter 10 and supplies the signal indicating the determined current position to the computer 26. .

  The various sensors 23 are a geomagnetic sensor, an acceleration sensor, a speed sensor, a gyro sensor, an engine speed sensor, a battery remaining amount sensor, a fuel remaining amount sensor, a temperature sensor, an atmospheric pressure sensor, and the like. A pressure-sensitive sensor is provided on the ground contact surface of the skid 12 of the helicopter 10. The pressure sensor signal is used to determine whether the helicopter 10 is currently landing.

  The data transmitter / receiver 24 performs data communication with the base station 5 via the wireless antenna 25. The computer 26 includes a CPU and a memory, and executes a process for autonomous flight of the helicopter 10 based on instructions from the base station 5 and measured values of various sensors 23.

  FIG. 3 is a block diagram of devices provided in each of the helicopter 10 and the base station 5. As shown in the figure, the GPS receiver 21, various sensors 23, the data transmitter / receiver 24, and the moving object side position locating device 100 are all communicably connected to a computer 26.

  The computer 26 is based on the information supplied from the GPS receiver 21, various sensors 23, the data transmitter / receiver 24, and the moving body side position locating device 100, via the control circuit 19 and the control mechanism 18, the power mechanism 16 and the steering mechanism 17. To control. The autonomous flight of the helicopter 10 is realized by the above control of the computer 26.

  The helicopter 10 is a flight mode (hereinafter, referred to as an autonomous flight mode) that flies autonomously based on position information supplied from the GPS receiver 21 or the mobile body position locating device 100, and a flight mode that is manually controlled (hereinafter, referred to as an autonomous flight mode). In addition, it is referred to as a manual flight mode.) Further, a flight mode by semi-autonomous control (hereinafter referred to as semi-autonomous flight mode) in which one of manual control and autonomous control is given priority according to the situation and controlled. Has two flight modes.

  In addition, the autonomous flight mode includes an autonomous flight mode based on information from the GPS receiver 21 (hereinafter referred to as a GPS autonomous flight mode (second flight mode)) and an autonomous flight mode (hereinafter referred to as a position location system) described later. , Referred to as a position determination autonomous flight mode (first flight mode).

  The data transmitter / receiver 24 receives information from the base station 5 such as instruction information for the flight of the helicopter 10 and device control information (hereinafter referred to as instruction information) for monitoring a high-voltage line or a power transmission line. Further, the data transmitter / receiver 24 transmits information collected by the helicopter 10 for the purpose of monitoring high voltage lines and power transmission lines (hereinafter referred to as provision information) to the base station 5. The provided information includes information acquired by the various sensors 23, video data taken by the video camera 27, and the like.

  The receiver 40 is a device used for manual control of the helicopter 10. The receiver 40 receives a radio signal transmitted from a transmitter 42 operated by an operator such as an operator or a tower monitor, and inputs a control signal included in the received signal to the control circuit 19.

  FIG. 4 is a diagram for explaining the operation of the helicopter 10 during flight when the above-described flight mode is set to the autonomous flight mode.

  In the figure, a position target value (latitude, longitude, altitude) of the helicopter 10 is supplied to the position control unit 411. The position target value is set automatically by the computer 26 or by an instruction from the base station 5.

  The position control unit 411 obtains a speed target value by comparing the current position of the helicopter 10 supplied from the GPS receiver 21 or the moving body position locating device 100 with the position target value, and speed-controls the obtained speed target value. To the unit 412.

  The speed control unit 412 obtains the attitude target value of the helicopter 10 by comparing the current speed of the helicopter 10 from the various sensors 23 and the given speed target value, and gives the obtained attitude target value to the attitude control unit 413.

  The attitude control unit 413 obtains the operation amount of the servo motor 18 by comparing the current attitude of the helicopter 10 obtained from the values supplied from the various sensors 23 and the attitude target value given from the speed control unit 412. The servo motor 18 is controlled according to the operation amount.

  Measurement values (current position, current speed, current posture) measured by the GPS receiver 21 and various sensors 23 after being controlled by the servo motor 18 are fed back to the position control unit 411, the speed control unit 412, and the posture control unit 413 as needed. Is done.

  As shown in FIG. 3, the base station 5 is provided with a data transmitter / receiver 51, a wireless antenna 52 connected thereto, a control computer 53, and a base station side location apparatus 200.

  The data transmitter / receiver 51 performs wireless communication with the data transmitter / receiver 24 mounted on the helicopter 10.

  The control computer 53 provides a user interface for an operator to give a flight control instruction and a control instruction of the video camera 27 (shooting start / end control, zoom control, shooting direction, etc.) to the helicopter 10. The control computer 53 includes map information, information indicating the landing site and landing target point, information indicating the position of the high-voltage line tower 2 and the section to be extended, which is necessary for the operator to give an instruction to the helicopter 10. Such information is stored. The operator can give necessary instructions to the helicopter 10 by using these devices. The helicopter 10 receives or stores the given instruction information, and autonomously flies according to the instruction information.

