Ground target positioning method and device based on rotor type unmanned aerial vehicle

Abstract

The invention belongs to the technical field of target tracking, and relates to a ground target positioning method and device based on a rotor type unmanned aerial vehicle. The method comprises the steps that S1, when the unmanned aerial vehicle is located at a certain air position, flight parameters of the air position are obtained, and the flight parameters comprise coordinates (x0, y0 and z0) of the unmanned aerial vehicle in a rectangular coordinate system, the current course angle alpha of the unmanned aerial vehicle and the pitch angle theta of a lens installed on the unmanned aerial vehicle and used for locking a ground target; the rectangular coordinate system takes a take-off point of the unmanned aerial vehicle as an original point, the east direction is an X axis, the north direction is a Y axis, and the vertical direction is a Z axis; and S2, resolving the position of the ground target. According to the invention, the method can achieve the quick and precise positioning of a ground target, requires a small number of platform airborne equipment, has a small impact on the endurance of an unmanned plane, is easy to operate, is small in calculation amount, and is high in anti-interference capability.

Description

Technical Field

[0001] The present application belongs to the field of target tracking technology, and in particular relates to a ground target positioning method and device based on a rotary-wing unmanned aerial vehicle. Background Art

[0002] With the development of drone technology in recent decades, drones have played an increasingly important role in modern warfare. Drones are low-cost and can be used to quickly obtain accurate targets of valuable enemy ground targets and carry out strikes, or send the precise location of the target to the military strike group to destroy the enemy's high-value targets and manpower in one fell swoop. In the fields of military, logistics, counter-terrorism, resource exploration, biological protection, forest and grassland inspection and firefighting, there is a widespread demand for accurate positioning of ground targets, and there is also a demand for trajectory recording and speed measurement for ground moving targets.

[0003] The existing narrow sense of aviation UAVs can be divided into two categories: rotary wing UAVs and fixed wing UAVs. These two types of UAVs have their own advantages and disadvantages and applicable occasions. For rotary wing UAVs, they are flexible to operate and easy to train. They can quickly change their spatial position in six directions according to the needs, and can achieve no-dead-angle reconnaissance of targets. In addition, the take-off and landing requirements of rotary wing UAVs are very low, and they can perform tasks in areas with complex spatial interference (such as cities with dense buildings, forests, factories, etc.); however, they have inherent disadvantages such as short endurance, short range, low practical ceiling, slow flight speed, and small payload carrying capacity. Generally, they can only operate within 10 kilometers of the take-off point. For fixed wing UAVs, they have advantages such as high practical ceiling, fast flight speed, long endurance (generally more than 10 hours), large payload carrying capacity, and can replace manned aircraft to carry out long-range strike missions; however, they have disadvantages such as relatively less flexible operation than rotary wing UAVs, inability to perform tasks in complex spatial areas, high requirements for take-off and landing sites, generally need auxiliary equipment, and relatively complex training. The advantages, disadvantages and applicable scenarios of rotary-wing UAVs and fixed-wing UAVs are basically complementary, and can form a combination of low-altitude front-line battlefield information acquisition and high-altitude long-range strikes.

[0004] The closer to the reconnaissance target, the higher the real-time positioning accuracy. Rotor-type UAVs have good low-altitude maneuverability and can stably hover to obtain ground information, which is very suitable for the precise positioning of ground targets. Existing UAV ground target positioning methods include: the UAV's own attitude and position information combined with laser ranging combined solution method, the target area terrain matching positioning method, the image recognition positioning method combined with high-definition satellite images of the target area, and the multi-base station assisted positioning method. The above-mentioned ground target positioning methods have the following shortcomings:

[0005] (1) Many onboard devices need to be carried. In the laser ranging method of solving the position, the laser ranging module needs to be integrated, which will reduce the endurance and range of the UAV. In addition, it is also necessary to solve the problems of data fusion and coordination between the camera module and the laser ranging module.

[0006] (2) Image recognition positioning and terrain matching positioning methods require relatively powerful computing power, which will affect the endurance of the UAV. In addition, the target needs to be marked in advance, which is not suitable for real-time positioning of dynamic targets. For binocular vision positioning, its effective positioning distance is short and the positioning accuracy is low.

[0007] (3) For positioning methods that require base station assistance, additional equipment is required, which is relatively costly.

