A power transmission and distribution pole composite cross arm unmanned aerial vehicle hoisting replacement method and system

Abstract

The application relates to a power transmission and distribution pole composite cross arm unmanned aerial vehicle hoisting replacement method and system, and relates to the technical field of pole cross arm assembly. The method comprises the following steps: acquiring a hoop pose parameter of a hoop; controlling the unmanned aerial vehicle to hoist the cross arm according to the hoop pose parameter, so that the cross arm is initially aligned with the hoop; acquiring an initial alignment trigger signal; controlling the unmanned aerial vehicle to hoist the cross arm according to the initial alignment trigger signal, so that the cross arm is accurately aligned with the hoop; acquiring an accurate alignment trigger signal; and prompting an operator to fix the cross arm on the hoop by using bolts according to the accurate alignment trigger signal. The application has the effect of improving the convenience of cross arm replacement.

Description

Technical Field

[0001] This application relates to the technical field of pole crossarm assembly, and in particular to a method and system for UAV hoisting and replacement of composite crossarms of power transmission and distribution poles. Background Technology

[0002] Composite crossarms for power transmission and distribution towers are a type of support structure used in power transmission lines. They are mainly made of high-performance composite materials and serve the dual functions of structural load-bearing and electrical insulation.

[0003] In related technologies, as the service life of the lines increases, the crossarms of old towers suffer from corrosion, aging, fatigue cracking and other problems, so they need to be replaced and maintained regularly. Currently, manual tower climbing is usually used in conjunction with large machinery such as truck cranes and crawler cranes for hoisting.

[0004] Regarding the aforementioned technologies, for crossarm replacement in complex terrains such as mountains, hills, swamps, and woodlands, large machinery such as truck cranes and crawler cranes have difficulty entering the site, resulting in difficulties in maintaining the tower crossarms, long power outage times, and inconvenience in crossarm replacement. There is still room for improvement. Summary of the Invention

[0005] To improve the ease of crossarm replacement, this application provides a method and system for UAV hoisting and replacement of composite crossarms on power transmission and distribution towers.

[0006] Firstly, this application provides a method for unmanned aerial vehicle (UAV) hoisting and replacement of composite crossarms on power transmission and distribution towers, employing the following technical solution: A method for replacing composite crossarms of power transmission and distribution towers using unmanned aerial vehicles (UAVs) includes: Obtain the clamp pose parameters; The UAV is controlled to lift the crossarm according to the clamp position parameters so that the crossarm and clamp are initially aligned; Obtain the initial alignment trigger signal; The drone is controlled to hoist the crossarm according to the initial alignment trigger signal so that the crossarm and the clamp are precisely aligned; Obtain a precise alignment trigger signal; Based on the precise alignment trigger signal, the operator is prompted to use bolts to secure the crossarm to the clamp.

[0007] Optionally, the steps of controlling the UAV to hoist the crossarm according to the initial alignment trigger signal to achieve precise alignment between the crossarm and the clamp include: The sling detection tension and the corresponding sling decomposition angle are obtained based on the initial alignment trigger signal; The tension and angle of the sling were analyzed to determine the amount of adjustment needed to stabilize the sling's posture. The drone is controlled to extend and retract the slings based on the sling stability attitude adjustment amount to stabilize the crossarm attitude. The drone is used to pre-process the clamps and crossarm to determine the precise alignment angle parameters when hoisting the crossarm. The precision alignment angle parameters are analyzed to determine the amount of adjustment required for precise sling alignment. The drone is controlled to adjust the slings according to the precise alignment adjustment amount, so that the crossarm is precisely aligned with the clamp.

[0008] Optionally, the steps of analyzing the sling tension and sling decomposition angle to determine the sling stability attitude adjustment amount include: The steady-state wind disturbance force components are determined based on the tension of the suspension cable and the angle of the cable decomposition. The tension of the slings was analyzed to determine the components of the dynamic gust disturbance force. The sum of the steady-state wind disturbance force component and the dynamic gust wind disturbance force component is calculated to generate the equivalent wind disturbance force of the suspender. The product of the equivalent wind disturbance force of the sling and the preset sling adjustment gain coefficient is calculated to generate the sling stability attitude adjustment amount.

[0009] Optionally, the steps of analyzing the tension of the slings to determine the dynamic gust disturbance components include: Determining the dynamic fluctuation component of tension based on the tension detected by the sling; Obtain the baseline sling tension and sling load-bearing weight; The tension and load-bearing weight of the reference sling are analyzed to generate the gust disturbance force conversion coefficient; The product of the tension dynamic fluctuation component and the gust disturbance conversion coefficient is calculated to generate the dynamic gust disturbance component.

[0010] Optionally, the steps of controlling the drone to pre-process the clamps and crossarm to determine the precise alignment angle parameters include: The drone is controlled to hoist the crossarm according to the preset friction pretreatment parameters to pretreat the clamps and crossarm. Obtain the additional contact force of the pretreated foreign object, the actual detected contact force, and the corresponding circumferential angle of the contact force; Based on the preset pitch angle model, the additional contact force of the pre-processed foreign object, the actual detected contact force and the corresponding contact force circumferential angle are calculated to generate the pitch direction angle. Based on the preset deflection direction model, the additional contact force of the pre-processed foreign object, the actual detected contact force, and the corresponding circumferential angle of the contact force are calculated to generate the deflection direction angle. Associate the pitch and yaw angles to generate precise alignment angle parameters.

[0011] Optionally, the step of controlling the UAV to hoist the crossarm according to preset friction pretreatment parameters to pretreat the clamps and crossarm includes: The drone is controlled to lift the crossarm according to the friction pretreatment parameters so that the clamp and the crossarm rub against each other to remove impurities; The drone is controlled to lift the crossarm according to the preset secondary contact parameters so that the clamp and the crossarm make contact again, and the measured contact force parameters are obtained. Determine the peak value and average value of the measured contact force based on the measured contact force parameters; The measured peak contact force and the measured average contact force are analyzed to determine the relative deviation of the foreign object contact force; When the relative deviation of the foreign object contact force exceeds the preset reference deviation threshold, a preset polishing prompt message is output to prompt the user until the relative deviation of the foreign object contact force does not exceed the reference deviation threshold.

