Flight obstacle avoidance method for pull line construction of unmanned aerial vehicle

Abstract

The invention discloses a flight obstacle avoidance method for unmanned aerial vehicle pull line construction, and relates to the technical field of unmanned aerial vehicle application, and the method comprises the following steps: obtaining ground surface high-precision point cloud data in a power transmission line and a corridor environment thereof through an unmanned aerial vehicle, and obtaining existing tower coordinate data from a database, and performing vectorization modeling on the working environment of the unmanned aerial vehicle according to the classified coordinate data to obtain an unmanned aerial vehicle flight space model, constructing a three-dimensional database, and planning an unmanned aerial vehicle flight path according to the distribution position of the power transmission line in the three-dimensional database. Marking the obstacle avoidance marking sites on the flight line of the unmanned aerial vehicle one by one to obtain obstacle avoidance point coordinates, and controlling the unmanned aerial vehicle to recover the traction rope along the flight line of the unmanned aerial vehicle; manual operation is replaced by the unmanned aerial vehicle, the unmanned aerial vehicle is matched with the variable-frequency winch, the strain tower take-up task is automatically completed in a cooperative mode, the operation efficiency and safety are improved, and the problems that wire clearing construction is difficult to control, low in efficiency, high in safety risk, high in green claim and the like are solved.

Description

Technical Field

[0001] The invention relates to the technical field of unmanned aerial vehicle application, and in particular to a flight obstacle avoidance method for unmanned aerial vehicle wire construction. Background Art

[0002] The demand for electricity is growing year by year. While many transmission lines are being put into construction and use, there are still a huge number of lines in the domestic power grid that need to be renovated and demolished. For example, old lines in cities, after reaching their service life, are not renovated and updated, which can easily cause broken lines to fall, towers to tilt or break, leading to traffic accidents, property safety accidents, and even serious threats to personal safety. It not only endangers the safe operation of the power system, but also has a bad social impact. In addition, although many transmission lines have not reached their service life, they need to be renovated and demolished due to the increase in regional power load, or new urban construction needs, so they also need to be demolished and buried.

[0003] At present, the dismantling of old power lines is mainly done manually. Not only is the preparation and construction process cumbersome, but also many factors such as safety and environment need to be considered, which consumes a lot of manpower and material resources and increases construction costs. In some environments with poor construction conditions, it is difficult to complete the construction process by manual labor alone because it is inconvenient to install construction equipment under the line. In view of the above technical defects, a solution is now proposed. Summary of the invention

[0004] The purpose of the present invention is to replace manual work with drones, and to use drones in conjunction with variable frequency winches to automatically and collaboratively complete the task of winding up the tension tower, improve work efficiency and safety, and solve the problems of difficult control, low efficiency, high safety risks, and high green compensation during wire removal construction.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a flight obstacle avoidance method for unmanned aerial vehicle wire construction, comprising the following steps: Step 1: Control the drone equipped with laser radar equipment to fly along the transmission line to obtain high-precision point cloud data of the surface of the transmission line and its corridor environment. Use the supporting data processing software to perform POS solution, data fusion and other pre-processing on the laser scanning data, and output point cloud data in a standard format; Step 2: Obtain the existing tower coordinate data from the database, determine the tower position based on the tower coordinate data, and then cut the point cloud data according to a certain channel width based on the influence of the tower position and voltage level on the environment. Cut each file of data into a file to obtain a file-by-file data set; Step 3: Classify the binned data set by machine learning classification algorithm, the binned data includes the coordinate data of power lines, towers, ground points, buildings, and vegetation, and vectorize the working environment of the UAV according to the classified coordinate data to obtain the UAV flight space model. Calculate the sag, the distance data between the hanging point and the tower body according to the UAV flight space model to obtain the coordinates of the obstacle avoidance mark location; Step 4: Obtain the parts structure drawings and parameter descriptions of the drone, power transmission line tower, traction rope, and cable retractor, and build a three-dimensional database based on the parts structure drawings and parameter descriptions; Step 5: Plan the UAV flight route according to the distribution of transmission lines in the three-dimensional database, mark the obstacle avoidance mark locations one by one on the UAV flight route to obtain the coordinates of the obstacle avoidance points, control the UAV to fly along the UAV flight route, and recycle the traction rope through the UAV during the flight, and cooperate with the autonomous control system of the cable retractor to complete the traction rope recovery.

