A method and device for planning and switching unmanned aerial vehicle routes

Abstract

The present application discloses a method and device for planning and switching routes of unmanned aerial vehicles, including: when the target route is a straight line, a perpendicular line is made to intersect the first target point of the route according to the current position of the unmanned aerial vehicle, and then an offset distance is set along the route to determine a second target point that changes in real time, and the unmanned aerial vehicle tracks the second target point and gradually approaches it until it flies along the target route. For arc routes, the azimuth of the unmanned aerial vehicle relative to the hovering center point is calculated, and the offset angle is added to determine the third target point. The third target point is updated in real time with the current position of the unmanned aerial vehicle, and the unmanned aerial vehicle is guided to cut into the target route and hover according to the specified hovering radius and direction. When switching routes, the route switching point is calculated according to the minimum turning radius and turning angle of the unmanned aerial vehicle, and the unmanned aerial vehicle is guided to transition from the current route to the next route in a smooth curve until it flies along the next route. The problem of how to enable unmanned aerial vehicles to more flexibly respond to external interference and the need to quickly approach routes or emergency route adjustments is solved.

Description

Technical Field

[0001] The present application relates to the field of UAV technology, and in particular to a method and device for UAV route planning and switching. Background Art

[0002] UAV route planning usually uses the method of indirectly controlling the flight trajectory by controlling the attitude of the UAV. This method guides the UAV to fly along the predetermined route by adjusting the attitude parameters of the UAV, such as pitch angle, roll angle and yaw angle.

[0003] However, this route planning method based on attitude control faces some challenges in practice. Since it is highly dependent on the dynamic characteristics of the drone and real-time sensor data, any external interference during the actual flight may have an adverse effect on the control effect, causing the drone to deviate from the planned route. In addition, this method shows problems of insufficient response or insufficient control precision when dealing with the need to quickly approach the route or make emergency route adjustments. Summary of the invention

[0004] In an embodiment of the present application, a method for planning and switching a drone route is provided to solve the problem of how to enable a drone to more flexibly respond to external interference and the need to quickly approach a route or make emergency route adjustments.

[0005] In a first aspect, an embodiment of the present application provides a method for planning and switching a route for a UAV, the method comprising: calculating and updating the position of a target point according to the current position of the UAV and the target route in two situations, so that the UAV tracks the target point and moves closer to the target route until it flies along the target route; the first situation is: when the target route is a straight line, a perpendicular line to the target route is made according to the current position of the UAV, and the intersection of the perpendicular line and the target route is taken as the first target point; a second target point is determined according to an offset distance along the direction of the target route, the second target point changes in real time according to the new position of the UAV, and the UAV tracks the second target point to fly closer to the target route until it flies along the target route; wherein the offset distance is the distance between the first target point and the second target point. The distance between two target points; the second situation is: when the target route is an arc, the azimuth of the current position of the UAV relative to the circling center point of the target route is calculated, and the third target point is determined based on the calculated azimuth plus an offset angle, and the UAV tracks the third target point during flight; the third target point is calculated and updated in real time based on the new position of the UAV, and the UAV gradually cuts into the target route until it flies along the target route and circles according to the specified circling radius and direction; when the UAV needs to switch from the current route to the next route, the route switching point is calculated and determined based on the minimum turning radius and turning angle of the UAV, and the UAV is guided to transition from the current route to the next route in a smooth curve until it flies along the next route.

[0006] In a possible implementation, the calculation formula for determining the offset distance is: ;in, is the offset distance, is the current flight speed of the drone, is the time constant, which determines the response speed of the drone to speed changes. is the maximum acceleration of the drone, is a safety factor.

[0007] In one possible implementation, the calculation method of the azimuth of the current position of the drone relative to the center point of the target route includes: setting the north direction to 0 degrees and the east direction to 90 degrees; taking the clockwise direction as positive, the azimuth is the angle between the line connecting the current position of the drone relative to the center point of the target route and the north direction.

[0008] In a possible implementation, the offset angle is determined in the following manner: the size of the offset angle is adjusted according to the current position of the UAV and the distance from the trajectory; if the current position of the UAV is inside the target route or is close to the trajectory, the offset angle will take a small value to ensure that the third target point is in front of the UAV; if the current position of the UAV is outside the target route, the offset angle will gradually increase as the trajectory distance increases, and a maximum offset angle value is set to prevent the UAV from deviating too far from the target route.

[0009] In a possible implementation, the trajectory distance is calculated by calculating the distance between the current position of the drone and the center point of the target route, and then subtracting a specified circling radius.

[0010] In a possible implementation, when the drone needs to switch from the current route to the next route, the route switching point is calculated and determined according to the minimum turning radius and turning angle of the drone, and the drone is guided to transition from the current route to the next route in a smooth curve until it flies along the next route, including: calculating the turning angle of the drone from the current route to the next route; wherein the turning angle is defined as the angle between the starting point of the next route and the extension line of the end of the current route; when the turning angle is less than a preset angle, executing the first flight step; when the turning angle is greater than the preset angle, executing the second flight step; the calculation formula for determining the preset angle is: ;in, is the preset angle, is the maximum permissible lateral deviation of the UAV, is the minimum turning radius of the drone, is the current flight speed of the drone, is the maximum acceleration of the drone.

