WO2021244545A1

WO2021244545A1 - Unmanned aerial vehicle guidance method, unmanned aerial vehicle, and storage medium

Info

Publication number: WO2021244545A1
Application number: PCT/CN2021/097755
Authority: WO
Inventors: 张添保
Original assignee: 深圳市道通智能航空技术股份有限公司
Priority date: 2020-06-05
Filing date: 2021-06-01
Publication date: 2021-12-09
Also published as: CN111522353A; CN111522353B

Abstract

An unmanned aerial vehicle (100) guidance method, an unmanned aerial vehicle (100), and a storage medium, relating to the field of unmanned aerial vehicles (100), the method comprising: acquiring a target trajectory (S20); if the curvature of the target trajectory and the current trajectory are not equal, then determining a turning point (P_T) on the basis of the current trajectory and the target trajectory (S21); acquiring a turning preparation distance (S_R) and a real-time distance of the unmanned aerial vehicle (100) (S22); and, when the real-time distance is less than or equal to the turning preparation distance (S_R), acquiring the flight direction and guidance law model of the unmanned aerial vehicle on the basis of the target trajectory, and controlling the flight of the unmanned aerial vehicle (100) (S23). The turning preparation distance (S_R) of the unmanned aerial vehicle (100) is calculated on the basis of the current flight state thereof, such that when the unmanned aerial vehicle (100) enters the turning preparation distance (S_R), the flight direction and guidance law model are switched in time to control the flight of the unmanned aerial vehicle (100), thereby ensuring that the unmanned aerial vehicle (100) accurately enters the target trajectory at the turning point (P_T), so that the unmanned aerial vehicle (100) flies on the target trajectory, thereby increasing the tracking precision of the unmanned aerial vehicle (100) to the target trajectory.

Description

UAV guidance method, UAV and storage medium

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on June 5, 2020, the application number is 2020105078169, and the application title is "A UAV Guidance Method, UAV and Storage Medium", and its entire contents Incorporated in this application by reference.

Technical field

The invention relates to the field of unmanned aerial vehicles, in particular to an unmanned aerial vehicle guidance method, an unmanned aerial vehicle and a storage medium.

Background technique

Fixed-wing UAVs are widely used in many fields due to their long flying distance and fast flying speed. Among them, fixed-wing UAVs mainly provide lift through their biplanes when flying, and only when the UAV's speed reaches a certain level can it provide sufficient lift.

Since the fixed-wing UAV cannot hover during the flight, when the fixed-wing UAV turns in flight, it will have a poor trajectory tracking effect for trajectories with unequal curvatures, resulting in large tracking errors.

Summary of the invention

An objective of the embodiments of the present invention is to provide a UAV guidance method, UAV and storage medium, which can improve the accuracy of UAV trajectory tracking.

In order to solve the above technical problems, the present invention provides the following technical solutions:

In a first aspect, an embodiment of the present invention provides a UAV guidance method, including: acquiring a target trajectory route;

If the curvatures of the target trajectory route and the current trajectory route are not equal, determining the turning point according to the current trajectory route and the target trajectory route;

Acquiring the turning preparation distance of the drone and the real-time distance between the guidance starting point of the drone and the turning point, wherein the guidance starting point is the current position point of the drone;

When the real-time distance is less than or equal to the turn preparation distance, obtain the flight direction and guidance law model of the drone according to the target trajectory, and control the drone according to the flight direction and the guidance law model. Drone flying.

Optionally, the acquiring the flying direction of the drone according to the target trajectory route includes:

Determine the guidance distance according to the target trajectory route;

Obtain the flying direction of the drone according to the guidance distance, the target trajectory route, and the guidance starting point of the drone, wherein the guidance distance is the distance between the guidance starting point and the guidance end point, and the guidance The end point is located on the target trajectory route.

Optionally, the obtaining the guidance law model of the drone according to the target trajectory route includes:

When the target trajectory route is a straight line, determining that the guidance law model is a straight-line guidance law model;

When the target trajectory is a curve, it is determined that the guidance law model is a curvilinear guidance law model.

Optionally, the acquiring the flying direction of the drone according to the guidance distance, the target trajectory route, and the guidance starting point of the drone includes:

Taking the guidance starting point as the origin of the coordinate system, the flying direction of the current trajectory route is the positive direction of the X axis, and establishing the coordinate system of the drone according to the right-hand rule;

Calculating the angle α between the straight line between the guiding start point and the guiding end point and the positive direction of the X-axis;

The flying direction of the drone is determined according to the included angle α.

Optionally, controlling the drone to fly according to the flight direction and the guidance law model includes:

Calculating the error distance between the current position point and the current expected position point;

Correcting the guidance law model according to the error distance;

According to the revised guidance law model and the flight direction, the UAV is controlled to continuously implement guidance operations on the current trajectory route.

