TWI720510B - Aircraft line-following control method and flight control method using the method - Google Patents

Abstract

The present invention provides a line-following control method of an aircraft, which is mainly to first subdivide a segmented image in the center of an image frame to generate multiple subdivided images, determine a flight direction according to the probability value of each subdivided image appearing to follow a target, and calculate Follow the center point of the target in the flight direction to determine a virtual flight coordinate based on the center point; while the flight control method first divides the image screen into multiple segmented images, and determines a flying direction according to the probability of each segmented image following the target. If the flight direction area is in the center of the screen, the line following control method is executed to generate a flight instruction; the present invention first determines the flight direction of the following target, and then further calculates the precise flight coordinates to achieve high-precision lines Follow the flight control.

Description

Aircraft line-following control method and flight control method using the method

A line-following control method for an aircraft and a flight control method using the method, in particular to a flight control method that implements high-precision line following by using a virtual target azimuth grid probability model.

In recent years, unmanned aerial vehicles have been widely used in difficult-to-reach spaces for image capture or environmental surveys. In addition to manual operation of the flight direction by personnel, the control method that enables unmanned aerial vehicles to automatically perform flight tasks according to specific conditions can greatly save manpower. And reduce human error of judgment. Among them, making the unmanned aerial vehicle fly along a following target is a frequently used flying method, such as image capturing and surveying along a river. The existing line following control of the aircraft does not require good accuracy along the line, that is to say, it is only required to control the aircraft to advance along the approximate direction of the line extension. For example, the existing control method is to first capture the image where the target follows the line, calculate the extension direction of the target follow line based on the image, and control the aircraft to move along the direction in which the target follows the line. When it is judged that the direction of the line changes, the aircraft is controlled to steer toward a steering angle according to the new extension direction, so as to fly along the new extension direction. However, if the direction of line extension is not completely consistent with the actual extension direction of the following target due to calculation errors based on the captured images, when the aircraft flies toward the calculated extension direction, the aircraft will deviate from the position of the following target. Even if the flight direction is corrected again according to the next calculation, the aircraft has already deviated from the position of the following target, and as a result, the unstable situation of flying sway or snaking occurs. If the above deviation from the following target is too large, the aircraft may completely lose the target.

In addition, the method of changing the following direction by turning is mainly to follow the lines on the plane below the aircraft. If the line to be followed is located on a front vertical plane, for example, the following target is a crack to be scanned on the wall of a building, high-voltage electrical tower inspection, equipment security inspection of skyscraper exterior walls, or wind turbine blade inspection, etc. , Because the height of these equipment or buildings is relatively high and poses a certain degree of risk to the mission executors, it is safer to use drones for missions. In these tasks, since it must move along a vertical plane, the aircraft cannot change the forward direction by turning the plane, because this will cause the aircraft to lose the line it is following in front of it, or to turn to the part of the line it has already followed. It can be seen from the above that the prior art control method of controlling the aircraft to turn on a horizontal plane by detecting the extension direction of the line to change the flying direction is not suitable for the application environment of following the line on the vertical plane. Therefore, the prior art line follow control method of the aircraft It is necessary to make further improvements and seek feasible solutions.

In view of the low accuracy of the flight control of the existing aircraft line following, when the detection and judgment error occurs, the flight will sway and snake, and when the error is serious, it will shift or lose the target. Therefore, the present invention provides an aircraft line following that can improve the accuracy. The control method. The main technical means adopted to achieve the foregoing objective is to make the foregoing method be executed by an aircraft controller. The aircraft line-following control method includes the following steps: subdividing a segmented image in the center of an image frame to generate a majority Determine the probability value of a following target in each of the subdivided images; determine a flight direction according to the probability value of each subdivided image, and calculate a center point of the following target in the flight direction; according to The center point of the following target determines a virtual flight coordinate.

According to the above-mentioned line-following control method, the following target is placed in the center of the image frame, that is, the center position the aircraft is aimed at at this time, and the split image in the center of the image frame is subdivided to produce multiple smaller ones. Divide the image again. Further, the flight direction is determined according to the probability values of the individual following targets in the multiple subdivided images in the center of the image frame, the center point of the following target in the flying party is calculated, and a virtual flight coordinate is determined accordingly.