[0011] In a possible implementation, when the turning angle is less than a preset angle, a first flight step is executed, including: calculating a first advance turning distance of the UAV according to the turning angle and the minimum turning radius of the UAV; multiplying the first advance turning distance of the UAV by the magnification to obtain a final advance turning distance of the UAV to obtain a final route switching point; wherein the final advance turning distance is the distance between the end of the current route and the first route switching point; determining whether the distance between the current position of the UAV and the end point of the current route is greater than the final advance turning distance; if the determination result is yes, the UAV continues to fly along the current route; if the determination result is no, the UAV gradually adjusts its flight trajectory from the current position along a first smooth transition curve, wherein the smooth curve is used to guide the UAV to pass through the first route switching point, and gradually approach and align with the next route until it flies along the next route.

[0012] In one possible implementation, when the turning angle is greater than a preset angle, a second flight step is executed, including: setting a maximum upper limit value between the distance between the second route switching point and the starting point of the next route; when the current position of the UAV reaches or approaches the maximum upper limit value, starting to gradually adjust its flight trajectory along a second smooth transition curve, and the second smooth transition curve is used to ensure that the UAV track is corrected and aligned with the next route after deviating from the next route for a certain distance until it flies along the next route.

[0013] In a possible implementation, the maximum upper limit value is determined according to a turning angle, a preset angle, and the performance of the drone; wherein the performance of the drone includes a minimum turning radius of the drone and a maximum acceleration of the drone.

[0014] In a second aspect, an embodiment of the present application provides a UAV route planning and switching device, which includes: a tracking module, which is used to calculate and update the position of a target point according to the current position of the UAV and the target route in two situations, so that the UAV tracks the target point to get closer to the target route until it flies along the target route; a second target point tracking module is used to make a perpendicular line to the target route according to the current position of the UAV when the target route is a straight line, and use the intersection of the perpendicular line and the target route as the first target point; determine the second target point according to the offset distance along the direction of the target route, the second target point changes in real time according to the new position of the UAV, and the UAV tracks the second target point to get closer to the target route until it flies along the target route; wherein the offset distance is the first target point. The distance between the mark and the second target point; the third target point tracking module is used to calculate the azimuth of the current position of the drone relative to the circling center point of the target route when the target route is an arc, and determine the third target point based on the calculated azimuth plus an offset angle, and the drone tracks the third target point during flight; the third target point is calculated and updated in real time based on the new position of the drone, and the drone gradually cuts into the target route until it flies along the target route and hovers according to the specified circling radius and direction; when the drone needs to switch from the current route to the next route, the route switching point is calculated and determined based on the drone's minimum turning radius and turning angle, and the drone is guided to transition from the current route to the next route in a smooth curve until it flies along the next route.

[0015] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects:

[0016] The embodiment of the present application provides a method for planning and switching a UAV route. By calculating and updating the position of a target point, the UAV can accurately track and approach the target route, significantly improving the flexibility and accuracy of the UAV route planning. When the target route is a straight line, the intersection of the vertical line between the current position of the UAV and the target route is determined as the first target point, providing a clear reference direction for the UAV. The second target point is determined according to the offset distance along the direction of the target route, and the target point changes dynamically with the real-time update of the position of the UAV. By tracking this dynamic second target point, the UAV can gradually adjust its flight trajectory until it flies completely along the target route. Not only is the tracking accuracy of the UAV for the straight route improved, but also its ability to cope with external interference is enhanced. When the target route is an arc, the azimuth of the current position of the UAV relative to the center point of the target route is calculated, and an offset angle is added to determine the third target point. The UAV tracks the third target point calculated and updated in real time, and can gradually cut into the target route and hover according to the specified hovering radius and direction. It ensures the stable flight and precise hovering of the UAV on the arc route, and improves the diversity and flexibility of its flight missions. In addition, when the drone needs to switch from the current route to the next route, the route switching point can be calculated and determined based on the drone's minimum turning radius and turning angle. When switching routes, the drone can transition from the current route to the next route in a smooth curve, avoiding flight jitter and deviation caused by route switching. It not only improves the smoothness and accuracy of the drone's route switching, but also ensures the safety and stability of the drone throughout the flight. This application achieves accurate tracking and approaching of the target route by the drone by dynamically calculating and updating the position of the target point, significantly improving the flexibility and accuracy of the drone's route planning. At the same time, the technology also enhances the drone's ability to cope with external interference and improves its flight stability and safety under different route conditions. It solves the problem of how to make drones more flexible in responding to external interference and the need to quickly approach routes or emergency route adjustments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A flowchart of a method for planning and switching a UAV route provided in an embodiment of the present application;

[0019] Figure 2A specific flow chart of executing the first flight step when the turning angle is less than a preset angle provided in an embodiment of the present application;

[0020] Figure 3 A specific flow chart of executing the second flight step when the turning angle is greater than a preset angle provided in an embodiment of the present application;

[0021] Figure 4 A schematic diagram of a first target point and a second target point provided in an embodiment of the present application;

