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 another overhead communication line 2B, the unmanned aircraft 3 moves directly below, above, or to the side of the overhead communication line 2A, and adjusts the measurement direction of the laser rangefinder 37 using the measurement direction adjustment unit 38 to point the laser rangefinder 37 towards the overhead communication line 2A to measure a first distance Xa to the overhead communication line 2A, and adjusts the measurement direction of the laser rangefinder 37 using the measurement direction adjustment unit 38 to point the laser rangefinder 37 towards the overhead communication line 2B to measure a second distance Xb to the overhead communication line 2B, and the equipment measurement unit 3j calculates the separation distance X between the overhead communication line 2A and the overhead communication line 2B based on the first distance Xa and the second distance Xb.

Description

Technical Field

[0001] This 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 with power plants such as dams and electrical substations. Such wiring stretched in the air is called an overhead line, and in particular, a communication cable stretched 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 or across rivers. Therefore, when performing maintenance work such as regular inspections, a large amount of time and labor are required.

[0003] By the way, there is known a system that enables inspection of power transmission and distribution facilities from a remote location by flying an unmanned aerial vehicle (so-called drone) along an overhead power transmission line and taking pictures of the power transmission and distribution facilities including the overhead power transmission line with a camera mounted on the unmanned aerial vehicle (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 are more prone to changes in their installation status compared to overhead power lines, and problems often arise, particularly regarding insufficient clearance between other overhead communication lines and insufficient clearance from the ground. This is because support poles are frequently used for laying and modifying overhead communication lines not only by power companies but also by other telecommunications companies and cable broadcasting operators, making it easy for changes in the position and sag of the overhead communication lines to occur. However, conventional inspection systems using unmanned aerial vehicles cannot measure the clearance between overhead communication lines or the clearance from the ground.

[0006] Therefore, the objective 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 problem]

[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 the object If the first overhead line is another second overhead line, the unmanned aircraft moves directly below, directly above, or directly beside the overhead line, and measures the first distance to the overhead line by adjusting the measurement direction of the laser rangefinder using the measurement direction adjustment means to adjust the measurement direction of the laser rangefinder, and measures the second distance to the second overhead line by adjusting the measurement direction of the laser rangefinder, and the separation distance calculation means calculates the separation distance between the first overhead line and the second overhead line based on the first distance and the second distance, characterized in that,

[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 that flies along the overhead line, wherein a laser rangefinder mounted on the unmanned aerial vehicle 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 overhead line inspection by the unmanned aerial vehicle, and the object is another second In the case of an overhead line, the unmanned aerial vehicle moves directly below, directly above, or directly beside the overhead line, and uses a measurement direction adjustment means to adjust the measurement direction of the laser rangefinder to point the laser rangefinder towards the overhead line and measure the first distance to the overhead line, and uses the measurement direction adjustment means to point the laser rangefinder towards the second overhead line and measure the second distance to the second overhead line, and uses the separation distance calculation means to calculate the separation distance between the first overhead line and the second overhead line based on the first distance and the second distance. [Effects of the Invention]

[0012] According to the inventions of claims 1 and 5, during an overhead line inspection, the distance between the overhead line and the object is measured using a laser rangefinder mounted on an unmanned aerial vehicle. This makes it possible to inspect not only the entire overhead line but also the distance between each part of the overhead line in detail. Furthermore, when measuring the distance between the overhead line and the object, a first distance to the overhead line and a second distance to the object are measured, and the distance between the overhead line and the object is calculated based on the first and second distances. This allows for accurate and reliable measurement of the distance between the overhead line and the object, even when it is difficult to measure the distance between the overhead line and the object.

[0013] According to the inventions of claims 1 and 5, when measuring the separation distance between an overhead wire and a second overhead wire, a first distance is measured from directly below, directly above, or directly beside the overhead wire to the overhead wire, a second distance is measured at the same location to the second overhead wire, and the separation distance is calculated based on the first distance and the second distance. Therefore, the separation distance can be measured accurately and reliably regardless of the relative position of the two overhead wires.

[0014] According to the invention of claim 2, it is possible to decide whether to continue or discontinue the overhead line inspection in accordance with weather information, and if the inspection is discontinued, the unmanned aircraft can be moved to a predetermined evacuation location, thereby preventing the unmanned aircraft from being damaged or crashing due to severe weather.