[0006] Furthermore, the specific process of constructing a three-dimensional database is as follows: S101. Import the structural drawings of the parts of the drone, power transmission line tower, traction rope, and cable retractor into the ProE software, build a parameter interface at a 1:1 ratio through the ProE software, plan the frame structure of each part on the parameter interface, and complete the adjustment of the frame structure of each part by adjusting the size; S102. Draw the lines of the frame structure of each part in the view, adjust the model by stretching, punching, rotating and building a reference axis, check and correct the model of each part after the model is established, and use 3DMax software to perform color control and texture correction to ensure the appearance consistency of the model and the original.

[0007] Furthermore, the specific process of recovering the traction rope by drone is as follows: S201, fix the recovery shaft frame equipped with the traction rope drum on the ground of the venue, and control the UAV to take off and hover on the venue; S202, connecting and fixing the rope end of the level I traction rope to the unhooking device below the UAV by a heavy hammer, and controlling the UAV to carry the traction rope and fly over the top of the first base tower; S203, when the drone drags the level I traction rope and flies over the first pole tower, the level I traction rope is passed through the line-laying pulley through the pulley device on the first pole tower, and then the traction rope is hung on the drone, and the drone is continuously controlled to fly to the next pole tower and repeat the above actions until it flies to the planned terminal pole tower, thereby completing the recovery of the level I traction rope; S204. After the recovery of the level I traction rope is completed, the recovery of the subsequent levels of traction ropes is carried out.

[0008] Furthermore, the specific process of completing the recovery of the traction rope between the two towers is as follows S301, after the drone is mounted with a traction rope, it flies from the starting pole tower to the terminal pole tower, and the length of the traction rope is continuously shortened, and the real-time position coordinates of the drone are obtained. S302, calculating the distance data of the traction rope required to be retracted according to the real-time position coordinates of the UAV, generating a parameter signal according to the distance data, and the winch automatically adjusts the speed of reeling in after obtaining the parameter signal to retract the traction rope completely; S303, when the wire-releasing wheel at the tower head is in motion and the traction rope is released, the UAV flies to the terminal tower, completes the traction rope recovery work between the two towers, and then flies to the tower head position of the next tower.

[0009] Furthermore, the specific process of calculating the distance that the traction rope needs to be retracted is as follows: S401, obtain the traction rope tension data F1 and F2 on both sides of the tower head pulley, and obtain the balanced tension data after homogenization ; S402, the balance tension data is negatively correlated with the distance between the two pole towers, and the catenary equation is calculated according to the coordinate positions of the two hanging points on the traction rope and the balance tension data, and then the line shape of the traction rope under the deadweight state is fitted to obtain the distance that the traction rope needs to be retracted.

[0010] Furthermore, an autonomous control system of a cable retractor includes a sensor module, a main control module, a drive module, a controlled module and a user console, wherein: The sensor module is used to measure the tightness of the tethered cable to obtain the measurement results. The measurement results are analyzed to determine the current requirements for the tethered UAV system to retract and release the cable, and the analysis results are sent to the main control module, thereby providing input information for the control scheme of the control system.

[0011] The sensor module is specifically a resistance displacement sensor on the cable retractor mechanical structure inlet and outlet The main control module receives and processes the analysis results, obtains a drive control signal through analysis, and sends the drive control signal to the controlled module; The main control module is specifically an embedded control board, which includes a main control board and an interface expansion board.

[0012] The controlled module receives the driving control signal from the main control module, drives the controlled object to produce corresponding actions, and realizes the retraction and extension operation of the tethered cable; The controlled module includes a wire-releasing component and a wire-retrieving component. The wire-releasing component includes a relay, an electromagnetic clutch and a drone. The wire-retrieving component includes a DC servo motor, a relay and an electromagnetic clutch.

[0013] The user console is used for users to perform related settings and control operations on the tethered drone; The user control console includes a manual / automatic operation switch, a manual drum steering switch, a manual drum speed control knob, a reset switch, and an emergency stop switch.

[0014] The controlled object is used to perform orderly pay-out and take-up operations on the moored cables.

[0015] The controlled object is specifically the roller device in the mechanical structure of the cable retractor. The roller device is driven by a DC servo motor to rotate, and at the same time is disconnected from the DC servo motor and rotates freely under the towing of the drone, thereby realizing the reeling and unreeling operations.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The obstacle avoidance method of the drone in the construction of the line pulling is to replace manual work with the drone, and use the drone to cooperate with the variable frequency winch. The center issues commands to control the drone route and the winch's line-winding speed, and automatically completes the tension tower line-winding task to improve work efficiency and safety, and solve the problems of difficult control, low efficiency, high safety risks, and high compensation for line removal construction. It solves the problem of difficult line removal of overhead lines, improves the construction safety index, simplifies the construction process, and improves work efficiency.