[0012] Optionally, the step of using bolts to secure the crossarm to the clamp, based on the precise alignment trigger signal prompting the operator, includes: The residual deflection angle amplitude is obtained based on the precise alignment trigger signal; The residual deflection angle magnitude is analyzed to generate a corrected tightening torque; Based on the tightening torque instructions, the operator uses bolts to secure the crossarm to the clamp.

[0013] Optionally, the step of analyzing the residual deflection angle magnitude to generate the corrected tightening torque includes: The residual deflection angle amplitude, the preset bolt reference diameter, and the preset bolt reference length are analyzed to determine the residual deflection angle torque amplification factor. The residual deflection torque amplification factor and the preset tightening friction factor are analyzed to generate the deflection torque correction factor; Calculate the product of the deflection angle torque correction factor and the preset reference tightening torque to generate the corrected tightening torque.

[0014] Secondly, this application provides a UAV hoisting and replacement system for composite crossarms of power transmission and distribution towers, which adopts the following technical solution: A UAV-based lifting and replacement system for composite crossarms of power transmission and distribution towers includes: The acquisition module is used to acquire the clamp pose parameters, initial alignment trigger signal, and precise alignment trigger signal; A memory for storing a program for a method of replacing a composite crossarm of a power transmission and distribution tower by unmanned aerial vehicle (UAV) as described in any of the preceding claims; The processor and the program in the memory can be loaded and executed by the processor to implement a method for replacing composite crossarms of power transmission and distribution towers by UAV as described in any of the above.

[0015] In summary, this application includes at least one of the following beneficial technical effects: 1. By controlling the drone to hoist the crossarm and align it with the clamp on the tower, the operator is instructed to use bolts to fix the crossarm to the clamp. This adapts to different terrains, reduces the difficulty of crossarm maintenance and replacement, and improves the convenience of crossarm replacement. 2. By controlling the sling stability attitude adjustment amount, the drone can retract and extend the sling, thereby overcoming the interference of external environmental wind on the attitude of the crossarm. Then, based on the precise alignment adjustment amount of the sling, the drone can retract and extend the sling, so that the screw holes of the crossarm correspond precisely with the screw holes on the clamp. There will be no excessive deviation angle, which would cause the crossarm to be unable to be stably fixed on the clamp even after the bolt is tightened to the set torque, thereby improving the stability of the crossarm assembly. 3. After analyzing and calculating the residual deflection angle amplitude, the corrected tightening torque is obtained, and the corrected tightening torque is output to prompt the operator to tighten the bolts with this torque. The influence of the angular deviation between the crossarm bolt hole and the clamp bolt hole on the fixed crossarm and clamp is fully considered, thereby improving the stability of the crossarm assembly. Attached Figure Description

[0016] Figure 1 This is a flowchart of a method for replacing the composite crossarm of a power transmission and distribution tower using a drone, as described in an embodiment of this application.

[0017] Figure 2 This is a flowchart of the steps in this application embodiment to control the UAV to hoist the crossarm according to the initial alignment trigger signal so that the crossarm and the clamp are precisely aligned.

[0018] Figure 3 This is a flowchart of the steps in this application embodiment to analyze the tension of the sling detection and the sling decomposition angle to determine the amount of sling stability attitude adjustment.

[0019] Figure 4 This is a flowchart of the steps in this application embodiment to analyze the tension of the sling detection to determine the dynamic gust disturbance component.

[0020] Figure 5 This is a flowchart of the steps in this application embodiment for controlling the UAV to preprocess the clamps and crossarm to determine the precise alignment angle parameters when hoisting the crossarm.

[0021] Figure 6 This is a flowchart of the steps in this application embodiment to control the UAV to hoist the crossarm according to preset friction pretreatment parameters in order to pretreat the clamp and the crossarm.

[0022] Figure 7 This is a flowchart of the steps in this application embodiment where the operator is prompted to use bolts to fix the crossarm to the clamp based on the precise alignment trigger signal.

[0023] Figure 8This is a flowchart of the steps in this application embodiment to analyze the residual deflection angle amplitude to generate a corrected tightening torque. Detailed Implementation

[0024] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figures 1 to 8 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the application.

[0025] Reference Figure 1 This application discloses a method for replacing composite crossarms of power transmission and distribution towers using unmanned aerial vehicles (UAVs), comprising the following steps: Step S100: Obtain the clamp pose parameters.

[0026] The clamp pose parameters are a set of data on the clamp's position and attitude parameters in space, including the three-dimensional spatial coordinates of the clamp flange and its pitch and yaw angles. These parameters provide data support for the UAV to align the crossarm with the clamp. In one embodiment, at least three non-collinear visual markers are set on the clamp surface. After the UAV approaches the clamp flange, an onboard binocular vision camera acquires an image of the clamp flange. After distortion correction of the clamp flange image, the pixel coordinates of the visual markers are extracted from the corrected image. A laser ranging module then detects the straight-line distance from the UAV to the clamp flange. Based on the parallax principle of binocular vision and the pixel coordinates of the visual markers, the three-dimensional coordinates of each visual marker in the camera coordinate system are calculated. Then, based on the known relative positional relationship of each visual marker on the clamp flange, coordinate system transformation converts the three-dimensional coordinates of each visual marker in the camera coordinate system into the three-dimensional position coordinates, pitch angle, and yaw angle of the clamp flange in the world coordinate system. In another embodiment, the clamp flange can be scanned by a lidar mounted on a drone to obtain three-dimensional point cloud data of the clamp flange. After filtering, segmenting and feature extraction of the point cloud data, the geometric features on the clamp flange are identified. Based on the extracted geometric features, the center position and axial direction of the clamp are fitted, and then the three-dimensional position coordinates, pitch angle and yaw angle of the clamp are calculated.

[0027] Step S101: Control the UAV to hoist the crossarm according to the clamp pose parameters so that the crossarm and clamp are initially aligned.

