Overhead line inspection system and overhead line inspection method

Abstract

This invention provides an overhead line inspection system and overhead line inspection method capable of measuring the separation distance of overhead communication lines. [Solution] In the overhead line inspection system 1, if the target object is the ground G and there is another overhead communication line 2B that acts as an obstacle between the overhead communication line 2A and the ground G, the unmanned aircraft 3 moves below the overhead communication line 2B and directly below the overhead communication line 2A, adjusts the measurement direction of the laser rangefinder 37 using the measurement direction adjustment unit 38 to point the laser rangefinder 37 directly downwards, irradiates the ground G with a laser using the laser pointer function of the laser rangefinder 37, stores the position K where the laser was irradiated as the measurement point, moves to the side of the overhead communication line 2A and measures the first distance Xa to the overhead communication line 2A, adjusts the measurement direction of the laser rangefinder 37 to position K using the measurement direction adjustment unit 38 and measures the second distance Xb to position K, and the equipment measurement unit 3j calculates the separation distance Y between the overhead communication line 2A and the ground G based on the first distance Xa and the second distance Xb.

Description

Technical Field

[0001] The present invention relates to an overhead line inspection system and an overhead line inspection method for performing inspection of overhead lines using an unmanned aerial vehicle.

Background Art

[0002] Power companies lay communication cables over a wide area supported by support poles such as utility poles for communication between power generation plants such as dams and electrical substations. Such wiring strung in the air is called an overhead line, and in particular, a communication cable strung in the air is called an overhead communication line. Overhead communication lines are laid not only in easily accessible places such as on roads, but also in mountainous areas and across rivers. Therefore, when performing maintenance work such as regular inspections, a large amount of time and labor are required.

[0003] By flying an unmanned aerial vehicle (so-called drone) along an overhead power transmission line and photographing power transmission and distribution equipment including the overhead power transmission line with a camera mounted on the unmanned aerial vehicle, a system has been known that enables inspection of power transmission and distribution equipment from a remote location (see, for example, Patent Document 1). If such an inspection system can be applied to the inspection of overhead communication lines, it will be possible to reduce the time and labor required for maintenance work such as regular inspections.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Overhead communication lines often have changing laying conditions compared to overhead power lines. In particular, problems often arise, such as insufficient separation distance from other overhead communication lines or insufficient separation distance from the ground. This is because on support poles, not only overhead communication lines of power companies but also laying and laying changes of overhead communication lines by other communication companies, cable broadcasting operators, etc. are frequently carried out, making it easy for changes to occur in the position and slack of the overhead communication lines. However, in conventional inspection systems using unmanned aerial vehicles, it is not possible to measure the separation distance between overhead communication lines or the separation distance from the ground.

[0006] Therefore, an object of this invention is to provide an overhead line inspection system and an overhead line inspection method capable of measuring the separation distance of overhead communication lines.

Means for Solving the Problems

[0007] To solve the above problems, the invention of claim 1 comprises an unmanned aerial vehicle that flies along an overhead line and inspects the overhead line, and a monitoring and control device that monitors and controls the inspection of the overhead line by the unmanned aerial vehicle, wherein the unmanned aerial vehicle comprises a laser rangefinder that measures a first distance to the overhead line and a second distance to an object to be measured for separation distance from the overhead line, separation distance calculation means that calculates the separation distance between the overhead line and the object based on the first distance and the second distance, and communication means that transmits inspection data including the separation distance to the monitoring and control device, wherein if the object is the ground and there is an obstacle between the overhead line and the ground, the unmanned aerial vehicle The overhead line inspection system is characterized by the following: moving below the obstacle and directly below the overhead line, adjusting the measurement direction of the laser distance meter using a measurement direction adjustment means to point the laser distance meter directly downward, irradiating the ground with a laser using the laser pointer function of the laser distance meter, storing the position where the laser was irradiated as a measurement point, moving to the side of the overhead line and measuring the first distance to the overhead line, adjusting the measurement direction of the laser distance meter to point the laser distance meter at the measurement point and measuring the second distance to the measurement point, and calculating the separation distance between the overhead line and the ground based on the first distance and the second distance using the separation distance calculation means.

[0008] The invention of claim 2 is characterized in that, in the overhead line patrol inspection system described in claim 1, the system comprises: a weather information acquisition means for acquiring weather information for the area in which the overhead line patrol inspection is performed; and a weather response control means for causing the unmanned aerial vehicle to continue the overhead line patrol inspection or to cause the unmanned aerial vehicle to stop the overhead line patrol inspection and move to a predetermined evacuation location, in accordance with the acquired weather information.

[0009] The invention of claim 3 is characterized in that, in the overhead line inspection system described in claim 2, the system comprises a pole-mounted takeoff and landing device, which is installed on a support pole supporting the overhead line and on which the unmanned aircraft can take off and land, and a power supply means for charging the battery of the unmanned aircraft when it lands on the takeoff and landing platform.

[0010] The invention of claim 4 is characterized in that, in the overhead line inspection system described in claim 3, it includes at least a function to transmit takeoff and landing information, including the takeoff and landing status and charging status of the unmanned aircraft, to the monitoring control device, and a function to control the opening and closing of the aircraft fixing part and to shut off the power supply unit from the pole-mounted takeoff and landing device to the unmanned aircraft based on control information received from the monitoring control device.

[0011] The invention of claim 5 is an overhead line inspection method for inspecting an overhead line using an unmanned aerial vehicle (UAV) flying along the overhead line, wherein a laser rangefinder mounted on the UAV measures a first distance to the overhead line and a second distance to an object to be measured for separation distance from the overhead line, calculates the separation distance between the overhead line and the object based on the first distance and the second distance, transmits inspection data including the separation distance to a monitoring and control device that monitors and controls the inspection of the overhead line by the UAV, and if the object is the ground and there is an obstacle between the overhead line and the ground, the UAV inspects the obstacle The device is characterized by moving below the overhead wire and directly below the overhead wire, using a measurement direction adjustment means to adjust the measurement direction of the laser distance meter to point the laser distance meter directly downward, irradiating the ground with a laser using the laser pointer function of the laser distance meter, storing the position where the laser was irradiated as a measurement point, moving to the side of the overhead wire and measuring the first distance to the overhead wire, using the measurement direction adjustment means to point the laser distance meter at the measurement point and measuring the second distance to the measurement point, and using the separation distance calculation means to calculate the separation distance between the overhead wire and the ground based on the first distance and the second distance. [Effects of the Invention]

[0012] According to the inventions of claim 1 and claim 5, during the inspection of overhead lines, the separation distance between the overhead line and the object is measured by a laser rangefinder mounted on an unmanned aircraft. Therefore, not only the overall inspection of the overhead line can be carried out, but also the separation distance at each part of the overhead line can be inspected in detail. Also, when measuring the separation distance between the overhead line and the object, the first distance to the overhead line and the second distance to the object are measured, and based on the first distance and the second distance, the separation distance between the overhead line and the object is calculated. Thus, even when it is difficult to measure the separation distance between the overhead line and the object, the separation distance between the overhead line and the object can be measured accurately and reliably.

[0013] According to the inventions of claim 1 and claim 5, when the object is the ground and there are obstacles between the overhead line and the ground, the position of the ground directly below the obstacle and directly below the overhead line is identified below the obstacle. The first distance from the side of the overhead line to the overhead line is measured, and the second distance from the same position to the position of the ground directly below the overhead line is measured. Based on the first distance and the second distance, the separation distance is calculated. Therefore, even when there are obstacles between the overhead line and the ground, the separation distance between the overhead line and the ground can be measured without moving to a position far from the overhead line and the ground, and the time taken for the measurement can be shortened.