[0008] In order to meet the needs of real-time positioning and speed measurement of ground targets by low, small and slow aircraft such as rotary-wing UAVs, a ground target positioning and speed measurement method was proposed. It can achieve relatively accurate positioning and speed measurement of ground targets without the need for complex fuselage equipment and other complex auxiliary equipment. Summary of the invention

[0009] In order to solve at least one of the above technical problems, the present application provides a ground target positioning method and device based on a rotary-wing UAV to achieve the positioning and speed measurement of ground targets.

[0010] The first aspect of the present application provides a ground target positioning method based on a rotary-wing UAV, which mainly includes:

[0011] Step S1, when the UAV is at a certain aerial position, obtain the flight parameters of the aerial position, the flight parameters include the coordinates (x0, y0, z0) of the UAV in a rectangular coordinate system, the current heading angle α of the UAV, and the pitch angle θ of a lens installed on the UAV for locking a ground target, the rectangular coordinate system takes the take-off point of the UAV as the origin, the east direction is the X axis, the north direction is the Y axis, and the vertical upward direction is the Z axis;

[0012] Step S2: Calculate the position (x, y, z) of the ground target based on the following formula:

[0013]

[0014] z=z * ;

[0015] Among them, z * is the height of the ground target. When the height of the ground target is consistent with the height of the UAV take-off point, the height of the ground target z * is 0, otherwise, an equation about the horizontal coordinate and / or vertical coordinate of the ground target is constructed through the flight parameters of at least two air positions to solve the height z of the ground target * .

[0016] Preferably, step S1 further comprises obtaining flight parameters of at least two aerial positions by:

[0017] Flying a single UAV to two or more aerial locations to obtain flight parameters at different aerial locations, and / or

[0018] The flight parameters at different aerial positions are obtained by using two or more drones at different aerial positions.

[0019] Preferably, step S2 further comprises:

[0020] Step S21: When the flight parameters of the two air positions are used to construct equations about the horizontal and vertical coordinates of the ground target to solve the height z of the ground target, * When the height of the ground target calculated based on the ground target abscissa equation and the height of the ground target calculated based on the ground target ordinate equation are averaged as the final height z of the ground target * , then based on the final ground target height z * Calculate the horizontal coordinates of the ground targets corresponding to the two aerial positions, and take the average value as the horizontal coordinate of the final ground target. At the same time, based on the height z of the final ground target * Calculate the ordinates of the ground target corresponding to the two aerial positions and take the average value as the final ordinate of the ground target;

[0021] Step S22: when multiple air position flight parameters are used to construct equations about the horizontal and vertical coordinates of the ground target to solve the height z of the ground target * When the position of the ground target is calculated for any two aerial positions in the manner of step S21, the final ground target position is obtained by calculating the average value.

[0022] Preferably, step S2 further comprises:

[0023] Step S3: Convert the ground target position into geographic coordinate system coordinates using the following formula:

[0024]

[0025] h o =h s +z;

[0026] Among them, J o , W o 、h o are the longitude, latitude and altitude of the ground target in the geographic coordinate system; J s , W s 、h sare the longitude, latitude and altitude of the take-off point of the drone; W is the latitude of the aerial position, R e is the radius of the Earth.

[0027] Preferably, step S2 further comprises:

[0028] Step S4: Estimate the moving speed of the ground target using the position data of the ground target at the latest moment and the position data of the ground target at the previous moment.

[0029] The second aspect of the present application provides a ground target positioning device based on a rotary-wing UAV, which mainly includes:

[0030] A flight parameter acquisition module is used to acquire the flight parameters of a certain aerial position when the drone is in the air. The flight parameters include the coordinates (x0, y0, z0) of the drone in a rectangular coordinate system, the current heading angle α of the drone, and the pitch angle θ of a lens installed on the drone for locking a ground target. The rectangular coordinate system takes the take-off point of the drone as the origin, the east direction is the X axis, the north direction is the Y axis, and the vertical upward direction is the Z axis.

[0031] The ground target position calculation module is used to calculate the position (x, y, z) of the ground target based on the following formula:

[0032]

[0033] z=z * ;

[0034] Among them, z * is the height of the ground target. When the height of the ground target is consistent with the height of the UAV take-off point, the height of the ground target z * is 0, otherwise, an equation about the horizontal coordinate and / or vertical coordinate of the ground target is constructed through the flight parameters of at least two air positions to solve the height z of the ground target * .