Optionally, the guidance law model includes the linear guidance law model or the curvilinear guidance law model, wherein:

The revised linear guidance law model is:

The revised curve guidance law model is:

Guidance for the speed factor K _V, K _φ is the roll angle guidance factor, K _x and K _y is the guidance error factor, the maximum velocity V _cmax is set by the user, the maximum roll angle φ _cmax provided for the control system of the aircraft, V _c is the speed of the pre-guide, φ _c for the front guide roll angle, α is linearly guided to the guide start point P ₀ P _N where the angle between the end of the X-axis positive direction.

Optionally, the calculating the turn preparation distance of the drone includes:

Calculate the turn preparation distance of the UAV according to the following formula:

S _R ＝3ηTV

S _R is the turn preparation distance, η is the roll angle pilot rate, T is the roll attitude angle control time constant, and V is the flight speed.

Optionally, the guiding distance is less than 2 times the radius of curvature of the current trajectory route.

In a second aspect, an embodiment of the present invention provides a non-volatile computer-readable storage medium, the non-volatile computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable The aircraft executes the UAV guidance method described in any one of the above.

In a third aspect, an embodiment of the present invention provides a drone, including

body;

Wings, mounted on the fuselage;

A power device installed in the fuselage and used to provide power for the drone;

Wherein, the power plant includes:

At least one processor; and,

A memory communicatively connected with the at least one processor; wherein,

The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor, so that the at least one processor can execute the unmanned aerial vehicle as described in any one of the above. Guide method.

Compared with the traditional technology, in the UAV guidance method, UAV and storage medium provided by the various embodiments of the present invention, the target trajectory route is obtained; if the curvature of the target trajectory route and the current trajectory route are not equal, then according to The current trajectory route and the target trajectory route determine the turning point; obtain the turning preparation distance of the drone, and the real-time distance between the drone's guidance starting point and the turning point; when the real-time distance is less than Or when it is equal to the turn preparation distance, obtain the flight direction and guidance law model of the drone according to the target trajectory, and control the drone to fly according to the flight direction and the guidance law model. Calculate the turning preparation distance according to the current flight status of the drone, so that when the drone enters the turning preparation distance, it can switch the flight direction and guidance law model in time to control the flight of the drone to ensure that the drone is at the turning point Time and accurately cut into the target trajectory route, and then make the UAV fly on the target trajectory route, thereby improving the UAV's tracking accuracy of the target trajectory route.

Description of the drawings

One or more embodiments are exemplified by the pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. The elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the attached drawings do not constitute a scale limitation.

FIG. 1 is a schematic structural diagram of an unmanned aerial vehicle provided by an embodiment of the present invention;

2 is a schematic diagram of trajectory routes with unequal curvatures provided by an embodiment of the present invention;

FIG. 3 is a schematic flow chart of an unmanned aerial vehicle guidance method provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a process for determining the flying direction of a drone according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of the flight angle of the UAV in different trajectory routes according to an embodiment of the present invention;

FIG. 6 is a schematic flowchart of a method for revising the guidance of an unmanned aerial vehicle according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a flying turn trajectory route of a drone provided by an embodiment of the present invention;

FIG. 8 is a schematic diagram of a flying turn trajectory route of a drone provided by an embodiment of the present invention;

FIG. 9 is a schematic diagram of a flying turn trajectory route of a drone provided by an embodiment of the present invention;

FIG. 10 is a schematic diagram of a flying turn trajectory route of a drone provided by an embodiment of the present invention.

detailed description

In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of the embodiments of the present invention, but not all of the embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

It should be noted that when an element is expressed as being "fixed to" another element, it can be directly on the other element, or there can be one or more elements in between. When an element is said to be "connected" to another element, it can be directly connected to the other element, or there may be one or more intervening elements in between. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this specification are for illustrative purposes only.

In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Please refer to FIG. 1, which is a schematic structural diagram of an unmanned aerial vehicle according to an embodiment of the present invention. As shown in FIG. 1, the unmanned aerial vehicle 100 includes a fuselage 11, wings 12 and a power unit 13. The wing 12 is installed on the fuselage 11 and fixedly connected to the fuselage 11, wherein the wing 12 and the fuselage 11 are integrally formed. An aileron rudder surface is provided on the trailing edge of the wing 12 for controlling the rolling motion of the UAV 100. It should be noted that FIG. 1 only exemplarily shows several rudder surfaces of the UAV 100. In other embodiments, other rudder surfaces or a larger number of rudder surfaces may also be included.

The power unit 13 is installed in the fuselage 11. The power unit 13 includes a motor and a propeller connected to the motor shaft. The motor can drive the propeller to rotate to provide power for the UAV 100 to achieve flight; the motor can also change the speed of the propeller by changing the speed of the propeller. The flight speed of the man-machine 100. When the power unit 13 is in communication with the flight control system, the flight control system can control the flight of the UAV 100 by controlling the motor.

