1. The method for correcting the target deviation of the power transmission line based on deep learning and one-hot coding is characterized by comprising the following steps of:

step 1, training a detection model to enable the loss function of the detection model to be minimum under a preset number of training rounds;

step 2, deploying a detection model to unmanned aerial vehicle edge terminal equipment;

step 3, acquiring a video stream of the unmanned aerial vehicle, acquiring a plurality of frame pictures from the video stream, converting the frame pictures into an image with a preset size through scaling, and performing pixel value normalization processing on the image with the preset size;

step 4, inputting the normalized image with the preset size into a detection model for detection;

step 5, outputting the central position of the rectangular detection frame of the target part by the detection model, calculating the central position of the current picture, and comparing the difference between the central position and the current picture to obtain the offset;

and 6, calculating the angle or the moving distance of the cradle head or the unmanned aerial vehicle which needs to rotate in the horizontal and vertical directions based on the offset, and adjusting the navigation attitude of the cradle head or the unmanned aerial vehicle based on the angle or the moving distance until the offset is in accordance with the expectation.

2. The transmission line target deviation rectifying method based on deep learning and one-hot coding as claimed in claim 1, wherein the scaling transformation in the step 3 is specifically:

wherein frameIn the form of an original video frame,resolutionthe size of the image required for the model,f _resize in order to be a function of the scaling of the image,input_frameis a video frame of the scaled input model.

3. The transmission line target deviation rectifying method based on deep learning and one-hot coding of claim 1, wherein the loss function L is:

wherein, y_iRepresenting the true class of the object, f (x)_i) Representing the class of objects predicted by the model,

L_regfor the detection of the box regression loss function, L_clsClassifying a loss function for the detection box;

test frame regression loss function L_regBySmooth _L1 The loss function and the IoU loss function are jointly formed;， ，

in the above two formulaef(x)Representing the prediction detection block output by the model,yrepresenting a real target frame, and the form is (x, y, w, h);intersectionwhich represents the area of the intersection of the two boxes,unionrepresenting the union area of the two boxes.

4. The transmission line target deviation rectifying method based on deep learning and one-hot coding as claimed in claim 1, wherein the offset calculation process specifically comprises:

m and n are the abscissa and the ordinate of the rectangular detection frame of the target part, and u and v are the abscissa and the ordinate of the center of the current picture; the final output is (offset)_m, offset_n) I.e. the offset of the center of the target part from the center of the picture in the horizontal and vertical directions, in pixels.

5. The transmission line target deviation rectifying method based on deep learning and one-hot coding as claimed in claim 1, wherein in step 6, the process of calculating the rotation angle or the movement distance is as follows:

wherein h is a mapping function of converting pixel units to angles, and g is a mapping function of converting pixel units to distance units.

6. The transmission line target deviation rectifying method based on deep learning and one-hot coding of claim 1, further comprising the step 7:

if the offset is less than or equal to the threshold, sending a photographing instruction to finish photographing operation;

judging whether a next waypoint exists or not, and if so, flying to the next waypoint;

if not, ending the task and returning.

7. The transmission line target deviation rectifying method based on deep learning and one-hot coding of claim 1, further comprising the step 8:

after each routing inspection period is finished, the correction information is uploaded to the control platform, the position information of the waypoint is updated, the accuracy is improved, and the correction information comprises routing inspection point information and correction amount corresponding to the routing inspection point; when the unmanned aerial vehicle patrols the navigation again, the deviation rectifying information is sent to the unmanned aerial vehicle.

8. The transmission line target deviation rectifying method based on deep learning and one-hot coding of claim 1, wherein in the step 7, the specific process of flying to the next waypoint is as follows:

initially, a flight trajectory path is constructed:

determining a target to be detected of each point to be detected, taking the target to be detected as a sphere center, determining a diameter based on a space interferent and a shooting distance, constructing a detectable spherical surface by using the sphere center and the diameter, acquiring a detectable domain on the detectable spherical surface through a constraint condition, and determining a plurality of waypoint positions from the detectable domain; obtaining a common tangent plane of adjacent detectable spherical surfaces, wherein the common tangent plane extends to two sides for a preset distance to form a flyable path; connecting each flight path to obtain a continuous flight track;

and flying to the next flight point based on the constructed flight track.