[0035] Preferably, the flight parameters of at least two air positions are obtained by:

[0036] Flying a single UAV to two or more aerial locations to obtain flight parameters at different aerial locations, and / or

[0037] The flight parameters at different aerial positions are obtained by using two or more drones at different aerial positions.

[0038] Preferably, the ground target position solving module comprises:

[0039] The dual air position solving ground target position unit is used to construct equations about the horizontal and vertical coordinates of the ground target through the flight parameters of the two air positions to solve the height z of the ground target * When the height of the ground target calculated based on the ground target abscissa equation and the height of the ground target calculated based on the ground target ordinate equation are averaged as the final height z of the ground target * , then based on the final ground target height z * Calculate the horizontal coordinates of the ground target corresponding to the two air positions, and take the average value as the horizontal coordinate of the final ground target. At the same time, based on the height z of the final ground target * Calculate the ordinates of the ground target corresponding to the two aerial positions and take the average value as the final ordinate of the ground target;

[0040] The multi-air position solving ground target position unit is used to construct equations about the horizontal and vertical coordinates of the ground target through multiple air position flight parameters to solve the height z of the ground target * When the ground target position is calculated by calling the dual-air position solving ground target position unit for any two air positions, the final ground target position is obtained by calculating the average value.

[0041] Preferably, the ground target positioning device further comprises:

[0042] The geographic coordinate system conversion module is used to convert the ground target position into the geographic coordinate system coordinates using the following formula:

[0043]

[0044] h o =h s +z;

[0045] Among them, J o , W o 、h o are the longitude, latitude and altitude of the ground target in the geographic coordinate system; J s , W s 、h s are the longitude, latitude and altitude of the take-off point of the drone; W is the latitude of the aerial position, R e is the radius of the Earth.

[0046] Preferably, the ground target positioning device further comprises:

[0047] The ground target moving speed calculation module is used to estimate the moving speed of the ground target using the position data of the ground target at the latest moment and the position data of the ground target at the previous moment.

[0048] This application can achieve rapid and accurate positioning of ground targets, requires few platform-borne equipment, has little impact on the UAV's endurance, is easy to operate, requires little calculation, and has strong anti-interference capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a flow chart of a preferred embodiment of the ground target positioning method based on a rotary-wing UAV of the present application.

[0050] Figure 2 For this application Figure 1 A schematic diagram of the rectangular coordinate system of the take-off point of the UAV and the positional relationship between the UAV and the target in the illustrated embodiment.

[0051] Figure 3 For this application Figure 1 A schematic diagram of positioning a single UAV at two measuring points in the illustrated embodiment.

[0052] Figure 4 This is a schematic diagram of target motion trajectory recording. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0054] The first aspect of the present application provides a ground target positioning method based on a rotary-wing UAV, such as Figure 1 As shown, it mainly includes:

[0055] Step S1, when the UAV is at a certain aerial position, obtain the flight parameters of the aerial position, the flight parameters include the coordinates (x0, y0, z0) of the UAV in a rectangular coordinate system, the current heading angle α of the UAV, and the pitch angle θ of a lens installed on the UAV for locking a ground target, the rectangular coordinate system takes the take-off point of the UAV as the origin, the east direction is the X axis, the north direction is the Y axis, and the vertical upward direction is the Z axis;

[0056] Step S2: Calculate the position (x, y, z) of the ground target based on the following formula:

[0057]

[0058] z=z * ;

[0059] Among them, z * is the height of the ground target. When the height of the ground target is consistent with the height of the UAV take-off point, the height of the ground target z * is 0, otherwise, an equation about the horizontal coordinate and / or vertical coordinate of the ground target is constructed through the flight parameters of at least two air positions to solve the height z of the ground target * .

[0060] The present application collects the flight parameters of the drone in step S1, and solves the position of the ground target in step S2. It should be noted that the flight parameters in step S1 include the conventional aircraft position and attitude parameters, as well as the lens pitch angle. In order to collect these parameters, the present application improves the drone, which integrates five functional modules: Beidou navigation module, high-precision gyroscope, data communication module, optical zoom photography system, and high-precision anti-shake gimbal.