[0028] After obtaining the clamp's position and attitude parameters, the four ends of the crossarm are fixed to the UAV via four slings. The slings can be independently controlled by a servo winch to control the pitch and yaw angles of the crossarm. After the UAV lifts the crossarm and takes off, the UAV's flight control system uses its own positioning system and sling attitude sensors to detect the current position and attitude parameters of the crossarm in real time. Then, it compares these parameters with the clamp's position and attitude parameters to calculate the positional and angular deviations between the crossarm and the clamp. These deviations are used as inputs to a PID controller. After PID calculation, the controller outputs the UAV's position adjustment and the sling adjustment. The UAV is then moved according to the position adjustment to reduce the positional deviation between the crossarm and the clamp. The servo winch is then adjusted according to the sling adjustment to reduce the angular deviation between the crossarm and the clamp. The initial alignment of the crossarm and the clamp is completed when the positional and angular deviations are less than the set thresholds.

[0029] Step S102: Obtain the initial alignment trigger signal.

[0030] The initial alignment trigger signal is a trigger signal to determine the initial alignment of the crossarm and the clamp. It indicates that the coarse alignment has been completed and the precise alignment can begin, thereby eliminating the problem that the rated torque cannot fix the crossarm and the clamp due to the position and angle deviation of the crossarm and the clamp. After the UAV flight control system calculates the difference between the crossarm attitude parameters and the clamp attitude parameters in real time, it activates the initial alignment trigger signal when it determines that the difference is within the set threshold range.

[0031] Step S103: Control the UAV to hoist the crossarm according to the initial alignment trigger signal so that the crossarm and the clamp are precisely aligned.

[0032] Upon receiving the initial alignment trigger signal, the processing terminal initiates the precise alignment process between the crossarm and the clamp. This involves controlling the drone to hoist the crossarm to ensure precise alignment between the crossarm and the clamp, further reducing the pitch and yaw angle deviations between them. This achieves a tight fit between the crossarm flange and the clamp flange, as well as coaxial bolt holes. For specific methods, refer to [reference needed]. Figure 2 The steps.

[0033] Step S104: Obtain the precise alignment trigger signal.

[0034] The precise alignment trigger signal is the trigger signal for precise alignment between the crossarm and the clamp, indicating that the pitch and yaw angle deviations between the crossarm and the clamp are extremely small. The crossarm and clamp can be fixed with bolts. Whether to output is determined by angle conditions and fit uniformity conditions. The fit is calculated by dividing the difference between the maximum and minimum contact forces by the average contact force, after ensuring that the pitch and yaw angles of the crossarm and clamp are both less than the maximum residual attitude yaw angle, and by using the contact force to obtain the contact force reference. Figure 5The actual method for obtaining the contact force in the steps will not be elaborated here. When the fit is determined to be less than the fit uniformity threshold, the precise alignment trigger signal is activated.

[0035] Step S105: Based on the precise alignment trigger signal, the operator is prompted to use bolts to fix the crossarm to the clamp.

[0036] Upon receiving the precise alignment trigger signal, it indicates that the crossarm and clamp are precisely aligned and can be secured with bolts. Therefore, after correcting the set torque based on the residual deflection angle, the operator is prompted to use bolts to fix the crossarm to the clamp according to the corrected torque, thereby improving the stability of the fixation. For specific methods, refer to [link to relevant documentation]. Figure 7 The steps.

[0037] Reference Figure 2 The steps for controlling the UAV to hoist the crossarm according to the initial alignment trigger signal to achieve precise alignment between the crossarm and the clamp include: Step S200: Obtain the sling detection tension and the corresponding sling decomposition angle based on the initial alignment trigger signal.

[0038] Upon receiving the initial alignment trigger signal, the process of precise alignment begins. This requires overcoming environmental interference to stabilize the crossarm before precisely aligning it with the clamp. Therefore, the tension of the sling and the corresponding sling decomposition angle are detected to provide data support for determining the degree of external interference and facilitate its elimination.

[0039] The tension of the slings used for hoisting the crossarm by the UAV is measured. The degree of external wind disturbance can be determined by the change in the tension of the slings. In this embodiment, four slings are used to hoist the crossarm. Each sling is equipped with an S-shaped tension sensor to detect the tension of the sling in real time. The sampling frequency is greater than 50Hz, thereby ensuring accurate detection of environmental wind disturbance.

[0040] The sling decomposition angle is the spatial angle between the sling and the vertical direction. The sling decomposition angle is used to decompose the sling tension into the degree of external wind disturbance. It is obtained by the inverse cosine function value of the quotient of the height difference between the two ends of the sling at the processing terminal and the real-time length of the sling.

[0041] Step S201: Analyze the tension and angle of the sling to determine the adjustment amount for the sling's stable posture.

[0042] The sling stability adjustment amount refers to the adjustment amount of the sling length to overcome external wind interference and maintain the stability of the crossarm. Each sling is adjusted independently, and the result is obtained by the processing terminal through analysis and calculation of the sling detection tension and sling decomposition angle. The specific method is described in [reference needed]. Figure 3 The steps.

[0043] Step S202: Control the UAV to extend and retract the sling according to the sling stability attitude adjustment amount to stabilize the crossarm attitude.

[0044] After determining the adjustment amount for the stable attitude of the sling, the processing terminal controls the servo winch corresponding to the sling to adjust the crossarm to stabilize the attitude of the sling, so that the force applied by the sling to the crossarm can counteract the external wind disturbance force, ensuring the stability of the crossarm attitude and facilitating precise alignment.

[0045] Step S203: Control the UAV to hoist the crossarm and pre-process the clamp and crossarm to determine the precise alignment angle parameters.

[0046] In this process, after stabilizing the attitude of the crossarm, the drone is controlled to hoist the crossarm, allowing the crossarm and clamp to rub against each other for pre-treatment. This removes foreign objects from the surface of the crossarm and clamp, preventing them from affecting the accuracy of the angle detection between the crossarm and clamp. It also ensures that foreign objects do not cause inaccurate docking between the crossarm and clamp, resulting in unstable fixation. The pre-treatment yields accurate alignment angle parameters, providing data support for the angle correspondence between the crossarm and clamp.