[0017] 2. The obstacle avoidance method of the drone's wire construction is to build a virtual scene of large-span tower assembly of transmission lines by combining the fractal Brownian motion mathematical model with Perlin noise. The Perlin noise obtained by multiple superpositions has strong fractal geometric characteristics. It can be simulated according to the specified transmission line large-span tower assembly data. At the same time, in order to enhance the image processing capability and improve the rendering efficiency, the large-span tower assembly data of the transmission line is divided into blocks according to the quadtree structure, giving full play to the computing function of the graphics processor, reducing the amount of data transmission between the video memory and the main memory, improving the parallel processing performance between the graphics processor and the central processing unit, improving the efficiency of drawing triangles, and enhancing the rendering effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The overall method flow diagram of the present invention is shown; Figure 2 A schematic diagram showing the process of recovering the traction rope of the drone of the present invention is shown; Figure 3 A schematic diagram of the structure of the autonomous control system of the cable retractor of the present invention is shown. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0020] like Figure 1-3 As shown, a flight obstacle avoidance method for UAV wire construction includes the following steps: Step 1: Control the drone equipped with laser radar equipment to fly along the transmission line to obtain high-precision point cloud data of the surface of the transmission line and its corridor environment. Use the supporting data processing software to perform POS solution, data fusion and other pre-processing on the laser scanning data, and output point cloud data in a standard format; Step 2: Obtain the existing tower coordinate data from the database, determine the tower position based on the tower coordinate data, and then cut the point cloud data according to a certain channel width based on the influence of the tower position and voltage level on the environment. Cut each file of data into a file to obtain a file-by-file data set; Step 3: Classify the binned data set by machine learning classification algorithm, the binned data includes the coordinate data of power lines, towers, ground points, buildings, and vegetation, and vectorize the working environment of the UAV according to the classified coordinate data to obtain the UAV flight space model. Calculate the sag, the distance data between the hanging point and the tower body according to the UAV flight space model to obtain the coordinates of the obstacle avoidance mark location; Step 4: Obtain the parts structure drawings and parameter descriptions of the drone, power transmission line tower, traction rope, and cable retractor, and build a three-dimensional database based on the parts structure drawings and parameter descriptions; The specific process of building a three-dimensional database is as follows: S101. Import the structural drawings of the parts of the drone, power transmission line tower, traction rope, and cable retractor into the ProE software, build a parameter interface at a 1:1 ratio through the ProE software, plan the frame structure of each part on the parameter interface, and complete the adjustment of the frame structure of each part by adjusting the size; S102. Draw the lines of the frame structure of each part in the view, adjust the model by stretching, punching, rotating and building a reference axis, check and correct the model of each part after the model is established, and use 3DMax software to perform color control and texture correction to ensure the appearance consistency of the model and the original.

[0021] A virtual scene of large-span tower assembly of transmission lines is constructed by combining the fractal Brownian motion mathematical model with Perlin noise. The Perlin noise obtained by multiple superpositions has strong fractal geometric characteristics. It can be simulated based on the specified large-span tower assembly data of transmission lines. At the same time, in order to enhance the image processing capability and improve the rendering efficiency, the large-span tower assembly data of transmission lines is divided into blocks according to the quadtree structure, giving full play to the computing function of the graphics processor, reducing the amount of data transmission between video memory and internal memory, improving the parallel processing performance between the graphics processor and the central processing unit, improving the efficiency of drawing triangles, and enhancing the rendering effect.

[0022] Step 5: Plan the UAV flight route according to the distribution of transmission lines in the three-dimensional database, mark the obstacle avoidance mark locations one by one on the UAV flight route to obtain the coordinates of the obstacle avoidance points, control the UAV to fly along the UAV flight route, and recycle the traction rope through the UAV during the flight, and cooperate with the autonomous control system of the cable retractor to complete the traction rope recovery.

[0023] The specific process of recovering the traction rope by drone is as follows: S201, fix the recovery shaft frame equipped with the traction rope drum on the ground of the venue, and control the UAV to take off and hover on the venue; S202, connecting and fixing the rope end of the level I traction rope to the unhooking device below the UAV by a heavy hammer, and controlling the UAV to carry the traction rope and fly over the top of the first base tower; S203, when the drone drags the level I traction rope and flies over the first pole tower, the level I traction rope is passed through the line-laying pulley through the pulley device on the first pole tower, and then the traction rope is hung on the drone, and the drone is continuously controlled to fly to the next pole tower and repeat the above actions until it flies to the planned terminal pole tower, thereby completing the recovery of the level I traction rope; S204. After the recovery of the level I traction rope is completed, the recovery of the subsequent levels of traction ropes is carried out.