[0014] According to the invention of claim 2, it is possible to determine whether to continue or abort the inspection of the overhead line according to the meteorological information, and when aborting, move the unmanned aircraft to a predetermined evacuation location. Therefore, it is possible to prevent the unmanned aircraft from being damaged or falling due to bad weather.

[0015] According to the invention of claim 3, a take-off and landing stand for the unmanned aircraft and a power supply means for charging the battery of the unmanned aircraft are provided on the support column of the overhead line. Therefore, even when the unmanned aircraft has flown far during the inspection, the unmanned aircraft can be properly evacuated. Also, since charging can be carried out during the inspection, it is possible to extend the flight distance (flight time) required for the inspection.

[0016] According to the invention of claim 4, the on-pole takeoff and landing device transmits takeoff and landing information including the takeoff and landing status, charging status, etc. of the unmanned aircraft to the monitoring and control device, and performs opening and closing control of the aircraft fixing part according to an instruction from the monitoring and control device. When an abnormality occurs in the power supply unit that charges the unmanned aircraft and overcharging occurs, etc., it has a function of cutting off the power supply unit according to an instruction from the monitoring and control device. Therefore, it is possible to confirm from a remote position the state of the unmanned aircraft after it has retreated and where it is. Furthermore, it is possible to stably protect the landed unmanned aircraft according to the monitoring results.

Brief Description of the Drawings

[0017] [Figure 1] It is a conceptual diagram showing the outline of an overhead line patrol and inspection system according to an embodiment of this invention. [Figure 2] It is a functional block diagram showing the functions of the monitoring and control device shown in FIG. 1. [Figure 3] It is a table showing an example of the data configuration of the weather response data in the weather response data storage unit shown in FIG. 2. [Figure 4] It is a front view showing the configuration of the unmanned aircraft shown in FIG. 1. [Figure 5] It is a side view showing a state in which the measurement direction of the laser rangefinder shown in FIG. 4 is changed. [Figure 6] It is a functional block diagram showing the functions of the unmanned aircraft shown in FIG. 4. [Figure 7] It is a side view showing the configuration of the on-pole takeoff and landing device shown in FIG. 1. [Figure 8] It is a functional block diagram showing the functions of the on-pole takeoff and landing device shown in FIG. 7. [Figure 9] It is an explanatory diagram showing a method for measuring the separation distance between an overhead communication line and the ground. [Figure 10] It is an explanatory diagram showing a method for measuring the separation distance when there is an obstacle between an overhead communication line and the ground. [Figure 11] It is an explanatory diagram showing a method for measuring the separation distance between overhead communication lines. [Figure 12]It is a flowchart showing the procedure of inspection by the overhead line inspection system shown in FIG. 1.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, this invention will be described based on the illustrated embodiments.

[0019] FIG. 1 is a conceptual diagram showing an overview of an overhead line inspection system 1 according to an embodiment of this invention. The overhead line inspection system 1 according to this embodiment is a system for inspecting an overhead communication line (overhead line) 2 laid by an electric power company for communication with, for example, a power plant or an electric substation by an unmanned aerial vehicle 3.

[0020] The overhead communication line 2 is a communication cable suspended in the air by a number of support poles 4 such as power poles and utility poles. On the support poles 4, not only the overhead communication line 2 of the electric power company but also overhead communication lines of other communication companies or cable television operators may be laid. Such overhead communication lines of other communication companies etc. are frequently re-laid according to contract changes with customers etc., so changes may occur in the separation distance between overhead communication lines, the separation distance between the overhead communication line and the ground, etc. The separation distance between overhead communication lines affects the generation of communication noise etc., and when the separation distance between the overhead communication line and the ground becomes short, it causes contact accidents with vehicles etc. Therefore, the overhead communication line 2 is regularly inspected.

[0021] The overhead line inspection system 1 according to this embodiment flies the unmanned aerial vehicle 3 along the overhead communication line 2, and measures the first distance to the overhead communication line 2 and the second distance to an object (ground or other overhead communication line) to be measured for the separation distance with respect to the overhead communication line 2 by a laser rangefinder mounted on the unmanned aerial vehicle 3, and calculates the separation distance between the overhead communication line 2 and the object based on the first distance and the second distance. Then, inspection data including the separation distance is transmitted from the unmanned aerial vehicle 3 to the monitoring and control device 5. Further, on the support pole 4, an on-pole takeoff / landing device 6 that enables the takeoff and landing of the unmanned aerial vehicle 3 is installed at predetermined intervals.

[0022] The unmanned aerial vehicle 3 is a so-called multi-rotor type drone. The unmanned aerial vehicle 3 has the function of being remotely controlled by the monitoring and control device 5, and the function of flying autonomously along a designated flight route (including altitude) without remote control. The flight position of the unmanned aerial vehicle 3 is detected based on position information received from GNSS satellites 7 such as GPS.

[0023] For example, the unmanned aircraft 3 autonomously flies along a predetermined route from its parking position to the starting point of the inspection of the overhead communication lines 2. From the starting point of the inspection, it autonomously flies while tracking the overhead communication lines 2 to be inspected. When measuring the separation distance between the overhead communication lines 2 and the separation distance between the overhead communication lines 2 and the ground, it flies under the remote control of the monitoring and control device 5.

[0024] During patrol inspections, the unmanned aerial vehicle 3 takes images (including moving and still images) of the overhead communication lines 2 and support poles 4, measures the distance between the overhead communication lines 2 and the distance between the overhead communication lines 2 and the ground, and transmits inspection data, including the captured images and measured distances, to the monitoring and control device 5. In addition, the unmanned aerial vehicle 3 periodically transmits self-management information, such as its current location and the charge level of its onboard battery, to the monitoring and control device.

[0025] The monitoring and control device 5 is a device for monitoring and controlling the inspection of the overhead communication line 2 by the unmanned aerial vehicle 3. For example, it is installed at the station of a maintenance worker responsible for the inspection of the overhead communication line 2 and is operated by the maintenance worker. The maintenance worker uses the monitoring and control device 5 to check the inspection data and self-management information received from the unmanned aerial vehicle 3 and has the unmanned aerial vehicle 3 perform the inspection of the overhead communication line 2 by remote or autonomous flight.

[0026] The on-pole takeoff / landing device 6 is installed on the support pole 4 at predetermined distance intervals, and includes a takeoff / landing platform 61 where the unmanned aircraft 3 can take off and land, and a control unit 62 that controls the takeoff / landing platform 61 and charges the battery of the unmanned aircraft 3 that has landed on the takeoff / landing platform 61. Since the overhead communication line 2 is laid over a wide area over a long distance, long-distance (long-time) flight is required for patrol inspection. However, since the unmanned aircraft 3 flies using the mounted battery as a power source, there is a limit to the flight distance. In addition, when flying for a long time, the weather may change and it may become difficult to fly. The on-pole takeoff / landing device 6 is provided to temporarily evacuate the unmanned aircraft 3 in case of such a decrease in the battery charge amount or weather change.