[0022] Figure 5 A schematic diagram of the change of the second target point provided in an embodiment of the present application;

[0023] Figure 6 A schematic diagram of a third target point determined when the target route is an arc provided in an embodiment of the present application;

[0024] Figure 7 A schematic diagram of a circling track process of cutting into a target route provided in an embodiment of the present application;

[0025] Figure 8 A schematic diagram of executing the first flight step provided in an embodiment of the present application;

[0026] Fig. 9 A schematic diagram of executing the second flight step provided in an embodiment of the present application;

[0027] Fig.10 A schematic diagram of a drone route planning and switching device provided in an embodiment of the present application;

[0028] Fig.11 A schematic diagram of a drone route planning and switching server provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] The following describes some of the techniques involved in the embodiments of the present application to facilitate understanding, and they should be considered as merely exemplary. Therefore, it should be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, some descriptions of well-known functions and structures are omitted in the following description.

[0031] The present application embodiment provides a method for planning and switching a UAV route, such as Figure 1 As shown, the method includes steps S101 to S106. Among them, Figure 1 This is only an execution order shown in the embodiment of the present application, and does not represent the only execution order of a drone route planning and switching method. If the final result can be achieved, Figure 1 The steps shown may be performed in parallel or reversed.

[0032] S101: There are two situations in which the position of the target point is calculated and updated according to the current position of the drone and the target route, so that the drone tracks the target point and moves closer to the target route until it flies along the target route.

[0033] S102: The first case is: when the target route is a straight line, a perpendicular line is drawn to the target route according to the current position of the UAV, and the intersection of the perpendicular line and the target route is taken as the first target point.

[0034] Figure 4 Schematic diagram of the first target point and the second target point provided in the embodiment of the present application. Figure 4 As shown in the figure, MN is the target route, that is, the predetermined flight path that the UAV needs to follow, point C is the second target point, point A is the current position of the UAV, indicating the specific position of the UAV at a certain moment, AB is the perpendicular line of the target route based on the current position of the UAV, and this line segment is the shortest distance line between the current position of the UAV and the target route, point B is the first target point, that is, the intersection of the perpendicular line AB and the target route MN, and point C is the second target point determined according to the offset distance.

[0035] S103: Determine a second target point according to the offset distance along the target route, the second target point changes in real time according to the new position of the drone, and the drone tracks the second target point to fly closer to the target route until it flies along the target route. The offset distance is the distance between the first target point and the second target point.

[0036] Figure 5 This is a schematic diagram of the change of the second target point provided in the embodiment of the present application. Figure 5 As shown in the figure, C1, C2 and C3 represent the second target points calculated based on the real-time position and offset distance of the drone at different time points. These second target points are distributed along the direction of the target route and change in real time as the drone moves. The drone tracks these second target points to move closer to the target route until it flies along the target route.

[0037] Furthermore, when the drone is at a certain initial position, the first second target point C1 can be determined according to the calculation formula of the position and the offset distance. The drone will then track point C1. As the drone moves, its position will change. At this time, it is necessary to recalculate the new second target point C2 according to the new position of the drone and the calculation formula of the offset distance. The drone will then adjust its flight trajectory to track point C2. This process will continue, and each time the drone moves to a new position, a new second target point, such as C3, will be calculated according to the calculation formula of the position and the offset distance. By constantly tracking these second target points that change in real time, the drone gradually adjusts its flight trajectory to get closer to the target route. Finally, when the drone is close enough to the target route, it will be able to fly stably along the target route.

[0038] The calculation formula for determining the offset distance is: .in, is the offset distance, is the current flight speed of the drone, is the time constant, which determines the response speed of the drone to speed changes. is the maximum acceleration of the drone, is a safety factor.

[0039] Specifically, the offset distance It is a distance set by the drone to maintain flight stability and safety when tracking the target route. This distance is based on the current flight speed of the drone. , time constant , maximum acceleration And safety factor The result of comprehensive calculation. The faster the current flight speed of the drone, the greater the offset distance required to maintain flight stability and safety. Because the faster the speed, the farther the drone flies in the same time, so more space is needed to cope with possible flight deviations. The time constant determines the response speed of the drone to speed changes. When the drone needs to adjust the speed, the larger the time constant, the longer it takes for the drone to adjust to the new speed. Therefore, in order to compensate for this delay, a larger offset distance is required to ensure that the drone does not deviate from the target route when adjusting the speed. The maximum acceleration of the drone limits the maximum acceleration it can generate during flight. When the current flight speed of the drone is high, in order to maintain flight stability and safety, a larger offset distance is required to ensure that the drone can proceed smoothly when it needs to slow down or adjust the flight trajectory. This is because a larger acceleration may cause the drone to change the flight state too quickly, thus affecting the stability and safety of the flight. The safety factor is an additional coefficient used to increase the safety of the offset distance. By adjusting the size of the safety factor, the calculation result of the offset distance can be optimized according to the specific flight environment and mission requirements of the drone.

[0040] S104: The second case is: when the target route is an arc, the azimuth of the current position of the drone relative to the circling center point of the target route is calculated, and a third target point is determined based on the calculated azimuth plus an offset angle, and the drone tracks the third target point.