  The monitoring computer 54 displays an image or a shadow image taken by the video camera 27 on the display device of the monitoring computer 54. The monitoring computer 54 displays real-time measurement values of various sensors of the helicopter 10. The operator can grasp the flight state of the helicopter 10 in real time by using these functions of the monitoring computer 54.

= Positioning system =
The mobile-side location locating device 100 mounted on the helicopter 10 and the base station-side location locating device 200 provided in the base station 5 are a location locating mechanism for acquiring the current position of the helicopter 10 in real time (hereinafter, referred to as “location positioning device”). , Referred to as a position location system). Hereinafter, the position location system will be described in detail.

  FIG. 5 is a block diagram for explaining the functions of the mobile-side position locating apparatus 100 and the base station-side position locating apparatus 200, which are components of the position locating system. As shown in the figure, the moving object side position locating device 100 includes a first direction measuring unit 110 and a first distance measuring unit 120. The base station side location apparatus 200 includes a second direction measuring unit 210 and a second distance measuring unit 220.

  The first direction measuring unit 110 of the mobile body side position locating device 100 and the second direction measuring unit 210 of the base station side position locating device 200 acquire information indicating the current direction of the helicopter 10 as viewed from the base station 5. .

  Hereinafter, the mechanism for measuring the direction constituted by the first direction measuring unit 110 and the second direction measuring unit 210 is referred to as a direction measuring system. As shown in the figure, the first direction measuring unit 110 includes a direction locating unit 111. The second direction measurement unit 210 includes a direction orientation signal transmission unit 211.

  In addition, the first distance measuring unit 150 of the mobile object-side location device 100 and the second distance measuring unit 250 of the base station-side location device 200 acquire information indicating the current distance of the helicopter 10 as viewed from the base station 5. To do.

  Hereinafter, a mechanism for distance measurement constituted by the first distance measurement unit 150 and the second distance measurement unit 250 is referred to as a distance measurement system. As shown in the figure, the first distance measuring unit 150 includes a first transmitting / receiving unit 151. The second distance measurement unit 250 includes a second transmission / reception unit 251.

<Direction measuring system>
First, the direction measurement system will be described. FIG. 6A shows a hardware configuration of the direction locating unit 111. As shown in the figure, the direction locator 111 includes a CPU 121, a memory 122, a wireless communication interface 123, an antenna 124, and a communication interface 125.

  The CPU 121 executes a program stored in the memory 122. The wireless communication interface 123 receives a position determination signal (first wireless signal), which will be described later, sent from the base station 5 via the antenna 124. The communication interface 125 communicates with the computer 26.

  FIG. 6B shows the function of the direction locator 111. As shown in the figure, the direction locator 111 includes a position locator signal receiver 131 and a position locator 132. The position location signal receiving unit 131 receives the position location signal transmitted from the base station 5. The position locating unit 132 locates the current direction of the helicopter 10 viewed from the base station 5 based on the position locating signal received by the position locating signal receiving unit 131.

  FIG. 7A shows a hardware configuration of the direction determination signal transmission unit 211. As shown in the figure, the direction determination signal transmission unit 211 includes a CPU 221, a memory 222, a wireless communication interface 223, and an antenna group 224 (hereinafter, each antenna (first antenna) constituting the antenna group 224 is denoted by reference numeral 2241). It is indicated by).

  The CPU 221 executes a program stored in the memory 222. The wireless communication interface 223 transmits a position location signal to be described later. The antenna group 224 includes a plurality of circularly polarized directivity antennas arranged adjacent to each other at a predetermined interval.

  The antenna group 224 is provided with a changeover switch 2242. The changeover switch 2242 selects any one of the antennas constituting the antenna group 224 and connects to the wireless communication interface 223.

  FIG. 7B shows the function of the directional signal transmission unit 211. As shown in the figure, the direction determination signal transmission unit 211 includes a position determination signal transmission unit 263. The position location signal transmission unit 263 transmits a radio signal (hereinafter referred to as a position location signal) used for locating the current direction of the helicopter 10 viewed from the base station 5.

  Next, a mechanism in which the direction measurement system having the above configuration acquires the current direction of the helicopter 10 viewed from the base station 5 will be described.

  The direction determination signal transmission unit 211 of the base station side position determination device 200 intermittently transmits a spectrum-spread position determination signal while periodically switching a plurality of antennas constituting the antenna group 224 in a time division manner. .

  On the other hand, the direction locating unit 111 of the mobile-side position locating device 100 receives position locating signals transmitted from the respective antennas constituting the antenna group of the base station 5 via the confident antenna 124.