9. Transmission line target deviation correcting system based on deep learning and one-hot coding, its characterized in that includes: a processor and a memory storing computer program instructions; the processor reads and executes the computer program instructions to implement the method of any one of claims 1-8.

10. A computer-readable storage medium having computer program instructions stored thereon which, when executed by a processor, implement the method of any one of claims 1-8.

Background

Unmanned aerial vehicles autonomously fly to patrol the power transmission line and gradually replace manual tower climbing patrol and manual unmanned aerial vehicle patrol.

However, in actual operation, the point location where the precise photographing is needed is missed, which often causes that the inspection task cannot be completed satisfactorily due to insufficient accuracy of manual operation, inaccurate position signals such as GPS or RTK, poor signal strength, signal loss, influence of wind force in the air on the hovering position, and the like.

Disclosure of Invention

The purpose of the invention is as follows: the method comprises the steps of detecting and identifying key parts in each inspection point position, and obtaining the offset required by deviation correction by comparing the central point position of the parts with the central point position of the current picture.

The technical scheme is as follows:

the method for correcting the target of the power transmission line based on deep learning and one-hot coding comprises the following steps:

step 1, training a detection model to enable the loss function of the detection model to be minimum under a preset number of training rounds;

step 2, deploying the detection model to unmanned aerial vehicle edge terminal equipment;

step 3, acquiring a video stream of the unmanned aerial vehicle, acquiring a plurality of frame pictures from the video stream, converting the frame pictures into an image with a preset size through scaling, and performing pixel value normalization processing on the image with the preset size;

step 4, inputting the normalized image with the preset size into a detection model for detection;

step 5, outputting the central position of the rectangular detection frame of the target part by the detection model, calculating the central position of the current picture, and comparing the difference between the central position and the current picture to obtain the offset;

and 6, calculating the angle or the moving distance of the cradle head or the unmanned aerial vehicle which needs to rotate in the horizontal and vertical directions based on the offset, and adjusting the navigation attitude of the cradle head or the unmanned aerial vehicle based on the angle or the moving distance until the offset is in accordance with the expectation.

According to an aspect of the present invention, the scaling transformation in step 3 is specifically:

wherein frameIn the form of an original video frame,resolutionthe size of the image required for the model,f _resize in order to be a function of the scaling of the image,input_frameis a video frame of the scaled input model.

According to one aspect of the invention, the loss function L is:

wherein, y_iRepresenting the true class of the object, f (x)_i) Representing the class of objects predicted by the model,

L_regfor the detection of the box regression loss function, L_clsClassifying a loss function for the detection box;

test frame regression loss function L_regBySmooth _L1 The loss function and the IoU loss function are jointly formed;

in the above two formulaef(x)Representing the prediction detection block output by the model,yrepresenting a real target frame, and the form is (x, y, w, h);intersectionwhich represents the area of the intersection of the two boxes,unionrepresenting the union area of the two boxes.

According to an aspect of the present invention, the offset calculation process specifically includes the following steps:

m and n are the abscissa and the ordinate of the rectangular detection frame of the target part, and u and v are the abscissa and the ordinate of the center of the current picture; the final output is (offset)_m, offset_n) I.e. the deviation of the center of the target part from the center of the picture in the horizontal and vertical directionsThe shift amount is in units of pixels.

According to an aspect of the present invention, in step 6, the process of calculating the angle of rotation or the moving distance is as follows:

wherein h is a mapping function of converting pixel units to angles, and g is a mapping function of converting pixel units to distance units.

According to one aspect of the invention, further comprising step 7:

if the offset is less than or equal to the threshold, sending a photographing instruction to finish photographing operation;

judging whether a next waypoint exists or not, and if so, flying to the next waypoint;

if not, ending the task and returning.

According to one aspect of the invention, further comprising step 8:

after each inspection cycle is completed, the correction information is uploaded to the control platform, the position information of the waypoint is updated, the accuracy is improved, and the correction information comprises inspection point information and correction amount corresponding to the inspection point.

