Method for selecting entry segment / waypoint and trajectory planning when UAV returns to the original route

Abstract

A method for selecting a cut-in segment / waypoint and a method for planning a trajectory when a UAV returns to the original route, the method for selecting a cut-in segment includes: selecting feature points, projecting the coordinates of the UAV into the segment, if the foot of the projection is within the segment, taking the foot of the projection as the feature point; if the foot of the projection is outside the segment, taking the waypoints at both ends of the segment that are closer to the UAV as the feature points; selecting the feature points to traverse each segment to obtain the feature points corresponding to each segment; calculating the weighted distance between the feature points corresponding to each segment and the coordinates of the UAV; selecting the segment corresponding to the minimum weighted distance as the cut-in segment when returning to the original route. The method for selecting a cut-in segment / waypoint and a method for planning a trajectory for a helicopter returning to the original route provided by an embodiment of the present invention can take into account both the strategic rationality and flight safety of the cut-in point selection when the helicopter is engaged in a return to the original route.

Description

Technical Field

[0001] The present invention relates to the technical field of flight control methods for unmanned aerial vehicles (UAVs), and in particular to a method for selecting a cut-in segment / waypoint and a method for planning a track when a UAV returns along an original route. Background Art

[0002] Unmanned helicopters and other UAVs (Unmanned Aerial Vehicles) usually have two flight modes when performing tasks remotely: one is the route flight mode, in which the unmanned helicopter flies autonomously according to the preset route; the other is the remote control flight mode (a type of automatic flight mode), in which the unmanned helicopter receives the measurement and control data link instructions in real time and follows the remote control instructions to fly. After completing the given task or in emergency situations such as the measurement and control data link communication interruption, the unmanned helicopter can enter the original route return mode in the route flight mode, select the most recently passed waypoint as the original route return entry waypoint, and fly back to the waypoint in the reverse direction along the preset route. However, in the remote control flight mode, the unmanned helicopter in the traditional method only selects the nearest waypoint as the original route return entry waypoint based on the distance between its own position and the waypoint position, resulting in insufficient engine power of the unmanned helicopter or causing the unmanned helicopter to enter a vortex ring state and other threats, posing a major safety hazard. Summary of the invention

[0003] In order to solve the defects of the above-mentioned prior art, an embodiment of the present invention provides a method for selecting a cut-in segment when a UAV returns to the original route, comprising:

[0004] Selection of feature points: Project the coordinates of the UAV into the flight segment. If the foot of the projection is within the flight segment, the foot of the projection is taken as the feature point; if the foot of the projection is outside the flight segment, the waypoints at both ends of the flight segment that are closer to the UAV are taken as the feature points;

[0005] The feature points are selected by traversing each flight segment to obtain the feature points corresponding to each flight segment;

[0006] Calculate the weighted distance between the feature point corresponding to each flight segment and the coordinates of the UAV according to L=H+V×W, where L represents the weighted distance, H represents the horizontal distance, V represents the vertical distance, and W represents the weight, and the weight W is a predetermined value;

[0007] The flight segment corresponding to the minimum weighted distance is selected as the cut-in flight segment when returning along the original route.

[0008] Preferably, the value of the weight is a pre-selected value.

[0009] Further preferably, the value of the weight is determined by the ratio of the maximum level flight rate and the maximum descent rate that the UAV can achieve.

[0010] Also preferably, the feature points are selected as follows:

[0011] First, determine the coordinate P of the UAV to the flight segment A i B i (i=1,2,3,……n) The foot of the projection C i Point coordinates,

[0012]

[0013] in,

[0014]

[0015]

[0016] n is a natural number, representing the flight segment number, A i Indicates the coordinates of the waypoint with smaller sequence number i in the flight segment, B i Indicates the coordinates of the waypoint with the larger i number in the flight segment;

[0017] Then, determine the foot of the perpendicular C i Is it in flight segment A? i B i inside, if Then the foot of the perpendicular C i Located in A i B i In the flight segment, select the foot of the vertical C i is the characteristic point M of this segment i ;like This indicates that the foot of the perpendicular C i Located in A i B i In addition to the flight segment, further judge and select as follows: Then select A i is the characteristic point M of the flight segment i Otherwise, select B i is the characteristic point M of the flight segment i .