[0061] As for the Beidou positioning module, since GPS, GLONASS, Galileo and other satellite positioning systems are not autonomously controlled and have unstable factors, this application uses the Beidou positioning module. The Beidou positioning module is used to achieve high-precision positioning of rotary-wing drones.

[0062] For the high-precision gyroscope, it is used to measure the current heading angle and attitude angle of the drone in real time. For the data communication module, it is used to remotely control the drone and transmit real-time data. For the optical zoom photography system, it is used to search and lock the target to be located. When the drone lens is zoomed to the wide-angle focal length, a large area is searched for the target; when it is zoomed to the medium-to-long focal length, the target is locked to reduce the measurement error of the drone attitude angle and the pitch angle of the gimbal, and reduce the solution error of the target position. For the high-precision anti-shake gimbal, it is used to measure the pitch angle of the drone lens in real time when the drone lens is locked on the target.

[0063] refer to Figure 2 Before step S1, the present application constructs a rectangular coordinate system with the take-off point of the drone as the origin, the x direction is due east of the earth, that is, parallel to the direction of increasing longitude of the latitude line (east longitude direction); the y direction is due north of the earth, that is, parallel to the direction of increasing longitude of the longitude line (north latitude direction); the z direction is perpendicular to the horizontal plane of the take-off point of the drone and passes through the center of the earth. Accordingly, when the drone locks the target, various parameters are sent to the control terminal through the data communication module, and the control terminal performs real-time calculation according to the formula of step S2.

[0064] From the formula in step S2, it can be seen that the only uncertain parameter is the height z of the ground target. * If the height of the ground target is consistent with or not much different from the height of the take-off point of the drone, for example, for some ground targets located in lakes, oceans, or plain areas with very little altitude change within a certain area, there is no need to pay attention to the height parameter, and it can be considered to be the same as the take-off height parameter of the drone. Otherwise, it is necessary to obtain the flight parameters of at least two aerial positions in step S1, and then solve them by jointly solving these flight parameters.

[0065] In some optional embodiments, step S1 further includes obtaining flight parameters of at least two aerial positions by:

[0066] A single UAV is flown to two or more aerial positions to obtain flight parameters at different aerial positions, and / or two or more UAVs are located at different aerial positions to obtain flight parameters at different aerial positions.

[0067] The two methods provided in this embodiment are a single UAV multi-measurement point positioning method and a multiple UAV single-measurement point positioning method, which are essentially the same, that is, obtaining multiple measurement points in order to jointly solve the ground target position.

[0068] In some optional implementations, step S2 further includes:

[0069] Step S21: When the flight parameters of the two air positions are used to construct equations about the horizontal and vertical coordinates of the ground target to solve the height z of the ground target, * When the height of the ground target calculated based on the ground target abscissa equation and the height of the ground target calculated based on the ground target ordinate equation are averaged as the final height z of the ground target * , then based on the final ground target height z * Calculate the horizontal coordinates of the ground targets corresponding to the two aerial positions, and take the average value as the horizontal coordinate of the final ground target. At the same time, based on the height z of the final ground target * Calculate the vertical coordinates of the ground target corresponding to the two aerial positions, and take the average value as the final vertical coordinate of the ground target.

[0070] This step gives the process of solving the ground target position by using two side points. Figure 3 , using subscripts 1 and 2 to represent the parameters of the first aerial position and the second aerial position respectively. For the target point, the x data of the two measuring points can be obtained by combining:

[0071]

[0072] The relative height z of the target object calculated by the x-direction data of the two measuring pointsx for:

[0073]

[0074] Where:

[0075]

[0076] Similarly, the y data of the two measuring points can be combined to obtain:

[0077]

[0078] Where:

[0079]

[0080] The relative height z of the target object calculated by the y direction data of the two measuring points y for:

[0081]

[0082] Then, the height z of the ground target calculated based on the ground target horizontal coordinate equation is x The height z of the ground target calculated based on the ground target ordinate equation y By finding the average value, we can get the final height z of the ground target. * :

[0083]

[0084] Then, the height z calculated above is substituted into the formula of step S1 to obtain:

[0085]

[0086] Finally, the horizontal and vertical coordinates calculated based on the two aerial positions are averaged to obtain the final horizontal and vertical coordinates of the ground target:

[0087]

[0088] Step S22: when multiple air position flight parameters are used to construct equations about the horizontal and vertical coordinates of the ground target to solve the height z of the ground target * When the position of the ground target is calculated for any two aerial positions in the manner of step S21, the final ground target position is obtained by calculating the average value.