[0047] The precise alignment parameters are the current deflection angles between the crossarm and the clamp, including the pitch angle and the yaw angle. The pitch angle is the angular deviation between the crossarm and the clamp along its length, and the yaw angle is the angular deviation between the crossarm and the clamp along its circumferential rotation direction. For specific determination methods, refer to [reference needed]. Figure 5 The steps.

[0048] Step S204: Analyze the precision alignment angle parameters to determine the precision alignment adjustment amount of the sling.

[0049] The precise alignment adjustment amount of the slings is the adjustment length of the slings that ensures the minimum deflection angle between the crossarm and the clamp. The four slings are arranged symmetrically in a rectangle at the four ends of the crossarm. The line connecting the front and rear slings corresponds to the pitch direction, and the line connecting the left and right slings corresponds to the deflection direction. Therefore, the pitch direction deflection angle in the precise alignment deflection angle parameter corresponds to the height difference between the front and rear sling suspension points. The distance between the front and rear sling suspension points is the length of the crossarm. Therefore, the displacement of the front suspension point is half the product of the positive pitch direction deflection angle and the crossarm length, and the displacement of the rear suspension point is half the product of the negative pitch direction deflection angle and the crossarm length. Similarly, the deflection direction deflection angle in the precise alignment deflection angle parameter corresponds to the height difference between the left and right sling suspension points. The distance between the left and right sling suspension points is the width of the crossarm. Therefore, the displacement of the left suspension point is half the product of the positive deflection direction deflection angle and the crossarm width, and the displacement of the right suspension point is half the product of the negative deflection direction deflection angle and the crossarm width. To ensure a smooth adjustment process, a sampling proportional-integral control algorithm is used to calculate the deviation and output the final precise alignment adjustment amount of the slings.

[0050] Step S205: Control the drone to adjust the sling according to the precise alignment adjustment amount so that the crossarm is precisely aligned with the clamp.

[0051] After determining the precise alignment adjustment amount of the slings, the pitch angle is adjusted first. Based on the pitch adjustment amount corresponding to the precise alignment adjustment amount of the slings, the two slings on the front are simultaneously retracted / released, and the two slings on the rear are simultaneously retracted / released, so that the angles of the crossarm and the clamp in the pitch direction correspond. Then, the deflection angle is adjusted. Based on the deflection adjustment amount corresponding to the precise alignment adjustment amount of the slings, the two slings on the left are simultaneously retracted / released, and the two slings on the right are simultaneously retracted / released, so that the angles of the crossarm and the clamp in the deflection direction correspond. After the adjustment is completed, the angles of the crossarm and the clamp correspond, and the additional torque loss caused by the angular misalignment of the crossarm and the clamp is minimized when the bolts are used to fix the crossarm and the clamp.

[0052] Reference Figure 3 The steps for analyzing the tension and angle of the sling to determine the adjustment amount for sling stability include: Step S300: Determine the steady-state wind disturbance force components based on the detected tension of the sling and the angle of sling decomposition.

[0053] Among them, the steady-state wind disturbance force component is the disturbance force of the continuous external wind on the crossarm. In the suspended state, the suspension point of the sling has no acceleration in the horizontal direction, and the net external force is zero. Therefore, the vertical component of the sling tension is used to bear the weight of the crossarm, while the horizontal component of the sling tension is used to balance the disturbance force of the external wind. Therefore, the steady-state wind disturbance force component can be obtained by calculating the product of the sine of the sling decomposition angle and the sling detection tension.

[0054] Step S301: Analyze the tension of the sling to determine the dynamic gust disturbance component.

[0055] The dynamic gust disturbance component is the interference force of external dynamic gusts on the crossarm, which is obtained by the processing terminal after analyzing and calculating the tension of the suspension cable. The specific method is as follows: Figure 4 The steps.

[0056] Step S302: Calculate the sum of the steady-state wind disturbance force component and the dynamic gust wind disturbance force component to generate the equivalent wind disturbance force of the sling.

[0057] Among them, the equivalent wind disturbance force of the sling is the total equivalent wind disturbance force of the external wind on the crossarm. The processing terminal adds the steady-state wind disturbance force component and the dynamic gust disturbance force component to cover both continuous wind and gust conditions, thus ensuring the accuracy of the sling adjustment length.

[0058] Step S303: Calculate the product of the equivalent wind disturbance force of the sling and the preset sling adjustment gain coefficient to generate the sling stable attitude adjustment amount.

[0059] The sling adjustment gain coefficient is a linear mapping coefficient from the equivalent wind disturbance force of a single sling to the sling length adjustment, reflecting the sling extension and retraction length required to offset a unit size of wind disturbance force. The unit is mm / N. It is obtained through experimental calibration: In a controlled wind field environment, the crossarm is placed in a suspended state, and the state of the sling is consistent with the actual working conditions. Then, a stable wind field is turned on at a set wind speed, with the initial gain coefficient set at 0.1 mm / N. The gain coefficient is gradually increased until the observed crossarm amplitude drops to the minimum. The gain coefficient at this point is determined as the sling gain coefficient. Then, the wind speed is changed to verify the adaptability of the gain coefficient at different wind speeds. When the adaptability is poor, the gain coefficient of the corresponding stage can be determined by segmenting the wind speed. The actual gain coefficient used is determined by detecting the wind speed under the working conditions.

[0060] The sling stability attitude adjustment amount in this step is the same as that in step S201. The adjustment length of the sling is obtained by the product of the equivalent wind disturbance force of the sling and the adjustment gain coefficient of the sling calculated by the processing terminal. Each sling is calculated independently, and the vector is formed after combination, which is the sling stability attitude adjustment amount.

[0061] Reference Figure 4 The steps for analyzing the tension of the slings to determine the dynamic gust disturbance components include: Step S400: Determine the dynamic fluctuation component of tension based on the tension detected by the sling.