According to an aspect of the present invention, in step 7, the specific procedure of flying to the next waypoint is as follows:

initially, a flight trajectory path is constructed:

determining a target to be detected of each point to be detected, taking the target to be detected as a sphere center, determining a diameter based on a space interferent and a shooting distance, constructing a detectable spherical surface by using the sphere center and the diameter, acquiring a detectable domain on the detectable spherical surface through a constraint condition, and determining a plurality of waypoint positions from the detectable domain; obtaining a common tangent plane of adjacent detectable spherical surfaces, wherein the common tangent plane extends to two sides for a preset distance to form a flyable path; connecting each flight path to obtain a continuous flight track;

and flying to the next flight point based on the constructed flight track.

Further, a power transmission line target deviation correcting system based on deep learning and one-hot coding is provided, which includes: a processor and a memory storing computer program instructions; the processor reads and executes the computer program instructions to implement the above-described method.

There is provided a computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the above-described method.

Has the advantages that: the invention can efficiently and quickly carry out deviation rectification processing on the image and ensure high-quality completion of tasks.

Drawings

FIG. 1 is a flow chart of the present invention.

Fig. 2 is a structural topology diagram of the present invention.

Fig. 3 is a schematic diagram of an embodiment of the present invention.

Fig. 4 is a schematic diagram of another embodiment of the present invention.

Fig. 5 is a schematic diagram of yet another embodiment of the present invention.

1 is the flight track, 2 is the detectable sphere, and 3 is the flyable path.

Detailed Description

Technical details and principles of the present invention are described in detail with reference to fig. 1, 2, 3 and 4.

As shown in fig. 1, for each waypoint, the drone hovers at the waypoint when it reaches a predetermined area. And shooting images or videos through the information acquisition unit, and detecting the target part of the waypoint. And detecting the image or a video frame image captured from the video, judging whether the offset of the center of the target part and the center of the picture in the horizontal direction and/or the vertical direction is larger than a threshold value, if so, indicating that the target part is far away from the center of the image and the shooting posture needs to be adjusted, and at the moment, adjusting the posture by adjusting the holder to obtain an expected shooting angle and obtain a picture with higher quality. And if the current position is not larger than the threshold value, sending a photographing instruction to carry out photographing, then judging whether a next waypoint exists, if the next waypoint does not exist, ending the task, and returning. If the next waypoint exists, flying to the next waypoint, hovering at the waypoint, and repeating the above steps.

In this embodiment, through the preliminary processing and the judgement to the video frame, whether preliminary detection image or video accord with relevant requirement, if do not accord with relevant requirement, carry out the processing of rectifying, until the image accords with the requirement, this scheme avoids finding the image after the return and does not accord with the regulation, and the condition that needs shoot again has improved the efficiency of patrolling the line.

In a further embodiment, the specific process for determining whether the image has skew is as follows.

The deep learning detection model detects the target part in the current picture, and meanwhile, detection results of other parts of the same type and other parts need to be eliminated. The detection result of the detection algorithm on the target is a rectangular detection frame, so that the position (m, n) of the center point of the rectangular detection frame can be calculated. The current picture resolution is a fixed value, so the center position (u, v) of the current picture can also be calculated. The coordinates of the central point of the detection frame and the central point of the picture are obtained, and the current detected coordinate can be calculated

The distance of the part (d) from the center of the screen, i.e., the amount of offset in the horizontal and vertical directions:

if the offset is smaller than the set threshold value, the target part is considered to be in the center of the picture, and the shooting task can be carried out. And if the offset in the horizontal direction or/and the vertical direction is still larger than the threshold value, adjusting the pitching angle or/and the horizontal angle of the holder until the offset is smaller than the threshold value, finishing the adjustment action of the holder, and performing a photographing task. And when all waypoints in the routing inspection task finish the shooting task, finishing the routing inspection task.