[0089] This step provides a method for calculating the position of ground targets at multiple measuring points. For N measuring points, the position of the ground target (x i ,y i ,zi ), the number of equations to be solved is Get The number of calculation points. According to the law of large numbers, for a data that satisfies the normal distribution, when the amount of data is large, its arithmetic mean is close to the exact value, so the more accurate coordinate position of the target point can be obtained by the following formula:

[0090]

[0091] In some optional implementations, step S2 further includes:

[0092] Step S3: Convert the ground target position into geographic coordinate system coordinates using the following formula:

[0093]

[0094] h o =h s +z;

[0095] Among them, J o , W o 、h o are the longitude, latitude and altitude of the ground target in the geographic coordinate system; J s , W s 、h s are the longitude, latitude and altitude of the take-off point of the drone; W is the latitude of the aerial position, R e is the radius of the Earth.

[0096] This embodiment is used to convert the coordinates of the ground target into the coordinates in the geographic coordinate system, that is, to solve the latitude, longitude and altitude parameters of the ground target. It should be noted that when two aerial positions are used to solve the position of the ground target, the dimension W at the aerial position in the parameters involved in this embodiment is the average value of the dimensions at the two aerial positions. In addition, the radius of the earth Re is calculated as follows:

[0097] Among them, R a =6378137.0, is the mean of the dimension W at multiple aerial positions.

[0098] In some optional implementations, step S2 further includes:

[0099] Step S4: Estimate the moving speed of the ground target using the position data of the ground target at the latest moment and the position data of the ground target at the previous moment.

[0100] For targets moving on the ground, since their positions are constantly changing, their moving paths will form a continuous trajectory from the start to the end of the drone target positioning. However, the target point positions obtained by the drone positioning solution are discrete points, which are distributed on the trajectory formed by the target movement, such as Figure 4 As shown in the figure, the shorter the time interval between two positioning of the target by the drone, the denser the distribution of positioning points on the trajectory line. The trajectory line can record the moving position of the target over a period of time, and determine its moving direction and the path it may take in the future.

[0101] By measuring the distance of the target in real time, the approximate moving speed of the target can be calculated. This embodiment uses the first-order difference quotient to approximate the moving speed of the target. For the convenience of expression, each coordinate recording moment is recorded as a node, and the node number of the latest moment is n. Then, there are two calculation schemes for calculating the speed of the target object:

[0102] Solution 1: Use the latest positioning data and the data from the previous moment to estimate the target moving speed, as shown in the following formula.

[0103]

[0104] Solution 2: When the positioning calculation interval is short and the target object is close to uniform motion, the formula shown above can be used to estimate the speed of the target object.

[0105]

[0106] Similarly, the moving direction of the target object can also be calculated (the east is the 0 degree angle direction and the counterclockwise direction is the positive direction). The calculation formula is as follows:

[0107]

[0108] This application has the following advantages:

[0109] 1. This method requires fewer platform-mounted equipment and has less impact on the drone's endurance.

[0110] 2. The positioning method is simple, the calculation amount is small, and the anti-interference ability is strong.

[0111] 3. Use a rotor-type UAV platform, which is low-cost and easy to operate.

[0112] 4. Using a single drone with two measuring points can achieve standard real-time positioning of ground targets. For targets in ocean and lake areas, using a single drone can achieve real-time positioning.

[0113] 5. Using two drones can achieve real-time positioning of ground targets without being affected by terrain.

[0114] 6. This method can calculate the altitude of ground targets.

[0115] 7. This method can realize the positioning of UAVs for ground targets, movement trajectory recording and quasi-real-time speed measurement.

[0116] The second aspect of the present application provides a ground target positioning device based on a rotary-wing UAV corresponding to the above method, mainly comprising:

[0117] A flight parameter acquisition module is used to acquire the flight parameters of a certain aerial position when the drone is in the air. The flight parameters include the coordinates (x0, y0, z0) of the drone in a rectangular coordinate system, the current heading angle α of the drone, and the pitch angle θ of a lens installed on the drone for locking a ground target. The rectangular coordinate system takes the take-off point of the drone as the origin, the east direction is the X axis, the north direction is the Y axis, and the vertical upward direction is the Z axis.