[0041] Figure 6 A schematic diagram of a third target point determined when the target route is an arc provided in an embodiment of the present application. Figure 6 As shown in the figure, point A is the current position of the drone, point F is the target route circling center point, and point G is the third target point determined by adding an offset angle to the calculated azimuth. is the azimuth, which is the angle between the line connecting the current position of the drone, point A, and the target flight path center point F and the true north direction. is the offset angle.

[0042] The calculation method of the azimuth of the current position of the drone relative to the target route circling center point includes: setting the true north direction as 0 degrees and the true east direction as 90 degrees. Taking the clockwise direction as positive, the azimuth is the angle between the line connecting the current position of the drone relative to the target route circling center point and the true north direction.

[0043] Specifically, the azimuth can be calculated using trigonometric functions and geometric knowledge. If you know the coordinates of the current position of the drone and the coordinates of the target route's circling center point, you can use the inverse tangent function to calculate this angle. Specifically, you need to determine the geographic coordinates or relative coordinates of the drone's current position point A and the target route's circling center point F. Calculate the line vector from point A to point F, which contains the length and direction information of the line. Use the inverse tangent function to calculate the angle between this line vector and the true north direction, i.e. the azimuth.

[0044] The offset angle is determined in the following ways: The offset angle is adjusted according to the distance between the current position of the drone and the track. If the current position of the drone is inside the target route or close to the track, the offset angle will take a small value to ensure that the third target point is in front of the drone. If the current position of the drone is outside the target route, the offset angle will gradually increase as the track distance increases. A maximum offset angle value is set to prevent the drone from deviating too far from the target route.

[0045] Specifically, the introduction of the offset angle is intended to guide the drone to fly along the circular route, rather than flying directly to the center point of the arc or deviating from the circular route. When the current position of the drone is inside the target route or close to the trajectory, in order to ensure that the drone can fly smoothly along the circular route, the offset angle will take a relatively small value. The advantage of this is that the third target point will be not far in front of the drone, allowing the drone to easily adjust its flight attitude and speed to maintain alignment with the target route. On the contrary, when the current position of the drone is outside the target route, the offset angle will gradually increase as the distance from the trajectory increases. The purpose of this is to guide the drone to get closer to the circular route by increasing the offset angle to prevent it from deviating too far from the target route.

[0046] It should be noted that in order to prevent the drone from seriously deviating from the target route due to excessive offset angle during flight, a maximum offset angle value needs to be set. The maximum offset angle value can be set to within 30 degrees. Of course, the maximum offset angle value can also be set to other values, and this application is not limited to the above values. When the calculated offset angle exceeds the value of this maximum offset angle, it should be limited to the maximum offset angle. Doing so can ensure the stability and safety of the drone during flight.

[0047] The trajectory distance is calculated by calculating the distance between the current position of the drone and the center point of the target route, and then subtracting the specified circling radius.

[0048] Specifically, the calculation formula of the trajectory distance is: Among them, d is the trajectory distance, AF is the distance between the current position of the drone and the circling center point of the target route, and r is the circling radius, that is, the radius of the target route.

[0049] Furthermore, it is necessary to determine the coordinates of the current position of the drone, point A, and the coordinates of the target route circling center point F. Use a distance calculation formula, such as the Euclidean distance formula, to calculate AF, which is the straight-line distance between point A and point F. Subtract the circling radius r from AF to obtain the trajectory distance d. When d>0, it means that the current position of the drone is outside the target route, and the flight path needs to be adjusted to get closer to the arc. When d=0, it means that the current position of the drone is exactly on the arc, and no additional path adjustment is required. When d<0, it means that there may be errors in the calculation or measurement, or the target route and circling radius need to be redefined.

[0050] S105: The third target point is calculated and updated in real time according to the new position of the UAV, and the UAV gradually cuts into the target route until it flies along the target route and hovers in the specified hovering radius and direction.

[0051] Figure 7 A schematic diagram of the circling track process of cutting into the target route provided in an embodiment of the present application. Figure 7 The whole process of the drone cutting into the target route from the current position and hovering on the route is shown. This cutting process requires the drone to have certain flight control capabilities and autonomous navigation capabilities to ensure the accuracy and safety of the cutting. Once the drone cuts into the target route, it will fly along the target route. During this process, the drone needs to maintain a stable flight state to ensure the continuity and safety of the flight. When the drone flies to the specified position along the target route, it will begin to hover according to the specified hovering radius and direction. The hovering radius refers to the radius of the target route. The hovering direction refers to whether the drone rotates clockwise or counterclockwise when circling. When the drone is circling, it needs to maintain a stable flight altitude and speed to ensure the continuity and stability of the hovering.

[0052] S106: When the UAV needs to switch from the current route to the next route, the route switching point is calculated and determined according to the minimum turning radius and turning angle of the UAV, and the UAV is guided to transition from the current route to the next route in a smooth curve until it flies along the next route.