The power unit 13 also includes a main controller. When the drone 100 performs a flight turn, the main controller controls the aileron rudder surface to tilt to a target tilt angle, and the drone 100 rolls according to the tilt angle. Thus, a roll angle is generated, and the UAV 100 realizes a turn according to the centripetal force generated by the roll angle.

It is understandable that when the curvature of the turning trajectory is equal, the drone controls the drone to fly on the desired flight trajectory according to the current flight state, so that the flight trajectory of the drone can be accurately tracked. However, when the curvature of the turning trajectory is not equal, it takes a certain response time for the UAV to control the aileron rudder surface tilt to produce a roll angle, so that the UAV performs a turning flight without being fully prepared for the turn. , Which makes the actual flight trajectory of the UAV deviate from the expected flight trajectory, which makes it impossible to accurately track the target trajectory of the UAV, which reduces the accuracy of the UAV's trajectory tracking.

Specifically, please refer to Figure 2. The following are examples of situations where the curvatures of drones are not equal when turning:

Case 1: The curvature radius as shown in Figure 2-1 changes from ∞ to radius R;

Case 2: The turning curvature radius shown in Figure 2-2 changes from radius R to ∞;

Case 3: The direction of the bending rate as shown in Figure 2-3 is not the same;

Case 4: As shown in Figure 2-4, the radius and direction of the curvature change.

It should be noted that FIG. 2 only exemplarily shows the curvature changes encountered by the drone when turning. In other embodiments, curvature changes in other situations may also be included.

The guidance method is a method of guiding and controlling the drone to fly to the target position according to a predetermined flight trajectory. It is understandable that the main controller of the drone continuously detects the drone and the target during the guidance process of the drone. The relative position relationship of the position, and the guidance information is generated to control the flight of the UAV.

The embodiment of the present invention provides a UAV guidance method, which is applied to the UAV, so that when the UAV is flying on a trajectory route with unequal curvatures, a suitable guidance law model can be selected according to the trajectory route. The guidance law model controls the drone to fly according to the desired trajectory, thereby improving the trajectory tracking accuracy of the drone.

The drone in the present invention can be any suitable type of high-altitude drone or low-altitude drone, including fixed-wing drones, rotary-wing drones, para-wing drones, or flapping-wing drones.

Specifically, please refer to Figure 3. The guidance method includes:

S20: Obtain the target trajectory route;

S21: If the curvature of the target trajectory route is not equal to the curvature of the current trajectory route, determine the turning point according to the current trajectory route and the target trajectory route;

Curvature is the rate of rotation of the tangent direction angle of the pointer to a point on the curve to the arc length. It is used to indicate the degree of deviation of the curve from a straight line. The greater the curvature, the greater the degree of curvature of the curve. Unequal curvature means that two curves have different radii of curvature and/or different directions at the contact point. Specifically, unequal curvature means that the two curves have different radii of curvature at the contact point and have the same direction of curvature; or, two The curvature radius of the curve at the contact point is the same, but the direction of curvature is different; or, the curvature radius and direction of the two curves at the contact point are different.

In the embodiment of the present invention, the turning point is the contact point between the current trajectory route and the target trajectory route, and the drone can turn at the turning point to the target trajectory route along the current trajectory route. The guidance method is used to control the UAV to accurately cut into the target trajectory route from the current trajectory route at the turning point.

It is understandable that the trajectory route includes a straight trajectory route and a curved trajectory route, wherein the curved trajectory route refers to a regular circular arc curve. In the embodiment of the present invention, at least one of the current trajectory route and the target trajectory route is a curved trajectory route. For example, if the current trajectory route is a straight trajectory route, the target trajectory route is a curved trajectory route; If the route is a curved trajectory, the target trajectory is a straight trajectory or a curved trajectory.

Specifically, the curvature of the current trajectory route and the target trajectory route are not equal, including different radii of curvature and/or different curvature directions, wherein the curvature direction includes a clockwise curvature direction or a counterclockwise curvature direction. It can be understood that the radius of curvature of the straight trajectory route is ∞, and the radius of curvature of the curved trajectory route is R. When any one of the current trajectory route and the target trajectory route is a straight trajectory route, and the other is a curved trajectory route, the curvature radius and the curvature direction of the current trajectory route and the target trajectory route are different; When the current trajectory route and the target trajectory route are both curved trajectory routes, then when the current trajectory route and the target trajectory route have different curvature directions and/or different curvature radii.

S22: Obtain the turning preparation distance of the drone and the real-time distance between the guidance starting point of the drone and the turning point, where the guidance starting point is the current position point of the drone;

Turn preparation distance refers to the safety distance required to control the roll angle of the UAV when turning in the current flight state. Within this safe distance, control the drone to produce a roll angle so that the drone can accurately cut into the target trajectory at the turning point. It is understandable that it takes a certain amount of time for the UAV to generate the roll angle corresponding to the target trajectory. If the UAV starts to generate the roll angle when it reaches the turning point, it will cause the UAV’s flight trajectory to deviate from all directions. The target trajectory route is described and the trajectory tracking error is generated. Therefore, in the embodiment of the present invention, according to the performance characteristics of the drone itself, the turn preparation distance of the drone in the current flight state is calculated to ensure that the drone can accurately reach the turning point. Cut into the target trajectory route at the turning point. Wherein, the flight status includes the current flight speed of the drone.