[0015] According to the invention of claim 3, since a landing and takeoff platform for an unmanned aerial vehicle and a power supply means for charging the battery of the unmanned aerial vehicle are provided on the support pole of the overhead line, the unmanned aerial vehicle can be properly evacuated even when it has flown a long distance for patrol inspection. In addition, since charging can be done in the middle of patrol inspection, it is possible to extend the flight distance (flight time) required for patrol inspection.

[0016] According to the invention of claim 4, the pole-mounted takeoff and landing device transmits takeoff and landing information, including the takeoff and landing status and charging status of the unmanned aircraft, to a monitoring control device, controls the opening and closing of the aircraft fixing part in accordance with instructions from the monitoring control device, and has a function to shut off the power supply unit in accordance with instructions from the monitoring control device if any abnormality occurs in the power supply unit that charges the unmanned aircraft and causes overcharging, so that the status of the unmanned aircraft after it has retreated can be checked from a distance, and furthermore, it is possible to stably protect the landed unmanned aircraft in accordance with the monitoring results. [Brief explanation of the drawing]

[0017] [Figure 1] This is a conceptual diagram showing an overview of an overhead line inspection system according to an embodiment of the present invention. [Figure 2] Figure 1 is a functional block diagram showing the functions of the monitoring and control device. [Figure 3] It is a table showing an example of the data configuration of the weather-corresponding data stored in the weather-corresponding data storage unit shown in FIG. 2. [Figure 4] It is a front view showing the configuration of the unmanned aerial vehicle 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 aerial vehicle shown in FIG. 4. [Figure 7] It is a side view showing the configuration of the pole takeoff and landing device shown in FIG. 1. [Figure 8] It is a functional block diagram showing the functions of the 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 the 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 the 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 patrol inspection by the overhead line patrol 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 patrol inspection system 1 according to an embodiment of this invention. The overhead line patrol inspection system 1 according to this embodiment is, for example, a system for patrolling and inspecting an overhead communication line (overhead line) 2 laid by a power company for communication with power plants, electrical substations, etc. by an unmanned aerial vehicle 3.

[0020] The overhead communication lines 2 are communication cables suspended in the air by numerous support poles 4, such as power poles and shared poles. These support poles 4 may also carry overhead communication lines from other telecommunications companies and cable broadcasting operators, in addition to the power company's overhead communication lines 2. Because these overhead communication lines from other telecommunications companies are frequently re-laid in response to changes in customer contracts, the separation distances between overhead communication lines and between overhead communication lines and the ground may change. The separation distances between overhead communication lines affect the generation of communication noise, and a short separation distance between overhead communication lines and the ground can cause collisions with vehicles. Therefore, periodic inspections of the overhead communication lines 2 are conducted.

[0021] The overhead line inspection system 1 according to this embodiment flies an unmanned aerial vehicle 3 along an overhead communication line 2, and uses a laser rangefinder mounted on the unmanned aerial vehicle 3 to measure a first distance to the overhead communication line 2 and a second distance to an object (the ground or other overhead communication line) that is the target of measurement for the separation distance from the overhead communication line 2. Based on the first and second distances, the separation distance between the overhead communication line 2 and the object is calculated. The inspection data, including the separation distance, is then transmitted from the unmanned aerial vehicle 3 to the monitoring and control device 5. In addition, pole-mounted takeoff and landing devices 6 that enable the unmanned aerial vehicle 3 to take off and land are installed on the support pole 4 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 pole-mounted landing and takeoff equipment 6 is installed on support poles 4 at predetermined distance intervals and includes a landing platform 61 on which an unmanned aircraft 3 can take off and land, and a control unit 62 that controls the landing platform 61 and charges the battery of the unmanned aircraft 3 when it lands on the landing platform 61. Since the overhead communication lines 2 are laid over a wide area over long distances, long-distance (long-duration) flights are necessary to conduct patrol inspections, but since the unmanned aircraft 3 flies using its onboard battery as a power source, there is a limit to its flight distance. In addition, if the aircraft is flying for a long time, the weather may change and it may become difficult to fly. The pole-mounted landing and takeoff equipment 6 is provided to temporarily move the unmanned aircraft 3 to safety when the battery charge level decreases or when the weather changes.