In other words, the probability value of the multiple subdivided images of the following target in the center of the screen determines a flight direction, so that the aircraft can actually move in the direction of the following target, and maintain the image of the following target on the aircraft. Center; further, because the virtual flight coordinates are determined according to a center point of the following target, that is, the center point is bound to be within the range of the following target, so the aircraft can accurately advance toward the virtual flight coordinates, and Ensure that the aircraft does not deviate from the area of the following target, achieving high-precision line tracking.

In addition, the present invention also provides an aircraft control method using the above-mentioned line-following control method, which is executed by an aircraft and includes the following steps: capturing an image frame, dividing the image frame into a plurality of segmented images; judging each segment A probability value of following the target appears in the image; a flying direction area is determined according to the probability value of following the target in each segmented image; when the flying direction area is located in a segmented image in the center of the image frame, the segmented image is performed Subdivide to generate a majority of subdivided images; determine the probability value of the following target in each subdivided image; determine a flight direction according to the probability value of each subdivided image, and calculate the following target in the flight direction Determine a virtual flight coordinate based on the center point of the following target; generate a flight command based on the virtual flight coordinate.

That is to say, the aircraft control method of the present invention applying the above-mentioned aircraft line following control method determines the actual flight direction and precise target coordinates of the aircraft through a two-stage judgment. First, the image frame is divided into multiple segmented images, and the probability value of following the target in each segmented image is judged to roughly determine the relative position of the following target with respect to the current position of the aircraft to determine a flight direction area. Accurately calculate the center point of the area where the following target is located in the direction area, so that the aircraft will advance toward the center point, ensuring that the flying direction of the aircraft and the location of the captured image frame are indeed moving along the following target.

That is to say, because the aircraft does not simply judge the extension direction of the following target and turn to the rough direction to fly, but accurately flies toward the direction of the following target and a precise punctuation, so it will not be affected by the extension direction of the line. Detecting errors and deviating or losing the following target can maintain the aircraft to move along the position of the following target with high accuracy.

10: Video screen

11: Follow the goal

110: center of gravity

101’: Midpoint of the nearest target width

G ₀ ~ G ₈ : Split image

G ₀₁ ~ G ₀₈ : Divide the image again

Fig. 1 is a flow chart of the method for controlling the line following of the aircraft of the present invention.

Figure 2 is a schematic diagram of the application of the aircraft line following control method of the present invention.

Fig. 3 is a flowchart of the first preferred embodiment of the aircraft line following control method of the present invention.

Fig. 4 is an application schematic diagram of the first preferred embodiment of the aircraft line following control method of the present invention.

Fig. 5 is a flowchart of the second preferred embodiment of the aircraft line following control method of the present invention.

6A to 6D are schematic diagrams of the application of the second preferred embodiment of the aircraft line following control method of the present invention.

Figure 7 is a flow chart of the flight control method applying the aircraft line control method of the present invention

Fig. 8 is a schematic diagram of the application of the flight control method using the aircraft line control method of the present invention

Fig. 9 is a flowchart of a third preferred embodiment of a flight control method using the aircraft line control method of the present invention.

FIG. 10 is a schematic diagram of the application of the third preferred embodiment of the flight control method using the aircraft line control method of the present invention.

FIG. 11 is a flowchart of a fourth preferred embodiment of a flight control method using the aircraft line control method of the present invention.

Regarding a preferred embodiment of the present invention, an aircraft line following control method is provided, which is executed by a controller of an aircraft, as shown in FIG. 1, which includes the following steps: a segmentation in the center of an image frame The image is subdivided to generate a plurality of subdivided images (S101); it is determined that a probability value of following the target appears in each subdivided image (S102); a flight direction is determined according to the probability value of each subdivided image, and calculated A center point of the following target in the flight direction (S103); a virtual flight coordinate is determined according to the center point of the following target (S104).