[0027] The unmanned aircraft 3, the monitoring and control device 5, and the on-pole takeoff / landing device 6 are connected so as to be able to communicate with each other via, for example, the mobile phone communication network 8. The monitoring and control device 5 transmits monitoring and control information to the unmanned aircraft 3 via the mobile phone communication network 8, and receives inspection data and own aircraft management information transmitted from the unmanned aircraft 3. The monitoring and control information includes remote operation information for flying the unmanned aircraft 3 by remote control and flight instruction information for autonomously flying the unmanned aircraft 3 along the instructed route.

[0028] In addition, the monitoring and control device 5 receives weather information of the area where the patrol inspection is performed from the weather information distribution system 9 connected via the mobile phone communication network 8, and controls the continuation or suspension of the patrol inspection based on the received weather information. This is because it is difficult to control the unmanned aircraft 3 in bad weather such as wind and rain, and there is a risk of crashing due to uncontrollability. The weather information includes weather condition information indicating the current weather condition and weather forecast information indicating the weather condition after a predetermined time (for example, 1 to several hours later).

[0029] The on-pole takeoff / landing device 6 has a function of monitoring the takeoff / landing status of the unmanned aircraft 3 and a function of monitoring the charging status. The on-pole takeoff / landing device 6 transmits takeoff / landing information including the takeoff / landing status and charging status obtained by monitoring to the monitoring and control device 5 via the mobile phone communication network 8.

[0030] The monitoring and control device 5 displays the inspection data and self-aircraft management information received from the unmanned aircraft 3, the weather information received from the weather information distribution system 9, and the takeoff and landing information received from the pole-mounted takeoff and landing device 6. The maintenance staff controls the unmanned aircraft 3 by the monitoring and control device 5 while checking the situation of the patrol inspection based on the inspection data, self-aircraft management information, takeoff and landing information, weather information, etc. displayed on the monitoring and control device 5.

[0031] Note that for the mobile phone communication network 8, the currently popular LTE line (so-called 4G line) is used, but a so-called 5G line may also be used, or the 4G line and 5G line may be switched and used according to the communication situation. Also, instead of the mobile phone communication network 8, satellite communication may be used. Furthermore, although the monitoring and control device 5, the pole-mounted takeoff and landing device 6, and the weather information distribution system 9 are connected by the mobile phone communication network 8, a wired communication network such as an optical communication line may be used for connection.

[0032] FIG. 2 is a block diagram showing the functional configuration of the monitoring and control device 5. The monitoring and control device 5 is constituted by a so-called computer system and functions as the monitoring and control device 5 by executing an overhead line patrol inspection program (not shown).

[0033] The monitoring and control device 5 includes an equipment data storage unit 51, an inspection data storage unit 52, a weather response data storage unit 53, a system control unit 54, a communication unit 55, and an operation terminal 56. In the figure, the dashed arrow lines indicated by the one-dot chain line show the flow of information used for the control of each part of the monitoring and control device 5 and the control of the unmanned aircraft 3, and the solid arrow lines indicate the flow of inspection data received from the unmanned aircraft 3, etc.

[0034] The equipment data storage unit 51 stores line information relating to the overhead communication line 2 that is subject to inspection. The line information includes, for example, the line name, line number, identification information of the support poles 4 included in the line, location information of the support poles 4 (e.g., latitude and longitude), the support altitude of the overhead communication line 2 on the support poles 4, and the installation position and set altitude of the pole-mounted landing and takeoff device 6. The equipment data storage unit 51 is connected to the system control unit 54, the communication unit 55, and the operation terminal 56.

[0035] The inspection data storage unit 52 stores inspection data of the overhead communication lines 2 received from the unmanned aerial vehicle 3. The inspection data includes images (including moving and still images) of the overhead communication lines 2 and support poles 4 taken by the unmanned aerial vehicle 3, the separation distance between the overhead communication lines 2, the separation distance between the overhead communication lines 2 and the ground, and measurement position data (e.g., latitude and longitude) indicating the location of the overhead communication line 2 where the separation distance was measured. The inspection data storage unit 52 is connected to the system control unit 54, the communication unit 55, and the operation terminal 56.

[0036] Furthermore, the inspection data storage unit 52 stores the self-management information received from the unmanned aerial vehicle 3 in association with it. Also, if the unmanned aerial vehicle 3 lands on the pole-mounted landing and takeoff device 6 during a patrol inspection, the takeoff and landing information transmitted from the pole-mounted landing and takeoff device 6 to the monitoring and control device 5 is stored in the inspection data storage unit 52 as one of the inspection data.

[0037] Furthermore, the overhead line inspection system 1 according to this embodiment is equipped with a function for communication between a maintenance worker stationed at a maintenance worker's base and a worker performing work near the overhead communication line 2, using an audio communication unit (including a sound-collecting microphone and speaker) mounted on the unmanned aerial vehicle 3. Using this function, the audio data of the conversation regarding the overhead communication line 2 between the maintenance worker and the worker may be stored in the inspection data storage unit 52 as one of the inspection data.

[0038] The weather response data storage unit 53 stores preset weather response data. The weather response data is data indicating criteria for determining whether to continue or cancel the patrol inspection by the unmanned aerial vehicle 3 according to the weather information received from the weather information distribution system 9. The weather response data storage unit 53 is connected to the system control unit 54 and the operation terminal 56.

[0039] The system control unit 54 has a function of comprehensively managing and controlling the entire overhead line patrol inspection system 1 including the monitoring control device 5. The system control unit 54 is connected to the equipment data storage unit 51, the inspection data storage unit 52, the weather response data storage unit 53, the communication unit 55, and the operation terminal 56.

[0040] The communication unit 55 transmits monitoring control information to the unmanned aerial vehicle 3 via the mobile phone communication network 8, and receives inspection data and self-aircraft management information from the unmanned aerial vehicle 3. Further, the communication unit 55 receives the takeoff / landing information of the unmanned aerial vehicle 3 from the pole-mounted takeoff / landing device 6 via the mobile phone communication network 8. Furthermore, the communication unit 55 receives the weather information of the area where the patrol inspection is performed from the weather information distribution system 9 according to the instruction of the system control unit 54. The communication unit 55 is connected to the equipment data storage unit 51, the inspection data storage unit 52, the system control unit 54, and the operation terminal 56.

[0041] The operation terminal 56 includes output means such as a monitor and input means such as a keyboard and a mouse, and has a function of operating the monitoring control device 5 and the unmanned aerial vehicle 3 by operating the keyboard etc. based on the information displayed on the monitor. The operation terminal 56 is connected to the equipment data storage unit 51, the inspection data storage unit 52, the weather response data storage unit 53, the system control unit 54, and the communication unit 55.

[0042] The maintenance staff operates the keyboard of the operation terminal 56 or the like to read out the line information of the aerial communication line 2 to be inspected from the equipment data storage unit 51 and display it on the monitor. The maintenance staff browses the line information displayed on the monitor, adds or modifies the line information as necessary, and formulates an inspection plan. In addition, the meteorological information received from the meteorological information distribution system 9 is displayed on the monitor, and the maintenance staff can refer to the meteorological information when formulating the inspection plan.

[0043] Based on the inspection plan formulated by the maintenance staff operating the operation terminal 56, the system control unit 54 generates monitoring control information for controlling the unmanned aerial vehicle 3. The generated monitoring control information is transmitted to the unmanned aerial vehicle 3 via the mobile phone communication network 8 by the communication unit 55.