[0018] An embodiment of the present invention further provides a method for selecting a waypoint when a UAV returns to the original route, comprising:

[0019] Selection of feature points: Project the coordinates P of the UAV into the flight segment. If the foot of the projection is within the flight segment, the foot of the projection is taken as the feature point; if the foot of the projection is outside the flight segment, the waypoints at both ends of the flight segment that are closer to the UAV are taken as the feature points.

[0020] The feature points are selected by traversing each flight segment to obtain the feature points corresponding to each flight segment;

[0021] Calculate the weighted distance between the feature point and the UAV corresponding to each flight segment according to L=H+V×W, where L represents the weighted distance, H represents the horizontal distance, V represents the vertical distance, and W represents the weight, and the weight W is a predetermined value;

[0022] Select the flight segment corresponding to the minimum weighted distance as the cut-in flight segment when returning to the original route;

[0023] If the characteristic point of the return segment is a perpendicular foot, the waypoint at the end of the segment with a smaller sequence number is selected as the entry waypoint; if the characteristic point of the return segment is a waypoint, the distance between the UAV and the waypoints at both ends of the segment is calculated, and the waypoint at the end with the smaller distance is selected as the entry waypoint.

[0024] Preferably, the value of the weight is a pre-selected value.

[0025] Preferably, the value of the weight is determined by the ratio of the maximum level flight rate and the maximum descent rate that the UAV can achieve.

[0026] Preferably, the feature points are selected as follows:

[0027] First, determine the coordinate P of the UAV to the flight segment A i B i (i=1,2,3,……n) The foot of the projection C i Point coordinates,

[0028]

[0029] in,

[0030]

[0031]

[0032] A is a natural number representing the flight segment number. i Indicates the coordinates of the waypoint with smaller sequence number i in the flight segment, B i Indicates the coordinates of the waypoint with the larger i number in the flight segment;

[0033] Then, determine the foot of the perpendicular C i Is it in flight segment A? i B i inside, if Then the foot of the perpendicular C i Located in A i B i In the flight segment, select the foot of the vertical C i is the characteristic point M of the flight segment i ;like This indicates that the foot of the perpendicular C i Located in Ai B i In addition to the flight segment, further judge and select as follows:

[0034] like Then select A i is the characteristic point M of the flight segment i Otherwise, select B i is the characteristic point M of the flight segment i .

[0035] An embodiment of the present invention further provides a method for trajectory planning when a UAV returns to the original route, which includes a step of selecting an entry segment when returning to the original route, and the entry segment selection step adopts any of the entry segment selection methods described above.

[0036] An embodiment of the present invention further provides a method for trajectory planning when a UAV returns to the original route, which includes a step of selecting an entry point when returning to the original route, and the entry point selection step adopts the entry point selection method as described in any one of the above items.

[0037] Compared with the prior art, the embodiments of the present invention have at least the following beneficial effects:

[0038] The method for selecting a route segment for UAV return-to-original route provided by the embodiment of the present invention can take into account both the strategic rationality of the route segment selection and the flight safety when the UAV is engaged in return-to-original route; the method for selecting a waypoint for UAV return-to-original route provided by the embodiment of the present invention can take into account both the strategic rationality of the waypoint selection and the flight safety when the UAV is engaged in return-to-original route, and has important significance and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of calculating the distance between an unmanned helicopter and each waypoint according to an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of calculating characteristic points of an unmanned helicopter and each flight segment according to an embodiment of the present invention;

[0041] Figure 3 is the vertical foot C of the unmanned helicopter in one embodiment of the present invention. i Schematic diagram when landing within the flight segment;

[0042] Figure 4 is the vertical foot C of the unmanned helicopter in one embodiment of the present invention. i Schematic diagram of falling outside the flight segment. DETAILED DESCRIPTION