Please refer to FIG. 2, which is a schematic diagram of the image frame 10. In step S101, a divided image G _{0 in the} center of the image frame 10 is further divided into a plurality of subdivided images G ₀₀ to G ₀₈ . Among them, the number G ₀₀ ~ G ₀₈ of each subdivided image is marked on the lower right corner of each subdivided image in the figure, and the probability value of the following target 11 in each subdivided image is marked on each subdivided image Upper right corner. In this embodiment, the divided image G ₀ is divided into nine subdivided images G ₀₀ ~ G ₀₈ , and the nine subdivided images are aligned with three rows and three columns, which is commonly known as the nine-square grid. Among them, the subdivided image G ₀₀ can be set to be located at the center of the image frame 10, that is, the position where the aircraft is facing at this time, and the remaining subdivided images G ₀₂ ~ G _{08 can} be set to be arranged counterclockwise from the top. .

In step S102, the probability value p(G _{0 i} ) of the following target 11 appearing in the multiple subdivided images is calculated, and the probability value of the following target 11 appearing is preferably that the following target 11 appears in the subdivided image The area ratio is calculated. For example, the probability value p( G _{0 i} ) in each subdivided image is calculated according to the following formula:

p( G _{0 i} ) = a ( G _{0 i} )/ A

Wherein, a ( G _{0 i} ) refers to the area of the following target 11 in each of the subdivided images G _0i , and A is the total area of the following target 11 in each of the subdivided images.

Referring to FIG. 3, in a first preferred embodiment of the present invention, in step S102, after the original probability value in each subdivided image is calculated (S1021), the following steps are further performed to obtain A probability value of following target 11 appears in each of the subdivided images: determine a reverse direction of flight inertia and a direction of flight inertia of the aircraft (S1022); when the probability value of the subdivided image located in the reverse direction of flight inertia is greater than 0, Set the probability value of the subdivided image to "0" (S1023); when the probability value of the subdivided image in the inertial direction of the flight is greater than 0, set the probability value of the subdivided image to "1" (S1024) .

Please refer to FIGS. 2 and 4 together. FIG. 2 is the original probability value of following the target 11 obtained according to the area calculation formula in each of the subdivided images in the image frame 10. For the convenience of description, define a Y-axis direction and a Z-axis direction of the image frame 10. Assuming that the aircraft is flying from the right side of the image frame 10, the following target 11 is flying to the left, and a flight inertia of the aircraft is a -y direction . Therefore, the reverse direction of the flight inertia is a +y direction, that is, on the right side of the _{subdivided image G 00.} According to steps S1021 and S2022, when the reverse direction of the flight inertia is determined, the probability value of the subdivided image in the reverse direction of the flight inertia is set to "0". In the example of Figure 4A, the subdivided image in the reverse direction of the flight inertia The image is G ₀₇ . In addition, preferably, since the subdivided image G ₀₀ is the position where the aircraft is currently aligned and does not belong to the flight direction to be selected, _{the probability value of G 00} can also be set to "0".

The above steps are used to eliminate the subdivided images in the direction of the aircraft at the previous moment, so as to avoid the situation that the flying direction determined according to the probability value of each subdivided image causes the aircraft to turn back repeatedly.

After the above adjustment steps, the probability value of each subdivided image is shown in Figure 4, which further sets _{the probability value of the subdivided image G 0i} in the flight inertia direction to "1", such as the subdivided image in Figure 4 Image G ₀₃ . In this way, in step S103, according _{to the probability values of each of the subdivided images G 00} ~ G _{08 , it can be determined that the direction of the subdivided image G 03} with the maximum probability value is the flight direction in which the aircraft should travel, and Then, a center point of the following target 11 in the flying direction is calculated. In the example shown in FIG. 4, it is the center point of the following target 11 in the _{subdivided image G 03.}

Please refer to FIGS. 5 and 6A. Preferably, the center point of the following target 11 is obtained according to the following steps: calculating the center of gravity 110 of the following target 11 in the subdivided image, and determining whether the center of gravity 110 is at the Follow the target 11 within the range (S1031); when the center of gravity is within the range where the following target 11 is located, set the center of gravity 110 as the center point of the following target 11 (S1032); when the center of gravity is not where the following target 11 is located Within the range, calculate a midpoint of the nearest target width of the center of gravity 110, and set the midpoint of the nearest target width 110' as the center point of the following target 11 (S1033).

