Rotor unmanned aerial vehicle collision method and device, unmanned aerial vehicle and storage medium

Abstract

The invention discloses a rotor unmanned aerial vehicle collision method and device, an unmanned aerial vehicle and a storage medium, which are used for performing target collision by using a flight control system on the unmanned aerial vehicle under the condition of GPS signal deficiency. The method comprises the following steps: determining a total horizontal acceleration of the unmanned aerial vehicle based on an inclination angle of the unmanned aerial vehicle in each control period and a predetermined maximum horizontal speed, and determining a horizontal speed estimation value based on the total horizontal acceleration; based on the parameters of the camera on the unmanned aerial vehicle and the attitude of the unmanned aerial vehicle, determining a missile-target line-of-sight unit vector under the north-east coordinate system, and determining a line-of-sight azimuth angle and a line-of-sight elevation angle according to the missile-target line-of-sight unit vector; and based on at least one of the horizontal speed estimation value, the sight azimuth angle or the sight elevation angle, realizing collision of the unmanned aerial vehicle to the target according to proportional guidance control and / or speed tracking control. According to the scheme, accurate impact on the target can still be achieved under the condition that GPS signals are lost.

Description

Technical Field

[0001] This application relates to the technical field of unmanned aerial vehicle (UAV) navigation control, and particularly to a method, device, UAV, and storage medium for a rotor UAV to impact a target. Background Art

[0002] With the development of intelligent control theory and technology, UAVs have been widely used in the military field, such as for reconnaissance or impact. Attack-type rotor UAVs with low cost, simple operation, and portability have become a better choice. However, the flight control system of existing rotor UAVs can only be normally guided when GPS signals are present, and a large number of rotor UAVs are not equipped with pods, but only with inexpensive strap-down cameras. Therefore, how to still achieve the impact on a target in the absence of GPS signals and relying on strap-down cameras has become an urgent problem to be solved. Summary of the Invention

[0003] In view of the above problems, this application is proposed to provide a method, device, UAV, and storage medium for a rotor UAV to impact a target that can overcome or at least partially solve the above problems.

[0004] According to one aspect of this application, a method for a rotor UAV to impact a target is provided, which is used to perform target impact using the flight control system on the UAV in the absence of GPS signals. The method includes: Based on the tilt angle of the UAV in each control period and a pre-determined maximum horizontal speed, determine the total horizontal acceleration of the UAV, and based on the total horizontal acceleration, determine an estimated value of the horizontal speed; Based on the parameters of the camera on the UAV and the attitude of the UAV, determine the unit vector of the line of sight between the projectile and the target in the north-east-down coordinate system, and determine the azimuth angle and elevation angle of the line of sight according to the unit vector of the line of sight between the projectile and the target; Based on at least one of the estimated value of the horizontal speed, the azimuth angle of the line of sight, or the elevation angle of the line of sight, achieve the impact of the UAV on the target according to proportional navigation control and / or speed tracking control.

[0005] In some embodiments, based on the tilt angle of the UAV in each control period and a pre-determined maximum horizontal speed, determining the total horizontal acceleration of the UAV and based on the total horizontal acceleration, determining an estimated value of the horizontal speed includes: Determine the horizontal acceleration generated due to the tilt of the UAV according to the relationship between the gravitational acceleration and the tilt angle of the UAV; Estimate the maximum horizontal speed of the UAV in each control period according to the functional relationship between the tilt angle and the maximum horizontal speed of the UAV determined through pre-tests; According to the relationship between the acceleration generated by air resistance and the current tilt angle, horizontal speed, and maximum horizontal speed of the UAV, express the acceleration generated by air resistance in terms of horizontal acceleration, and determine the total horizontal acceleration of the UAV. By performing integral calculation on the total horizontal acceleration and combining with the horizontal speed of the previous control period, obtain the estimated value of the horizontal speed of the current control period.

[0006] In some embodiments, the impact of the UAV on the target based on at least one of the estimated horizontal speed, line-of-sight azimuth angle, or line-of-sight elevation angle, and achieved by proportional guidance control and / or speed tracking control includes: Based on the control of the vertical speed of the UAV, divide the impact control of the UAV on the target into multiple stages, including: the stage of yawing the nose towards the target, the stage of rushing to the handover point while controlling the line-of-sight elevation angle within the impactable range of the target, the stage of speed tracking guidance for the target, and / or the proportional guidance stage.