  When a plurality of base stations 5 are provided adjacent to each other, each base station 5 must share a synchronization signal 811 between the base stations 5 in order to prevent radio wave interference between the base stations 5. Thus, transmission control is performed so that the position location signals are not transmitted simultaneously from two or more base stations 5 that may cause radio wave interference.

  FIG. 8 shows the data structure of the position location signal. As shown in the figure, the position location signal 800 includes the above-described synchronization signal 811, location code 812, antenna information 813, and measurement signal 814.

  The synchronization signal 811 is made up of a total of 48 bits of data including, for example, a 32-bit preamble signal and a 16-bit synchronization signal. The location code 812 (UCODE) is an identifier indicating the installation location of the base station 5, and is composed of, for example, a 128-bit code assigned to each location according to a uniform standard.

  The antenna information 813 includes 16 bits of data indicating the installation positions of the antennas 2241 constituting the antenna group 224, the identifiers of the antennas 2241, the directivity directions of the antennas 2241, and the like. The measurement signal 814 is a signal used to detect the direction of the helicopter 10 viewed from the base station 5 and includes, for example, a spreading code of 2048 chips.

  FIG. 9 is a diagram for explaining the relative positional relationship between the antenna group 224 provided in the direction determination signal transmission unit 211 of the base station 5 and the antenna 124 provided in the direction determination unit 111 of the helicopter 10. In the figure, each antenna 2241 is illustrated in a plan view so that the arrangement and shape of each antenna 2241 can be easily understood, but each antenna 2241 constituting the antenna group 224 of the base station 5 is actually Is also provided so that the directing direction faces upward (the zenith direction).

  In the example shown in the figure, the antenna group 224 is an antenna 2241 and the center of each is 3 cm (this interval corresponds to a quarter wavelength when a 2.4 GHz band radio wave is used as the positioning signal 800). Four circularly polarized directional antennas arranged adjacent to each other in a substantially square shape are provided.

As shown in the figure, if the angle between the zenith direction and the direction of the antenna 124 on the helicopter 10 side viewed from the antenna group 224 of the base station 5 is α,
α = arcTan (D (m) / L (m)) = arcSin (ΔL (cm) / 3 (cm))
...... Formula 1
There is a relationship. Here, ΔL (cm) is a difference in propagation path length to the antenna 124 on the helicopter 10 side for specific two of the four antennas 2241.

Here, if the phase difference between the positioning signals 800 transmitted from the two specific antennas 2241 constituting the antenna group 224 is Δθ, between the above-described ΔL, Δθ and the wavelength λ of the positioning signals 800. Is
ΔL (cm) = Δθ / 2π / λ (cm) Equation 2
There is a relationship.

Here, since the location signal 800 is a radio wave in the 2.4 GHz band, λ≈12 (cm).
α = arcSin (2Δθ / π) (3)
It becomes. The above equation indicates that the direction (α) of the helicopter 10 from the base station 5 can be obtained by measuring the phase difference Δθ. The detection ability of the phase difference Δθ is about ± (180 ° / 1024) ≈ ± 0.2 ° when a 10-bit A / D converter is used.

  The mobile body location apparatus 100 acquires information indicating the direction of the helicopter 10 viewed from the base station 5 in real time by the above mechanism, and supplies the acquired information to the computer 26 in real time.

  As for the above, for example, “Yasunori Takeuchi, Kiminori Kono, Minoru Kono,“ Development of a location detection system using 2.4 GHz band ”,“ The 56th Association of Electrical and Information Society China Branch 56th Annual Meeting ”,“ Japanese Patent Laid-Open No. 2007-212424, “Japanese Patent Laid-Open No. 2007-264680”, and the like are described.

<Distance measurement system>
Next, the distance measurement system will be described. FIG. 10 shows the configuration of the first transmission / reception unit 151 and the second transmission / reception unit 251. As shown in the figure, the first transmission / reception unit 151 includes a signal generation unit 1011, a signal processing unit 1012, a transmission unit 1013, a reception unit 1014, an antenna switching unit 1015, and an antenna 1016.

  Among these, the signal generation unit 1011 generates a signal for requesting distance measurement (hereinafter referred to as a distance measurement request signal). The transmission unit 1013 amplifies the signal supplied from the signal generation unit 1011 and supplies the amplified signal to the antenna 1016. The receiving unit 1014 amplifies the signal supplied from the antenna 1016 and supplies the amplified signal to the processing unit 1112.

  The signal processing unit 1012 measures the distance between the first transmission / reception unit 101 and the second transmission / reception unit 102 based on the signal supplied from the reception unit 1014. The antenna switching unit 1115 performs connection switching of the antenna 1016 to either the transmission unit 1013 or the reception unit 1014. The antenna switching unit 1115 performs, for example, the connection switching in a time division manner.