[0044] The communication unit 55 transmits the inspection data and the own aircraft management information received from the unmanned aerial vehicle 3 to the system control unit 54 and stores them in the inspection data storage unit 52. The system control unit 54 displays the received inspection data and the like on the monitor of the operation terminal 56. Thereby, the maintenance staff can remotely operate the unmanned aerial vehicle 3 while monitoring the inspection of the aerial communication line 2 in real time.

[0045] The communication unit 55 and the meteorological information distribution system 9 correspond to the meteorological information acquisition means according to the present invention. The system control unit 54 functions as a weather response control means for continuing the inspection of the aerial communication line 2 by the unmanned aerial vehicle 3 or stopping the inspection of the aerial communication line 2 by the unmanned aerial vehicle 3 and moving it to a predetermined evacuation location according to the acquired meteorological information.

[0046] When the system control unit 54 receives the weather forecast information (weather forecast after a predetermined time) of the area where the inspection is to be carried out from the meteorological information distribution system 9, it determines the response by referring to the weather response data in the weather response data storage unit 53, displays an alarm for stopping the inspection on the monitor of the operation terminal 56, and also notifies it by an alarm sound or voice.

[0047] [[ID=十九]] Figure 3 shows the weather-corresponding data 531 stored in the weather-corresponding data storage unit 53. The weather-corresponding data 531 is classified into "weather classifications" A to G based on, for example, "weather", "temperature (°C)", "precipitation (mm / h)", "wind speed (m / s)", "system evaluation (warning classification)", and "response of maintenance staff (warning judgment / flight control)".

[0048] Weather classification A represents a weather condition where the weather is sunny or cloudy, the temperature is 0°C or higher and 35°C or lower, the precipitation is 0 mm, and the wind speed is less than 2 m / s. In the system control unit 54, no warning classification is set when the weather forecast information corresponds to weather classification A. Therefore, no warning is notified from the operation terminal 56, and the maintenance staff continues the patrol inspection.

[0049] Weather classification B represents a weather condition where the temperature is less than 0°C and higher than -5°C or higher than 35°C and lower than 40°C. Also, weather classification C represents a weather condition where the weather is rain or snow and the precipitation is 1 mm / h or more and less than 5 mm / h. Furthermore, weather classification D represents a weather condition where the wind speed is 2 m / s or more and less than 5 m / s. When the weather forecast information corresponds to weather classification B, the system control unit 54 notifies the operation terminal 56 of a "temperature caution" warning. Also, when the weather forecast information corresponds to weather classification C, the system control unit 54 notifies the operation terminal 56 of a "rainfall caution" warning. Furthermore, when the weather forecast information corresponds to weather classification D, the system control unit 54 notifies the operation terminal 56 of a "wind speed caution" warning.

[0050] When a warning of "temperature caution", "rainfall caution", or "wind speed caution" is notified, the maintenance staff prepares for the evacuation of the unmanned aircraft 3 and, for example, stops the patrol inspection within 20 minutes and evacuates the unmanned aircraft 3 to a safe location.

[0051] Weather classification E is a weather condition where the temperature is below -5°C or above 40°C. Weather classification F is a weather condition where the weather is rainy or snowy and the precipitation exceeds 5 mm / h. Furthermore, weather classification G is a weather condition where the wind speed exceeds 5 m / s. If the weather forecast information corresponds to weather classification E, the system control unit 54 will notify the operation terminal 56 of a "temperature warning". Furthermore, if the weather forecast information corresponds to weather classification F, the system control unit 54 will notify the operation terminal 56 of a "rainfall warning". Furthermore, if the weather forecast information corresponds to weather classification G, the system control unit 54 will notify the operation terminal 56 of a "wind speed warning".

[0052] When a "temperature warning," "rainfall warning," or "wind speed warning" is issued, maintenance personnel shall prepare to evacuate the unmanned aerial vehicle 3, immediately cease patrol inspections, and evacuate the unmanned aerial vehicle 3 to a safe location. The evacuation location for the unmanned aerial vehicle 3 may be the maintenance personnel station where the unmanned aerial vehicle 3 is housed, or the nearest pole-mounted landing gear 6.

[0053] Furthermore, the specifications defined for each weather classification may be arbitrarily changed depending on the flight performance of the unmanned aerial vehicle 3, the weather conditions of the patrol and inspection area, etc.

[0054] Figure 4 is a front view showing the configuration of the unmanned aerial vehicle 3. The unmanned aerial vehicle 3 is a multi-rotor type drone and comprises a main body 31, multiple (for example, four) rotor units 32, a pair of landing skids 33, an operation camera 34, a tracking camera 35, an inspection camera 36, ​​a laser rangefinder 37, a measurement direction adjustment unit (measurement direction adjustment means) 38, a communication antenna 39, a GNSS antenna 3a, an LED light 3b, multiple obstacle sensors 3c, a solar panel 3d, and an audio communication unit 3e.

[0055] The main body 31 consists of, for example, a box-shaped housing, a control circuit installed inside the housing, a battery, and the like. The multiple rotor units 32 consist of arms extending radially from the sides of the main body 31, motors installed at the ends of the arms, and propellers attached to the motors. The unmanned aerial vehicle 3 can ascend, descend, move forward, backward, left and right, rotate, and hover by adjusting the rotation speed of the propellers of the multiple rotor units 32.

[0056] The pair of landing skids 33 are the legs that the unmanned aircraft 3 touches when it lands. A portion 331 of the pair of landing skids 33 functions as a contact point that electrically connects the battery in the main body 31 to the control unit 62 of the pole-mounted landing device 6 when the aircraft lands on the pole-mounted landing device 6.

[0057] The operational camera 34 is mounted on top of the main unit 31 and consists of a 360° camera covered by a transparent dome-shaped cover. The operational camera 34 captures images of the entire surroundings of the unmanned aerial vehicle 3. The captured video and still images are transmitted to the monitoring and control device 5 as inspection data and displayed on the operation terminal 56, and are used to check the surrounding conditions when remotely controlling the unmanned aerial vehicle 3.

[0058] The tracking camera 35 is used to autonomously fly while tracking the overhead communication line 2 to be inspected. The tracking camera 35 photographs the overhead communication line 2 to be inspected, and the captured image is analyzed by the control circuit in the main unit 31 to detect the overhead communication line 2. The control circuit in the main unit 31 controls multiple rotor units 32 to fly while tracking the detected overhead communication line 2.

[0059] The inspection camera 36 is installed at the bottom of the main unit 31 and consists of a 360° camera covered by a transparent dome-shaped cover. The inspection camera 35 photographs the overhead communication line 2 which is inspected by the unmanned aerial vehicle 3. The captured video and still images are transmitted to the monitoring and control device 5 as inspection data and displayed on the operation terminal 56, and are used to check the status of the overhead communication line 2.

[0060] Furthermore, the operational camera 34 and the inspection camera 36 may be used with their respective purposes reversed depending on the relative positions of the unmanned aerial vehicle 3.

[0061] The laser distance meter 37 irradiates the overhead communication line 2 to be measured with laser light, receives the reflected light, and measures the distance based on the time difference between irradiation and reception, and the phase difference between the irradiated light and the reflected light. The laser distance meter 37 also has a laser pointer function that irradiates an object with laser light in the visible wavelength range to indicate the irradiation position. This laser pointer function is used to measure the separation distance between the overhead communication line 2 and the object, as described later.