[0007] In some embodiments, the control logic executed in the stage of yawing the nose towards the target includes at least one of the following: Control the expected value of the yaw angle of the UAV to gradually approach the line-of-sight azimuth angle value, so that the nose of the UAV turns towards the target direction; Control the expected value of the pitch angle of the UAV to gradually approach zero; Control the expected value of the vertical speed of the UAV to approach zero; Control the expected value of the roll angle of the UAV to approach zero.

[0008] In some embodiments, the control logic executed in the stage of rushing to the handover point while controlling the line-of-sight elevation angle within the impactable range of the target includes at least one of the following: Control the expected value of the yaw angle of the UAV to be equal to the line-of-sight azimuth angle value, and keep the nose of the UAV facing the target; The control of the expected value of the pitch angle of the UAV includes: if the line-of-sight elevation angle is greater than zero, at this time the height of the target is greater than the height of the UAV, then control the expected value of the pitch angle to approach and even be zero; if the line-of-sight elevation angle is less than the first threshold, then control the expected value of the pitch angle to approach and even be zero; if the line-of-sight elevation angle is between zero and the second threshold, then control the expected value of the pitch angle to approach and even be equal to the line-of-sight elevation angle, and control the UAV to fly forward and upward at the same time; The control of the expected vertical velocity of the UAV includes: multiplying the difference between the optimal ballistic impact angle and the current line-of-sight elevation angle by a proportional term to obtain the expected line-of-sight elevation angle rate, and adjusting the expected vertical velocity so that the current line-of-sight elevation angle rate gradually approaches the expected line-of-sight elevation angle rate. When the expected line-of-sight elevation angle rate is greater than zero, control the expected vertical velocity to make the UAV descend; when the expected line-of-sight elevation angle rate is less than zero, control the expected vertical velocity to make the UAV climb. The control of the expected roll angle of the UAV includes: determining the expected horizontal lateral acceleration based on the product of the estimated value of the line-of-sight azimuth angle rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal velocity; determining the expected vertical acceleration that meets the straight flight expectation based on the expected pitch angle and the gravitational acceleration; and determining the expected roll angle based on the arctangent of the quotient of the expected horizontal lateral acceleration and the expected vertical acceleration.

[0009] In some embodiments, the control logic executed during the stage of velocity tracking and guidance for the target includes at least one of the following: Controlling the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value to keep the nose of the UAV facing the target; Controlling the expected pitch angle of the UAV to be equal to the line-of-sight elevation angle value; The control of the expected vertical velocity of the UAV includes: determining the expected vertical velocity based on the product of the tangent value of the negative line-of-sight elevation angle and the estimated horizontal velocity; The control of the expected roll angle of the UAV includes: determining the expected horizontal lateral acceleration based on the product of the estimated value of the line-of-sight azimuth angle rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal velocity; determining the expected vertical acceleration that meets the straight flight expectation based on the expected pitch angle and the gravitational acceleration; and determining the expected roll angle based on the arctangent of the quotient of the expected horizontal lateral acceleration and the expected vertical acceleration.

[0010] In some embodiments, the control logic executed during the proportional navigation stage includes at least one of the following: Controlling the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value to keep the nose of the UAV facing the target; Controlling the expected pitch angle of the UAV to be equal to the line-of-sight elevation angle value; The control of the expected vertical velocity of the UAV includes: adding the expected elevation angle rate of velocity in the previous control cycle to the product of the proportional term of the proportional navigation algorithm in the vertical plane, the line-of-sight elevation angle rate between the missile and the target, and the time interval between two adjacent control cycles to obtain the expected elevation angle rate of velocity in the current control cycle. Then, determine the expected vertical velocity based on the product of the tangent value of the negative expected elevation angle rate of velocity in the current control cycle and the estimated horizontal velocity. The expected value of the roll angle for controlling the drone includes: determining the expected value of the horizontal lateral acceleration based on the product of the estimated values of the line-of-sight azimuth rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal speed; determining the vertical acceleration value that conforms to the straight flight expectation based on the expected value of the pitch angle and the gravitational acceleration; and determining the expected value of the roll angle based on the arctangent of the quotient of the expected value of the horizontal lateral acceleration and the expected value of the vertical acceleration.