  As shown in the figure, the second transmitting / receiving unit 251 includes an antenna 1021, an antenna switching unit 1022, a receiving unit 1023, a transmitting unit 1024, and a synchronization control unit 1025.

  Among these, the reception unit 1023 generates a signal obtained by demodulating / amplifying the signal supplied from the antenna 1021 and supplies the generated signal to the synchronization control unit 1025. The synchronization control unit 1025 generates a clock signal synchronized with the starting point signal based on a starting point signal described later included in the signal supplied from the receiving unit 1023, and a signal that is synchronized or orthogonal to the generated clock signal (hereinafter, referred to as the starting point signal). , Referred to as a distance measurement signal).

  The transmission unit 1024 amplifies the distance measurement signal supplied from the synchronization control unit 1025 and supplies the amplified signal to the antenna 1021. The antenna switching unit 1022 switches the connection of the antenna 1021 to either the transmission unit 1024 or the reception unit 1023. The antenna switching unit 1022 performs, for example, the connection switching in a time division manner.

  FIG. 11A shows a configuration of a radio signal 1100 (second radio signal) transmitted from the first transmission / reception unit 151 to the second transmission / reception unit 251. As shown in the figure, the radio signal 1100 includes a system synchronization signal 1111, a MAC layer 1112, and an origin signal 1113.

  The system synchronization signal 1111 is a signal for synchronizing processing timing between the first transmission / reception unit 151 and the second transmission / reception unit 251, and is composed of, for example, a unique word of a plurality of bits. The MAC layer 1112 includes the identification number of the first transmission / reception unit 151, the identification number of the other party (second transmission / reception unit 251), a notification signal, and the like. The origin signal 1113 is a signal used to establish highly accurate synchronization between the first transmission / reception unit 151 and the second transmission / reception unit 251, and is, for example, a single modulation signal having a low frequency.

  FIG. 11B shows a configuration of a radio signal 1150 (third radio signal) transmitted from the second transmission / reception unit 251 to the first transmission / reception unit 151. The system synchronization signal 1151 and the MAC layer 1152 are the same as the system synchronization signal 1111 and the MAC layer 1112 in the radio signal 1100.

  The distance measurement signal 1153 is a signal used to accurately measure the distance between the first transmission / reception unit 151 and the second transmission / reception unit 251, and is a single modulated signal having a low frequency, or synchronized with each other or A plurality of orthogonal signals.

  FIG. 12 shows configurations of the signal generation unit 1011 and the signal processing unit 1012 included in the first transmission / reception unit 151. As shown in the figure, the signal generation unit 1011 and the signal processing unit 1012 include a reference oscillator 1311, a distance measurement request signal generation unit 1313, a distance calculation unit 1343, a phase measurement unit 1344, a distance measurement signal reproduction unit 1345, and a connection terminal. 1346, 1347 are provided.

  The reference oscillator 1311 generates a clock signal. The distance measurement request signal generation unit 1313 generates a distance measurement request signal based on the clock signal supplied from the reference oscillator 1311 and supplies the distance measurement request signal to the connection terminal 1346.

  The distance measurement signal reproduction unit 1345 reproduces (extracts or demodulates) the distance measurement signal 1253 included in the wireless signal 1150 supplied from the connection terminal 1347.

  In the following description, the distance measurement signal reproduced by the distance measurement signal reproduction unit 1345 is referred to as a reproduction distance measurement signal. The phase measurement unit 1344 measures the phase of the distance measurement signal using the clock signal generated by the reference oscillator 1311. The distance calculation unit 1343 measures the distance between the first transmission / reception unit 151 and the second transmission / reception unit 251 based on the phase measured by the phase measurement unit 1344.

  FIG. 13 illustrates a configuration of the synchronization control unit 1025 included in the second transmission / reception unit 251. As shown in the figure, the synchronization control unit 1025 includes an origin signal reproduction unit 1311, a synchronization detection unit 1312, a distance measurement signal generation unit 1313, a synchronization oscillation unit 1314, a reference oscillator 1315, and connection terminals 1316 and 1317.

  The starting point signal reproduction unit 1311 extracts the starting point signal 1113 included in the wireless signal 1100 supplied from the connection terminal 1316. The reference oscillator 1315 generates a clock signal. The synchronization detection unit 1312 samples the starting point signal 1113 using the clock signal supplied from the reference oscillator 1315, and supplies the sampled signal to the synchronization oscillation unit 1314 as an external synchronization signal.

  The synchronous oscillation unit 1314 is configured using a synchronous or asynchronous counter, and generates an oscillation signal synchronized with the start signal 1113 by setting or resetting the counter with an external synchronization signal. The synchronous oscillation unit 1314 continuously generates the oscillation signal synchronized with the starting point signal 1113 after the starting point signal 1113 is not supplied from the starting point signal reproducing unit 1311. The distance measurement signal generation unit 1313 supplies the oscillation signal synchronized with the starting signal supplied from the synchronous oscillation unit 1314 to the connection terminal 1317 as the distance measurement signal 1153.