Wherein, the position coordinates (l _y , l _z ) of the center of gravity described in step S1031 can be calculated according to the following formula:

Among them, ( y _i , z _i ) is the coordinate of each pixel covered by the following target 11 in the subdivided image, and M is the total number of pixels covered by the following target 11 in the subdivided image.

Please refer to Figures 6A to 6D. According to geometric principles, the center of gravity calculated by the above formula may not be within the range where the following target 11 is located. Therefore, as shown in FIGS. 6A and 6B, when the center of gravity is within the range of the following target 11, it is determined that the center of gravity is the required center point in step S103, and the white point 110 in the figure is calculated The center of gravity 110 of the following target 11 in the subdivided image G _0i , and the center of gravity 110 is within the range of the following target 11, so it is determined that the center of gravity 110 is the center point of the following target 11 in the subdivided image; As shown in FIGS. 6C and 6D, when it is determined that the center of gravity 110 is not within the range where the following target 11 is located, a correction calculation is performed to calculate a width midpoint of the following target 11 that is the closest to the position of the center of gravity 110, And take the nearest target width midpoint 110' as the center point, where the white point is the center of gravity 110 of the following target 11 in the subdivided image calculated by the above formula, and the black point is the center point obtained by correction . The midpoint of the nearest target width can be obtained according to the following calculation method: determine the center of gravity in the Y-axis direction and the Z-axis direction which is closer to the following target in one of the directions, set this direction as a correction center direction; determine the following target A width in the direction of the correction center, and the center point is set as a midpoint of the width.

Taking the example of FIG. 6C to illustrate, in the subdivided image G _0i , the center of gravity 110 is relatively close to the following target 11 in the Z-axis direction, so the Z-axis direction is set as the correction center direction. Further, a width of the following target in the Z-axis direction of the center of gravity 110 is determined, and the midpoint of the following target in the width is set as the center point. The coordinates of the midpoint of the width ( l _y ', l _z ' ) can be obtained according to the following calculation formula:

Wherein, l _{z_max} and l _{z_min} are respectively a Z-axis coordinate value of a boundary point farther from the center of gravity 110 of the following target 11 in the Z-axis direction, and a Z-axis coordinate value of a boundary point closer to the center of gravity 110 in the Z-axis direction.

If the center of gravity 110 is closer to the following target 11 in a Y-axis direction, the Y-axis direction is set as the correction center direction, and a width of the following target in the Y-axis direction of the center of gravity is determined, and the The midpoint of the width of the following target 11 in the Y-axis direction is set as the center point 110'. The calculation method is similar to the foregoing method of calculating the midpoint of the width in the Z-axis direction, and will not be repeated here.

In this way, the center of gravity located outside the range of the following target is translated to the midpoint of the nearest target width to ensure that the center point obtained according to the foregoing step S1031 will be located within the following target 11 and is not located at the previous moment of the aircraft Therefore, the virtual flight coordinates determined according to the center point can indeed make the aircraft fly along the following target 11 without deviating from the position where the following target 11 is located.

The second preferred embodiment provided by the present invention is a flight control method using the above-mentioned line following control method. Please refer to FIG. 7, which includes the following steps: capturing an image frame and dividing the image frame into a plurality of Segmented images (S701); determine the probability value of a following target in each segmented image (S702); determine a flying direction area according to the probability value of following the target in each segmented image (S703); when the flying direction area In the center of the image frame (S704), execute the above-mentioned line-following control method: subdivide the segmented image in the center of the image frame to generate a majority of subdivided images (S101); determine that the following target appears in each subdivided image The probability value of (S102); determine a flight direction according to the probability value of each subdivided image, and calculate a center point of the following target in the flight direction (S103); determine a virtual flight according to the center point of the following target Coordinates (S104) A flight instruction is generated according to the virtual flight coordinates (S705).