In a further embodiment, the process of building a network model for the target detection task is as follows:

for the real-time nature that detects the discernment to the target part when adapting to unmanned aerial vehicle flight, designed lightweight network model: the SPP feature pyramid structure does not adopt any convolution calculation, only uses the maximum value pooling operation, effectively increases the reception field of the backbone feature, and reduces the model calculation amount so as to achieve the purposes of reducing the calculation time and accelerating the calculation.

The SPP feature pyramid structure adopts maximum pooling to replace convolution operation, and has the following advantages:

for the output of the backbone network with larger resolution, a pooling sliding window with larger size is also adopted: when corresponding to the outputs of the second, third and fourth layers of backbone networks, the pooling sliding windows of 13 × 13, 9 × 9 and 5 × 5 are adopted; compared with the traditional characteristic pyramid structure, the size of the convolution kernel is usually 3 x 3 or 5 x 5, and in the design, the size of the pooled sliding window is larger than that of the convolution, so that a larger receptive field can be obtained, and the overall characteristics of the target can be extracted more easily;

when the maximum pooling is used for feature fusion, no calculation parameter needs to be stored in the SPP structure because the pooling does not involve in the calculation of parameters; if the conventional feature pyramid structure is used, even if the output layer of each backbone network passes through only one convolution layer, the parameter number of each convolution layer is k × ic × oc, where k denotes the size of the convolution kernel, ic denotes the number of channels of the input feature vector, and oc denotes the number of channels of the output feature vector. And the features are fused through pooling, the parameter number of the model is 0, and the parameter number of the whole model is greatly reduced, so that the aim of accelerating model operation in lightweight model design is fulfilled.

In other words, the detection model includes a four-level backbone network unit for extracting features, a Spatial Pyramid Pooling unit (SPP) for extracting fixed-size features, and a detection head for outputting results. By designing a larger pooling window, a larger receptive field is obtained.

Because the unmanned aerial vehicle can only allow to rectify a deviation for one target in a picture when flying in the air, in actual operation, multiple kinds of parts and multiple same kinds of parts may appear in the picture. Therefore, in the process of model training, one-hot unique coding is used for training, namely, only the largest part sample in a picture is used as a positive sample, and other parts are used as negative samples.

Specifically, as shown in fig. 4, a total of four insulator strings appear in the screen. In training, only fitting needs to be carried out on the largest insulator string in the current picture, the classification of the insulator string is marked as 1, and the classifications of the other three insulator strings are marked as 0. When the detection network is trained, the one-hot unique code of the image is [1, 0, 0, 0], that is, only the largest target is a positive sample, and the other targets are negative samples. Through the one-hot single-hot coding, the network can automatically learn to find the largest sample in the picture after training, so that the purpose of automatically filtering other parts in inspection is achieved.

The whole process is as follows:

firstly, acquiring a video stream by a cloud deck camera of an unmanned aerial vehicle, and extracting a video frame from the video stream; the video frame is transformed into the image size required by the model through scaling, and the pixel value is normalized,

where frame is the original video frame, resolution is the image size required by the model, f_resizeFor an image scaling function, input _ frame is a video frame of the scaled input model;

inputting the scaled and normalized video frame into a model, and starting a detection task, wherein a loss function of the model is as follows: （1）

wherein L is_regFor the detection of the box regression loss function, L_clsClassifying a loss function for the detection box;

（2）

regression loss of detection frameThe loss function is formed by Smooth_L1The loss function and the IoU loss function are jointly formed; （3）

（4）

in the above two formulas, f (x) represents a prediction detection frame output by the model, y represents a real target frame, and the forms are (x, y, w, h); intersections represents the intersection area of the two frames, and unions represents the union area of the two frames;

（5）

wherein y is_iRepresenting the true class of the object, f (x)_i) Representing the class of objects predicted by the model.

Next, the detection model is trained such that it has a minimum loss function for a certain number of training rounds:

（6）

x denotes an input image and θ denotes model parameters.

Then, calculating the center position (x, y) of the rectangular detection frame of the target part output by the model, calculating the center (u, v) of the current picture, and comparing the difference between the two:

（7）

the final output is (offset)_x, offset_y) The offset of the center of the target part from the center of the picture in the horizontal and vertical directions is taken as a unit;

can learn through the conversion that cloud platform or unmanned aerial vehicle need be at the level and the angle or the displacement distance that need rotate in the vertical direction: （8）

wherein h is a mapping function of converting pixel units to angles, and g is a mapping function of converting pixel units to distance units.