[0118] The ground target position calculation module is used to calculate the position (x, y, z) of the ground target based on the following formula:

[0119]

[0120] z=z * ;

[0121] Among them, z * is the height of the ground target. When the height of the ground target is consistent with the height of the UAV take-off point, the height of the ground target z * is 0, otherwise, an equation about the horizontal coordinate and / or vertical coordinate of the ground target is constructed through the flight parameters of at least two air positions to solve the height z of the ground target * .

[0122] In some optional implementations, the flight parameters of at least two aerial positions are obtained by:

[0123] Flying a single UAV to two or more aerial locations to obtain flight parameters at different aerial locations, and / or

[0124] The flight parameters at different aerial positions are obtained by using two or more drones at different aerial positions.

[0125] In some optional implementations, the ground target position solving module includes:

[0126] The dual air position solving ground target position unit is used to construct equations about the horizontal and vertical coordinates of the ground target through the flight parameters of the two air positions to solve the height z of the ground target *When the height of the ground target calculated based on the ground target abscissa equation and the height of the ground target calculated based on the ground target ordinate equation are averaged as the final height z of the ground target * , then based on the final ground target height z * Calculate the horizontal coordinates of the ground target corresponding to the two air positions, and take the average value as the horizontal coordinate of the final ground target. At the same time, based on the height z of the final ground target * Calculate the ordinates of the ground target corresponding to the two aerial positions and take the average value as the final ordinate of the ground target;

[0127] The multi-air position solving ground target position unit is used to construct equations about the horizontal and vertical coordinates of the ground target through multiple air position flight parameters to solve the height z of the ground target * When the ground target position is calculated by calling the dual-air position solving ground target position unit for any two air positions, the final ground target position is obtained by calculating the average value.

[0128] In some optional implementations, the ground target positioning device further includes:

[0129] The geographic coordinate system conversion module is used to convert the ground target position into the geographic coordinate system coordinates using the following formula:

[0130]

[0131] h o =h s +z;

[0132] Among them, J o , W o 、h o are the longitude, latitude and altitude of the ground target in the geographic coordinate system; J s , W s 、h s are the longitude, latitude and altitude of the take-off point of the drone; W is the latitude of the aerial position, R e is the radius of the Earth.

[0133] In some optional implementations, the ground target positioning device further includes:

[0134] The ground target moving speed calculation module is used to estimate the moving speed of the ground target using the position data of the ground target at the latest moment and the position data of the ground target at the previous moment.

[0135] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A ground target positioning method based on a rotary-wing UAV, characterized in that: include: Step S1, when the UAV is at a certain aerial position, obtain the flight parameters of the aerial position, the flight parameters include the coordinates (x0, y0, z0) of the UAV in a rectangular coordinate system, the current heading angle α of the UAV, and the pitch angle θ of a lens installed on the UAV for locking a ground target, the rectangular coordinate system takes the take-off point of the UAV as the origin, the east direction is the X axis, the north direction is the Y axis, and the vertical upward direction is the Z axis; Step S2: Calculate the position (x, y, z) of the ground target based on the following formula: z=z * ; Among them, z * is the height of the ground target. When the height of the ground target is consistent with the height of the UAV take-off point, the height of the ground target z * is 0, otherwise, an equation about the horizontal coordinate and / or vertical coordinate of the ground target is constructed through the flight parameters of at least two air positions to solve the height z of the ground target * .

2. The ground target positioning method based on a rotary-wing UAV according to claim 1, characterized in that: Step S1 further includes obtaining flight parameters of at least two aerial positions by: Flying a single UAV to two or more aerial locations to obtain flight parameters at different aerial locations, and / or The flight parameters at different aerial positions are obtained by using two or more drones at different aerial positions.