[0053] Specifically, in a UAV flight mission, when a series of straight routes are set for the UAV and it is expected to fly along the broken line segments composed of these routes, the turning process of the UAV between different routes becomes particularly critical. In order to ensure that the UAV can maintain the stability and continuity of flight when switching routes, it is necessary to consider the limitations of the actual turning radius of the UAV and transition with a suitable curve at the turning point of the route. In order to achieve this goal, the present application enables the UAV to switch the target route from the current route to the next route at the appropriate time. During the switching process, the route switching point is calculated and determined based on the minimum turning radius and turning angle of the UAV. This switching point ensures that the UAV can transition from the current route to the next route with a smooth curve, thereby avoiding flight instability caused by sharp turns.

[0054] When the drone needs to switch from the current route to the next route, the route switching point is calculated and determined based on the drone's minimum turning radius and turning angle, and the drone is guided to transition from the current route to the next route in a smooth curve until it flies along the next route, including: calculating the turning angle of the drone from the current route to the next route. The turning angle is defined as the angle between the starting point of the next route and the extension line of the end of the current route. When the turning angle is less than the preset angle, the first flight step is executed. The calculation formula for determining the preset angle is: .in, is the preset angle, is the maximum permissible lateral deviation of the UAV, is the minimum turning radius of the drone, is the current flight speed of the drone, is the maximum acceleration of the drone.

[0055] Specifically, the maximum permissible lateral deviation of a drone limits the maximum distance that the drone can deviate from the intended route during a route switch. For example, in certain precision mapping or surveillance missions, the drone needs to stay within a very narrow route, so In other missions, such as search and rescue, drones may need greater flexibility to cover a wider area, so The setting may be relatively large. The minimum turning radius of the drone indicates the minimum radius that the drone can maintain when turning. The maximum acceleration of the drone indicates the maximum speed change rate that the drone can achieve in a short period of time.

[0056] Figure 2 The specific flow chart of executing the first flight step when the turning angle is less than the preset angle provided in the embodiment of the present application is as follows: Figure 2 As shown, it includes steps S201 to S205.

[0057] S201: Calculate a first advance turning distance of the UAV according to the turning angle and the minimum turning radius of the UAV.

[0058] Figure 8 A schematic diagram of performing the first flight step provided in an embodiment of the present application. Figure 8 As shown in the figure, point A is the current position of the drone, LM is the current route of the drone, and MN is the next route. is the turning angle, P is the first advance turning distance, The final route switching point. is the final advance turning distance, is the first smooth transition curve, is the minimum turning radius of the drone.

[0059] Specifically, when the drone performs the first flight step, in order to ensure that the drone can smoothly transition from the current route to the next route, an advance turning distance needs to be calculated. This distance ensures that when the drone starts turning, it can complete the turn with its minimum turning radius, and the route after the turn remains tangent to both target routes (i.e., the current route and the next route).

[0060] The calculation formula for the first advance turn distance is: .in, is the first advance turning distance, is the minimum turning radius of the drone, is the turning angle.

[0061] S202: Multiply the first advance turning distance of the drone by the magnification to obtain a final advance turning distance of the drone to obtain a final route switching point, wherein the final advance turning distance is the distance between the end of the current route and the first route switching point.

[0062] Specifically, during the flight of the drone, due to factors such as inertia, it takes a certain amount of time for the drone to change from a level flight attitude to a turning attitude. In order to ensure that the drone can start turning in advance and accurately to avoid deviations when switching routes, it is necessary to amplify the first advance turning distance calculated previously. Specifically, the first advance turning distance Multiply by a magnification factor k to get the final advance turn distance of the drone The magnification k ranges from 1 to 2, which ensures that the drone has enough time and space to smoothly transition from level flight to turning attitude, thus avoiding deviation when switching routes. The final advance turning distance after magnification It can be calculated by the following formula: . Where k is the magnification, is the first advance turn distance. Final advance turn distance It is the distance between the end of the current route and the first route switching point. When the drone reaches the point where it should start turning, it should start turning to ensure a smooth transition to the next route. Defined as the first route switching point.

[0063] S203: Determine whether the distance between the current position of the drone and the end point of the current route is greater than the final advance turn distance.

[0064] If the judgment result is yes, step S204 is executed: the UAV continues to fly along the current route.

[0065] Specifically, in this case, since the drone is far enough away from the end of the route and has not yet reached the point where it needs to turn in advance, i.e., the final route switching point, the drone will continue to fly along the current route. This ensures that the drone can stably maintain the current route before turning and prepare for the subsequent turning action.

[0066] If the judgment result is no, execute step S205: the UAV gradually adjusts its flight trajectory along the first smooth transition curve starting from the current position, and the smooth curve is used to guide the UAV to pass through the first route switching point, and gradually approach and align with the next route until flying along the next route.

[0067] Specifically, when the drone approaches the point where it needs to turn ahead, that is, the distance between the current position and the end point of the route is not greater than the final advance turning distance, the drone will begin to adjust its flight trajectory along the first smooth transition curve. This smooth transition curve (such as The smooth transition curve is usually designed as a continuous curve with a gradually changing curvature to ensure that the drone can maintain a stable flight during the turn. The starting point of the first smooth transition curve is located on the current route, the end point is located on the next route, and passes through the first route switching point calculated previously. The drone will gradually adjust its flight trajectory along the first smooth transition curve to ensure a smooth transition to the next route. During the adjustment process, the drone's control system will monitor its flight status in real time and make fine adjustments as needed to maintain flight stability and accuracy.