Specifically, the turning preparation distance of the drone is calculated according to the following formula:

S _R ＝3ηTV

Wherein, the roll angle pilot rate η and the roll attitude angle control time constant T are pre-stored in the UAV. In the embodiment of the present invention, the roll attitude angle control time constant T is the UAV generating the roll It can be understood that the value of the pre-stored roll attitude angle control time constant T is also different for each drone according to its own parameters; the roll angle pilot rate η takes a value between 0.3 and 0.5 between. It can be seen that the turn preparation distance S _R is positively correlated with the current flight speed V of the drone. The faster the current flight speed V is, the _{greater the turn preparation distance S R of} the drone is.

In some embodiments, the turn preparation distance may be determined according to the comprehensive performance of the drone, and the turn preparation distance may be set to a constant value and stored in the drone.

The real-time distance refers to the distance between the current position of the drone and the turning point. When the current trajectory of the drone is a straight trajectory, the real-time distance is the current of the drone. The straight-line distance between the location point and the turning point; when the current trajectory route of the drone is a curved trajectory route, the real-time distance is the length of the curve between the current location point of the drone and the turning point .

S23: When the real-time distance is less than or equal to the turn preparation distance, obtain the flight direction and guidance law model of the drone according to the target trajectory, and control according to the flight direction and the guidance law model The drone flies.

Wherein, the flight direction is used to indicate the deviation of the drone relative to the current flight direction, and the deviation angle is used to identify its size and direction. If the deviation angle is greater than zero, the drone is controlled to move in a clockwise direction Flying; if the offset angle is equal to zero, the UAV is controlled to fly straight forward; if the offset angle is less than zero, the UAV is controlled to fly in a counterclockwise direction.

The guidance law model is used to define the law of the UAV flying according to the trajectory route and determine the trajectory route of the UAV flight. Wherein, the trajectory route includes a straight trajectory route or a curved trajectory route. It is understandable that each trajectory route corresponds to a guidance law model. In the embodiment of the present invention, the guidance law model includes a linear guidance law model or a curvilinear guidance law model. Model. When the trajectory is a straight trajectory, the linear guidance model is selected to guide the UAV to fly; when the trajectory is a curved trajectory, the curved guidance model is selected to guide the UAV to fly.

In the embodiment of the present invention, the flight direction and guidance law model of the drone are determined according to the real-time distance and the turn preparation distance. First, determine whether the real-time distance is less than or equal to the turn preparation distance;

If not, the UAV has not yet entered the turn preparation distance range. The UAV obtains its flight direction and guidance law model according to the current trajectory, and controls it according to the flight direction and the guidance law model. The drone flies. Specifically, when the current trajectory route is a straight line, it is determined that the guidance law model is a straight-line guidance law model; when the current trajectory route is a curve, it is determined that the guidance law model is a curvilinear guidance law model.

If yes, the UAV has entered the turn preparation distance range, the UAV obtains its flight direction and guidance law model according to the target trajectory, and controls the UAV according to the flight direction and the guidance law model. Drone flying. Specifically, when the target trajectory route is a straight line, it is determined that the guidance law model is a linear guidance law model; when the target trajectory route is a curve, it is determined that the guidance law model is a curvilinear guidance law model.

It should be noted that, in the embodiment of the present invention, the process of guiding the UAV to fly from the current trajectory path into the target trajectory path is called a complete guidance process. It is understandable that when the drone receives a turning flight instruction, the drone generates a current trajectory route and a target trajectory route according to the turning flight instruction, and executes the above-mentioned trajectory route on the current trajectory route and the target trajectory route. In the guidance method, after the drone cuts into the target trajectory route at the turning point, the drone will fly according to the guidance law model corresponding to the target trajectory route until the drone receives a turning flight instruction or other flight instructions.

It should also be noted that, during a complete guidance process of the drone, after the drone has flew for a long time according to the guidance law model, it returns to step S22 to follow the current situation of the drone. The flight status calculates the turn preparation distance and the real-time distance, and then determines the flight direction of the drone and the guidance law model to guide the drone to fly. Of course, the flight time of the aforementioned drone according to the guidance law model can be set to be longer or shorter than one step time, which is not limited here.

In the embodiment of the present invention, the target trajectory route is acquired; if the curvature of the target trajectory route and the current trajectory route are not equal, the turning point is determined according to the current trajectory route and the target trajectory route; and the turning point of the drone is calculated Preparation distance, and the real-time distance between the guidance starting point of the drone and the turning point; when the real-time distance is less than or equal to the turning preparation distance, the drone is acquired according to the target trajectory route Flight direction and guidance law model, and control the drone to fly according to the flight direction and the guidance law model. Calculate the turning preparation distance according to the current flight status of the drone, so that when the drone enters the turning preparation distance, it can switch the flight direction and guidance law model in time to control the flight of the drone to ensure that the drone is at the turning point Time and accurately cut into the target trajectory route, and then make the UAV fly on the target trajectory route, thereby improving the UAV's tracking accuracy of the target trajectory route.

