Electric power inspection method based on long-endurance hybrid tilt-rotor unmanned aerial vehicle

Abstract

The invention discloses an electric power inspection method based on a long-endurance hybrid tilt-rotor unmanned aerial vehicle, and the method comprises the steps: designing an unmanned aerial vehicle which comprises a fuselage, two wings, a micro gas turbine hybrid power generation system, two oil tanks, an undercarriage, a rotor electric power system, a communication system, a monitoring alarm system, a flight control system, a high-definition camera, a thermal infrared imager and laser radar equipment; planning the route of the unmanned aerial vehicle: designing a routing inspection sequence as follows: channel 1-channel 2-tower-return, setting scanning points according to the routing inspection sequence, and finishing the route planning of the unmanned aerial vehicle in combination with the scanning points and the routing inspection sequence; according to the method, the inspection efficiency of the power transmission line can be greatly improved, and the method has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the field of general aviation technology, and particularly to a power inspection method based on a long-endurance hybrid tilt-rotor unmanned aerial vehicle. Background Art

[0002] With the rapid development of the grid intelligence of the State Grid Corporation, the traditional manual regular inspection mode for transmission lines not only has a high labor intensity, but also takes a long time and has low efficiency. Some line segments cannot be inspected due to terrain factors, making it extremely difficult to maintain the lines and no longer meeting the actual needs of grid development. As a new means of power inspection, the three-dimensional inspection technology of unmanned aerial vehicles is gradually replacing the traditional manual regular inspection mode, and unmanned aerial vehicles have currently been widely applied and promoted in power inspection.

[0003] Drones can be equipped with high-definition cameras and infrared thermal imagers to conduct all-round and multi-angle inspections of transmission lines. These devices can quickly detect defects such as broken insulators, broken wires, and tilted towers, and detect the temperature distribution of the line, timely discover overheating hazards, effectively improve inspection efficiency and accuracy, and ensure the safe operation of transmission lines. In substations, drones can automatically fly according to preset routes to inspect substation equipment, including transformers, switches, switches, mutual inductors, etc. By shooting images and video information such as the appearance of the equipment and instrument readings, and transmitting them to the background for analysis by operation and maintenance personnel, abnormal conditions of the equipment can be discovered in time, realizing intelligent inspection of substations; drones can integrate thermal imaging technology, identify temperature abnormalities, and compare them with preset thresholds to effectively discover hidden fault points. During nighttime operations, drones focus on detecting abnormal heating in key parts such as conductors, wire clamps, drainage wires, insulators, poles and tension pipes based on thermal imaging data to ensure the safe and stable operation of the power system. When power facilities are damaged due to power failures or natural disasters, drones can quickly reach the scene, survey and locate the fault area, provide accurate information for repair personnel, and help formulate repair plans. At the same time, drones can also carry emergency communication equipment to establish temporary communication links in the event of communication interruption to ensure smooth communication for repair command. After natural disasters, drones can conduct a comprehensive disaster assessment of power facilities in the affected areas, provide a scientific basis for the power department to formulate post-disaster recovery and reconstruction plans, and speed up the restoration of power supply. In my country, most power lines are located in remote areas with few people and inconvenient transportation. The use of drone inspection technology can break through geographical barriers and effectively cover power line corridors. Drones are equipped with laser radars, which take advantage of their high-altitude operation to accurately collect three-dimensional point cloud data of conductors and vegetation, and monitor the status of buildings along the way to ensure the safe and efficient operation of power channels. In cities, power poles and towers are often located in narrow spaces with dense pedestrian and vehicle traffic. Utilizing the high-altitude perspective and flexibility of drones, they can traverse complex environments for all-round photography and scanning, and use professional software to perform in-depth processing and analysis of the collected data to ensure the comprehensiveness of inspections and the accuracy of point cloud data, and to improve the level of intelligence in urban distribution network operation and maintenance. Drones can be used for obstacle removal operations and insulator cleaning. During obstacle removal operations, drones equipped with flamethrowers can quickly remove foreign objects entangled on high-voltage wires. When cleaning insulators, drones can accurately locate dirty areas and flush them, reducing the frequency of manual high-altitude operations and improving operational safety and efficiency.