[0062] Among them, the tension dynamic fluctuation component is the high-frequency oscillation component caused by gusts in the tension of the sling. When the crossarm is subjected to gusts, it enters an accelerated swing process, at which time the tension exhibits a high-frequency oscillation component. A first-order high-pass digital filter is used to filter the tension of the sling, thereby filtering out the low-frequency steady-state component and retaining the high-frequency tension dynamic fluctuation component. In this embodiment, the cutoff frequency of the first-order high-pass digital filter is sampled at 0.5Hz, corresponding to the typical duration of the gust.

[0063] Step S401: Obtain the reference sling tension and sling load.

[0064] The reference sling tension is the tension on the sling during steady-state lifting in windless conditions. It can be obtained by calculating the cosine of the angle between the sling and the vertical reference, and then dividing one-quarter of the crossarm weight by the cosine of the angle between the sling and the vertical reference.

[0065] The load-bearing capacity of a sling is the weight of the crossarm borne by each sling, which is one-quarter of the crossarm weight.

[0066] Step S402: Analyze the reference sling tension and sling load to generate gust disturbance conversion coefficients.

[0067] Among them, the gust disturbance force conversion coefficient is the proportional coefficient that converts the tension fluctuation amplitude into horizontal wind disturbance force. It is obtained by calculating the quotient of the load-bearing weight of the sling and the tension of the reference sling. The tension of the reference sling is used to bear the load-bearing weight of the sling. By calculating the quotient of the load-bearing weight of the sling and the tension of the reference sling, the proportion of weight converted into tension can be clearly defined.

[0068] Step S403: Calculate the product of the tension dynamic fluctuation component and the gust disturbance conversion coefficient to generate the dynamic gust disturbance component.

[0069] In this step, the dynamic wind disturbance component is the same as that in step S301. It is obtained by calculating the product of the tension dynamic fluctuation component and the gust disturbance conversion coefficient by the processing terminal. When the crossarm is disturbed by gusts, the lateral linear acceleration generates a component in the axial direction of the sling, which causes the tension to fluctuate dynamically. Under the small angle approximation, the quotient of the tension dynamic fluctuation component and the reference sling tension is equal to the quotient of the lateral linear acceleration and the gravitational acceleration. The dynamic gust disturbance component is equal to the product of the sling bearing mass and the lateral linear acceleration. After combining the two and eliminating the lateral linear acceleration, we get the dynamic gust disturbance component, which is equal to the product of the tension dynamic fluctuation component and the quotient of the sling bearing weight and the reference sling tension, that is, the product of the tension dynamic fluctuation component and the gust disturbance conversion coefficient.

[0070] Reference Figure 5 The steps for controlling the drone to hoist the crossbeam and pre-process the clamps and crossbeam to determine the precise alignment angle parameters include: Step S500: Control the UAV to hoist the crossarm according to the preset friction pretreatment parameters to pretreat the clamp and crossarm.

[0071] Among them, the friction pretreatment parameters are parameters that control the friction between the crossarm and the clamp to remove foreign objects, including feed speed, contact force threshold, circumferential swing angle and swing period, etc. The specific values ​​are set by the operator according to the actual situation.

[0072] The UAV controls the crossarm to approach the clamp along the normal direction of the clamp at a feed speed corresponding to the friction pretreatment parameters. When the thin-film pressure sensor on the clamp detects that the contact force reaches the contact force threshold, the feed stops. Then, according to the circumferential swing angle and swing period corresponding to the friction pretreatment parameters, the crossarm is controlled to swing circumferentially back and forth along the clamp normal, thereby causing the clamp and crossarm to rub against each other to remove surface dust, rust debris, and other impurities. This avoids affecting the accuracy of subsequent contact force-based angle analysis and the degree of contact between the crossarm and clamp due to impurities. For specific methods, refer to [link to relevant documentation]. Figure 6 The steps.

[0073] Step S501: Obtain the pre-treated foreign object's additional contact force, the actual detected contact force, and the corresponding contact force circumferential angle.

[0074] The actual contact force detected is the contact force between the crossarm and the clamp after pretreatment. Multiple thin-film pressure sensors are evenly distributed circumferentially on the clamp flange surface. After pretreatment, the UAV moves the crossarm again, causing the crossarm and the clamp to swing and contact again. When the crossarm swings to different positions, the corresponding pressure sensor detects the contact force between the crossarm and the clamp.

[0075] The additional contact force due to foreign objects is the additional contact force between the crossarm and the clamp caused by the foreign object. After the processing terminal calculates the average value of the actual detected contact force, it calculates the absolute value of the difference between the actual detected contact force and the average contact force, which reflects the additional contact force of the foreign object at this location.

[0076] The circumferential angle of the contact force is the circumferential angle of the actual detected contact force on the clamp flange. It is determined during the installation of the diaphragm pressure sensor and is linked to the output of the actual detected contact force.

[0077] Step S502: Based on the preset pitch angle model, calculate the additional contact force of the pre-processed foreign object, the actual detected contact force, and the corresponding circumferential angle of the contact force to generate the pitch direction angle.

[0078] The pitch angle model is used to calculate the pitch direction deflection angle, and its specific expression is as follows: .

[0079] In the formula, The pitch angle is the deflection angle. The preset diameter of the sensor distribution circle. The preset sensor equivalent stiffness coefficient, For the first One sensor, This represents the total number of sensors. For the first The actual contact force detected by each sensor No. Pre-treatment of foreign objects by each sensor with additional contact force. No. The circumferential angle of the contact force of each sensor.

[0080] The diameter of the sensor distribution circle is the same as that of the thin-film pressure sensor, and is directly measured by the operator when setting up the sensor.

[0081] The sensor equivalent stiffness coefficient is the linear proportionality coefficient between the sensor's axial deformation and the output contact force. It is obtained through experimental calibration: using the same thin-film pressure sensor, the axial compression displacement is gradually applied to the sensor at a set speed, and the output force value under different displacements is recorded. Multiple uniformly distributed calibration points are selected to plot the displacement-force curve and perform linear fitting. The slope of the fitted straight line is the sensor equivalent stiffness coefficient.