The flight control method is executed by an aircraft and includes a camera module and a controller. The camera module is used to capture an image frame and generally faces the front of the aircraft. Please also refer to Figure 8. After the camera module captures the image frame 10, it first divides the image frame 10 into a plurality of divided images G ₀ ~ G ₈ (S701), where G ₀ is located on the frame The divided images in the center, G ₁ ~ G ₈ are arranged counterclockwise from the top of the image frame 10. Wherein, the number G ₀ to G _{8 of} each divided image is marked on the lower left corner of each divided image, and the probability value of the following target 11 in each divided image is marked on the upper right corner of each divided image. In this embodiment, the image frame 10 is divided into nine divided images G ₀ to G ₈ , and the nine divided images G ₀ to G _{8 are} aligned in three rows and three columns, which is commonly known as the nine-square grid.

Then calculate the probability value p( G _i ) of the following target 11 in each of the segmented images G ₀ to G ₈ (S702). The calculation method of the probability value is similar to the calculation method of calculating the probability value of the following target 11 in each of the subdivided images in step S102, that is, calculating the area of the following target 11 in each of the segmented images G ₀ ~ G ₈ The ratio is calculated as follows:

p( G _i ) = a' ( G _i )/ A'

Wherein, a '(G _i) of the means to follow the target 11 in each of the divided image G ₀ ~ G ₈ in the area, A' total area that follows the target image 11 in the screen 10.

In step S703, a flight direction area is determined according to the probability value of each segmented image calculated in the previous step. Among them, the probability value of each segmented image calculated in the previous step represents the proportion of the following target 11 contained in each segmented image. When _{the probability value in one of the segmented images G i} is "0", it means the The following target 11 does not appear in the divided image; when _{the probability value in one of the divided images G i} is not "0", it means that the following target 11 appears in the divided image. Therefore, according to the probability value in each segmented image, the distribution profile of the following target 11 in the image frame 10 can be determined, and a flying direction area can be determined accordingly.

Please refer to FIG. 9, in a third preferred embodiment of the present invention, preferably, in the step (S703) of determining a flight direction area according to the probability value of following the target 11 in each of the segmented images, it is based on The following sub-steps determine: determine whether the probability value of following the target of the segmented image in the center of the image frame 10 is "0" (S7031); when the probability value of following the target of the segmented image in the center of the image frame 10 is not "0" ", set the segmented image in the center of the image frame 10 as the flight direction area (S7032); when the probability of the segmented image in the center of the image frame 10 to follow the target is "0", determine whether the other segmented images follow the target Whether the probability value is "0" (S7033); when the probability values of other segmented images following the target are all "0", the method process ends (S7034); when the probability value of at least one segmented image following the target is not "0" ", set the segmented image with the maximum probability value as the flight direction area (S7035).

Please refer to FIG. 8, when the _{probability value of the following target appearing in the divided image G 0} in the center of the image frame 10 is not "0", it means that the following target 11 is indeed located in the divided image G ₀ in the center of the image frame 10. As shown in Fig. 4, it also means that the aircraft does not deviate from the following target 11. Therefore, the segmented image G _{0 in the} center of the image frame 10 is set as the flight direction area (S704), and the line following control of steps S101~S104 is performed. According to the method, _{the virtual flight coordinates in the segmented image G 0} are accurately generated, and then a flight instruction is generated (S705), so that the aircraft continues to fly along the following target 11.

Conversely, when the probability value of the segmented image G ₀ in the center of the screen to follow the target 11 is "0", the following target 11 does not appear in the segmented image G ₀ in the center of the screen, indicating that the aircraft has deviated from the following target 11 Therefore, the segmented image with the maximum probability value is set as the flight direction area (S7035). Take the image frame 10 shown in FIG. 10 as an example. The following target 11 in the image frame 10 does not appear in the divided image G ₀ in the center of the screen, and the divided image with the largest probability value is the divided image G directly above. ₁ , therefore, the range of the segmented image G ₁ is determined to be the flight direction area.