[0004] Currently, the commonly used types of power inspection drones mainly include: unmanned helicopters, multi-rotor drones, fixed-wing drones, and compound-wing drones. At present, power inspection drones usually use lithium batteries to provide power for them. Affected by the low energy density of the batteries, only the fixed-wing drones have a relatively long endurance time, while the endurance times of the other types of drones are relatively short, which cannot meet the requirements of long-endurance power inspection operations and severely limit the operation efficiency of power inspection. Although the fixed-wing drones have a relatively long endurance time, they cannot take off and land vertically and require a relatively long runway for takeoff and landing operations, so their application environment is limited. Therefore, it is extremely urgent to develop a power inspection method for a long-endurance hybrid tilt-rotor drone based on power inspection. Summary of the Invention

[0005] In view of this, the present invention provides a power inspection method based on a long-endurance hybrid tilt-rotor drone to achieve long-distance channel inspection and tower hovering inspection tasks in harsh environments.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: A power inspection method based on a long-endurance hybrid tilt-rotor drone, including:

[0007] Design a drone, including: a fuselage, two wings, a micro gas turbine hybrid power generation system, two fuel tanks, a landing gear, a rotor electric power system, a communication system, a monitoring and warning system, a flight control system, a high-definition camera, an infrared thermal imager, and a lidar device;

[0008] Among them, the rotor electric power system controls the vertical takeoff and horizontal flight working states of the drone through a tilt-rotor mechanism.

[0009] Drone route planning: Identify the towers to be inspected and the two adjacent channels of the towers, and design the inspection sequence as: Channel 1 → Channel 2 → Tower → Return. Set the scanning points according to the inspection sequence, and complete the drone route planning by combining the scanning points and the inspection sequence;

[0010] The drone conducts inspections according to the drone route planning. The high-definition camera, infrared thermal imager, and lidar device send the collected data to the monitoring and warning system. The monitoring and warning system diagnoses the data and feeds back the fault information obtained from the diagnosis to the terminal platform through the communication system;

[0011] Among them, the monitoring and warning system completes the defect detection of the towers and their channels by comparing the collected data with the sample data.

[0012] Preferably, the rotor electric power system is composed of 6 propellers, adopts a single upper wing V-tail layout aerodynamic structure, and a tilt-rotor 2+2+2 power mode.

[0013] Preferably, in the UAV route planning, the number of scanning points set on the pole tower is not less than 8, and the number of scanning points in each channel is not less than 4.

[0014] Preferably, the communication system is composed of an inertial navigation INS and a global positioning system GPS.

[0015] Preferably, the UAV conducts inspections according to the UAV route planning, and the inspection process is as follows:

[0016] 1) Channel inspection: When the UAV vertically takes off to the route planning height, the tilt-rotor mechanism rotates the propeller by 90°, and enters the level flight mode. First, conduct the inspection of Channel 1. When the UAV approaches the scanning point in Channel 1 during level flight, the UAV decelerates, and at the same time, the tilt-rotor mechanism rotates the propeller by 90°, and the propeller reaches the horizontal state. After completing the data collection using a high-definition camera, an infrared thermal imager, and a lidar device, the tilt-rotor mechanism rotates the propeller by 90°, and the propeller reaches the vertical state. The UAV continues to fly horizontally to the next scanning point, and repeats the above steps to complete the inspection operation of all scanning points; that is, the inspection of Channel 1 is completed; repeat the inspection operation steps of Channel 1 to complete the inspection of Channel 2;

[0017] 2) Pole tower inspection. The UAV docks at the pole tower position according to the route planning. Subsequently, the UAV vertically takes off and hovers after reaching Pole Tower Inspection Point 1. After completing the data collection using a high-definition camera, an infrared thermal imager, and a lidar device and classifying and storing according to the position tags, call the monitoring and warning system to judge abnormal situations. If abnormal situations are found, transmit the abnormal situations to the terminal platform. After waiting for the confirmation of the terminal platform, complete the next inspection operation according to the confirmation instruction; respectively complete the inspection operations of Scanning Point 2, Scanning Point 3,..., up to Scanning Point 8;

[0018] The UAV vertically takes off to the specified height, and at the same time rotates the propeller of the tilt-rotor mechanism by 90°, and the propeller reaches the horizontal state. The UAV returns to the takeoff and landing point.