[0068] When the turning angle is greater than the preset angle, the second flight step is executed.

[0069] Figure 3 The specific flow chart of executing the second flight step when the turning angle is greater than the preset angle provided in the embodiment of the present application is as follows: Figure 3As shown, it includes step S301 to step S302.

[0070] S301: Setting a maximum upper limit value between the distance between the second route switching point and the starting point of the next route.

[0071] Fig. 9 A schematic diagram of performing the second flight step provided in an embodiment of the present application. Fig. 9 As shown in the figure, LM is the current route of the drone, and MN is the next route. is the turning angle, is the second route switching point, is the maximum upper limit value, is the second smooth transition curve, is the minimum turning radius of the drone.

[0072] Specifically, when the turning angle becomes too large, the first route switching point determined by the above formula may be too far from the starting point M of the next route. This situation will cause the drone to start turning to the new route too early, causing its actual flight trajectory to seriously deviate from the original expectation that it should fly in the LMN direction. In order to avoid this problem, The core purpose of this measure is to prevent the drone from being in extreme situations (i.e. turning angles). This setting ensures that the flight trajectory of the drone is closer to expectations while meeting the basic requirement that it should fly roughly in the LMN direction. It is worth noting that there is a close relationship between the maximum upper limit value and the flight speed of the drone. Generally, as the flight speed of the drone increases, the required turning radius and the distance to turn in advance will also increase accordingly. Therefore, when determining the maximum upper limit value, the key factor of the drone's flight speed needs to be fully considered. For example, if the maximum upper limit is not set, the drone's track will deviate significantly to the outside of MN. However, after the maximum upper limit rule is introduced, even at such an extreme turning angle, the drone's track can be corrected in time after deviating a certain distance and finally converge to the new route MN. This process is as follows Figure 8 As shown, it clearly demonstrates the route conversion process of the drone under the maximum upper limit rule.

[0073] The maximum upper limit value is determined based on the turning angle, the preset angle, and the performance of the drone, wherein the performance of the drone includes the minimum turning radius of the drone and the maximum acceleration of the drone.

[0074] The maximum upper limit of the distance between the second route switching point and the starting point of the next route is calculated as follows: .in, is the maximum upper limit value, and is the adjustment coefficient, which is adjusted according to the performance of the drone. is the minimum turning radius of the drone, is the maximum acceleration of the drone, is the turning angle, is the preset angle.

[0075] Specifically, It is mainly related to the dynamic characteristics of the drone during the turning process, especially the factors related to acceleration and speed change. The determination rules include the following aspects: Lighter drones require smaller values, because they respond more quickly to changes in acceleration. The higher the speed, the faster it can adjust its flight attitude, so it needs a smaller value to avoid over-adjustment. Faster flight speeds require larger To ensure that the drone has enough time and distance to complete a smooth turn. For missions that require high stability, more fine-tuning may be required. value to ensure smoothness during the transition.

[0076] Mainly related to the geometric characteristics of the drone, especially the minimum turning radius The determination rules include the following aspects: UAVs with larger wingspans and better maneuverability may have smaller The smaller the minimum turning radius of a drone, the more flexible it is in adjusting its flight direction, so it may be smaller. In complex or restricted flight environments, a larger value to ensure the drone has enough room to complete the turn.

[0077] S302: When the current position of the UAV reaches or approaches the maximum upper limit, it starts to gradually adjust its flight trajectory along the second smooth transition curve. The second smooth transition curve is used to ensure that the UAV track is corrected and aligned with the next route after deviating from the next route for a certain distance until it flies along the next route.

[0078] Specifically, once the current position of the drone reaches or approaches the previously calculated maximum upper limit , it needs to start along the second smooth transition curve Gradually adjust its flight trajectory. This smooth transition curve ensures that the drone can make corrections after deviating from the next route MN for a certain distance, and finally align with the next route and continue to fly along it. Fig. 9 In the figure, you can see a smooth transition curve like this It connects the second route switching point E' and a point on the next route MN The drone will fly along this curve to ensure that it can smoothly transition from the current route LM to the next route MN.

[0079] The present application also provides a drone route planning and switching device 1000, such as Fig.10 As shown, the device includes: a target point updating module 1001, a second target point tracking module 1002 and a third target point tracking module 1003.

[0080] The target point update module 1001 is used to calculate and update the position of the target point according to the current position of the drone and the target route in two situations, so that the drone tracks the target point and moves closer to the target route until it flies along the target route.

[0081] The second target point tracking module 1002 is used to make a perpendicular line to the target route according to the current position of the drone when the target route is a straight line, and the intersection of the perpendicular line and the target route is used as the first target point. The second target point is determined according to the offset distance along the target route direction, and the second target point changes in real time according to the new position of the drone. The drone tracks the second target point to fly closer to the target route until it flies along the target route. Among them, the offset distance is the distance between the first target point and the second target point.