3. The ground target positioning method based on a rotary-wing UAV as claimed in claim 1, characterized in that: Step S2 further comprises: Step S21: When the flight parameters of the two air positions are used to construct equations about the horizontal and vertical coordinates of the ground target to solve the height z of the ground target, * When the height of the ground target calculated based on the ground target abscissa equation and the height of the ground target calculated based on the ground target ordinate equation are averaged as the final height z of the ground target * , then based on the final ground target height z * Calculate the horizontal coordinates of the ground targets corresponding to the two aerial positions, and take the average value as the horizontal coordinate of the final ground target. At the same time, based on the height z of the final ground target * Calculate the ordinates of the ground target corresponding to the two aerial positions and take the average value as the final ordinate of the ground target; Step S22: when multiple air position flight parameters are used to construct equations about the horizontal and vertical coordinates of the ground target to solve the height z of the ground target * When the position of the ground target is calculated for any two aerial positions in the manner of step S21, the final ground target position is obtained by calculating the average value.

4. The ground target positioning method based on a rotary-wing UAV according to claim 1, characterized in that: Step S2 further includes: Step S3: Convert the ground target position into geographic coordinate system coordinates using the following formula: h o =h s +z; Among them, J o , W o 、h o are the longitude, latitude and altitude of the ground target in the geographic coordinate system; J s , W s 、h s are the longitude, latitude and altitude of the take-off point of the drone; W is the latitude of the aerial position, R e is the radius of the Earth.

5. The ground target positioning method based on a rotary-wing UAV as claimed in claim 1, characterized in that: Step S2 further includes: Step S4: Estimate the moving speed of the ground target using the position data of the ground target at the latest moment and the position data of the ground target at the previous moment.

6. A ground target positioning device based on a rotary-wing UAV, characterized in that: include: A flight parameter acquisition module is used to acquire the flight parameters of a certain aerial position when the drone is in the air. The flight parameters include the coordinates (x0, y0, z0) of the drone in a rectangular coordinate system, the current heading angle α of the drone, and the pitch angle θ of a lens installed on the drone for locking a ground target. The rectangular coordinate system takes the take-off point of the drone as the origin, the east direction is the X axis, the north direction is the Y axis, and the vertical upward direction is the Z axis. The ground target position calculation module is used to calculate the position (x, y, z) of the ground target based on the following formula: z=z * ; Among them, z * is the height of the ground target. When the height of the ground target is consistent with the height of the UAV take-off point, the height of the ground target z * is 0, otherwise, an equation about the horizontal coordinate and / or vertical coordinate of the ground target is constructed through the flight parameters of at least two air positions to solve the height z of the ground target * .

7. The ground target positioning device based on a rotary-wing UAV as claimed in claim 6, characterized in that: Get the flight parameters of at least two air locations by: Flying a single UAV to two or more aerial locations to obtain flight parameters at different aerial locations, and / or The flight parameters at different aerial positions are obtained by using two or more drones at different aerial positions.

8. The ground target positioning device based on a rotary-wing UAV as claimed in claim 6, characterized in that: The ground target position solving module comprises: The dual air position solving ground target position unit is used to construct equations about the horizontal and vertical coordinates of the ground target through the flight parameters of the two air positions to solve the height z of the ground target * When the height of the ground target calculated based on the ground target abscissa equation and the height of the ground target calculated based on the ground target ordinate equation are averaged as the final height z of the ground target * , then based on the final ground target height z * Calculate the horizontal coordinates of the ground target corresponding to the two air positions, and take the average value as the horizontal coordinate of the final ground target. At the same time, based on the height z of the final ground target * Calculate the ordinates of the ground target corresponding to the two aerial positions and take the average value as the final ordinate of the ground target; The multi-air position solving ground target position unit is used to construct equations about the horizontal and vertical coordinates of the ground target through multiple air position flight parameters to solve the height z of the ground target * When the ground target position is calculated by calling the dual-air position solving ground target position unit for any two air positions, the final ground target position is obtained by calculating the average value.

9. The ground target positioning device based on a rotary-wing UAV as claimed in claim 6, characterized in that: The ground target positioning device also includes: The geographic coordinate system conversion module is used to convert the ground target position into the geographic coordinate system coordinates using the following formula: h o =h s +z; Among them, J o , W o 、h o are the longitude, latitude and altitude of the ground target in the geographic coordinate system; J s , W s 、h s are the longitude, latitude and altitude of the take-off point of the drone; W is the latitude of the aerial position, R e is the radius of the Earth.

10. The ground target positioning device based on a rotary-wing UAV as claimed in claim 6, characterized in that: The ground target positioning device also includes: The ground target moving speed calculation module is used to estimate the moving speed of the ground target using the position data of the ground target at the latest moment and the position data of the ground target at the previous moment.

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