Finally, the unmanned aerial vehicle main control unit obtains Ang_camOr Dist_droneThe rear control holder or the unmanned aerial vehicle sails and looks like the figure

3, correcting the deviation.

It should be noted that, during the initial execution, the process of training the detection model is performed after the picture is acquired. After training is completed, the obtained model is directly deployed on the unmanned aerial vehicle, and the video frames in the video stream collected by the unmanned aerial vehicle can be directly processed without being trained again. Thus, the above steps may be adjusted when performed. Meanwhile, in the training process, after the target part is subjected to the single-hot coding, the maximum sample can be automatically searched in a video frame in the subsequent detection process, and other parts are filtered.

After the model is deployed to the unmanned aerial vehicle, image scaling is carried out on each video frame of a video stream acquired by the unmanned aerial vehicle, the video frame is adjusted to the preset size meeting the requirement of the detection model, then pixel value normalization processing is carried out on the scaled image, normalization is carried out from [0,255] to [0,1], then the video frame after scaling and normalization processing is input into the detection model in real time, and deviation rectification processing is carried out, and the specific process is as described above.

After the deviation rectifying process, in the picture taken at each point location, the key part is located in the center of the picture, and fig. 3 is an example picture. In fig. 3, the left diagram is the insulator cross arm side hanging point of the inspection point location key part before deviation correction. The position of the picture is deviated from the upper left, and the deviation exists between the picture and the central position of the picture in the horizontal direction and the vertical direction; the right picture is the part already in the center of the picture after the deviation correction.

In a further embodiment, if the offset is still larger than the threshold value after the correction, the correction is performed again until the condition is met. And after the conditions are met, sending a photographing instruction to finish photographing operation. In this context, taking a picture is meant to include taking a photograph, as well as taking a video, and then extracting a frame of the video from the video as a photograph.

Therefore, in this embodiment, whether the shooting angle meets the requirement is judged at the waypoint, the images or videos which do not meet the requirement are screened out, after meeting the requirement, the pictures are taken, stored and returned, and the pictures which do not meet the requirement are detected and identified on site. Therefore, through the process, the quality and the qualification rate of the pictures can be greatly improved, and the condition that the pictures are unqualified and need to be shot again after the return voyage is reduced. Through this kind of mode, the efficiency of patrolling the line has been improved greatly.

In further embodiments, the following point identification goal de-skew may be implemented, including: insulator string, insulator cross arm side hanging point, insulator wire side hanging point, ground wire cross arm, whole tower, tower head, tower body, tower footing.

Because in the electric power field of patrolling the line, current patrolling line unmanned aerial vehicle or relevant equipment do not have marginal computing power, can not the on-the-spot quality of tentatively judging the picture, consequently, need to patrol the line and accomplish the back, in case the image quality problem appears, need the secondary to patrol the line and shoot, prolonged the time of patrolling the line greatly, influence and patrol line efficiency. And adopt prior art to patrol the line operation, because can't know the accurate angle of shooing, image quality qualification rate itself is just lower, moreover because can't accurate control shoot the parameter, the quality of image is difficult to improve. And if the existing image recognition algorithm is adopted, the calculated amount is very large, the power consumption is high, the endurance of the unmanned aerial vehicle is influenced, and the line patrol mileage is not high.

For this reason, through above-mentioned embodiment, set up the module of rectifying on unmanned aerial vehicle, judge the quality of image fast through lightweight model, when improving image shooting quality, reduce power consumption, improved unmanned aerial vehicle greatly and patrolled the efficiency of line, reduce the emergence of the repeated line situation of patrolling. Meanwhile, the dependence on manual operation is reduced, and the convenience degree of operation can be greatly improved.

After adopting above-mentioned lightweight image module of rectifying, in order to further reduce the electric quantity consumption, improve inspection distance and efficiency, further optimization scheme is as follows:

after each inspection cycle is completed, the correction information is uploaded to the control platform, the position information of the waypoint is updated, the accuracy is improved, and the correction information comprises inspection point information and correction amount corresponding to the inspection point.