[0043] like Figure 1In the waypoint schematic diagram shown, waypoint 1 is the return point. When the unmanned helicopter returns to the original route at point P, when selecting the waypoint closest to its own position as the return entry point, it will give priority to waypoint 2 for return. The return path is: waypoint 2 → waypoint 1, but in fact, this return path has flight safety hazards, especially in certain high-altitude scenarios. The inventors have found that the traditional return entry point selection method, in some special cases, or when the preset route is complex, may select a waypoint that is not on the same horizontal plane as the unmanned helicopter, but has a relatively small vertical distance - which can be simply called the "three-dimensional distance" with the smallest waypoint as the original return entry point. If the waypoint is higher than the current altitude of the unmanned helicopter, it will cause the unmanned helicopter to quickly climb to the waypoint, which may cause insufficient engine power; if the waypoint is lower than the current altitude of the unmanned helicopter, it will cause the unmanned helicopter to quickly descend to the waypoint, and there is a threat of entering a vortex ring state, which poses a major safety hazard.

[0044] The purpose of the present invention is to provide a reasonable entry segment / waypoint selection method when an unmanned helicopter or the like is put into a return-to-origin mode, thereby improving the strategic rationality and flight safety of unmanned helicopters or other UAVs when they are put into a return-to-origin mode.

[0045] In the present invention, the so-called return to the original route does not refer to the original route of the helicopter, etc., but the reverse original route of the preset waypoint. The so-called remote control flight mode is a kind of automatic flight mode. The helicopter, etc., follows the speed command sent by the ground system to fly in the remote control mode. For example, if the ground sends a forward flight of 10m / s, the unmanned helicopter, etc., will keep following the command and keep flying forward at a speed of 10m / s until receiving other commands. The so-called flight segment refers to the route segment between two preset adjacent waypoints.

[0046] The following will be combined with the attached embodiment of the present invention Figure 1-4 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Example 1

[0048] A method for planning a UAV's trajectory when returning to the original route, comprising a step of selecting an entry segment when returning to the original route, wherein the step of selecting an entry segment comprises: selecting a waypoint on each segment, and if the foot of the projection of the waypoint C i In this segment, the foot of the vertical C i is a feature point; if the foot of the perpendicular C projected by the UAV to the waypoint in the flight segment iOutside the flight segment, the waypoints at both ends of the flight segment that are closer to the UAV are used as the feature points. The schematic diagram of the selection method is as follows: Figure 2 As shown in the figure, P represents the starting position of the UAV returning to the original route. Assume that the feature point M of segment i i Coordinates (m ix ,m iy ,m iz ), the helicopter coordinate P is (p x ,p y ,p z ), then the characteristic point M of flight segment i i Weighted distance d from helicopter P i for:

[0049] d i =h i +v i *w

[0050] Among them, the horizontal distance Vertical distance v i =|m iz -p z |,w is the selected weight value, m ix ,m iy ,m iz Represent the feature points M i The coordinate values ​​on the x-axis, y-axis, and z-axis, p x ,p y ,p z Represent the coordinate values ​​of P on the x-axis, y-axis, and z-axis respectively.

[0051] Choose the weighted distance d i Minimum flight segment dmin is the return segment. If the feature point M i C i :Select the waypoint A with the smaller serial number in this segment i As the entry point, return to the original route; if the characteristic point M of the route segment i Waypoint: Calculate the distance between the helicopter and the waypoints at both ends of the flight segment, and select the waypoint at the end with the smaller distance as the entry waypoint for returning along the original route.

[0052] Then, the weighted distance between each of the feature points and the UAV is calculated according to L=H+V×W, wherein L represents the weighted distance, H represents the horizontal distance, V represents the vertical distance, W represents the weight, and the weight W is a predetermined value; finally, the segment corresponding to the minimum value of the weighted distance is selected as the return segment.