  FIG. 14 shows a detailed configuration of the synchronous oscillator 1314. In the figure, reference numerals 1411 and 1413 are changeover switches, reference numerals 1412a to 1412n are two or more counters, and reference numerals 1414, 1415 and 1416 are connection terminals.

  The external synchronization signal based on the starting point signal supplied to the connection terminal 1414 is sequentially connected to the counters 1412a to 1412n by the changeover switch 1411, whereby the counters 1412a to 1412n are sequentially reset. A clock signal is supplied to the connection terminal 1416 from the reference oscillator 1315, and the values of the counters 1412a to 1412n are counted down in synchronization with the set or reset timing of the external synchronization signal. The counted down output signals are sequentially switched by the changeover switch 1413 and supplied to the distance measurement signal generation unit 1313 through the connection terminal 1415.

  Next, a mechanism for acquiring the current distance of the helicopter 10 viewed from the base station 5 by the distance measurement system having the above configuration will be described.

  FIG. 15 is a timing chart for explaining a mechanism of distance measurement by the distance measurement system having the above configuration. In the figure, reference numeral 1511 denotes a waveform of the start signal 1113 included in the wireless signal 1100 transmitted from the first transmission / reception unit 151, and reference numeral 1512 denotes a wireless signal 1150 transmitted from the second transmission / reception unit 251. The waveform of the distance measurement signal 1153 included, and reference numeral 1513 is the waveform of the reproduction distance measurement signal reproduced by the distance measurement signal reproduction unit 1245 of the first transmission / reception unit 151.

  In the figure, transmission of the origin signal 1113 is started from the helicopter 10 side at the time t0, and transmission of the distance measurement signal 1153 is started from the base station 5 side at the time t1 in response to the reception of the origin signal 1113. In response to reception of 1153, generation of a reproduction distance measurement signal is started on the helicopter 10 side at time t2.

Here, the waveform 1611 of the starting point signal 1113 transmitted from the first transmission / reception unit 151 is represented as A · sin (2πf ₁ t), the distance from the first transmission / reception unit 151 to the second transmission / reception unit 251 is L, and the speed of light is c. , The waveform 1511 of the origin signal 1113 received by the second transmitting / receiving unit 251 changes in amplitude from A to B due to attenuation or the like, and the phase changes by (2πL (f ₁ / c). B · sin {2πf ₁ t + (2πL (f ₁ / c)}.

On the other hand, if the second transmitter / receiver 251 generates the distance measurement signal 1153 synchronized with the origin signal 1113 by reproducing the origin signal 1113, the waveform 1512 is similarly B · sin {2πf ₁ t + (2πL (f ₁ / c)}.

When the distance measurement signal 1153 is transmitted from the second transmission / reception unit 251 at a time-division timing, and again propagates the distance L and is received by the first transmission / reception unit 151, the waveform 1513 of the reproduction distance measurement signal based on the received signal. Is C · sin {2πf ₁ t + (4πLf ₁ ) / c)}.

Here, if the first transmission / reception unit 151 measures the phase difference between the clock signal used to generate the start signal 1511 and the reproduction distance measurement signal, ΔΦ = {4πL (f1 / c)}. Therefore, if this value is substituted into L = c · ΔΦ / 4πf ₁ , the distance L from the first transmission / reception unit 151 to the second transmission / reception unit 251 can be obtained.

  The mobile-side position locating device 100 acquires information indicating the distance from the base station 5 to the helicopter 10 in real time by the above mechanism, and supplies the acquired information to the computer 26 in real time.

  As for the mechanism for acquiring the distance from the base station 5 to the helicopter 10 described above, for example, a technique related to “Japanese Patent Application No. 2009-206078” is described.

= Landing motion =
Next, the operation | movement at the time of landing of the helicopter 10 which consists of the above structure is demonstrated. FIG. 16 is a flowchart for explaining the operation of the helicopter 10 during landing. Hereafter, the operation | movement at the time of landing of the helicopter 10 is demonstrated with the same figure.

  An autonomous flight mode in which the helicopter 10 autonomously flies in accordance with a route designated by the base station 5 while confirming its current position based on information from the GPS receiver 21 while flying over the landing field (heliport). That is, it is flying in the GPS autonomous flight mode (S1611). During the flight in the GPS autonomous flight mode, the helicopter 10 determines at any time whether or not it is necessary to land on the landing field (S1612).