[0019] Preferably, the monitoring and warning system diagnoses abnormal situations for different positions of the inspection; constructs a key component image feature library according to different inspection positions, labels according to the inspection positions, and determines whether there are faults in the inspection line and the pole tower by means of graphic comparison. If a fault is detected, upload the fault information to the terminal platform for warning.

[0020] The present invention provides a power inspection method based on a long-endurance hybrid tilt-rotor UAV. This method adopts an autonomous inspection mode, with characteristics such as simple operation, high processing speed, and high accuracy, which can greatly improve the inspection efficiency of transmission lines and has broad application prospects. Description of the Drawings

[0021] Figure 1Schematic diagram of the inspection operation of the drone channel provided by the present invention;

[0022] Figure 2 Schematic diagram of the inspection operation of the drone tower provided by the present invention;

[0023] Figure 3 Flow chart of the monitoring and warning system provided by the present invention;

[0024] Figure 4 Schematic diagram of the structure of the long-endurance hybrid tilt-rotor drone for power inspection provided by the present invention. Detailed implementation manners

[0025] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0026] Currently, the commonly used drone models for power inspection mainly include four types: unmanned helicopters, multi-rotor drones, fixed-wing drones, and compound-wing drones. In the application of power inspection, the characteristics of different types of drones include:

[0027] Unmanned helicopter: The unmanned helicopter is not affected by the runway of the takeoff and landing site, can take off and land vertically, and is flexible in flight. It can quickly and accurately complete the inspection operation of the transmission line tower channel. However, due to the generally large size of the unmanned helicopter rotor, the takeoff operation radius is relatively large, and it is difficult to take off and land in some areas with lush vegetation in mountainous environments. Moreover, the unmanned helicopter usually uses lithium batteries as the power source, and the endurance time is relatively short, which seriously restricts the inspection operation distance of the unmanned helicopter. Currently, the unmanned helicopter is mainly used for flight inspection of one or two towers within the visual range that are inconvenient for people to reach.

[0028] Multi-rotor drone: The multi-rotor drone is a flight device that can take off and land vertically. It is generally used for various types of flight inspection tasks such as parameter collection of power grid equipment and fault finding of transmission lines. During the inspection operation of the transmission line, it can complete the lean inspection work of fixed-point targets such as transmission line tower equipment and insulators. The multi-rotor drone inspection system can carry load devices such as visible light and infrared, is flexible to control, hovers accurately, and can meet the requirements of high-definition and non-destructive shooting. It is suitable for the inspection tasks of fittings, pins and line faults of overhead transmission lines, and realizes the fixed-point lean inspection operation of transmission line equipment. However, the multi-rotor drone usually uses lithium batteries as the power source, and multiple power systems work simultaneously, resulting in a relatively low comprehensive efficiency of the system and a short endurance time, and it can only meet the inspection operation tasks and emergency inspection operations of short distances.

[0029] Fixed-wing UAV: Due to its airframe structure, a fixed-wing UAV cannot hover in the air. It has a relatively high flight speed and can quickly conduct inspection operations on transmission line corridors. It has a relatively long endurance time and is mainly used for visual inspection of long-distance transmission line corridors. It can carry out UAV flight inspection operations on relevant transmission line corridors such as goafs and fault zones. The main disadvantage of fixed-wing UAVs is that they require a relatively long runway for takeoff and landing operations, and their application environment is limited. In mountainous areas with relatively harsh conditions, fixed-wing UAVs generally cannot be applied.

[0030] Compound-wing UAV: As a new type of aircraft that combines a fixed-wing aircraft and a helicopter, a compound-wing UAV has two power systems for flight. One is used for vertical takeoff and landing and hovering in the air like an ordinary multi-rotor UAV, and the other power system is used for high-speed flight like a fixed-wing UAV.