[0053] In this embodiment, the value of the weight W can be a pre-selected value, such as a value selected by experience, or preferably a value calculated according to the relevant performance parameters of the UAV. For example, the value of the weight is determined by the ratio of the maximum level flight speed and the maximum descent speed that the UAV can achieve. For example, if the maximum level flight speed of the unmanned helicopter is 30m / s and the maximum descent speed is 2m / s, the value of the weight W is 30 / 2=15.

[0054] In this embodiment, the feature points are determined as follows:

[0055] First, determine the UAV coordinate P to segment A i B i (i=1,2,3,……n) The foot of the projection C i Point coordinates,

[0056]

[0057] in,

[0058]

[0059]

[0060] P represents the UAV coordinates, n is a natural number representing the flight segment number, A i Indicates the coordinates of the waypoint with smaller sequence number i in the flight segment, B i Indicates the coordinates of the waypoint with the larger i number in the flight segment;

[0061] Then, determine the foot of the perpendicular C i Is it in flight segment A? i B i inside, if Then the foot of the perpendicular C i Located in A i B i In the flight segment, Figure 3 As shown, select the foot of the perpendicular C i is the characteristic point M of the flight segment i ;like This indicates that the foot of the perpendicular C i Located in A i B i Outside the flight segment, such as Figure 4 As shown, at this time, further judgment, if Then select A i is the characteristic point M of the flight segment i Otherwise, select B i is the characteristic point M of the flight segment i .

[0062] The weighted distance between each of the feature points and the UAV is calculated according to L=H+V×W, wherein L represents the weighted distance, H represents the horizontal distance, V represents the vertical distance, and W represents the weight, and the weight W is a predetermined value.

[0063] Finally, the flight segment corresponding to the minimum weighted distance is selected as the cut-in flight segment when returning along the original route.

[0064] Example 2

[0065] A method for planning a track when a UAV returns to the original route, comprising a step of selecting a waypoint when returning to the original route, wherein the step of selecting the waypoint includes:

[0066] A waypoint is selected on each segment. If the foot of the perpendicular of the projection of the waypoint is within the segment, the foot of the perpendicular is taken as the feature point; if the foot of the perpendicular of the projection of the UAV to the waypoint in the segment is outside the segment, the waypoints at both ends of the segment that are closer to the UAV are taken as the feature points; the weighted distance between each feature point and the UAV is calculated according to L=H+V×W, wherein L represents the weighted distance, H represents the horizontal distance, V represents the vertical distance, W represents the weight, and the weight W is a predetermined value; the segment with the smallest weighted distance is selected as the return segment; if the feature point of the return segment is the foot of the perpendicular, the waypoint at the end with a smaller serial number in the segment is selected as the entry waypoint; if the feature point of the return segment is a waypoint, the distance between the UAV and the waypoints at both ends of the segment is calculated, and the waypoint at the end with a smaller distance is selected as the entry waypoint.

[0067] In this embodiment, the value of the weight W can be a pre-selected value, such as a value selected by experience, or preferably a value calculated according to the relevant performance parameters of the UAV. For example, the value of the weight is determined by the ratio of the maximum level flight rate and the maximum descent rate that the UAV can achieve. For example, if the maximum level flight rate of the unmanned helicopter is 30m / s and the maximum descent rate is 2m / s, the value of the weight W is 30 / 2=15. The feature points are determined as follows:

[0068] First, determine the UAV coordinate P to segment A i B i (i=1,2,3,……n) The foot of the projection C i Point coordinates,

[0069]

[0070] in,

[0071]

[0072]

[0073] P represents the UAV coordinates, n is a natural number representing the flight segment number, A i Indicates the coordinates of the waypoint with smaller sequence number i in the flight segment, B i Indicates the coordinates of the waypoint with the larger i number in the flight segment;

[0074] Then, determine the foot of the perpendicular C i Is it in flight segment A? i B i inside, if Then the foot of the perpendicular C i Located in A i B i In the flight segment, select the foot of the vertical C i is the characteristic point M of the flight segment i ;like This indicates that the foot of the perpendicular C i Located in A i B i In addition to the flight segment, further judgment, if Then select A i is the characteristic point M of the flight segment i Otherwise, select B i is the characteristic point M of the flight segment i .