[0062] Figure 5 is a side view of the laser distance meter 37 and the measurement direction adjustment unit 38 as seen from the direction of arrow S in Figure 4. The measurement direction adjustment unit 38 rotates the rear end of the laser distance meter 37 around a horizontal rotation axis using a motor or the like, thereby rotating the laser distance meter 37 as shown by the dashed line in the figure, and adjusting the measurement direction and the irradiation direction of the laser pointer. The measurement direction adjustment unit 38 is used to measure the distance between the overhead communication line 2 and the object, which will be described later.

[0063] The communication antenna 39 is an antenna used by the control circuit within the main unit 31 to communicate with the monitoring and control device 5 via the mobile phone communication network 8. The GNSS antenna 3a is an antenna used to receive position information from the GNSS satellite 7.

[0064] LED light 3b is used to illuminate overhead communication lines 2 and support poles 4 during patrol inspections. Additionally, LED light 3b functions as a night recognition light to signal the aircraft's position to surrounding aircraft during nighttime flights.

[0065] The obstacle sensors 3c are, for example, ultrasonic sensors, and multiple sensors are installed on the main body 31 and rotor section 32 of the unmanned aerial vehicle 3 to detect objects present around the unmanned aerial vehicle 3. When the unmanned aerial vehicle 3 is performing autonomous flight, the control device in the main body 31 controls the unmanned aerial vehicle 3 to avoid obstacles detected by the obstacle sensors 3c. When the unmanned aerial vehicle 3 is flying remotely, the detection results of obstacles from the obstacle sensors 3c are transmitted to the monitoring control device 5. Maintenance personnel can use the detection results of the obstacle sensors 3c as a reference to fly the vehicle while avoiding obstacles.

[0066] The solar panel 3d generates electricity from sunlight while the unmanned aircraft 3 is in flight. The amount of electricity generated by this solar panel 3d is sufficient to supply the power necessary to transmit information such as the aircraft's position to the monitoring and control device 5 in the event that the unmanned aircraft 3 makes an emergency landing due to battery depletion or other reasons.

[0067] The voice communication unit 3e consists of, for example, a sound-collecting microphone and a speaker, and is provided for communication between maintenance personnel stationed at the maintenance personnel station and workers performing work near the overhead communication line 2. Voice data of voice input by the maintenance personnel from the operation terminal 56 is transmitted to the unmanned aerial vehicle 3 via the mobile phone communication network 8 and output from the speaker of the voice communication unit 3e. In addition, voice spoken by workers near the overhead communication line 2 is input to the sound-collecting microphone of the voice communication unit 3e, and the voice data is transmitted to the monitoring and control device 5 via the mobile phone communication network 8 and output from the speaker of the operation terminal 56.

[0068] Figure 6 is a block diagram showing the functional configuration of the unmanned aerial vehicle 3. The unmanned aerial vehicle 3 comprises the voice communication unit 3e, the flight control unit 3f, the communication unit 3g, the flight unit 3h, the patrol and inspection unit 3i, the equipment measurement unit 3j, and the device support unit 3k. In the figure, the dashed lines indicate the flow of information used to control the unmanned aerial vehicle 3, and the solid lines indicate the flow of inspection data generated by the unmanned aerial vehicle 3.

[0069] The aircraft control unit 3f is comprised of a control circuit installed within the housing of the main unit 31 and comprehensively controls the entire unmanned aircraft 3. The aircraft control unit 3f is connected to the communication unit 3g, the flight unit 3h, the patrol and inspection unit 3i, the equipment measurement unit 3j, the device support unit 3k, and the voice communication unit 3e.

[0070] The communication unit 3g connects to the mobile phone communication network 8 via the communication antenna 39, receives monitoring and control information from the monitoring and control device 5, and transmits inspection data and self-management information to the monitoring and control device 5. The communication unit 3g also receives position information from GNSS satellites 7 via the GNSS antenna 3a. The communication unit 3g is connected to the aircraft control unit 3f, the patrol and inspection unit 3i, the equipment measurement unit 3j, and the voice communication unit 3e.

[0071] The flight unit 3h comprises the aforementioned multiple rotor units 32 and a battery, and controls the unmanned aircraft 3 under the control of the flight control unit 3f. The battery is connected to supply power to various parts of the unmanned aircraft 3. The battery is also electrically connected to the contact points 331 provided on the pair of landing skids 33 described above. The flight unit 3h is connected to the flight control unit 3f.

[0072] The patrol and inspection unit 3i has the unmanned aerial vehicle 3 autonomously fly and inspect the overhead communication line 2. Specifically, the patrol and inspection unit 3i analyzes images captured by the tracking camera 35 described above to detect the overhead communication line 2, and controls the flight unit 3h via the flight control unit 3f to autonomously fly along the detected overhead communication line 2. The patrol and inspection unit 3i also photographs the overhead communication line 2 and support poles 4 with the inspection camera 36 described above, and transmits the captured moving and still images as inspection data from the communication unit 3g to the monitoring and control device 5. The patrol and inspection unit 3i is connected to the flight control unit 3f and the communication unit 3g.

[0073] The equipment measurement unit 3j measures the separation distance between the overhead communication lines 2 and the separation distance between the overhead communication lines 2 and the ground using the laser rangefinder 37 and the measurement direction adjustment unit 38 described above. It also transmits the measured separation distance as inspection data from the communication unit 3g to the monitoring and control device 5. The equipment measurement unit 3j is connected to the aircraft control unit 3f and the communication unit 3g.

[0074] The device support unit 3k controls the aforementioned LED light 3b, multiple obstacle sensors 3c, and solar panel 3d, etc. The device support unit 3k is connected to the aircraft control unit 3f.

[0075] Figure 7 is a side view showing the configuration of the pole-mounted landing and takeoff device 6 installed on the support column 4. The pole-mounted landing and takeoff device 6 comprises a landing and takeoff platform 61 and a control unit 62.

[0076] The landing platform 61 comprises a platform body 611, an aircraft fixing section 612, and a pair of power supply terminals 613. The platform body 611 consists of a plate-like body with one end fixed to a support column 4 and protruding to the side of the support column 4, and has an area on which an unmanned aircraft 3 can land. The aircraft fixing section 612 is movably mounted on the upper surface of the platform body 611, and when the unmanned aircraft 3 lands on the platform body 611, it clamps onto a pair of landing skids 33 to fix the unmanned aircraft 3 in place. The pair of power supply terminals 613 are installed on the platform body 611 so that their upper parts protrude from the upper surface of the platform body 611, and when the unmanned aircraft 3 lands on the platform body 611, they contact the contact sections 331 of the pair of landing skids 33. The pair of power supply terminals 613 are connected to the control unit 62 using external wiring.

[0077] The control unit 62 comprises a unit body 621, a communication antenna 622, and a surveillance camera 623. Power is supplied to the control unit 62 from a low-voltage power line 41 connected to a pole-mounted transformer (not shown). The unit body 621 consists of a box-shaped enclosure housing control circuits and the like, and is installed on a support pole 4 by a mounting frame 624. A solar panel 625 is installed on the top of the unit body 621. The communication antenna 622 is provided for the control unit 62 to communicate with the monitoring and control device 5 via a mobile phone communication network 8. The surveillance camera 623 consists of a 360° camera covered by a dome-shaped cover, and photographs the pole-mounted takeoff and landing device 6 and the unmanned aircraft 3 that has landed on the takeoff and landing platform 61, and transmits the captured video and still images as takeoff and landing information to the monitoring and control device 5.