  For example, the helicopter 10 has received a landing instruction from the base station 5, the helicopter 10 has reached the sky above the landing site, and the remaining amount of the storage battery supplying power to the electric system of the helicopter 10 is a predetermined threshold value. That the remaining amount of fuel (mounted fuel) required for driving the power mechanism 16 has fallen below a predetermined threshold, data to be collected during flight (images, images, measured values of various sensors, etc.) ) Is recorded, it is determined that it is necessary to land on the landing site for the reason that the remaining capacity of the recording medium for recording is equal to or less than a predetermined threshold.

  If it is determined that landing is necessary (S1612: YES), the helicopter 10 acquires the current position of the helicopter 10 from the GPS receiver 21. Then, a landing site is selected based on the map information stored in the memory of the computer 26 or the information on the landing site, and the position (latitude, longitude, altitude) of the base station 5 attached to the selected landing site is acquired. . The helicopter 10 selects, for example, a landing site that is the shortest distance from its current position. For example, a landing site that does not have facilities (charging facilities, fuel supply stands, etc.) that meet the purpose (charging, refueling, etc.) is not selected.

  In this way, the helicopter 10 determines at any time whether or not landing is necessary during autonomous flight, and automatically sets the landing target point when it is determined that landing is necessary. When landing is necessary, the helicopter 10 can be automatically landed at an appropriate landing target point.

  Next, the helicopter 10 sets the position of the base station 5 selected in S1613 as the position target value shown in FIG. 4 (S1614), and a position location signal 800, a radio signal 1100, transmitted from the selected base station 5, And the radio signal 1150 reception standby (monitoring) is started (for example, the reception frequency (reception channel) of the mobile-side position locating device 100 is adjusted to the frequency of the base station 5 selected in S1613), and the GPS autonomous flight mode is set. The autonomous flight toward the sky above the base station 5 is started (S1615).

  In this embodiment, it is determined whether or not the flight can be performed in the positioning autonomous flight mode based on whether or not the received electric field strength of the positioning signal 800 reaches the required strength. It may be determined whether or not it is possible to fly in the positioning autonomous flight mode based on whether or not the received electric field strength of the received radio signal 1150 is greater than the required strength.

During the flight over the base station 5, the helicopter 10 is necessary for the received electric field strength of the positioning signal 800 transmitted from the base station 5 selected in S1613 to safely fly in the positioning autonomous flight mode. It is determined at any time whether or not the threshold value is over (S1616).
If it is determined that the received electric field strength of the position determination signal 800 is equal to or higher than a threshold necessary for safe flight in the position determination autonomous flight mode (S1616: YES), the flight mode is determined from the GPS autonomous flight mode. The autonomous flight mode is switched to start the autonomous flight in the positioning autonomous flight mode (S1617, S1618).

  During autonomous flight in the positioning autonomous flight mode, the helicopter 10 determines at any time whether or not it has landed at the landing site where the base station 5 set as the position target value in S1614 is attached (S1619). Note that whether or not the vehicle has landed on the landing site is determined based on a signal from a pressure sensor provided on the ground contact surface of the skid 12 of the helicopter 10, for example.

  Whether the helicopter 10 has a received electric field strength of the positioning signal 800 transmitted from the base station 5 during the autonomous flight in the positioning autonomous flight mode is greater than or equal to a threshold necessary for safely flying in the positioning autonomous flight mode. It is determined at any time whether or not (S1620). If the received electric field strength of the position determination signal 800 is less than the threshold (S1620: NO), the flight mode is immediately switched from the position determination autonomous flight mode to the GPS autonomous flight mode (S1621).

<Positioning autonomous flight mode>
FIG. 17 is a flowchart for explaining the operation of the helicopter 10 during autonomous flight in the position determination autonomous flight mode. Hereinafter, it will be described with reference to FIG.

  When the flight in the position locating autonomous flight mode is started, the helicopter 10 starts to descend toward the landing target point of the landing field based on the information from the moving body side position locating device 100 (S1711).

  During the descent toward the landing target point, the helicopter 10 determines from time to time whether or not the distance from its current position to the landing target point is equal to or less than a preset threshold value (S1712). When the distance to the landing target point is equal to or less than the threshold (S1712: YES), the helicopter 10 starts autonomous flight directly above the landing target point (S1713).

  During the flight directed directly above the landing target point, the helicopter 10 determines from time to time whether or not its current position has reached directly above the landing target point (S1714). When the current position of the aircraft reaches directly above the landing target point (S1714: YES), the helicopter 10 performs a landing operation (for example, autonomous flight that decelerates or decelerates the flight speed to a speed that does not damage the aircraft). Is started (S1715).

  FIG. 18 is a diagram illustrating an example of autonomous flight of the helicopter 10 described in conjunction with FIG. The distance L (m) shown in the figure is the distance from the base station 5 of the helicopter 10. Also, θ is the direction viewed from the base station 5 of the helicopter 10.