[0024] The specific process of completing the recovery of the traction rope between two towers is as follows S301, after the drone is mounted with a traction rope, it flies from the starting pole tower to the terminal pole tower, and the length of the traction rope is continuously shortened, and the real-time position coordinates of the drone are obtained. S302, calculating the distance data of the traction rope required to be retracted according to the real-time position coordinates of the UAV, generating a parameter signal according to the distance data, and the winch automatically adjusts the speed of reeling in after obtaining the parameter signal to retract the traction rope completely; S303, when the wire-releasing wheel at the tower head is in motion and the traction rope is released, the UAV flies to the terminal tower, completes the traction rope recovery work between the two towers, and then flies to the tower head position of the next tower.

[0025] The specific process for calculating the distance the traction rope needs to be retracted is as follows: S401, obtain the traction rope tension data F1 and F2 on both sides of the tower head pulley, and obtain the balanced tension data after homogenization ; S402, the balance tension data is negatively correlated with the distance between the two pole towers, and the catenary equation is calculated according to the coordinate positions of the two hanging points on the traction rope and the balance tension data, and then the line shape of the traction rope under the deadweight state is fitted to obtain the distance that the traction rope needs to be retracted.

[0026] An autonomous control system for a cable retractor, the autonomous control system comprising a sensor module, a main control module, a drive module, a controlled module and a user console, wherein: The sensor module is used to measure the tightness of the tethered cable to obtain the measurement results. The measurement results are analyzed to determine the current requirements for the tethered UAV system to retract and release the cable, and the analysis results are sent to the main control module, thereby providing input information for the control scheme of the control system.

[0027] The sensor module is specifically a resistance displacement sensor on the cable retractor mechanical structure inlet and outlet The main control module receives and processes the analysis results, obtains a drive control signal through analysis, and sends the drive control signal to the controlled module; The main control module is specifically an embedded control board, which includes a main control board and an interface expansion board.

[0028] The controlled module receives the driving control signal from the main control module, drives the controlled object to produce corresponding actions, and realizes the retraction and extension operation of the tethered cable; The controlled module includes a wire-releasing component and a wire-retrieving component. The wire-releasing component includes a relay, an electromagnetic clutch and a drone. The wire-retrieving component includes a DC servo motor, a relay and an electromagnetic clutch.

[0029] The user console is used for users to perform related settings and control operations on the tethered drone; The user control console includes a manual / automatic operation switch, a manual drum steering switch, a manual drum speed control knob, a reset switch, and an emergency stop switch.

[0030] The controlled object is used to perform orderly pay-out and take-up operations on the moored cables.

[0031] The controlled object is specifically the roller device in the mechanical structure of the cable retractor. The roller device is driven by a DC servo motor to rotate, and at the same time is disconnected from the DC servo motor and rotates freely under the towing of the drone, thereby realizing the reeling and unreeling operations.

[0032] The present invention uses drones to replace manual work, and uses drones to cooperate with variable frequency winches. The center issues commands to control the drone route and the winch winding speed, and automatically completes the tension tower winding task to improve work efficiency and safety, solving the problems of difficult control, low efficiency, high safety risks, and high green compensation during wire removal construction. It solves the problem of difficult wire removal of overhead lines, improves the construction safety index, simplifies the construction process, and improves work efficiency.

[0033] The size of the interval and threshold is set to facilitate comparison. The size of the threshold depends on the amount of sample data and the number of bases set by technical personnel in this field for each group of sample data; as long as it does not affect the proportional relationship between the parameter and the quantized value.