[0075] Then, the weighted distance between each of the feature points and the UAV is calculated according to L=H+V×W, wherein L represents the weighted distance, H represents the horizontal distance, V represents the vertical distance, and W represents the weight, and the weight W is a predetermined value.

[0076] Then, the flight segment corresponding to the minimum weighted distance is selected as the return flight segment.

[0077] Finally, make the following judgments and choices:

[0078] If the characteristic point of the return segment is a perpendicular foot, the waypoint at the end of the segment with a smaller sequence number is selected as the entry waypoint; if the characteristic point of the return segment is a waypoint, the distance between the UAV and the waypoints at both ends of the segment is calculated, and the waypoint at the end with the smaller distance is selected as the entry waypoint.

[0079] The following is a comparison between a test example of an embodiment of the present invention and a traditional method:

[0080] In the local navigation coordinate system (the x-axis points to the east, the y-axis points to the north, and the z-axis is perpendicular to the plane formed by the x-axis and the y-axis and points to the sky), there is a set of waypoint coordinates as shown in Table 1 below:

[0081] Table 1

[0082]

[0083] Assume that the unmanned helicopter returns to the original route at the coordinate point (120,10,30). Figure 1 As shown in Figure 1, if the traditional method is used to select the return point, the unmanned helicopter will only select the nearest waypoint as the return point based on the distance between its own position and the waypoint position. Figure 1 As shown, the calculation results of the distance between the unmanned helicopter and each waypoint are shown in Table 2 below:

[0084] Table 2

[0085]

[0086] After calculation, the unmanned helicopter is closest to waypoint 2, so it will choose waypoint 2 as the entry point for returning to the original route, and will fly to waypoint 2 at a larger descent rate. The return path is: waypoint 2 → waypoint 1. This return path has a great safety hazard.

[0087] The method of the present invention is used to select the entry point for returning to the original route. The characteristic points between the unmanned helicopter and each flight segment (the route between two adjacent waypoints constitutes a flight segment) are found by calculation, and the weighted distance between the characteristic points of each flight segment and the unmanned helicopter is calculated. The flight segment with the smallest weighted distance is selected as the return flight segment. Finally, a waypoint is selected in the flight segment as the entry point for returning to the original route according to the judgment. The calculation of the characteristic points between the unmanned helicopter and each flight segment is as follows: Figure 1 Selecting the weight value w = 12.5, the weighted distance calculation results between the unmanned helicopter and the feature point are shown in Table 3 below:

[0088] Table 3

[0089]

[0090] After calculation, the unmanned helicopter is closest to feature point 5, that is, the unmanned helicopter is closest to segment 5 (the route between waypoints 5 and 6), and feature point 5 is located in this segment, so waypoint 5 with a smaller sequence number at both ends of the segment is selected as the entry point for the return. Finally, the return path of the unmanned helicopter is: waypoint 5→waypoint 4→waypoint 3→waypoint 2→waypoint 1, which is the best return path.

[0091] The methods of various embodiments of the present invention can be applied to a variety of flight modes, especially when the UAV switches from the remote control flight mode to the "return to home mode", which can greatly improve flight safety.