  A broken line 1811 is a target route during flight directed directly above the landing target point in S1713 of FIG. 17, and a broken line 1812 is a target route during landing operation in S1715 of FIG. A position 1813 is a start position of the landing operation of S1715 in FIG. 17 (position of height l (m) from the landing target point), and a position 1814 is a landing target point of the helicopter 10.

  As shown in the figure, during the flight toward the position just above the landing target point in S1713 of FIG. 17, the helicopter 10 moves in the horizontal direction by L · sin θ (m) while descending by L · cos θ-1 (m). The target route 1811 is maintained by controlling the power mechanism 16 and the steering mechanism 17 so as to move. Further, during the landing operation in S1715 of FIG. 17, the helicopter 10 controls the power mechanism 16 and the steering mechanism 17 so as to decelerate to the speed at which the helicopter 10 can land while l (m) descends, and then the target route 1812 is reached. Descent along.

  Thus, since the helicopter 10 autonomously flies by switching the flight method step by step when approaching the landing target time, the helicopter 10 can be landed safely and quickly at the landing target point.

  As described above, according to the unmanned flight system 1 of the present embodiment, the helicopter 10 can be reliably landed at the landing target point by autonomous flight based on the current position determined by the position determination system. In particular, the positioning system uses the high frequency of about 2.4 GHz as the radio signal 1100 and the radio signal 1150 described above, and the current direction of the helicopter 10 viewed from the base station 5 with high accuracy on the order of several cm, and the base station 5 To the helicopter 10 can be determined. For this reason, the helicopter 10 can be landed at the landing target point with high accuracy and safety by autonomous flight.

  In addition, the helicopter 10 performs autonomous flight in the GPS autonomous flight mode, for example, when flying over the sky, and starts autonomous flight toward the landing target point in the positioning autonomous flight mode when it is determined that the flight can be performed in the positioning autonomous flight mode. To do. For this reason, when the received electric field intensity of the position determination signal 800 does not reach the required intensity, it is possible to reliably prevent the autonomous flight from being performed in the position determination autonomous flight mode. It can safely fly autonomously.

  By the way, description of the above embodiment is for making an understanding of this invention easy, and does not limit this invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

  For example, in the above description, the direction locating unit 111 is provided on the helicopter 10 side, and the direction locating signal transmission unit 211 is provided on the base station 5 side. Conversely, the direction locating signal transmission unit 211 is provided on the helicopter 10 side. The direction locating unit 111 may be provided on the base station 5 side. In this case, since the current direction of the helicopter 10 viewed from the base station 5 is determined on the base station 5 side, if the determined current direction is notified to the helicopter 10 by wireless communication, the helicopter 10 The current direction determined by the side can be acquired.

  In the above description, the first transmission / reception unit 151 is provided on the helicopter side and the second transmission / reception unit 251 is provided on the base station 5 side. Conversely, the second transmission / reception unit 251 is provided on the helicopter 10 side. The first transmission / reception unit 151 may be provided on the base station 5 side. In this case, since the current distance is determined from the base station 5 to the helicopter 10 on the base station 5 side, if the determined current distance is notified to the helicopter 10 by wireless communication, the helicopter 10 side determines the current distance. The obtained current distance can be acquired.

  If an automatic refueling facility and an automatic power supply facility for the helicopter 10 are provided at the landing target point, not only can the helicopter 10 land unattended, but also the refueling and power supply to the helicopter 10 can be completely unmanned. it can.

  A communication facility for communicating with a remote place is provided at the landing target point, and the provided information collected by the data transmitter / receiver 24 when the helicopter 10 landed at the landing target point is automatically sent to the remote place by the communication facility. You may make it transmit. According to this, the provision information collected by the helicopter 10 in a remote place can be quickly acquired. Even when the landing site is unmanned, the provided information can be acquired at a remote location.

DESCRIPTION OF SYMBOLS 1 Unmanned flight system 5 Base station 10 Helicopter 100 Mobile body side location apparatus 200 Base station side location apparatus 110 First direction measurement part 111 Direction measurement part 131 Position measurement signal reception part 132 Position measurement part 210 Second direction measurement part 211 Direction Positioning signal transmission unit 231 Positioning signal transmission unit 150 First distance measurement unit 151 First transmission / reception unit 250 Second distance measurement unit 251 Second transmission / reception unit 800 Position determination signal (first radio signal)
1100 Radio signal (second radio signal)
1150 Radio signal (third radio signal)

Claims (8)