[0082] The module 1003 for tracking the third target point is used to calculate the azimuth of the current position of the drone relative to the circling center point of the target route when the target route is an arc, and determine the third target point based on the calculated azimuth plus an offset angle, and the drone tracks the third target point during flight. The third target point is calculated and updated in real time based on the new position of the drone, and the drone gradually cuts into the target route until it flies along the target route and hovers according to the specified circling radius and direction. When the drone needs to switch from the current route to the next route, the route switching point is calculated and determined based on the drone's minimum turning radius and turning angle, and the drone is guided to transition from the current route to the next route in a smooth curve until it flies along the next route.

[0083] Some modules in the apparatus described in the present application can be described in the general context of computer executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0084] The devices or modules described in the above application embodiments can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, the above devices are described in various modules according to their functions. When implementing the embodiments of the present application, the functions of each module can be implemented in the same or multiple software and / or hardware. Of course, the module that implements a certain function can also be implemented by combining multiple sub-modules or sub-units.

[0085] The methods, devices or modules described in this application can be implemented in the form of computer-readable program codes. The controller can be implemented in any appropriate manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program codes (such as software or firmware) that can be executed by the (micro)processor, logic gates, switches, application-specific integrated circuits (English: Application Specific Integrated Circuit, referred to as: ASIC), programmable logic controllers and embedded microcontrollers. Examples of controllers include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in the form of pure computer-readable program codes, the controller can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, this controller can be considered as a hardware component, and the devices included in it for implementing various functions can also be regarded as structures within the hardware component. Or even, the means for realizing various functions may be regarded as both a software module for realizing the method and a structure within a hardware component.

[0086] like Fig.11As shown, an embodiment of the present application also provides a drone route planning and switching server, including a memory 1101 and a processor 1102; the memory 1101 is used to store computer executable instructions; the processor 1102 is used to execute computer executable instructions to implement a drone route planning and switching method described above in an embodiment of the present application.

[0087] An embodiment of the present application also provides a computer-readable storage medium, which stores executable instructions. When a computer executes the executable instructions, it can implement the drone route planning and switching method described above in the embodiment of the present application.

[0088] It can be seen from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on this understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, or it can be reflected in the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a mobile terminal, a server, or a network device, etc.) to execute the method described in the embodiment of the present application.

[0089] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. All or part of this application can be used in many general or special computer system environments or configurations.

[0090] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by 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 present application.

Claims

1. A method for planning and switching unmanned aerial vehicle routes, characterized in that: include: There are two situations: the position of the target point is calculated and updated according to the current position of the UAV and the target route, so that the UAV tracks the target point and moves closer to the target route until it flies along the target route; The first case is: when the target route is a straight line, a perpendicular line is drawn to the target route according to the current position of the UAV, and the intersection of the perpendicular line and the target route is taken as the first target point; A second target point is determined according to the offset distance along the target route direction, the second target point changes in real time according to the new position of the UAV, and the UAV tracks the second target point to fly closer to the target route until it flies along the target route; wherein the offset distance is the distance between the first target point and the second target point; The second case is: when the target route is an arc, the azimuth of the current position of the drone relative to the circling center of the target route is calculated, and the third target point is determined based on the calculated azimuth plus an offset angle, and the drone tracks the third target point. The third target point is calculated and updated in real time based on the new position of the drone. The drone gradually cuts into the target route until it flies along the target route and hovers according to the specified hovering radius and direction. The hovering radius refers to the radius of the target route, and the hovering direction refers to whether the drone rotates clockwise or counterclockwise when circling. In a UAV flight mission, when a series of straight routes are set for the UAV and it is expected to fly along the broken line segments formed by these routes, when the UAV needs to switch from the current route to the next route, the route switching point is calculated and determined based on the UAV's minimum turning radius and turning angle, and the UAV is guided to transition from the current route to the next route in a smooth curve until it flies along the next route; The calculation formula for determining the offset distance is: ;in, is the offset distance, is the current flight speed of the drone, is the time constant, which determines the response speed of the drone to speed changes. is the maximum acceleration of the drone, is the safety factor; The calculation method of the azimuth of the current position of the drone relative to the target route circling center point includes: setting the due north direction as 0 degrees and the due east direction as 90 degrees; taking the clockwise direction as positive, the azimuth is the angle between the line connecting the current position of the drone relative to the target route circling center point and the due north direction; The offset angle is determined in the following manner: the size of the offset angle is adjusted according to the distance between the current position of the drone and the track; if the current position of the drone is inside the target route or close to the track, the offset angle will take a small value to ensure that the third target point is in front of the drone; if the current position of the drone is outside the target route, as the track distance increases, the offset angle will gradually increase, and a maximum offset angle value is set to prevent the drone from deviating too far from the target route; The trajectory distance is calculated by calculating the distance between the current position of the drone and the center point of the target route, and then subtracting the specified circling radius; When the UAV needs to switch from the current route to the next route, the route switching point is calculated and determined according to the minimum turning radius and turning angle of the UAV, and the UAV is guided to transition from the current route to the next route in a smooth curve until it flies along the next route, including: calculating the turning angle of the UAV from the current route to the next route; wherein the turning angle is defined as the angle between the starting point of the next route and the extension line of the end of the current route; when the turning angle is less than the preset angle, the first flight step is executed; when the turning angle is greater than the preset angle, the second flight step is executed; the calculation formula for determining the preset angle is: ;in, is the preset angle, is the maximum permissible lateral deviation of the UAV, is the minimum turning radius of the drone, is the current flight speed of the drone, is the maximum acceleration of the drone.