The optimal waypoint position information and the optimal deviation correction information are found through the previous line patrol or a plurality of times, the pictures do not need to be processed again in the subsequent line patrol process, the calculated amount and the energy consumption are reduced, and the overall efficiency of the rear system is improved. Therefore, through upgrading and optimizing the control platform, when the unmanned aerial vehicle subsequently cruises or changes the unmanned aerial vehicle, deviation correction information such as navigation point position information and deviation correction amount can be quickly issued, repeated calculation is not needed, and the cruise efficiency is greatly improved. And obtaining at least one optimal inspection point information and corresponding deviation correction amount through iteration of preset times, and continuously optimizing to improve inspection efficiency and quality.

For example, when an unmanned aerial vehicle is replaced for cruising, relevant deviation correction information is issued, deployed and updated to the unmanned aerial vehicle, the unmanned aerial vehicle flies to a waypoint position in the cruising process, and the posture is adjusted according to the deviation correction amount of the waypoint position to take a picture without or for multiple times of posture adjustment of a holder. The cruising efficiency and the unmanned aerial vehicle management and control efficiency are improved. No matter change an unmanned aerial vehicle or follow-up cruising of same unmanned aerial vehicle, all need not to all rectify the operation at every turn, reduced the power consumption and the time of the process of rectifying, improved efficiency. Through multiple times of processing, the optimal patrol parameters can be obtained, and when the related parameters are more than two, such as two relatively optimal waypoint positions and deviation correction amount, redundant patrol information can be provided.

In a further embodiment, if the subsequent waypoint location information and the deviation correction information change, the new deviation correction information is updated to the control platform, thereby providing new effective information in the subsequent operation.

In a further embodiment, the corrected flight course is optimized in order to further improve the cruising mileage, cruising efficiency and cruising quality.

As shown in fig. 5, under many working conditions, a plurality of targets to be inspected exist at the same inspection point, for example, the same power tower, and in order to take a picture meeting the quality requirement, the targets need to fly around the power tower, so as to find the best shooting position of each target to be inspected. And because the shooting environment often receives the influence of weather, electric wire, can't obtain reaching the optimum shooting point, simultaneously, every detection target shoots, and the route of flight is relatively far away, and every target all needs the operation of rectifying a deviation at least once, therefore the work load of rectifying a deviation still is great, still can influence unmanned aerial vehicle's continuation of the journey. For this purpose, the following scheme is further provided.

And flying to the next flight point based on the constructed flight track.

The process of constructing the flight path (flight path) capable of reducing the flight mileage and the correction workload is specifically as follows:

initially, a flight trajectory path is constructed:

firstly, determining a target to be detected of each point to be detected, determining the diameter or the equatorial radius of an ellipsoid by taking the target to be detected as the spherical center or the ellipsoidal pole diameter based on a spatial interferent and a shooting distance, and constructing a detectable spherical surface by using the spherical center and the diameter or constructing a detectable ellipsoidal surface by using the ellipsoidal pole diameter and the equatorial radius;

as shown in fig. 5, there are 3 targets to be inspected on the power tower on the left side, 2 targets to be inspected on the right side, and different targets to be inspected have a certain distance in space, and when the targets to be inspected are smaller than a predetermined size, the targets to be inspected are regarded as points to be observed, and the diameter is determined based on the working distance of the camera and the space constraint. For example, the preferred working distance of the camera is 5-15 meters, and there is an obstruction of the power line at 8 meters, then a value is selected between 10-15 meters, which is used as the diameter to construct the detectable sphere. Part of the object to be inspected, even if large, may have its physical center selected as the center of sphere as long as it is within a predetermined range.

When a certain size of the object to be detected is larger than a predetermined size, for example, the length of the insulating string is long, and even if the detectable spherical surface is constructed by selecting the midpoint as the center of the sphere, the problem of low local shooting quality also exists.