As a result, the flight direction area is not in the center of the screen, that is, the flight direction area is not the segmented image G _{0 in the} center of the screen, and a further step of correcting the aircraft's own position (S707) must be performed.

As shown in FIG. 11, the aforementioned step of correcting the position of the aircraft includes the following sub-steps: calculating a center point of the following target in the flight direction area (S7071); determining a virtual flight coordinate according to the center point of the following target (S7072) ; Generate a flight instruction according to the virtual flight coordinates (S7073).

Preferably, the calculation method of calculating the center point of the following target 11 in the flight direction area in step S7071 is similar to the method of calculating the center point of the following target 11 in the flight direction in the aforementioned step S103, and includes the following steps: calculation The center of gravity of the following target in the segmented image, and determine whether the center of gravity is within the range of the following target; when the center of gravity is within the range of the following target, set the center of gravity as the center point of the following target; If the center of gravity is not within the range where the following target is located, calculate a midpoint of the nearest target width of the center of gravity, and set the midpoint of the nearest target width as the center point of the following target.

Wherein, the center of gravity (l _y , l _z ) of the following target 11 in the segmented image can be calculated by the following formula:

Among them, ( y _i , z _i ) is the coordinate of each pixel covered by the following target 11 in the segmented image, and M is the total number of pixels covered by the following target 11 in the segmented image.

When the calculated center of gravity ( l _y ,l _z ) is within the range of the following target 11 in the flight direction area, then the center of gravity is determined to be the center point; when the center of gravity ( l _y ,l _z ) is not at the Within the range of the following target 11, a further correction calculation is performed to calculate a width midpoint of the following target 11 closest to the position of the center of gravity, and the nearest target width midpoint is the center point. The method and result of the correction calculation are the same as the calculation method of the center point of the following target 11 in the subdivided image shown in FIGS. See the image frame 10 shown in FIG. 10, according to the method of calculating the center point, the center of gravity can be obtained in the direction of flight is the region segmentation image white point of the G _1, and after the correction calculated by the center point dividing the image G _shown in black dots.

In step S7072, it is determined that the center point is the virtual flight coordinates, and a flight instruction is further generated according to the virtual flight coordinates, so as to further control the aircraft to fly according to the flight instruction, so as to follow the segmentation of the target 11 in the center of the image frame 10. In the image. In this way, the position correction of the aircraft itself can be completed, so that the following target 11 returns to the center of the field of view of the camera module of the aircraft, and after returning to the first step of the aircraft control method, the aircraft line-following control method is successively executed, so that the aircraft continues Fly along the following target 11.

Preferably, the flight command ( v _y , v _z ) is calculated according to the following formula: Δ y = ( l _y - c _y ) or ( l _y' - c _y )

Δ z = ( l _z - c _z ) or ( l _z' - c _z )

v _y =Δ y / λ,v _z =Δ z / λ

Wherein, (c _y, c _z) that its own current position coordinates of the aircraft, preferably for the center point of the picture image coordinate, [lambda] is a time constant becomes variable, the flight instruction (v _y, v _z) is a speed instruction.

In summary, the high-precision line following method and flight control method proposed by the present invention enable an aircraft that performs line-following flight according to this method to keep the center of the camera module's field of view aligned with the following target line even if it is slightly affected. The external force makes the following target leave the center of the image screen, and the position of the aircraft can be adjusted immediately through its own position correction step. With clear flight instructions, the following target returns to the center of the image screen and ensures that the aircraft follows the following target with high accuracy. Fly within the width.

Furthermore, since the virtual flight coordinates are generated and the flight instructions are generated accordingly, instead of generating the steering angle to change the facing direction and flight direction of the aircraft, the aircraft can continue to face the following target on the front vertical plane, and The following target will not be lost due to changing the facing direction, and it can be applied to various application environments and flight missions where the following target is on a plane or a vertical plane below.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed as above in preferred embodiments, it is not intended to limit the present invention. Anyone familiar with the professional technology Personnel, without departing from the scope of the technical solution of the present invention, when the technical content disclosed above can be used to make slight changes or modification into equivalent embodiments with equivalent changes, but any content that does not deviate from the technical solution of the present invention, according to the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments are still within the scope of the technical solutions of the present invention.