[0082] When the two flanges of the crossarm and the clamp are in contact at a slight angle, the contact pressure is linearly distributed along the circumference. Correspondingly, on the sensors evenly arranged circumferentially, the contact force is distributed as a cosine function. Assuming the pitch angle is... The diameter of the sensor distribution circle is Then, the circumferential angle of any contact force on the distribution circle is... The axial contact deformation at the location is When a thin-film pressure sensor operates within its elastic range, the contact force and deformation satisfy Hooke's Law: After association, we get When a foreign object is present on the flange surface, the contact force is equal to the sum of the contact force generated by the rigid body deflection angle and the additional contact force from the foreign object. Therefore, the contact force corresponding to the true deflection angle is equal to the measured value minus the additional value, i.e. By performing a cosine-weighted summation on the full-circumference sensor, we obtain... When the sensors are uniformly distributed circumferentially, the summation of the orthogonal functions satisfies Therefore, the above model is obtained after sorting.

[0083] The pitch angle is the angle between the crossarm flange and the clamp flange in the pitch direction. The larger the angle, the worse the alignment accuracy between the crossarm and the clamp, and the greater the torque loss when the clamp and crossarm are fixed with bolts. The pitch angle is calculated by the processing terminal by substituting the pre-treated foreign object additional contact force, the actual detected contact force and the corresponding contact force circumferential angle into the pitch angle model.

[0084] Step S503: Calculate the additional contact force of the pre-processed foreign object, the actual detected contact force, and the corresponding circumferential angle of the contact force based on the preset deflection direction model to generate the deflection direction angle.

[0085] The deflection direction model is a model for calculating the deflection direction and angle, and its specific expression is as follows: .

[0086] In the formula, The deflection angle is the direction of the deflection. The preset diameter of the sensor distribution circle. The preset sensor equivalent stiffness coefficient, For the first One sensor, This represents the total number of sensors. For the first The actual contact force detected by each sensor No. Pre-treatment of foreign objects by each sensor with additional contact force. No. The circumferential angle of the contact force of each sensor.

[0087] The principle of this model is the same as that of the pitch and yaw model, except that the cosine weights are replaced with sine weights, and the orthogonal yaw direction components are extracted, thereby decoupling the pitch and yaw directions for calculation.

[0088] The deflection angle is the angle between the crossarm flange and the clamp flange in the deflection direction. The larger the angle, the worse the alignment accuracy between the crossarm and the clamp, and the greater the torque loss when the clamp and crossarm are fixed with bolts. It is calculated by the processing terminal by substituting the pre-treated foreign object additional contact force, the actual detected contact force and the corresponding contact force circumferential angle into the deflection direction model.

[0089] Step S504: Associate the pitch direction deflection and yaw direction deflection to generate precise alignment deflection parameters.

[0090] In this step, the precise alignment angle parameter is the same as that in step S203. The processing terminal combines the pitch direction angle and the yaw direction angle to form a two-dimensional angle vector.

[0091] Reference Figure 6 The steps for controlling the UAV to hoist the crossarm according to preset friction pretreatment parameters to pretreat the clamps and crossarm include: Step S600: Control the UAV to hoist the crossarm according to the friction pretreatment parameters so that the clamp and the crossarm rub against each other to remove impurities.

[0092] The UAV controls the crossarm to approach the clamp along the normal direction of the clamp with the feed speed corresponding to the friction pretreatment parameters. When the thin film pressure sensor on the clamp detects that the contact force reaches the contact force threshold, the feed stops. Then, according to the circumferential swing angle and swing period corresponding to the friction pretreatment parameters, the crossarm is controlled to swing circumferentially along the clamp normal, so that the clamp and the crossarm rub against each other to remove surface impurities such as floating dust, rust debris and other impurities.

[0093] Step S601: Control the UAV to hoist the crossarm according to the preset secondary contact parameters so that the clamp and the crossarm make contact again, and obtain the measured contact force parameters.

[0094] The secondary contact parameter is a contact parameter used to determine whether the pretreatment is complete. The difference between it and the friction pretreatment parameter is that there is no need to feed the crossarm; it is only necessary to control the circumferential reciprocating swing of the crossarm.

[0095] After pretreatment, the UAV is controlled to continue driving the crossarm to circumferentially reciprocate based on the secondary contact parameters. At this time, the crossarm continues to rub against the clamp, and the measured contact force parameters are detected, thus providing data support for determining whether the influence of foreign objects is minimized.

[0096] The measured contact force parameter is the actual value of the contact force during the secondary contact process between the crossarm and the clamp, which is detected and output by a thin-film pressure sensor.

[0097] Step S602: Determine the peak value and average value of the measured contact force based on the measured contact force parameters.

[0098] Among them, the measured peak contact force is the maximum contact force during the secondary contact process between the crossarm and the clamp, which is determined by the processing terminal after comparing the contact force in the measured contact force parameters.

[0099] The average measured contact force is the average contact force during the secondary contact process between the crossarm and the clamp, which is obtained by the processing terminal after averaging the contact force in the measured contact force parameters.

[0100] Step S603: Analyze the measured peak contact force and the measured average contact force to determine the relative deviation of the foreign object contact force.

[0101] Among them, the relative deviation of foreign object contact force is the proportion of the contact force caused by the foreign object that exceeds the average contact force. It is obtained by calculating the difference between the measured peak contact force and the measured average contact force and the quotient of the measured average contact force. The larger the relative deviation of foreign object contact force, the larger the size of the foreign object.

[0102] Step S604: When the relative deviation of the foreign object contact force exceeds the preset reference deviation threshold, output the preset polishing prompt information to prompt until the relative deviation of the foreign object contact force does not exceed the reference deviation threshold.

[0103] The reference deviation threshold is the minimum deviation that determines whether foreign objects will affect the accuracy of the crossarm and clamp angle analysis and the stability of the fixation. For example, 30% is used as the reference deviation threshold.