In this case: the length direction of the ellipse is extended, two end points of the object to be detected are used as focuses of the ellipse, the two sides of the ellipse are extended outwards by a preset length to form a long axis of the ellipse, the shooting distance is used as an equator radius (a short axis on a certain ellipse section), and the ellipse is rotated around the long axis to form an ellipsoid.

Acquiring a detectable domain on the detectable spherical surface through constraint conditions, and determining a plurality of waypoint positions from the detectable domain;

because the detectable sphere that forms, the point on the sphere all is best shooting point not, for example on lower hemisphere, because the shooting angle problem of camera, upwards rotates, may be blocked by the unmanned aerial vehicle body, consequently, can't form better shooting angle, in other shooting region, also can have space constraint or other constraints such as sheltering from or obstacle.

Therefore, the best detection area on the detectable spherical surface may be partial spherical surfaces, the partial spherical surfaces form a detectable domain, and a better waypoint position is calculated based on the detectable domain or is judged through the shot images of different points. At least two shooting positions corresponding to each object to be inspected are formed so as to provide sufficient positions and form allowance.

The processing for an ellipsoid is similar to the processing for a sphere.

Then, a common tangent plane of the adjacent detectable spherical surfaces is obtained, and the common tangent plane extends towards two sides for a preset distance to form a flyable path;

this flyable path is easier to generate between adjacent points to be inspected (in the case of power towers). In the same point to be inspected, different detectable areas of the target to be inspected are firstly calculated to obtain the tangent planes of different detectable spherical surfaces, and then the tangent planes are extended for a preset distance along the direction vertical to the tangent planes to form a flyable path. Since the flyable path is a rectangular solid space, a plurality of flight lines can be generated in the rectangular solid space. If there is a physical obstruction, it can fly in a curved or arc in a rectangular parallelepiped path to avoid the obstruction.

Meanwhile, the non-optimal shooting area of the spherical surface can be detected, but the spherical surface can fly, no flight obstacle exists or the spherical surface can fly in an arc line to bypass the obstacle, so that the construction of a flyable route can not be influenced in the actual path design.

Then, the flight paths are connected to obtain a continuous flight path.

As shown in fig. 5, based on the constructed flyable routes of different detectable spherical surfaces, a connection route is constructed at the end of the flyable route to form at least one flying track, thereby realizing automatic routing inspection.

In a further embodiment, when there is overlap between adjacent detectable spheres, the shooting position and the offset are calculated in the overlap area to achieve shooting of different targets at one position. In the embodiment, the flying distance can be reduced by calculating the flying points, the posture of the holder or the unmanned aerial vehicle can be adjusted by N-1 times or N times of offset at one position, so that a plurality of targets to be detected can be shot, and the flying distance is reduced, wherein N is a natural number.

By the one-hot coding method, even if a plurality of target parts exist in the same picture, one target can be identified and taken as a main target, so that the processing requirements of the image can be met.

In a further embodiment, a shooting interval is planned on a flight route, during the flight, when the unmanned aerial vehicle travels to the shooting interval, a camera and offset parameters relevant to shooting are called to carry out video shooting, and video frames are extracted from video data to serve as image data to be stored.

For example, a plurality of waypoint positions with better shooting angles exist on the detectable spherical surface of a certain target to be detected, the waypoint positions are extended outwards, or different waypoint positions are connected to form a shooting area, and corresponding images meet the requirements in the shooting area, so that the target to be detected can fly along the shooting area and can be directly shot without hovering and standing still. Therefore, if the parameters of the camera or the pan-tilt are required to be adjusted at the relevant position, the parameters can be adjusted before reaching the shooting area, so that shooting can be immediately carried out after reaching the shooting area, and better videos and pictures are formed.

That is to say, in this embodiment, the waypoint position that the preferred was shot can be through constructing detectable sphere, and look for detectable region, find a plurality of shooting position, and form and can collect the preferred shooting and the integrative region of preferred flight, realize in the flight, directly shoot, and need not hover and shoot, improved efficiency of patrolling and examining greatly and shot the quality.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the details of the embodiments, and various equivalent modifications can be made within the technical spirit of the present invention, and the scope of the present invention is also within the scope of the present invention.