Claims (7)

An aircraft line-following control method, executed by a controller of an aircraft, includes the following steps: subdividing a divided image in the center of an image frame to generate a plurality of subdivided images, and the multiple subdivided images are formed into rows and columns Alignment; determine the probability value of a following target appearing in each of the subdivided images; wherein, the probability value of the following target appearing in each of the subdivided images is calculated according to the area ratio of the following target in the subdivided image ; Determine a flight direction according to the probability value of each subdivided image, and calculate a center point of the following target in the flight direction; wherein, the flight direction is determined according to the direction of the subdivided image with the maximum probability value ; Set the center point as a virtual flight coordinate. The line-following control method of an aircraft according to claim 1, wherein the step of determining a probability value of following a target in each of the subdivided images further includes the following steps: determining a flight inertia reverse direction and a flight of the aircraft Inertial direction; when the probability value of the subdivided image located in the opposite direction of the flight inertia is greater than 0, the probability value of the subdivided image is set to "0"; when the probability value of the subdivided image located in the direction of the flight inertia is greater than 0, set the probability value of the subdivided image to "1". The aircraft line-following control method of claim 1, wherein the center point of the following target is obtained according to the following steps: calculate the center of gravity of the following target in the subdivided image, and determine whether the center of gravity is in the following target Within the scope of When the center of gravity is within the range where the following target is located, set the center of gravity as the center point of the following target; when the center of gravity is not within the range where the following target is located, calculate the midpoint of a nearest target width of the center of gravity and set the nearest The midpoint of the target width is the center point of the following target. A flight control method, executed by an aircraft, includes the following steps: capturing an image frame, dividing the image frame into a plurality of segmented images, and each of the segmented images is aligned in rows and columns; judging that a follower appears in each of the segmented images The probability value of the target, where the probability value of the following target appearing in each segmented image is calculated according to the area ratio of the following target in the segmented image; a value is determined according to the probability value of the following target in each segmented image Flight direction area; among them, when the probability value of the segmented image in the center of the image frame to follow the target is not "0", set the segmented image in the center of the image frame as the flight direction area; when the flight direction area is in the image In the center of the screen, the aircraft line-following control method described in any one of request items 1 to 3 is executed to generate a virtual flight coordinate; a flight instruction is generated according to the virtual flight coordinate. The flight control method of claim 4, wherein after determining a flight direction area according to the probability value in each of the segmented images, it further includes the following step: when the flight direction area is not in the center of the image frame, perform a self-position correction Step, make the flying direction area in the center of the image frame; wherein, the step of performing self-position correction includes the following sub-steps: calculating a center point of the following target in the flying direction area; and setting the center of the following target The point is set as a virtual flight coordinate; a flight instruction is generated according to the virtual flight coordinate. The flight control method according to claim 4, wherein the step of determining a flight direction area according to the probability value of following the target in each divided image includes the following sub-steps: determining the following substep of the divided image in the center of the image frame Whether the probability value of the target is "0"; when the probability value of the segmented image in the center of the image frame is not "0", set the segmented image in the center of the image frame as the flight direction area; when the image frame The probability value of following the target of the segmented image in the center is "0", judge whether the probability value of following the target of other segmented images is "0"; when the probability value of following the target of other segmented images is all "0", end this Method flow; when the probability value of other segmented images following the target is not "0", set the segmented image with the largest probability value as the flight direction area. The flight control method according to claim 4, wherein, in the step of dividing the image frame into a plurality of divided images, the image frame is divided into nine divided images, and each divided image is divided into three rows and three rows. Positive; In the step of dividing the divided image in the center of the image screen into multiple subdivided images, the divided image in the center of the image screen is divided into nine subdivided images, and each subdivided image is divided into three rows and three rows. Positive.

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