[0078] Figure 8 is a block diagram showing the functional configuration of the pole-mounted landing and takeoff device 6. The pole-mounted landing and takeoff device 6 comprises a takeoff and landing control unit 63, an aircraft fixing unit 612, a monitoring unit 64, a communication unit 65, a voltage conversion unit 66, an AC-DC conversion unit 67, a power supply unit 68, a storage battery 69, a power supply terminal 613, and a solar panel 625. In the figure, dashed lines indicate the flow of information used to control each part of the pole-mounted landing and takeoff device 6, broken lines indicate the flow of power supplied to the landed unmanned aircraft 3, and solid lines indicate the flow of takeoff and landing information.

[0079] The takeoff and landing control unit 63 is composed of a control circuit installed within the housing of the control unit 62 and comprehensively controls the entire pole-mounted takeoff and landing device 6. The takeoff and landing control unit 63 is connected to the aircraft fixing unit 612, the monitoring unit 64, the communication unit 65, and the power supply unit 68.

[0080] The monitoring unit 64 includes the aforementioned monitoring camera 623, a landing sensor (not shown) that detects when the unmanned aircraft 3 has landed on the landing platform 61, and a charging monitoring unit (not shown) that monitors the charging status of the unmanned aircraft 3 by the power supply unit 68. The monitoring unit 64 transmits the image captured by the monitoring camera 623, the detection result from the landing sensor, and the monitoring result from the charging monitoring unit as takeoff and landing information to the monitoring control device 5. The monitoring unit 64 is connected to the takeoff and landing control unit 63, the communication unit 65, and the power supply unit 68.

[0081] As described above, the aircraft fixing unit 612 is movably mounted on the upper surface of the base body 611. When the landing sensor detects that the unmanned aircraft 3 has landed on the takeoff / landing base 61, the aircraft fixing unit 612 secures the unmanned aircraft 3 by clamping the pair of landing skids 33 in accordance with the instructions of the takeoff / landing control unit 63. The aircraft fixing unit 612 is connected to the takeoff / landing control unit 63.

[0082] Furthermore, the pole-mounted takeoff and landing device 6 has the function of receiving remote control information from the monitoring and control device 5. This function allows maintenance personnel to perform operations such as opening and closing the aircraft fixing section 612 using the takeoff and landing control unit 63, or shutting off the power supply circuit if any abnormality occurs in the power supply circuit, such as when overcharging occurs from the power supply unit 68 to the unmanned aircraft 3.

[0083] The communication unit 65 connects to the mobile phone communication network 8 via the communication antenna 622, thereby transmitting takeoff and landing information to the monitoring and control device 5, and also transmitting control signals from the monitoring and control device 5 to the takeoff and landing control unit 63. The communication unit 65 is connected to the takeoff and landing control unit 63 and the monitoring unit 64.

[0084] The voltage conversion unit 66 converts the commercial voltage (single-phase three-wire 200V) supplied from the pole-mounted transformer via the low-voltage lighting line 41 to single-phase 100V. The AC-DC conversion unit 67 converts the single-phase 100V converted by the voltage conversion unit 66 into DC at a predetermined voltage. The converted DC electricity is supplied to the power supply unit 68 and also charges the storage battery 69. The storage battery 69 supplies power to the power supply unit 68 when the commercial power supply is interrupted due to a power outage or the like.

[0085] When the landing sensor detects that the unmanned aircraft 3 has landed on the takeoff and landing platform 61, the power supply unit 68 supplies power to the power supply terminal 613 in accordance with the instructions of the takeoff and landing control unit 63. As a result, the battery of the unmanned aircraft 3 is charged via the power supply terminal 613 and the contact portion 331 of the landing skid 33. In addition, the AC-DC converter 67 converts the DC electricity generated by the solar panel 625 into a predetermined voltage and supplies it to the power supply unit 68 and the storage battery 69.

[0086] Next, we will explain a method for measuring the distance between the overhead communication line 2 and the target object using an unmanned aerial vehicle 3.

[0087] Figure 9 is an explanatory diagram illustrating a method for measuring the separation distance between the overhead communication line 2 and the ground G. During the inspection of the overhead communication line 2 by the unmanned aerial vehicle 3, the maintenance worker observes the inspection data image on the control terminal 56. If it is determined that measurement of the separation distance is necessary, the flight mode of the unmanned aerial vehicle 3 is switched from autonomous flight mode for inspection to remote flight mode, and the separation distance is measured by remote control.

[0088] The unmanned aerial vehicle 3 moves from position [a], where it was flying along the overhead communication line 2 and conducting inspections, to directly below the overhead communication line 2A to be measured [b]. While hovering at position [b], the unmanned aerial vehicle 3 uses the measurement direction adjustment unit 38 to point the laser rangefinder 37 straight up (at an elevation angle of +90° with respect to the horizontal plane) and measures the first distance Ya to the overhead communication line 2A.

[0089] Next, the unmanned aerial vehicle 3 hovers at position [b] and uses the measurement direction adjustment unit 38 to point the laser rangefinder 37 straight down (at a downward angle of -90° relative to the horizontal plane) to measure the second distance Yb ​​to the ground G. Then, the equipment measurement unit 3j of the unmanned aerial vehicle 3 adds the first distance Ya and the second distance Yb ​​to calculate the separation distance Y between the overhead communication line 2A and the ground G. The calculated separation distance Y is transmitted to the monitoring and control device 5 as inspection data.

[0090] To move the unmanned aerial vehicle 3 directly below the overhead communication line 2A, for example, the laser rangefinder 37 is pointed straight up using the measurement direction adjustment unit 38, and the laser beam is directed straight up using the radar pointer function of the laser rangefinder 37. The unmanned aerial vehicle 3 is then remotely controlled while checking the image from the operation camera 34 to direct the laser beam onto the overhead communication line 2A. This allows the unmanned aerial vehicle 3 to be moved directly below the overhead communication line 2A.

[0091] Figure 10 is an explanatory diagram illustrating a method for measuring the distance between an overhead communication line 2A and the ground G when another overhead communication line 2B, which acts as an obstacle, is located directly below the overhead communication line 2A to be inspected.

[0092] The unmanned aerial vehicle 3 moves from its position [a], where it was flying along the overhead communication line 2 and conducting inspections, to a position [b] below the overhead communication line 2B, which is an obstacle, and directly below the overhead communication line 2A, which is the target of measurement. The laser pointer function described above is used to move the unmanned aerial vehicle 3 directly below the overhead communication line 2B.

[0093] The unmanned aerial vehicle 3 hovers at position [b] and uses the measurement direction adjustment unit 38 to point the laser rangefinder 37 straight down (at a downward angle of -90° relative to the horizontal plane), and uses the laser pointer function to shine a laser beam towards the ground G directly below the overhead communication line 2A. The position K on the ground G where the laser beam is shone is photographed and stored by the inspection camera 36.

[0094] Next, the unmanned aircraft 3 moves from position [b] to position [c] directly beside the overhead communication line 2A. The laser pointer function described above is used to move the unmanned aircraft 3 to beside the overhead communication line 2A and to transmit control signals from the monitoring and control device 5 to the takeoff and landing control device 63.

[0095] While hovering at position [c], the unmanned aerial vehicle 3 uses the measurement direction adjustment unit 38 to point the laser rangefinder 37 towards the overhead communication line 2A directly to the side and measures the first distance Xa to the overhead communication line 2A. Next, while hovering at position [c], the unmanned aerial vehicle 3 uses the measurement direction adjustment unit 38 to point the laser rangefinder 37 towards position K and measures the second distance Xb to position K.