[0027] The unmanned aerial vehicle 3, the monitoring and control device 5, and the pole-mounted takeoff and landing device 6 are connected to each other so that they can communicate with one another, for example, via a mobile phone communication network 8. The monitoring and control device 5 transmits monitoring and control information to the unmanned aerial vehicle 3 via the mobile phone communication network 8 and receives inspection data and self-management information transmitted from the unmanned aerial vehicle 3. The monitoring and control information includes remote control information for flying the unmanned aerial vehicle 3 remotely and flight instruction information for flying the unmanned aerial vehicle 3 autonomously along a specified route.

[0028] Furthermore, the monitoring and control device 5 receives weather information for the area where the patrol inspection is being conducted from the weather information distribution system 9, which is connected via the mobile phone communication network 8, and controls whether to continue or cancel the patrol inspection based on the received weather information. This is because the unmanned aerial vehicle 3 is difficult to control in bad weather conditions such as wind and rain, and there is a risk of crashing due to loss of control. The weather information includes weather current conditions information, which shows the current weather conditions, and weather forecast information, which shows the weather conditions after a predetermined time (for example, 1 to several hours later).

[0029] The pole-mounted landing and takeoff device 6 has functions to monitor the takeoff and landing status of the unmanned aircraft 3 and to monitor its charging status. The pole-mounted landing and takeoff device 6 transmits takeoff and landing information, including the takeoff and landing status and charging status obtained through monitoring, to the monitoring and control device 5 via the mobile phone communication network 8.

[0030] The monitoring and control device 5 displays inspection data and self-management information received from the unmanned aerial vehicle 3, weather information received from the weather information distribution system 9, and takeoff and landing information received from the pole-mounted takeoff and landing device 6. Maintenance personnel control the unmanned aerial vehicle 3 using the monitoring and control device 5 while confirming the status of patrol inspections based on the inspection data, self-management information, takeoff and landing information, and weather information displayed on the monitoring and control device 5.

[0031] The cellular network 8 uses the currently widespread LTE network (so-called 4G network), but a so-called 5G network may also be used, or the 4G and 5G networks may be switched depending on the communication conditions. In addition, satellite communication may be used instead of the cellular network 8. Furthermore, although the monitoring and control device 5, the pole-mounted landing and takeoff device 6, and the weather information distribution system 9 are connected by the cellular network 8, they may also be connected using a wired communication network such as an optical fiber network.

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

[0033] The monitoring and control device 5 comprises an equipment data storage unit 51, an inspection data storage unit 52, a weather-related data storage unit 53, a system control unit 54, a communication unit 55, and an operation terminal 56. In the figure, the dashed lines indicate the flow of information used for controlling each part of the monitoring and control device 5 and for controlling the unmanned aerial vehicle 3, while the solid lines indicate the flow of inspection data and other information received from the unmanned aerial vehicle 3.

[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-responsive data storage unit 53 stores pre-set weather-responsive data. This weather-responsive data is data that indicates the criteria for deciding whether to continue or discontinue patrol inspections by the unmanned aerial vehicle 3, based on weather information received from the weather information distribution system 9. The weather-responsive data storage unit 53 is connected to the system control unit 54 and the operation terminal 56.

[0039] The system control unit 54 has the function of comprehensively managing and controlling the entire overhead line inspection system 1, including the monitoring and 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-related data storage unit 53, the communication unit 55, and the operation terminal 56.

[0040] The communication unit 55 transmits monitoring and control information to the unmanned aerial vehicle 3 via the mobile phone communication network 8 and receives inspection data and self-management information from the unmanned aerial vehicle 3. The communication unit 55 also receives takeoff and landing information of the unmanned aerial vehicle 3 from the pole-mounted takeoff and landing device 6 via the mobile phone communication network 8. Furthermore, the communication unit 55 receives weather information for the area where patrol inspections are being conducted from the weather information distribution system 9 in accordance with instructions from 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 operating terminal 56 is equipped with output means such as a monitor and input means such as a keyboard and mouse, and has the 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 operating 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] Maintenance personnel use the keyboard of the operation terminal 56 to read the track information of the overhead communication lines 2 that are subject to inspection from the equipment data storage unit 51 and display it on the monitor. Maintenance personnel view the track information displayed on the monitor, add or modify the track information as needed, and formulate an inspection plan. In addition, weather information received from the weather information distribution system 9 is displayed on the monitor, allowing maintenance personnel to refer to the weather information when formulating the inspection plan.