2. The method for UAV route planning and switching according to claim 1, characterized in that: When the turning angle is less than the preset angle, executing the first flight step includes: Calculate the first advance turning distance of the drone according to the turning angle and the minimum turning radius of the drone; The first advance turning distance of the UAV is multiplied by the magnification to obtain the final advance turning distance of the UAV to obtain the final route switching point; wherein the final advance turning distance is the distance between the end of the current route and the first route switching point; Determine whether the distance between the current position of the drone and the end point of the current route is greater than the final advance turn distance; If the judgment result is yes, the drone continues to fly along the current route; If the judgment result is no, the UAV gradually adjusts its flight trajectory along the first smooth transition curve starting from the current position, and the smooth curve is used to guide the UAV to pass through the first route switching point, and gradually approach and align with the next route until flying along the next route.

3. The method for UAV route planning and switching according to claim 2, characterized in that: When the turning angle is greater than the preset angle, executing the second flight step includes: Set the maximum upper limit of the distance between the second route switching point and the starting point of the next route; When the current position of the UAV reaches or approaches the maximum upper limit, it begins to gradually adjust its flight trajectory along the second smooth transition curve. The second smooth transition curve is used to ensure that the UAV track is corrected and aligned with the next route after deviating from the next route for a certain distance until it flies along the next route.

4. The method for UAV route planning and switching according to claim 3, characterized in that: The maximum upper limit value is determined according to the turning angle, the preset angle and the performance of the drone; wherein the performance of the drone includes the minimum turning radius of the drone and the maximum acceleration of the drone.

5. A drone route planning and switching device, characterized in that: include: The target point update module is used to calculate and update the position of the target point according to the current position of the drone and the target route in two situations, so that the drone can track the target point and move closer to the target route until it flies along the target route; The second target point tracking module is used to draw a perpendicular line to the target route according to the current position of the UAV when the target route is a straight line, and take the intersection of the perpendicular line and the target route as the first target point; A second target point is determined according to the offset distance along the target route direction, the second target point changes in real time according to the new position of the UAV, and the UAV tracks the second target point to fly closer to the target route until it flies along the target route; wherein the offset distance is the distance between the first target point and the second target point; The module for tracking the third target point is used to calculate the azimuth of the current position of the drone relative to the circling center point of the target route when the target route is an arc, determine the third target point based on the calculated azimuth plus an offset angle, and the drone tracks the third target point during flight; the third target point is calculated and updated in real time based on the new position of the drone, and the drone gradually cuts into the target route until it flies along the target route and circles according to the specified circling radius and direction; the circling radius refers to the radius of the target route, and the circling direction refers to whether the drone rotates clockwise or counterclockwise when circling; in the drone flight mission, when a series of straight routes are set for the drone and it is expected that it will fly along the broken line segments formed by these routes, when the drone needs to switch from the current route to the next route, the route switching point is calculated and determined based on the drone's minimum turning radius and turning angle, and the drone is guided to transition from the current route to the next route in a smooth curve until it flies along the next route; The calculation formula for determining the offset distance is: ;in, is the offset distance, is the current flight speed of the drone, is the time constant, which determines the response speed of the drone to speed changes. is the maximum acceleration of the drone, is the safety factor; The calculation method of the azimuth of the current position of the drone relative to the target route circling center point includes: setting the due north direction as 0 degrees and the due east direction as 90 degrees; taking the clockwise direction as positive, the azimuth is the angle between the line connecting the current position of the drone relative to the target route circling center point and the due north direction; The offset angle is determined in the following manner: the size of the offset angle is adjusted according to the distance between the current position of the drone and the track; if the current position of the drone is inside the target route or close to the track, the offset angle will take a small value to ensure that the third target point is in front of the drone; if the current position of the drone is outside the target route, as the track distance increases, the offset angle will gradually increase, and a maximum offset angle value is set to prevent the drone from deviating too far from the target route; The trajectory distance is calculated by calculating the distance between the current position of the drone and the center point of the target route, and then subtracting the specified circling radius; When the UAV needs to switch from the current route to the next route, the route switching point is calculated and determined according to the minimum turning radius and turning angle of the UAV, and the UAV is guided to transition from the current route to the next route in a smooth curve until it flies along the next route, including: calculating the turning angle of the UAV from the current route to the next route; wherein the turning angle is defined as the angle between the starting point of the next route and the extension line of the end of the current route; when the turning angle is less than the preset angle, the first flight step is executed; when the turning angle is greater than the preset angle, the second flight step is executed; the calculation formula for determining the preset angle is: ;in, is the preset angle, is the maximum permissible lateral deviation of the UAV, is the minimum turning radius of the drone, is the current flight speed of the drone, is the maximum acceleration of the drone.

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