[0096] The equipment measurement unit 3j of the unmanned aerial vehicle 3 uses the Pythagorean theorem "Y 2 =Xb 2 -Xa 2 Based on this, the separation distance Y from the overhead communication line 2A to the ground G is calculated from the first distance Xa and the second distance Xb (Y = √Xb 2 -Xa 2 The calculated separation distance Y is transmitted to the monitoring and control device 5 as inspection data.

[0097] In the above calculation, the distance Xb from position [b] to position K was used to calculate the separation distance Y from the overhead communication line 2A to the ground G. However, when pointing the laser rangefinder 37 from position [c] towards position K, the angle θk between the line connecting position [c] and position K and the horizontal plane can be determined, and this θk can be used to calculate the separation distance Y from the overhead communication line 2A to the ground G using the trigonometric formula "Y = Xa · tanθk".

[0098] Furthermore, if the ground G is flat, the distance between the overhead communication line 2 and the ground G can be measured by moving the unmanned aerial vehicle 3 directly beside the overhead communication line 2 and measuring the distance to the ground G while hovering at that position.

[0099] Figure 11 is an explanatory diagram illustrating a method for measuring the separation distance between two overhead communication lines 2A and 2B. The unmanned aerial vehicle 3 moves from its position [a], where it was flying along the overhead communication line 2 and conducting inspections, to a position [b] directly beside the overhead communication line 2A, which is the target of inspection. The laser pointer function described above is used to move the unmanned aerial vehicle 3 to a position directly beside the overhead communication line 2A.

[0100] The unmanned aerial vehicle 3 hovers at position [c] and uses the measurement direction adjustment unit 38 to point the laser rangefinder 37 towards the overhead communication line 2A directly to the side, measuring the first distance Xa to the overhead communication line 2A. Next, the unmanned aerial vehicle 3 hovers at position [b] and uses the measurement direction adjustment unit 38 to point the laser rangefinder 37 towards the overhead communication line 2B, measuring the second distance Xb to the overhead communication line 2B. The rotation angle θ when pointing the laser rangefinder 37 towards the overhead communication line 2B is also measured.

[0101] The equipment measurement unit 3j of the unmanned aerial vehicle 3 assumes that the intersection point M of a straight line a, which is an extension of the line connecting position [b] and the overhead communication line 2A, and a straight line b, which is drawn perpendicularly from the overhead communication line 2B, and the straight line X, which connects the overhead communication line 2A and the overhead communication line 2B, are the distance between the overhead communication line 2A and the overhead communication line 2B. The equipment measurement unit 3j then uses trigonometric functions to find the length of straight line a (Xb·cosθ-Xa) and the length of straight line b (Xb·sinθ), and calculates the distance X using the following formula (1) based on the Pythagorean theorem. The calculated distance X is transmitted to the monitoring and control device 5 as inspection data.

[0102] X = √(Xb·cosθ - Xa) 2 +(Xb·sinθ) 2 ...(1) Note that when measuring the separation distance between two overhead communication lines 2, if the two overhead communication lines 2 are at the same height, that is, if the two overhead communication lines 2 are arranged horizontally, the measurement method shown in Figure 11 cannot be used. In such cases, it is advisable to move the unmanned aerial vehicle 3 directly above or directly below one of the overhead communication lines 2 and measure the separation distance using the same method as in Figure 11.

[0103] Next, the operation of the above embodiment will be explained based on the flowchart shown in Figure 12. Based on the control information received from the monitoring and control device 5, the unmanned aircraft 3 performs autonomous flight from the parking location to the starting point of the patrol inspection of the overhead communication line 2 (step S1).

[0104] Upon arriving at the starting position for the patrol inspection, the unmanned aircraft 3 autonomously flies along the overhead communication line 2 based on images captured by the tracking camera 35. During this autonomous flight, the inspection camera 36 photographs the overhead communication line 2 and the support pole 4, and transmits these images to the monitoring and control device 5 as inspection data (step S2).

[0105] During the inspection of the overhead communication line 2 by the unmanned aerial vehicle 3, the maintenance worker observes the inspection data image on the control terminal 56. If it is determined that it is necessary to measure the separation distance (YES in step S3), the maintenance worker switches the flight mode of the unmanned aerial vehicle 3 from autonomous flight mode for inspection to remote flight mode and measures the separation distance by remote control (step S4).

[0106] In step 4, as shown in Figure 9, the distance between the overhead communication line 2 and the ground is measured, or as shown in Figure 10, the distance between the overhead communication line 2 and the ground is measured while avoiding obstacles, or as shown in Figure 11, the distance between the two overhead communication lines 2 is measured. The unmanned aircraft 3 transmits the measured distance as inspection data to the monitoring and control device 5 and resumes patrol inspection (step S2).

[0107] The maintenance worker checks the self-management information transmitted from the unmanned aerial vehicle 3 using the control terminal 56. If the battery charge level is low (YES in step S5), the maintenance worker lands the unmanned aerial vehicle 3 on the nearest pole-mounted landing device 6 (step S6) and charges the battery of the unmanned aerial vehicle 3 (step S7). Once charging is complete, the maintenance worker takes off the unmanned aerial vehicle 3 from the pole-mounted landing device 6 and resumes patrol inspections (step S2). During an inspection of the overhead communication line 2, if the monitoring and control device 5 acquires weather information from the weather information distribution system 9 and issues a warning indicating the need for evacuation preparation or evacuation as shown in Figure 3 (YES in step S8), the maintenance worker will move the unmanned aircraft 3 to the nearest pole-mounted landing gear 6 or parking area by autonomous flight or remote control (step S9), and then discontinue the inspection. However, if it is known from the weather information that the weather will improve, the inspection may be resumed after the evacuation.

[0108] Once the inspection of the overhead communication line 2 is complete (step S10), the unmanned aircraft 3 will return to its parking location by autonomous flight (step S11). If the battery charge level decreases during the return journey, it may land on the pole-mounted landing gear 6 to recharge.

[0109] As described above, according to the overhead line inspection system 1 of this embodiment, during the inspection of the overhead communication line 2, the distance between the overhead communication line 2 and the target object is measured by the laser rangefinder 37 mounted on the unmanned aerial vehicle 3. Therefore, it is possible not only to inspect the entire overhead communication line 2, but also to inspect the distance between each part of the overhead communication line 2 in detail.

[0110] Furthermore, when measuring the distance between the overhead communication line 2 and the object, a first distance to the overhead communication line 2 and a second distance to the object are measured, and the distance between the overhead communication line 2 and the object is calculated based on the first and second distances. Therefore, even when it is difficult to measure the distance between the overhead communication line 2 and the object, the distance between the overhead communication line 2 and the object can be measured accurately and reliably.

[0111] Furthermore, according to the overhead line inspection system 1 of this embodiment, when the object is the ground G, a first distance from directly below the overhead communication line 2 to the overhead communication line 2 is measured, a second distance from the same position to the ground G is measured, and the separation distance is calculated by adding the first distance and the second distance. Therefore, the separation distance between the overhead communication line 2 and the ground can be measured without moving to a position far away from the overhead communication line 2 and the ground G, and the time required for measurement can be shortened.