[0092] It should be noted that the phrases "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include certain features, structures or characteristics, but not every embodiment may include the certain features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing certain features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0093] In addition, spatially relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0094] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for selecting a cut-in segment when a UAV returns to its original route, characterized in that: include: Selection of feature points: projecting the coordinates of the UAV into the flight segment. If the foot of the projection is within the flight segment, the foot of the projection is taken as the feature point. If the foot of the projection is outside the flight segment, the waypoints at both ends of the flight segment that are closer to the UAV are taken as the feature points; The feature points are selected by traversing each flight segment to obtain the feature points corresponding to each flight segment; Calculate the weighted distance between the feature point corresponding to each flight segment and the coordinates of the UAV according to L=H+V×W, where L represents the weighted distance, H represents the horizontal distance, V represents the vertical distance, and W represents the weight, and the weight W is a predetermined value; Select the flight segment corresponding to the minimum weighted distance as the cut-in flight segment when returning to the original route; The feature points are selected as follows: First, determine the coordinate P of the UAV to the flight segment A i B i (i=1,2,3,……n) The foot of the projection C i Point coordinates, in, n is a natural number, representing the flight segment number, A i Indicates the coordinates of the waypoint with smaller sequence number i in the flight segment, B i Indicates the coordinates of the waypoint with the larger i number in the flight segment; Then, determine the foot of the perpendicular C i Is it in flight segment A? i B i inside, if Then the foot of the perpendicular C i Located in A i B i In the flight segment, select the foot of the vertical C i is the characteristic point M of the flight segment i ;like This indicates that the foot of the perpendicular C i Located in A i B i In addition to the flight segment, further judge and select as follows: like Then select A i is the characteristic point M of the flight segment i Otherwise, select B i is the characteristic point M of the flight segment i like Then select A i is the characteristic point M of the flight segment i Otherwise, select B i is the characteristic point M of the flight segment i .

2. The method for selecting a cut-in flight segment according to claim 1, characterized in that: The value of the weight is determined by the ratio of the maximum level flight rate and the maximum descent rate that the UAV can achieve.

3. A method for selecting a waypoint when a UAV returns to its original route, characterized in that: include: Selection of feature points: Project the coordinates P of the UAV into the flight segment. If the foot of the projection is within the flight segment, the foot of the projection is taken as the feature point; if the foot of the projection is outside the flight segment, the waypoints at both ends of the flight segment that are closer to the UAV are taken as the feature points. The feature points are selected by traversing each flight segment to obtain the feature points corresponding to each flight segment; Calculate the weighted distance between the feature point and the UAV corresponding to each flight segment according to L=H+V×W, where L represents the weighted distance, H represents the horizontal distance, V represents the vertical distance, and W represents the weight, and the weight W is a predetermined value; Select the flight segment corresponding to the minimum weighted distance as the cut-in flight segment when returning to the original route; If the characteristic point of the return segment is a perpendicular foot, the waypoint at the end of the segment with a smaller sequence number is selected as the entry waypoint; if the characteristic point of the return segment is a waypoint, the distance between the UAV and the waypoints at both ends of the segment is calculated, and the waypoint at the end with the smaller distance is selected as the entry waypoint; The feature points are selected as follows: First, determine the coordinate P of the UAV to the flight segment A i B i (i=1,2,3,……n) The foot of the projection C i Point coordinates, in, n is a natural number, representing the flight segment number, A i Indicates the coordinates of the waypoint with smaller sequence number i in the flight segment, B i Indicates the coordinates of the waypoint with the larger i number in the flight segment; Then, determine the foot of the perpendicular C i Is it in flight segment A? i B i inside, if Then the foot of the perpendicular C i Located in A i B i In the flight segment, select the foot of the vertical C i is the characteristic point M of the flight segment i ;like This indicates that the foot of the perpendicular C i Located in A i B i In addition to the flight segment, further judge and select as follows: like Then select A i is the characteristic point M of the flight segment i Otherwise, select B i is the characteristic point M of the flight segment i .

4. The method for selecting a waypoint according to claim 3, wherein: The value of the weight is determined by the ratio of the maximum level flight rate and the maximum descent rate that the UAV can achieve.

5. A method for planning a UAV's trajectory when returning to the original route, characterized in that: The method comprises a step of selecting an entry segment when returning to the original route, wherein the step of selecting an entry segment adopts the method for selecting an entry segment according to any one of claims 1 to 2.

6. A method for planning a UAV's trajectory when returning to the original route, characterized in that: The method comprises a step of selecting a waypoint to be entered when returning to the original route, wherein the step of selecting the waypoint to be entered adopts the method for selecting the waypoint to be entered according to any one of claims 3 to 4.

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