[0031] At present, traditional compound-wing UAVs in the market mostly adopt a 4+1 or 4+2 propeller layout, and the power motors cannot be tilted, resulting in low aerodynamic efficiency, poor wind resistance, and inability to ensure flight safety. At the same time, because they use a lithium battery power supply system, hovering during flight will greatly reduce their endurance time and cannot meet the requirements of long-distance corridor inspection and tower hovering inspection tasks.

[0032] In view of the current application status of power inspection UAVs, such as low safety, short endurance time, and low inspection efficiency, and the inability to simultaneously complete inspection operations on power towers and their adjacent corridors, a power inspection method based on a long-endurance hybrid tilt-rotor UAV is proposed, including:

[0033] 1) Design the UAV. As shown in Figure 3 , the design content of the mechanical and electrical connection structure of this UAV includes: a fuselage 1, two wings 2, a set of micro gas turbine hybrid power generation system 3, two fuel tanks 4, a set of landing gear 5, six sets of rotor electric power systems 6 composed of propellers, a set of communication system 7, a set of high-definition cameras 8, a set of infrared thermal imagers 1 set, and lidar equipment 9, a single-wing V-tail layout aerodynamic structure 10, a set of flight control systems 11; a set of monitoring and warning systems 12.

[0034] The UAV adopts an upper-wing V-tail aerodynamic structure design in terms of aerodynamic layout; the power system adopts a tilt-rotor 2+2+2 power mode, and the rotor power system composed of 6 propellers ensures the UAV's vertical take-off and level flight operating states; a micro gas turbine hybrid power generation system is used to provide power for the UAV, ensuring that the aircraft's flight time is not less than 3 hours; the UAV has intelligent platform functions and can realize autonomous charging, fuel replenishment, autonomous inspection, route planning, laser modeling, autonomous graphic analysis, intelligent recognition and intelligent diagnosis. Equipped with high-definition cameras, infrared thermal imagers and lidar equipment, and with the help of computer bionic vision technology, the drone can simultaneously complete the 8-point scanning inspection of the tower and the inspection of two adjacent channels of the tower. By comparing the collected data with the sample data, it can complete the defect detection of the tower and its channels, and transmit the alarm information to the terminal platform based on the detection results. When operating in complex terrain (such as mountains, rivers, forests, etc.), the GPS signal is weak. In order to ensure the reliability of flight, the drone uses a communication system composed of inertial navigation (INS) and satellite positioning navigation (GPS) for autonomous inspection, which prevents the risk of the drone crashing due to loss of communication signals during its inspection.

[0035] The UAV uses a micro gas turbine hybrid power generation system to provide power for the UAV, ensuring a long flight time for the UAV; the UAV should be able to complete the inspection tasks of power towers and adjacent channels under autonomous flight;

[0036] The drone has both the ability of vertical take-off and landing and hovering in the air of ordinary helicopters and the high-speed cruising flight capability of fixed-wing drones. It has high wind resistance and reliability and can meet the long-distance channel inspection and tower hovering inspection tasks in harsh environments. It is of great significance to realize the comprehensive, three-dimensional, intelligent, rapid, efficient and safe inspection of drones, and its application prospects in power operation and maintenance will be very broad.

[0037] 2) UAV route planning: mark the towers and channels to be inspected, and the inspection order is: channel 1 → channel 2 → tower → return. Set scanning points according to the inspection order, where the number of scanning points set on the tower is not less than 8, and the number of scanning points for each channel is not less than 4; combine the scanning points and inspection order to complete the UAV route planning, such as Figure 1 and Figure 2 As shown;

[0038] 3) When the drone is turned on for inspection, when it can rise to the planned flight altitude, the tilt-rotor mechanism rotates the propeller 90° and enters the level flight mode. First, the inspection of channel 1 is carried out. The channel scanning points are as follows: Figure 1As shown in the figure, when the UAV flies horizontally and approaches the designated scanning point of Channel 1, the UAV decelerates, and at the same time, the tilt-rotor mechanism rotates the propeller by 90°. When the propeller reaches the horizontal state, after the high-definition camera, infrared thermal imager, and lidar equipment complete data collection; the tilt-rotor mechanism rotates the propeller by 90°, and the propeller reaches the vertical state. The UAV continues to fly horizontally to the next scanning point and repeats the above steps to complete the inspection operation of all scanning points; that is, the inspection of Channel 1 is completed; repeat the inspection operation steps of Channel 1 to complete the inspection of Channel 2.