[0034] The above formulas are all dimensionless and numerical calculations. The formula is a formula obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formula are set by technicians in this field according to actual conditions. The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A flight obstacle avoidance method for UAV wire construction, characterized in that: The following steps are involved: Step 1: Control the drone equipped with laser radar equipment to fly along the transmission line to obtain high-precision point cloud data of the surface of the transmission line and its corridor environment. Use the supporting data processing software to perform POS solution, data fusion and other pre-processing on the laser scanning data, and output point cloud data in a standard format; Step 2: Obtain the existing tower coordinate data from the database, determine the tower position based on the tower coordinate data, and then cut the point cloud data according to a certain channel width based on the influence of the tower position and voltage level on the environment. Cut each file of data into a file to obtain a file-by-file data set; Step 3: Classify the binned data set by machine learning classification algorithm, the binned data includes the coordinate data of power lines, towers, ground points, buildings, and vegetation, and vectorize the working environment of the UAV according to the classified coordinate data to obtain the UAV flight space model. Calculate the sag, the distance data between the hanging point and the tower body according to the UAV flight space model to obtain the coordinates of the obstacle avoidance mark location; Step 4: Obtain the parts structure drawings and parameter descriptions of the drone, power transmission line tower, traction rope, and cable retractor, and build a three-dimensional database based on the parts structure drawings and parameter descriptions; Step 5: Plan the UAV flight route according to the distribution of transmission lines in the three-dimensional database, mark the obstacle avoidance mark locations one by one on the UAV flight route to obtain the coordinates of the obstacle avoidance points, control the UAV to fly along the UAV flight route, and recycle the traction rope through the UAV during the flight.

2. The flight obstacle avoidance method for UAV wire construction according to claim 1 is characterized in that: The specific process of building a three-dimensional database is as follows: S101. Import the structural drawings of the parts of the drone, power transmission line tower, traction rope, and cable retractor into the ProE software, build a parameter interface at a 1:1 ratio through the ProE software, plan the frame structure of each part on the parameter interface, and complete the adjustment of the frame structure of each part by adjusting the size; S102. Draw the lines of the frame structure of each part in the view, adjust the model by stretching, punching, rotating and building a reference axis, check and rectify the model of each part after the model is established, and perform color control and texture correction on it through 3DMax software.

3. The flight obstacle avoidance method for UAV wire construction according to claim 1 is characterized in that: The specific process of recovering the traction rope by drone is as follows: S201, fix the recovery shaft frame equipped with the traction rope drum on the ground of the venue, and control the UAV to take off and hover on the venue; S202, connecting and fixing the rope end of the level I traction rope to the unhooking device below the UAV by a heavy hammer, and controlling the UAV to carry the traction rope and fly over the top of the first base tower; S203, when the drone drags the level I traction rope and flies over the first pole tower, the level I traction rope is passed through the line-laying pulley through the pulley device on the first pole tower, and then the traction rope is hung on the drone, and the drone is continuously controlled to fly to the next pole tower and repeat the above actions until it flies to the planned terminal pole tower, thereby completing the recovery of the level I traction rope; S204. After the recovery of the level I traction rope is completed, the recovery of the subsequent levels of traction ropes is carried out.

4. The flight obstacle avoidance method for UAV wire construction according to claim 3 is characterized in that: The specific process of completing the recovery of the traction rope between two towers is as follows S301, after the drone is mounted with a traction rope, it flies from the starting tower to the terminal tower to obtain the real-time position coordinates of the drone. S302, calculating the distance data of the traction rope required to be retracted according to the real-time position coordinates of the UAV, generating a parameter signal according to the distance data, and the winch automatically adjusts the speed of reeling in after obtaining the parameter signal to retract the traction rope completely; S303, when the wire-releasing wheel at the tower head is in motion and the traction rope is released, the UAV flies to the terminal tower, completes the traction rope recovery work between the two towers, and then flies to the tower head position of the next tower.

5. The flight obstacle avoidance method for UAV wire construction according to claim 4 is characterized in that: The specific process for calculating the distance the traction rope needs to be retracted is as follows: S401, obtain the traction rope tension data F1 and F2 on both sides of the tower head pulley, and obtain the balanced tension data after homogenization ; S402, the balance tension data is negatively correlated with the distance between the two pole towers, and the catenary equation is calculated according to the coordinate positions of the two hanging points on the traction rope and the balance tension data, and then the line shape of the traction rope under the deadweight state is fitted to obtain the distance that the traction rope needs to be retracted.

6. The flight obstacle avoidance method for UAV wire construction according to claim 1, characterized in that: An autonomous control system for a cable retractor, the autonomous control system comprising a sensor module, a main control module, a drive module, a controlled module and a user console, wherein: The sensor module is used to measure the tightness of the tethered cable to obtain the measurement results. By analyzing the measurement results, the current requirements for the tethered UAV system to retract and release the cable are determined, and the analysis results are sent to the main control module. The main control module receives and processes the analysis results, obtains a drive control signal through analysis, and sends the drive control signal to the controlled module; The controlled module receives the driving control signal from the main control module, drives the controlled object to produce corresponding actions, and realizes the retraction and extension operation of the tethered cable; The user console is used for users to perform related settings and control operations on the tethered drone; The controlled object is used to perform orderly pay-out and take-up operations on the moored cables.

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