[0104] When the processing terminal determines that the relative deviation of the foreign object contact force exceeds the reference deviation threshold, it indicates that the foreign object is too large and will cause the clamp and crossarm to not fit properly. Therefore, a grinding prompt message is output to remind the operator to grind the contact surface of the clamp and crossarm until the relative deviation of the foreign object contact force does not exceed the reference deviation threshold.

[0105] Reference Figure 7 The steps for securing the crossbeam to the clamp using bolts, based on the precise alignment trigger signal, include: Step S700: Obtain the residual deflection angle amplitude based on the precise alignment trigger signal.

[0106] When a precise alignment trigger signal is received, it indicates that the crossarm and clamp are aligned. At this time, the set torque can be directly sampled to prompt the operator to fix the crossarm and clamp with bolts. However, there will still be a slight deflection angle when the crossarm and clamp are aligned. The torque obtained after correcting the set torque based on the slight deflection angle is more stable for fixing the crossarm and clamp. Therefore, the residual deflection angle amplitude is detected.

[0107] The residual deflection amplitude is the amplitude of the tiny deflection angle that exists after the crossarm and the clamp are aligned. After determining the pitch angle and yaw angle through the contact force, the residual deflection amplitude can be obtained by taking the square root of the sum of the squares of the two.

[0108] Step S701: Analyze the residual deflection angle magnitude to generate the corrected tightening torque.

[0109] The corrected tightening torque is the torque adjusted based on the slight misalignment between the crossarm and the clamp during alignment. It is obtained by analyzing the residual misalignment amplitude using the processing terminal. For specific methods, please refer to [link / reference needed]. Figure 8 The slight misalignment between the crossarm and the clamp during the alignment process will generate additional frictional resistance torque, resulting in insufficient actual preload under the same torque.

[0110] Step S702: Based on the corrected tightening torque prompt, the operator uses bolts to secure the crossbeam to the clamp.

[0111] After determining the correct tightening torque, the system provides text and voice prompts to the operator, instructing them to use a torque wrench to tighten the bolts onto the flanges of the crossarm and clamp, thereby securing the crossarm to the clamp.

[0112] Reference Figure 8 The steps for analyzing the residual deflection angle magnitude to generate the corrected tightening torque include: Step S800: Analyze the residual deflection angle amplitude, the preset bolt reference diameter, and the preset bolt reference length to determine the residual deflection angle torque amplification factor.

[0113] The bolt reference diameter is the diameter of the bolt, and the bolt reference length is the length of the bolt, which is obtained by the operator measuring the bolt being used.

[0114] The residual deflection angle torque amplification factor is the relative proportion of the additional torque caused by the small deflection angle of the crossarm and the clamp. It is obtained by calculating the product of the residual deflection angle amplitude and the bolt reference diameter and the quotient of twice the bolt reference length.

[0115] Step S801: Analyze the residual deflection torque amplification factor and the preset tightening friction factor to generate the deflection torque correction factor.

[0116] The tightening friction coefficient is the friction coefficient between the bolt and the flange, which is obtained by fitting a friction test using a sample made of the same material as the flange and the bolt.

[0117] The deflection angle torque correction factor is the amplification factor of a small deflection angle on the reference tightening torque. It is obtained by multiplying the residual deflection angle torque amplification factor and the tightening friction coefficient by 1, calculated by the processing terminal. During bolt rotation, the equivalent radial slip of the support surface is proportional to the deflection angle, with the maximum slip being... , The reference diameter of the bolt. The residual deflection angle amplitude and the relative slip ratio are given. , The reference length of the bolt, and the additional frictional resistance torque. Positive pressure Multiply by the coefficient of friction Multiply by the equivalent radius of action, i.e. Under ideal fit conditions, the relationship between tightening torque and preload is as follows: , The torque coefficient, taking into account the effects of thread friction and bearing surface friction, is calibrated under ideal conditions. Therefore, the ratio of the additional torque to the reference torque is... .

[0118] The equivalent radius of action is the relative radial slip effect of the support surface caused by the residual deflection angle amplitude of the bolt. In torque calculation, the equivalent conversion characteristic length reflects the degree by which the bolt has deviated from the residual deflection angle amplitude. This is equivalent to the friction force acting on an additional lever arm with a length equal to the equivalent radius of action. Therefore, the additional torque can be determined by calculating the product of the friction force and the equivalent radius of action.

[0119] Step S802: Calculate the product of the deflection angle torque correction coefficient and the preset reference tightening torque to generate the corrected tightening torque.

[0120] The reference tightening torque is the torque required for the bolts to stably fix the crossarm and clamp under ideal fit conditions, which is obtained by the operator through actual measurement.

[0121] The corrected tightening torque in this step is the same as the corrected tightening torque in step S701, and is obtained by the processing terminal by calculating the product of the deflection angle torque correction coefficient and the reference tightening torque.

[0122] Based on the same inventive concept, embodiments of this application provide a UAV hoisting and replacement system for composite crossarms of power transmission and distribution towers, comprising: The acquisition module is used to acquire the clamp position parameters, initial alignment trigger signal, precise alignment trigger signal, sling detection tension, sling decomposition angle, reference sling tension, sling load-bearing weight, pre-treated foreign object additional contact force, actual detection contact force, contact force circumferential angle, measured contact force parameters, and residual deflection angle amplitude. A memory for storing a program for a method of replacing composite crossarms of power transmission and distribution towers using a drone; The processor and memory can load and execute programs to implement a method for replacing composite crossarms of power transmission and distribution towers using unmanned aerial vehicles (UAVs).

[0123] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0124] This application provides a computer-readable storage medium storing a computer program that can be loaded by a processor and executed as a method for unmanned aerial vehicle (UAV) hoisting and replacing composite crossarms of power transmission and distribution towers.

[0125] Computer storage media include, for example, USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media that can store program code.

[0126] Based on the same inventive concept, this application provides a smart terminal, including a memory and a processor. The memory stores a computer program that can be loaded and executed by the processor to perform a method for unmanned aerial vehicle (UAV) hoisting and replacement of composite crossarms of power transmission and distribution towers.