[0039] After the inspection of the channel is completed, the UAV docks at the designated position of the pole tower according to the route plan. The pole tower scanning points are as Figure 2 shown. The UAV starts to lift vertically to the pole tower scanning point 1 and hovers. After the high-definition camera, infrared thermal imager, and lidar equipment complete data collection and classify and store it according to the position label, the monitoring and warning system is called to judge abnormal situations. If abnormal situations are found, the abnormal situations need to be immediately transmitted to the terminal platform. After waiting for the confirmation of the terminal platform, the next inspection operation is completed according to the confirmation instruction; the inspection operations of scanning point 2, scanning point 3... up to scanning point 8 are completed respectively.

[0040] After completing the pole tower inspection task, the UAV lifts vertically to the designated height, and at the same time rotates the propeller of the tilt-rotor mechanism by 90°. When the propeller reaches the horizontal state, the UAV returns to the takeoff and landing point.

[0041] In order to ensure that the communication signal is not lost during the inspection process, the inertial navigation (INS) and satellite positioning navigation (GPS) systems are turned on at the same time.

[0042] Among them, the monitoring and warning system can diagnose situations such as wire icing, strand breakage, insulator rupture, and insulator loss for different positions of the inspection. First, it is necessary to construct image feature libraries of key components such as wire icing, strand breakage, insulator rupture, and insulator loss according to different inspection positions respectively, and label them according to the inspection positions. Whether there are faults in the inspection line and pole tower is determined by means of graphic comparison. If a fault is detected, the fault information is uploaded to the terminal platform for warning; its flow chart is as Figure 3 shown, and the flow steps are as follows:

[0043] Step 1: The monitoring and warning system first initializes the system.

[0044] Step 2: Call to collect image sample data, and transmit the scanning point image sample data collected by the high-definition camera, infrared thermal imager, and lidar equipment to the monitoring and warning system memory.

[0045] Step 3: Search for position label information according to the scanning point image sample data.

[0046] Step 4: Call the image feature library of the corresponding scanning point according to the position tag information;

[0047] Step 5: Compare the image sample data with the image feature library to determine whether there is a fault at the scanning point;

[0048] Step 6: If it is determined that there is no fault at the scanning point, generate an inspection report;

[0049] Step 7: If it is determined that there is a fault, it is necessary to determine whether the UAV returns;

[0050] Step 8: If it is confirmed that it is necessary to return, start the UAV return procedure, and the UAV returns to the UAV takeoff and landing point;

[0051] Step 9: If it is confirmed that there is no need to return, generate an inspection report and record the fault information.

[0052] The above monitoring and warning system comprehensively and intelligently analyzes the inspection image data by comparing the image sample data with the image feature library. The information in the image is extracted by first identifying the structure, then the device position tag, and then judging the abnormal situation, and the image is structurally represented, greatly improving the efficiency and accuracy of manual image recognition; the method provided by the present invention can automatically identify abnormal situations such as bird nests, wire icing, broken strands, insulator rupture, insulator missing, foreign object hanging, and insulator damage on transmission lines and towers, and upload warning information to the system platform; this method can also automatically generate an inspection report according to the inspection situation, and at the same time provide an inspection report template to facilitate the generation specifications of reports in different requirements; explore and research the hybrid positioning signal guarantee technology in the UAV inspection operation of transmission lines.

[0053] This method can retrieve inspection images in multiple ways such as line, tower information, device type, fault type, inspection plan, etc. according to requirements, facilitate the search for abnormal situations, and provide historical image backtracking and comparison functions, providing a reliable decision-making basis for fault solution and avoiding fault occurrence;

[0054] The specific inspection operation tasks have the following characteristics:

[0055] It can quickly conduct long-distance and large-area inspections on the transmission line corridor, and timely discover corridor hidden dangers (external damage, mountain fires), such as Figure 1 shown.