The flight direction is used to indicate the deviation of the UAV relative to the current flight direction. It is understandable that when the UAV is flying on different trajectory routes, the flight direction of the UAV is obtained according to its flying trajectory. . Specifically, please refer to Figure 4. Obtaining the flying direction of the UAV according to the trajectory of the UAV includes:

S31: Determine the guidance distance according to the trajectory route;

S32: Obtain the flying direction of the drone according to the guidance distance, the trajectory route, and the guidance starting point of the drone.

Wherein, the trajectory route of the drone includes a current trajectory route and/or a target trajectory route. Specifically, when the real-time distance is less than or equal to the turn preparation distance, the drone follows the target trajectory route Determine the guidance distance, and obtain the flight direction of the drone according to the guidance distance, the target trajectory route and the guidance starting point of the drone; when the real-time distance is greater than the turn preparation distance, the The drone determines the guidance distance according to the current trajectory route, and obtains the flying direction of the drone according to the guidance distance, the current trajectory route, and the guidance starting point of the drone.

In the embodiment of the present invention, the guidance distance refers to the straight-line distance between the guidance start point and the guidance end point, where the guidance start point refers to the location point of the drone at the current time, and the guidance end point refers to the location point of the drone at the current time. As the starting point, the guiding distance is the length, and the intersection point on the trajectory route or the trajectory route extension line. Wherein, the trajectory route refers to the trajectory route corresponding to the current guidance law model of the drone. When the real-time distance is greater than the turn preparation distance, the UAV flies on the current trajectory route according to the guidance law model, that is, the trajectory route is the current trajectory route; when the real-time distance is less than or equal to the During the turn preparation distance, the drone flies on the target trajectory route according to the guidance law model, that is, the trajectory route is the current trajectory route.

In order to determine the flight direction more intuitively and accurately, the obtaining the flight direction of the drone according to the guidance distance, the target trajectory route and the guidance starting point of the drone includes:

S321: Taking the guidance starting point as the origin of the coordinate system, and taking the flying direction of the drone at the guidance starting point as the positive X-axis direction, and establishing the coordinate system of the drone according to the right-hand rule;

S322: Calculate the angle α between the straight line where the guiding start point and the guiding end point are and the positive direction of the X-axis;

S323: Determine the flying direction of the drone according to the included angle α.

Specifically, see Figure 5, when the track is a curved trajectory path as shown in Figure 5-1, the guide with the guide start point P ₀ P _N where the end point of line with the X-axis positive direction If the angle α>0, the flying direction of the drone is clockwise; when the trajectory is a straight trajectory as shown in Figure 5-2, the guidance starting point P ₀ and the guidance end point _{The angle α between the line where PN} is and the positive direction of the X axis is α=0, then the flying direction of the UAV is straight forward; when the trajectory is a curved trajectory as shown in Fig. 5-3 when the guide guide start point P ₀ and the end point of line P _N where the X-axis positive direction is an angle α <0, the direction of flight of the UAV flight counterclockwise.

It can be seen that the guidance distance is used to assist the drone in determining its offset direction relative to the current flight direction. In the embodiment of the present invention, the guidance distance is less than twice the current trajectory route. The radius of curvature, and, during the guiding process, the guiding distance is a fixed value.

In the embodiment of the present invention, the guidance distance is determined according to the trajectory, and the current position of the drone is taken as the origin of coordinates, and the flying direction of the drone at the current position is the positive direction of the X axis. The rule establishes a coordinate system in which the flight direction of the drone is calculated, which improves the accuracy of calculating the flight direction of the drone.

It is understandable that flight errors will inevitably occur in the flight control of the UAV. In order to improve the accuracy of the flight control and reduce the flight error, please refer to FIG. 6, an embodiment of the present invention provides a UAV flight control method , In order to correct the errors that occur during the flight of the UAV, the method includes:

S41: Calculate the error distance between the current position point and the current expected position point;

Specifically, the difference between the X-axis coordinate of the current desired position point in the coordinate system and the X-axis coordinate of the current position point is calculated respectively to obtain the first coordinate difference; and the current desired position is calculated separately A point is a second coordinate difference between the Y-axis coordinate of the drone coordinate system and the Y-axis coordinate of the current position point to obtain the second coordinate difference. Suppose the current desired position point is P _0c , and its corresponding coordinate position in the above-mentioned coordinate system is

The current position point is P ₀ , and its corresponding coordinate position in the above-mentioned coordinate system is

Then, the coordinate difference between the current location point of the drone and the current desired location point is:

Wherein, e _x is the first coordinate difference, and e _y is the second coordinate difference.