[0127] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0128] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Any feature disclosed in this specification (including the abstract and drawings) may be replaced by other equivalent or similar features unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is only one example of a series of equivalent or similar features.

Claims

1. A method for unmanned aerial vehicle (UAV) hoisting and replacement of composite crossarms on power transmission and distribution towers, characterized in that, include: Obtain the clamp pose parameters; The UAV is controlled to lift the crossarm according to the clamp position parameters so that the crossarm and clamp are initially aligned; Obtain the initial alignment trigger signal; The drone is controlled to hoist the crossarm according to the initial alignment trigger signal so that the crossarm and the clamp are precisely aligned; Obtain a precise alignment trigger signal; Based on the precise alignment trigger signal, the operator is prompted to use bolts to secure the crossarm to the clamp; The steps for controlling the UAV to hoist the crossarm according to the initial alignment trigger signal to achieve precise alignment between the crossarm and the clamp include: The sling detection tension and the corresponding sling decomposition angle are obtained based on the initial alignment trigger signal; The tension and angle of the sling were analyzed to determine the amount of adjustment needed to stabilize the sling's posture. The drone is controlled to extend and retract the slings based on the sling stability attitude adjustment amount to stabilize the crossarm attitude. The drone is used to pre-process the clamps and crossarm to determine the precise alignment angle parameters when hoisting the crossarm. The precision alignment angle parameters are analyzed to determine the amount of adjustment required for precise sling alignment. The drone is controlled to adjust the sling release and retraction based on the precise alignment of the sling to ensure that the crossarm is precisely aligned with the clamp. The steps for controlling a drone to hoist a crossbeam and pre-process the clamps and crossbeam to determine the precise alignment angle parameters include: The drone is controlled to hoist the crossarm according to the preset friction pretreatment parameters to pretreat the clamps and crossarm. Obtain the additional contact force of the pretreated foreign object, the actual detected contact force, and the corresponding circumferential angle of the contact force; Based on the preset pitch angle model, the additional contact force of the pre-processed foreign object, the actual detected contact force and the corresponding contact force circumferential angle are calculated to generate the pitch direction angle. Based on the preset deflection direction model, the additional contact force of the pre-processed foreign object, the actual detected contact force, and the corresponding circumferential angle of the contact force are calculated to generate the deflection direction angle. Associate the pitch and yaw angles to generate precise alignment angle parameters; The steps for securing the crossarm to the clamps using bolts, based on the precise alignment trigger signal, include: The residual deflection angle amplitude is obtained based on the precise alignment trigger signal; The residual deflection angle magnitude is analyzed to generate a corrected tightening torque; Based on the tightening torque instructions, the operator uses bolts to secure the crossarm to the clamp.

2. The method for UAV hoisting and replacement of composite crossarms on power transmission and distribution towers according to claim 1, characterized in that, The steps for analyzing the tension and angle of the sling to determine the adjustment amount for sling stability include: The steady-state wind disturbance force components are determined based on the tension of the suspension cable and the angle of the cable decomposition. The tension of the slings was analyzed to determine the components of the dynamic gust disturbance force. The sum of the steady-state wind disturbance force component and the dynamic gust wind disturbance force component is calculated to generate the equivalent wind disturbance force of the suspender. The product of the equivalent wind disturbance force of the sling and the preset sling adjustment gain coefficient is calculated to generate the sling stability attitude adjustment amount.

3. The method for unmanned aerial vehicle (UAV) hoisting and replacement of composite crossarms on power transmission and distribution towers according to claim 2, characterized in that, The steps for analyzing the tension of the slings to determine the dynamic gust disturbance components include: Determining the dynamic fluctuation component of tension based on the tension detected by the sling; Obtain the baseline sling tension and sling load-bearing weight; The tension and load-bearing weight of the reference sling are analyzed to generate the gust disturbance force conversion coefficient; The product of the tension dynamic fluctuation component and the gust disturbance conversion coefficient is calculated to generate the dynamic gust disturbance component.

4. The method for unmanned aerial vehicle (UAV) hoisting and replacement of composite crossarms on power transmission and distribution towers according to claim 1, characterized in that, The steps for controlling the UAV to hoist the crossarm according to preset friction pretreatment parameters to pretreat the clamps and crossarm include: The drone is controlled to lift the crossbeam according to the friction pretreatment parameters so that the clamp and the crossbeam rub against each other to remove impurities. The drone is controlled to lift the crossarm according to the preset secondary contact parameters so that the clamp and the crossarm make contact again, and the measured contact force parameters are obtained. Determine the peak value and average value of the measured contact force based on the measured contact force parameters; The measured peak contact force and the measured average contact force are analyzed to determine the relative deviation of the foreign object contact force; When the relative deviation of the contact force of the foreign object exceeds the preset reference deviation threshold, a preset polishing prompt message is output to prompt until the relative deviation of the contact force of the foreign object does not exceed the reference deviation threshold.

5. The method for unmanned aerial vehicle (UAV) hoisting and replacement of composite crossarms on power transmission and distribution towers according to claim 1, characterized in that, The steps for analyzing the residual deflection angle magnitude to generate the corrected tightening torque include: The residual deflection angle amplitude, the preset bolt reference diameter, and the preset bolt reference length are analyzed to determine the residual deflection angle torque amplification factor. The residual deflection torque amplification factor and the preset tightening friction factor are analyzed to generate the deflection torque correction factor; Calculate the product of the deflection angle torque correction factor and the preset reference tightening torque to generate the corrected tightening torque.

6. A UAV hoisting and replacement system for composite crossarms of power transmission and distribution towers, characterized in that, include: The acquisition module is used to acquire the clamp pose parameters, initial alignment trigger signal, and precise alignment trigger signal; A memory for storing a program for a method of replacing a composite crossarm of a power transmission and distribution tower by UAV as described in any one of claims 1 to 5; The processor and the program in the memory can be loaded and executed by the processor to implement the method for UAV hoisting and replacement of composite crossarms of power transmission and distribution towers as described in any one of claims 1 to 5.

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