A method for supporting landing of an unmanned air vehicle,
A plurality of first antennas arranged adjacent to each other at intervals are added to the landing target point,
Transmitting a plurality of first radio signals having different phases from each of the first antennas;
The unmanned air vehicle transmits a second radio signal;
A second antenna for transmitting a third radio signal synchronized with the second radio signal at the landing target point;
The unmanned air vehicle is
Direction of the first radio signal received from each of the first antennas and viewed from the landing target point based on a phase difference of the first radio signals transmitted from each of the different first antennas Get
Receiving the third radio signal;
Based on the phase difference between the second radio signal and the third radio signal, obtain the distance from the landing target point to itself,
Gets the acquired the direction its current location based on said distance, have rows autonomous flight towards the landing target point in the first flight mode to fly based on the acquired current position,
Judging whether or not landing is necessary during the autonomous flight based on a predetermined condition,
If it is determined that landing is necessary, the landing target point is automatically set,
Determining at any time whether the received electric field strength of at least one of the first radio signal and the third radio signal is greater than or equal to a preset threshold;
A method for supporting landing of an unmanned air vehicle, wherein autonomous flight toward the landing target point in the first flight mode is started when it is determined that the received electric field strength is equal to or greater than the threshold value . A method for supporting landing of an unmanned air vehicle according to claim 1 , comprising:
The predetermined condition is:
Whether or not the flight has been completed for the preset scheduled flight route,
Whether or not the remaining capacity of the installed storage battery is below a preset threshold,
Whether or not the amount of fuel onboard is below a preset threshold,
Whether or not the remaining capacity of the recording medium for recording data to be collected during the flight is below a preset threshold value,
A method of supporting landing of an unmanned air vehicle characterized by being at least one of the above. A method for supporting landing of an unmanned air vehicle according to claim 1, comprising:
The unmanned air vehicle is
Perform autonomous flight in the second flight mode, where you get your current position from the GPS receiver and fly,
Determining at any time whether the received electric field strength of at least one of the first radio signal and the third radio signal is greater than or equal to a preset threshold;
A method of supporting landing of an unmanned air vehicle, wherein autonomous flight toward the landing target point in the first flight mode is started when it is determined that the received electric field strength is equal to or greater than the threshold value. A method for supporting landing of an unmanned air vehicle according to claim 1, comprising:
The unmanned air vehicle is
After the start of the autonomous flight in the first flight mode,
It is determined at any time whether or not the distance to the landing target point is below a preset threshold,
When it is determined that the distance to the landing target point is equal to or less than the threshold value, autonomous flight is started directly above the landing target point in the first flight mode,
Judge at any time whether or not it has reached directly above the landing target point,
A method for supporting landing of an unmanned air vehicle, wherein a landing operation toward the landing target point is started when it is determined that the position has reached directly above the landing target point. The own direction seen from the landing target point based on the phase difference of the plurality of first radio signals having different phases transmitted from each of the plurality of first antennas arranged adjacent to each other at the landing target point. Get
Transmitting a second radio signal, receiving a third radio signal synchronized with the second radio signal transmitted from a second antenna provided adjacent to the landing target point, and receiving the second radio signal and the second radio signal, Based on the phase difference of the third radio signal, obtain the distance from the landing target point to itself,
Gets the acquired the direction its current location based on said distance, have rows autonomous flight towards the landing target point in the first flight mode to fly based on the acquired current position,
Judging whether or not landing is necessary during the autonomous flight based on a predetermined condition,
If it is determined that landing is necessary, the landing target point is automatically set,
Determining at any time whether the received electric field strength of at least one of the first radio signal and the third radio signal is greater than or equal to a preset threshold;
An unmanned aerial vehicle, which starts autonomous flight toward the landing target point in the first flight mode when it is determined that the received electric field strength is equal to or greater than the threshold value . An unmanned air vehicle according to claim 5 ,
The predetermined condition is:
Whether or not the flight has been completed for the preset scheduled flight route,
Whether or not the remaining capacity of the installed storage battery is below a preset threshold,
Whether or not the amount of fuel onboard is below a preset threshold,
Whether or not the remaining capacity of the recording medium for recording data to be collected during the flight is below a preset threshold value,
A method of supporting landing of an unmanned air vehicle characterized by being at least one of the above. An unmanned air vehicle according to claim 5 ,
Perform autonomous flight in the second flight mode, where you get your current position from the GPS receiver and fly,
Determining at any time whether the received electric field strength of at least one of the first radio signal and the third radio signal is greater than or equal to a preset threshold;
An unmanned aerial vehicle characterized by starting autonomous flight toward the landing target point in the first flight mode when it is determined that the received electric field strength is equal to or greater than the threshold value. An unmanned air vehicle according to claim 5 ,
After the start of the autonomous flight in the first flight mode,
It is determined at any time whether or not the distance to the landing target point is below a preset threshold,
When it is determined that the distance to the landing target point is equal to or less than the threshold value, autonomous flight is started directly above the landing target point in the first flight mode,
Judge at any time whether or not it has reached directly above the landing target point,
An unmanned aerial vehicle characterized by starting a landing operation toward the landing target point when it is determined that the position has reached directly above the landing target point.

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