S42: Correct the guidance law model according to the error distance;

In the embodiment of the present invention, the guidance law model includes a linear guidance law model or a curvilinear guidance law model, and the error distance obtained by the above calculation is used to correct the linear guidance law model or the curvilinear guidance law model. The linear guidance law model is:

The revised curve guidance law model is:

Wherein, K _V is the velocity guidance _factor, K φ is the roll angle guidance factor, K _x and K _y is the guidance error factor, V _cmax for the user to set the maximum speed, φ _cmax system arranged to control roll of the aircraft maximum angle, V _c is the speed of the front guide, φ _c for the front guide roll angle, α as a guide start point P ₀ and the angle between the straight guide and the end point X-axis positive direction P _N is located.

It is understandable that the leading guidance speed V _c and the leading guidance roll angle φ _{c are} the guidance parameters generated by the drone according to the guidance law model, and the drone controls the drone according to the above guidance parameters. Man-machine flight.

S43: According to the revised guidance law model and the flight direction, control the UAV to continuously implement a guidance operation on the current trajectory route.

In the embodiment of the present invention, the error distance between the current position point of the drone and the current expected position point is calculated, and the error distance is used to correct the linear guidance law model or the curvilinear guidance law model. The UAV is made to fly according to the revised guidance law model, thereby reducing the flight error of the UAV and improving the tracking accuracy of the UAV on the trajectory.

In order to explain in more detail that the UAV uses the above guidance method to make it accurately cut into the target trajectory route from the current trajectory at the turning point, the curvature of the UAV when the above-mentioned UAV turns is not used in the following. Take an equal situation as an example, and describe in detail the guidance process of the UAV during flight:

Please refer to Fig. 7, when the current trajectory route is a straight trajectory route and the target trajectory route is a curved trajectory route, obtain the turning preparation distance and the real-time distance of the UAV, and determine whether the real-time distance is less than the Turn preparation distance; if not, select the linear guidance law model; if yes, select the curvilinear guidance law model.

Specifically, as shown in Fig. 7, the current position point of the UAV at _{P 0} _{, the current position point P 0} is taken as the origin of the coordinate system, and the flight direction of the current trajectory is the positive direction of the X axis, according to The right-hand rule establishes the coordinate system of the UAV; _PN is the intersection point of the current trajectory route with P ₀ as the starting point of guidance and the length of the guidance distance L as the length of the current trajectory, which is the guidance end point; P _T is the turning point and α is the point flight said guide start point P ₀ and the angle between the guide end point of line P _N where the X-axis positive direction, the UAV includes the following three stages:

Stage I: When the UAV is flying on the straight trajectory and does not enter the turn preparation distance range, that is, when the real-time distance is greater than the turn preparation distance, the guidance starting point P ₀ and the guidance ending point P _{The straight line where N} is located coincides with the X axis, and the included angle α=0, the UAV selects the straight-line guidance law model according to the current straight-line trajectory as the guidance law model of the current flight, and according to the straight-line guidance The law model guides the UAV to fly straight forward.

Stage II: When the UAV enters the turn preparation distance range, that is, when the real-time distance is less than or equal to the turn preparation distance, the UAV's guidance law model is switched from the linear guidance law model to curve guidance law model, wherein the end guide is located on the target track P _N route guidance start point P ₀ and the angle α of the straight line and the X axis guide P _N where the end point of> 0, the no The man-machine guides the UAV to fly in a clockwise direction according to the curve guidance law model. It should be noted that the flight of the UAV at this stage is a transitional stage from the current trajectory route to the target trajectory route. Therefore, the flight trajectory route at this stage is neither similar to a straight trajectory nor approximate It is a curvilinear trajectory route, but a trajectory route between a straight trajectory route and a curved trajectory route.

Stage III: When the drone reaches or flies over the turning point P _T , the drone accurately cuts into the target trajectory route from a straight trajectory route, that is, a curved trajectory route, and continues to follow the curve guidance law model and The flight direction controls the drone to fly. It should be noted that when the UAV flies over the turning point, it can be understood that the UAV has completed the flight of the UAV from the current trajectory route according to the above-mentioned guidance method of the UAV. Trajectory route tracking of the target trajectory route.

When the current trajectory route is a curved trajectory route and the target trajectory route is a straight trajectory route, acquiring the turning preparation distance and the real-time distance of the drone, and judging whether the real-time distance is less than the turning preparation distance; if No, select the curvilinear guidance law model; if yes, select the linear guidance law model.