[0043] The system control unit 54 generates monitoring and control information for controlling the unmanned aerial vehicle 3 based on the patrol and inspection plan formulated by the maintenance personnel operating the operation terminal 56. The generated monitoring and 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 self-management information received from the unmanned aerial vehicle 3 to the system control unit 54 and stores it in the inspection data storage unit 52. The system control unit 54 displays the received inspection data and other information on the monitor of the operation terminal 56. This allows maintenance personnel to remotely control the unmanned aerial vehicle 3 while monitoring the patrol inspection of the overhead communication line 2 in real time.

[0045] The communication unit 55 and the weather information distribution system 9 correspond to the weather information acquisition means according to the present invention, and the system control unit 54 functions as a weather-response control means that, in accordance with the acquired weather information, causes the unmanned aerial vehicle 3 to continue patrolling and inspecting the overhead communication line 2, or causes the unmanned aerial vehicle 3 to stop patrolling and inspecting the overhead communication line 2 and move to a predetermined evacuation location.

[0046] When the system control unit 54 receives weather forecast information (weather forecast for a predetermined time period) for the area where the patrol inspection is to be conducted from the weather information distribution system 9, it refers to the weather response data in the weather response data storage unit 53 to decide on a course of action, displays an alert to cancel the patrol inspection on the monitor of the operation terminal 56, and also notifies the user with an alarm sound or voice message.

[0047] Figure 3 shows the weather-related data 531 stored in the weather-related data storage unit 53. The weather-related 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 category)," and "maintenance personnel response (warning judgment / aircraft control)."

[0048] Weather classification A refers to weather conditions where the weather is sunny or cloudy, the temperature is between 0°C and 35°C, the precipitation is 0 mm, and the wind speed is less than 2 m / s. The system control unit 54 does not set a warning classification when the weather forecast information corresponds to weather classification A. Therefore, no warning is issued from the operation terminal 56, and the maintenance personnel continue their patrol inspection.

[0049] Weather classification B refers to weather conditions where the temperature is below 0°C to -5°C or above, or above 35°C to 40°C. Weather classification C refers to weather conditions where the weather is rainy or snowy with precipitation of 1 mm / h to less than 5 mm / h. Furthermore, weather classification D refers to weather conditions where the wind speed is between 2 m / s and less than 5 m / s. If the weather forecast information corresponds to weather classification B, 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 C, 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 D, the system control unit 54 will notify the operation terminal 56 of a "wind speed warning".

[0050] If a warning for "temperature," "rainfall," or "wind speed" is issued, maintenance personnel will prepare to evacuate the unmanned aircraft 3, for example, by ceasing patrol inspections within 20 minutes and moving 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 aircraft 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 another second overhead line, the unmanned aircraft Move directly below, above, or to the side of the aforementioned overhead line, The laser distance meter is directed towards the overhead wire by the measurement direction adjusting means for adjusting the measurement direction of the laser distance meter, and the first distance to the overhead wire is measured. The laser distance meter is directed towards the second overhead wire using the measurement direction adjustment means, and the second distance to the second overhead wire is measured. The separation distance calculation means calculates the separation distance between the first overhead line and the second overhead line 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 another second overhead line, the unmanned aircraft Move directly below, above, or to the side of the aforementioned overhead line, The laser distance meter is directed towards the overhead wire by the measurement direction adjusting means for adjusting the measurement direction of the laser distance meter, and the first distance to the overhead wire is measured. The laser distance meter is directed towards the second overhead wire using the measurement direction adjustment means, and the second distance to the second overhead wire is measured. The separation distance calculation means calculates the separation distance between the first overhead line and the second overhead line based on the first distance and the second distance. An overhead line inspection method characterized by the following.

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