[0112] Furthermore, according to the overhead line inspection system 1 of this embodiment, if the object is the ground and there is an obstacle between the overhead communication line 2 and the ground G, the position K of the ground G below the obstacle and directly below the overhead communication line 2 is identified, a first distance from directly beside the overhead communication line 2 to the overhead communication line 2 is measured, a second distance from the same position to the position K of the ground G directly below the overhead communication line 2 is measured, and the separation distance is calculated based on the first distance and the second distance. Therefore, even if there is an obstacle between the overhead communication line 2 and the ground G, the separation distance between the overhead communication line 2 and the ground G can be measured without moving to a position far away from the overhead communication line 2 and the ground G, and the time required for measurement can be shortened.

[0113] Furthermore, according to the overhead line inspection system 1 of this embodiment, when measuring the separation distance between overhead communication line 2A and overhead communication line 2B, a first distance is measured from directly below, directly above, or directly beside overhead communication line 2A to overhead communication line 2A, and a second distance is measured from the same position to overhead communication line 2B. The separation distance is then calculated based on the first and second distances. Therefore, regardless of the relative positions of the two overhead communication lines 2A and 2B, the separation distance can be measured accurately and reliably.

[0114] Furthermore, according to the overhead line inspection system 1 of this embodiment, it is possible to decide whether to continue or discontinue the inspection of the overhead communication lines 2 in accordance with weather information, and if the inspection is discontinued, the unmanned aircraft 3 can be moved to a predetermined evacuation location, thereby preventing the unmanned aircraft 3 from being damaged or crashing due to severe weather.

[0115] Furthermore, according to the overhead line patrol and inspection system 1 of this embodiment, a pole-mounted landing and takeoff device 6 capable of landing and charging the unmanned aerial vehicle 3 is provided on the support pole 4 of the overhead communication line 2. Therefore, even if the unmanned aerial vehicle 3 flies a long distance for patrol and inspection, it can be appropriately moved to a safe location. In addition, since charging can be done in the middle of the patrol and inspection, it is possible to extend the flight distance (flight time) required for the patrol and inspection.

[0116] Furthermore, according to the overhead line inspection system 1 of this embodiment, the pole-mounted landing and takeoff device 6 transmits landing and takeoff information, including the landing and takeoff status and charging status of the unmanned aircraft 3, to the monitoring and control device 5, controls the opening and closing of the aircraft fixing part 612 in accordance with instructions from the monitoring and control device 5, and has a function to shut off the power supply unit 68 in accordance with instructions from the monitoring and control device 5 if any abnormality occurs in the power supply unit 68 that charges the unmanned aircraft 3, such as overcharging, so that the state of the unmanned aircraft 3 after it has retreated can be confirmed from a distance, and furthermore, the unmanned aircraft 3 that has landed can be stably protected in accordance with the monitoring results.

[0117] Although embodiments of this invention have been described above, the specific configuration is not limited to the embodiments described above, and any design changes, etc., that do not depart from the spirit of this invention are also included.

[0118] For example, in the above embodiment, maintenance personnel check weather information and decide whether to continue or discontinue the patrol inspection. However, the monitoring and control device 5 or the unmanned aircraft 3 may decide whether to continue or discontinue the patrol inspection, and if it is discontinued, it may autonomously fly to a safe position.

[0119] Furthermore, while we have described a system for inspecting overhead communication lines, it can also be applied to inspecting power lines such as transmission and distribution lines. [Explanation of Symbols]

[0120] 1. Overhead Line Inspection System 2. Overhead communication lines (overhead lines) 3. Unmanned aircraft 37 Laser rangefinder 38 Measurement direction adjustment section (measurement direction adjustment means) 3j Equipment Measurement Unit (Separation Distance Calculation Means) 4 Support pillar 5. Monitoring and Control Device 54 System Control Unit (Weather-Responsive Control Means) 6. Pole-mounted landing gear 61 Takeoff and landing racks 62 Control unit (power supply means) 7 GNSS satellites 8. Mobile phone network 9. Weather Information Distribution System

Claims

1. An unmanned aerial vehicle that flies along overhead lines and inspects said overhead lines, The system includes a monitoring and control device for monitoring and controlling the inspection of overhead lines by the unmanned aircraft, The aforementioned unmanned aircraft, A laser distance meter that measures a first distance to the overhead line and a second distance to an object whose separation distance from the overhead line is to be measured, A separation distance calculation means for calculating the separation distance between the overhead line and the object based on the first distance and the second distance, A communication means for transmitting inspection data, including the separation distance, to the monitoring and control device, Equipped with, If the object is the ground and there is an obstacle between the overhead line and the ground, the unmanned aircraft will Moving below the aforementioned obstacle and directly below the aforementioned overhead wire, The laser rangefinder is pointed directly downwards by the measurement direction adjustment means, the laser pointer function of the laser rangefinder is used to project a laser onto the ground, and the position where the laser is projected is stored as the measurement point. Move to the side directly beside the overhead line, The first distance to the overhead line is measured, The laser distance meter is directed towards the measurement point using the measurement direction adjustment means, and the second distance to the measurement point is measured. The separation distance calculation means calculates the separation distance between the overhead line and the ground based on the first distance and the second distance. An overhead line inspection system characterized by the following:

2. A weather information acquisition means for acquiring weather information in the area where the overhead line inspection is carried out, A weather-responsive control means that, in accordance with the acquired weather information, causes the unmanned aerial vehicle to continue its patrol and inspection of the overhead lines, or to cause the unmanned aerial vehicle to cease its patrol and inspection of the overhead lines and move to a predetermined evacuation location, The overhead line inspection system according to claim 1, characterized by comprising:

3. A landing platform is installed on a support column that supports the overhead wire, and from which the unmanned aircraft can take off and land, The pole-mounted landing and takeoff system includes a power supply means for charging the battery of the unmanned aircraft that has landed on the aforementioned landing and takeoff platform. The overhead line inspection system according to feature 2.

4. The pole-mounted landing and takeoff device includes, at a minimum, a function to transmit landing and takeoff information, including the landing and takeoff status and charging status of the unmanned aircraft, to the monitoring and control device, and a function to control the opening and closing of the aircraft fixing part and to shut off the power supply unit from the pole-mounted landing and takeoff device to the unmanned aircraft based on control information received from the monitoring and control device. The overhead line inspection system according to feature 3.

5. An overhead line inspection method comprising inspecting the overhead line using an unmanned aerial vehicle flying along the overhead line, A laser rangefinder mounted on the aforementioned unmanned aerial vehicle is used to measure a first distance to the overhead wire and a second distance to the object whose separation distance from the overhead wire is to be measured. Based on the first distance and the second distance, the separation distance between the overhead line and the object is calculated. The inspection data, including the separation distance, is transmitted to a monitoring and control device that monitors and controls the inspection of the overhead lines by the unmanned aircraft. If the object is the ground and there is an obstacle between the overhead line and the ground, the unmanned aircraft will Moving below the aforementioned obstacle and directly below the aforementioned overhead wire, The laser rangefinder is pointed directly downwards by the measurement direction adjustment means, the laser pointer function of the laser rangefinder is used to project a laser onto the ground, and the position where the laser is projected is stored as the measurement point. Move to the side directly beside the overhead line, The first distance to the overhead line is measured, The laser distance meter is directed towards the measurement point using the measurement direction adjustment means, and the second distance to the measurement point is measured. The separation distance calculation means calculates the separation distance between the overhead line and the ground based on the first distance and the second distance. An overhead line inspection method characterized by the following.

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