Specifically, please refer to Fig. 8, the current position of the UAV at _{P 0} _{, the current position P 0} is the origin of the coordinate system, the flight direction of the current trajectory is the positive direction of the X axis, according to the right hand The rule establishes the coordinate system of the UAV; _PN is the intersection point of the current trajectory route with P ₀ as the starting point of guidance and the length of the guidance distance L as the length of the current trajectory, that is, the guidance end point; P _T is the turning point, and α is the a guide start point P ₀ and the angle between the guide end point of line P _N where the X-axis positive direction, the UAV flight includes the following three stages:

Phase I: When the UAV is flying on the curved trajectory and has not entered the turn preparation distance range, that is, when the real-time distance is greater than the turn preparation distance, the guidance starting point P ₀ and the guidance ending point P _If the angle α between the straight line where N is and the positive direction of the X axis is <0, the UAV selects the curvilinear guidance law model according to the current curvilinear trajectory route as the guidance law model of the current flight, and according to the curvilinear guidance law The model guides the drone to fly in a counterclockwise direction.

Phase II: When the UAV enters the turn preparation distance range, that is, when the real-time distance is less than or equal to the turn preparation distance, the UAV's guidance law model is switched from the curve guidance law model to linear guidance law model, wherein the end guide is located on the target track P _N route guidance start point P ₀ and the angle α of the straight line and the X axis guide P _N where the end point of <0, the no The man-machine guides the UAV to fly in a counterclockwise direction according to the curve guidance law model. It should be noted that the flight of the UAV at this stage is a transitional stage from the current trajectory route to the target trajectory route. Therefore, the flight trajectory route at this stage is neither similar to a straight trajectory nor approximate It is a curvilinear trajectory route, but a trajectory route between a straight trajectory route and a curved trajectory route.

Stage III: When the UAV arrives at or flies over the turning point P _T , the UAV accurately cuts into the target trajectory route from a curved trajectory route, that is, a straight trajectory route, and continues to follow the linear guidance law model and The flight direction controls the drone to fly. It should be noted that when the UAV flies over the turning point, it can be understood that the UAV has completed the flight of the UAV from the current trajectory route according to the above-mentioned guidance method of the UAV. Trajectory route tracking of the target trajectory route.

When the current trajectory route is a first curved trajectory route, the target trajectory route is a second curved trajectory route, wherein the curvatures of the first curved trajectory route and the second curved trajectory route are not equal.

Specifically, please refer to FIGS. 9 and 10 together. In FIG. 9, the radius of curvature of the first curved trajectory route and the second curved trajectory route are the same, and the directions are different; in FIG. 10, the first curved trajectory The radius of curvature and direction of the route and the second curved track route are different.

It is understandable that the guidance law models corresponding to the above-mentioned first curved trajectory route and the second trajectory route are both curved guidance law models, and the curved guidance law model has different outputs according to the curvature radius and direction angle of different curved trajectories. The guidance parameters.

Specifically, taking the current position point P ₀ as the origin of the coordinate system, the flying direction of the current trajectory route is the positive direction of the X axis, and the coordinate system of the drone is established according to the right-hand rule; P _N is expressed as P ₀ is the starting point of guidance, and the intersection of the current trajectory route or the extension of the current trajectory route with the guidance distance L as the length is the guidance end point; P _T is the turning point, and α is the guidance starting point P ₀ and the guidance end point P _{The angle between the line where N} is and the positive direction of the X-axis, the flight of the UAV mainly includes the following three stages:

Stage I: When the UAV is flying on the first curved trajectory and does not enter the turn preparation distance range, that is, when the real-time distance is greater than the turn preparation distance, the guidance starting point P ₀ and the guidance P _N where the end point of line with angle α of the X-axis positive direction is <0, then the UAV guidance law model curve selected as the current flight guidance law model curve according to the first track path, and according to the curve The guidance law model guides the UAV to fly in a counterclockwise direction.

Stage II: When the UAV enters the turn preparation distance range, that is, when the real-time distance is less than or equal to the turn preparation distance, the UAV's guidance law model is still a curved guidance law model, ⅰ stage is different and, at this stage, the end of the guide is located on the target track P _N route, the guiding angle α of the straight line and the X axis of the guide start point P ₀ where the end point P _N> 0: The UAV guides the UAV to fly in a clockwise direction according to the curve guidance law model. It should be noted that the flight of the UAV at this stage is a transitional stage from the first curved trajectory route to the second curved trajectory route. Therefore, the flight trajectory route at this stage is neither similar to the first curve. The trajectory route is not similar to the second curved trajectory route, but a trajectory route between the first curved trajectory route and the second curved trajectory route.

Stage III: When the UAV reaches or flies over the turning point P _T , the UAV accurately cuts into the first curved trajectory route from the first curved trajectory line, and continues to follow the curved guidance law model and flight direction Control the drone to fly. It should be noted that when the UAV flies over the turning point, it can be understood that the UAV has completed the flight of the UAV from the current trajectory route according to the above-mentioned guidance method of the UAV. Trajectory route tracking of the target trajectory route.

The above-described device or device embodiments are merely illustrative. The unit modules described as separate components may or may not be physically separated, and the components displayed as modular units may or may not be physical units. , Which can be located in one place, or can be distributed to multiple network module units. Some or all of the modules can be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

Through the description of the above implementation manners, those skilled in the art can clearly understand that each implementation manner can be implemented by means of software plus a general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution essentially or the part that contributes to the related technology can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk , CD-ROM, etc., including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiment.