[0056] Adopt an 8-point scanning inspection strategy, which can complete fixed-point inspections of power towers, and timely discover defects in towers, fittings, etc., such as Figure 2 shown.

[0057] It has the functions of an intelligent platform and can perform operations such as autonomous charging, fuel replenishment, autonomous inspection, route planning, laser modeling, autonomous graphic analysis, intelligent recognition, and intelligent diagnosis. The operation radius is not less than 150 km.

[0058] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A power inspection method based on a long-endurance hybrid tilt-rotor UAV, characterized in that: include: Design of UAV, including: fuselage, two wings, micro gas turbine hybrid power generation system, two fuel tanks, landing gear, rotor electric power system, communication system, monitoring and warning system, flight control system, high-definition camera, infrared thermal imager and laser radar equipment; The rotor electric power system controls the vertical take-off and horizontal flight of the UAV through the tilt-rotor mechanism; UAV route planning: mark the tower to be inspected and the two adjacent channels of the tower, design the inspection sequence as: channel 1 → channel 2 → tower → return, set scanning points according to the inspection sequence, and complete the UAV route planning by combining the scanning points and the inspection sequence; The drone conducts inspections according to the drone route planning, and the high-definition camera, infrared thermal imager and laser radar equipment send the collected data to the monitoring and alarm system, which diagnoses the data and feeds back the diagnosed fault information to the terminal platform through the communication system; The monitoring and alarm system completes the defect detection of the tower and its channels by comparing the collected data with the sample data.

2. The power inspection method based on a long-endurance hybrid tilt-rotor UAV according to claim 1 is characterized in that: The rotor electric power system is composed of 6 propellers, adopts an upper wing V-tail layout aerodynamic structure, and a tilt-rotor 2+2+2 power mode.

3. The power inspection method based on a long-endurance hybrid tilt-rotor UAV according to claim 1 is characterized in that: In the UAV route planning, the number of scanning points set on the tower is not less than 8, and the number of scanning points in each channel is not less than 4.

4. The power inspection method based on a long-endurance hybrid tilt-rotor UAV according to claim 1 is characterized in that: The communication system is composed of inertial navigation INS and satellite positioning navigation GPS.

5. The power inspection method based on a long-endurance hybrid tilt-rotor UAV according to claim 1 is characterized in that: The drone performs inspection according to the drone route planning, and the inspection process is as follows: 1) Channel inspection: When the UAV is vertically lifted to the planned flight altitude, the tilt-rotor mechanism rotates the propeller 90° and enters the level flight mode. Channel 1 is inspected first. When the UAV approaches the scanning point in channel 1 in level flight, the UAV decelerates and the tilt-rotor mechanism rotates the propeller 90° to a horizontal state. After the high-definition camera, infrared thermal imager and lidar equipment are used to complete data collection, the tilt-rotor mechanism rotates the propeller 90° to a vertical state. The UAV continues to fly level to the next scanning point and repeats the above steps to complete the inspection of all scanning points. The inspection of channel 1 is completed; repeat the inspection steps of channel 1 to complete the inspection of channel 2; 2) Tower inspection: The drone stops at the tower position according to the route planning, and then the drone starts to rise to the tower inspection point 1 and hovers. It uses high-definition cameras, infrared thermal imagers and lidar equipment to complete data collection and classify and store according to location tags, and then calls the monitoring and alarm system to judge abnormal situations. If an abnormal situation is found, the abnormal situation will be transmitted to the terminal platform. After waiting for the terminal platform to confirm, the next inspection operation will be completed according to the confirmation instruction; the inspection operations of scanning point 2, scanning point 3..., to scanning point 8 are completed respectively; The drone is lifted to the specified height, and the propeller of the tilt-rotor mechanism is rotated 90° to the horizontal state, and the drone returns to the take-off and landing point.

6. The power inspection method based on a long-endurance hybrid tilt-rotor UAV according to claim 1 is characterized in that: The monitoring and alarm system diagnoses abnormal conditions at different inspection locations; constructs an image feature library of key components according to different inspection locations, and labels them according to the inspection locations, and determines whether there are faults in the inspection lines and towers through graphic comparison. If a fault is detected, the fault information is uploaded to the terminal platform for alarm.

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