The embodiment of the present invention provides a non-volatile computer-readable storage medium, the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are executed by one or more processors, for example, execute the above Describe the method steps of Figures 3, 4, and 6.

The embodiment of the present invention provides a computer program product, which includes one or more processors and a memory, and the processors and the memory may be connected through a bus or in other ways.

As a non-volatile computer-readable storage medium, the memory can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The processor executes various functional applications and data processing of the server by running non-volatile software programs, instructions, and modules stored in the memory.

The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some embodiments, the memory may optionally include a memory remotely arranged with respect to the processor, and these remote memories may be connected to the processor through a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

The program instructions/modules are stored in the memory, and when executed by the one or more processors, the UAV guidance method in any of the foregoing method embodiments is executed, for example, the above-described FIG. 3 and FIG. 4 and Figure 6 method steps.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; under the idea of the present invention, the technical features of the above embodiments or different embodiments can also be combined. The steps can be implemented in any order, and there are many other variations in the different aspects of the present invention as described above. For the sake of brevity, they are not provided in details; although the present invention has been described in detail with reference to the foregoing embodiments, the ordinary person in the art The skilled person should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or equivalently replace some of the technical features; and these modifications or replacements do not divorce the essence of the corresponding technical solutions from the implementations of the present invention. Examples of the scope of technical solutions.

Claims

An unmanned aerial vehicle guidance method, characterized in that it comprises:

Obtain the target trajectory route;

If the curvatures of the target trajectory route and the current trajectory route are not equal, the turning point is determined according to the current trajectory route and the target trajectory route;

Acquiring the turning preparation distance of the drone and the real-time distance between the guidance starting point of the drone and the turning point, wherein the guidance starting point is the current position point of the drone;

When the real-time distance is less than or equal to the turn preparation distance, obtain the flight direction and guidance law model of the drone according to the target trajectory, and control the drone according to the flight direction and the guidance law model. Drone flying.
The method according to claim 1, wherein the obtaining the flying direction of the drone according to the target trajectory route comprises:

Determine the guidance distance according to the target trajectory route;

Obtain the flying direction of the drone according to the guidance distance, the target trajectory route, and the guidance starting point of the drone, wherein the guidance distance is the distance between the guidance starting point and the guidance end point, and the guidance The end point is located on the target trajectory route.
The method according to claim 2, wherein the acquiring the flying direction of the drone according to the guidance distance, the target trajectory route, and the guidance starting point of the drone comprises:

Taking the guidance starting point as the origin of the coordinate system, the flying direction of the current trajectory route is the positive direction of the X axis, and establishing the coordinate system of the drone according to the right-hand rule;

Calculating the angle α between the straight line where the guiding start point and the guiding end point are and the positive direction of the X-axis;

The flying direction of the drone is determined according to the included angle α.
The method according to any one of claims 1 to 3, wherein obtaining a guidance law model of the UAV according to the target trajectory route comprises:

When the target trajectory route is a straight line, determining that the guidance law model is a straight-line guidance law model;

When the target trajectory is a curve, it is determined that the guidance law model is a curvilinear guidance law model.
The method according to claim 4, wherein the controlling the flight of the drone according to the flight direction and the guidance law model comprises:

Calculating the error distance between the current position point and the current expected position point;

Correcting the guidance law model according to the error distance;

According to the revised guidance law model and the flight direction, the drone is controlled to fly.
The method according to claim 5, wherein the revised linear guidance law model is:

The revised curve guidance law model is:

Wherein, K V is the velocity guidance factor, K φ is the roll angle guidance factor, K x and K y is the guidance error factor, V cmax for the user to set the maximum speed, φ cmax system arranged to control roll of the aircraft maximum angle, V c is the speed of the front guide, φ c for the front guide roll angle, α is linearly guided to the guide start point P 0 P N where the angle between the end of the X-axis positive direction.
The method according to claim 1, wherein the obtaining the turn preparation distance of the UAV comprises:

Calculate the turn preparation distance of the UAV according to the following formula:

S R ＝3ηTV

Among them, S R is the turn preparation distance, η is the roll angle pilot rate, T is the roll attitude angle control time constant, and V is the flight speed.
The method according to claim 4, wherein the guiding distance is less than 2 times the radius of curvature of the current trajectory route.
A non-volatile computer-readable storage medium, wherein the non-volatile computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to make the drone execute The UAV guidance method described in any one of 1 to 8.
An unmanned aerial vehicle, characterized in that it comprises

body;

Wings, mounted on the fuselage;

A power device installed in the fuselage and used to provide power for the drone;

Wherein, the power plant includes:

At least one processor; and,

A memory communicatively connected with the at least one processor; wherein,

The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor, so that the at least one processor can execute any one of claims 1 to 8. UAV guidance method.