[0011] According to another aspect of the present application, a rotor drone impact device is provided for using the flight control system on the drone to perform target impact in the absence of GPS signals. The device includes: A horizontal speed estimation module, adapted to determine the total horizontal acceleration of the drone based on the tilt angle of the drone in each control cycle and a pre-determined maximum horizontal speed, and determine the estimated value of the horizontal speed based on the total horizontal acceleration; A line-of-sight angle determination module, adapted to determine the unit vector of the line of sight between the projectile and the target in the north-east-earth coordinate system based on the parameters of the camera on the drone and the attitude of the drone, and determine the line-of-sight azimuth angle and the line-of-sight elevation angle according to the unit vector of the line of sight between the projectile and the target; A target impact control module, adapted to implement the impact of the drone on the target based on at least one of the estimated value of the horizontal speed, the line-of-sight azimuth angle, or the line-of-sight elevation angle, according to proportional navigation control and / or speed tracking control.

[0012] According to yet another aspect of the present application, a drone is provided, including: a processor and a memory arranged to store computer-executable instructions, and the executable instructions, when executed, cause the processor to execute the rotor drone impact method according to any one of the above embodiments.

[0013] According to still another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores one or more programs, and the one or more programs, when executed by a processor, implement the rotor drone impact method according to any one of the above.

[0014] As can be seen from the above, according to the rotor drone impact method disclosed in the present application, first, the estimated value of the horizontal speed of the drone is determined based on the tilt angle of the drone and a pre-determined maximum speed, the line-of-sight azimuth angle and the elevation angle are determined according to the camera parameters and the attitude of the drone, and then the guidance control of the drone is implemented based on the above-determined parameters using the proportional navigation algorithm or the speed tracking control algorithm, so as to achieve the precise impact of the drone on the target even in the absence of GPS signals.

[0015] The above description is only an overview of the technical solution of the present application. In order to better understand the technical means of the present application, it can be implemented according to the content of the specification. Moreover, in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are hereinafter given. Brief Description of the Drawings

[0016] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of illustrating the preferred embodiments and are not considered to be a limitation of the present application. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 A flowchart showing the method for a rotor UAV to impact according to some embodiments of the present application; Figure 2 A trajectory diagram showing a UAV impacting a billboard target according to some embodiments of the present application; Figure 3 A multi-perspective diagram showing a UAV impacting a billboard target according to some embodiments of the present application; Figure 4 A structural diagram showing a rotor UAV impact device according to some embodiments of the present application; Figure 5 A structural diagram showing a UAV flight control system according to an embodiment of the present application. Detailed Description of the Embodiments

[0017] The exemplary embodiments of the present application will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be fully conveyed to those skilled in the art.

[0018] The main idea of the embodiments of this application is as follows: For a rotary-wing unmanned aerial vehicle (UAV), without relying on the presence of GPS signals in the flight scenario, it is only necessary to install a height sensor such as a barometer in the flight control system to achieve impact. The main steps include estimating the horizontal speed, calculating the line-of-sight angle, and then using the proportional navigation method and the speed tracking method based on the above parameters to achieve impact guidance. The strap-down camera on the UAV is horizontally installed at the head of the UAV, and the optical axis of the camera is parallel to the x-axis of the airframe. During the entire impact process, the pitch angle and yaw angle of the UAV are adjusted so that the optical axis of the camera always aims at the target, that is, the target object is always at the center of the camera screen. By adjusting the roll angle of the UAV, the horizontal lateral movement of the UAV is controlled. The algorithm of this embodiment outputs commands such as the expected values of the yaw angle, pitch angle, roll angle, and vertical speed to the flight control system to control the movement of the UAV in the vertical and horizontal directions.

[0019] The above-mentioned impact includes but is not limited to hitting, aiming at, diving, pursuing, guiding, and colliding with the target, and can be used not only for military purposes. For example, using a UAV to inspect other targets such as other UAVs, animals, and dealing with the firing of ammunition at a fire source, etc. In some specific embodiments, the UAV tracks and hunts animals, and anesthetic guns or net guns are installed at the nose direction. It dives towards the animal, and during the diving process, the nose will always aim at the target object, so the muzzle will also always aim at the target object. The net gun or anesthetic gun can be fired after entering the range, and after firing, the operator raises the UAV and moves it away.

[0020] Figure 1 The flowchart of the impact method of a rotary-wing UAV according to an embodiment of the present application is shown. This method can be implemented through a program in the flight control system of the UAV. A camera and a barometer are provided on the UAV to perform target impact using the flight control system on the UAV in the case of GPS signal loss. The method includes the following steps: Step S110: Determine the total horizontal acceleration of the UAV based on the tilt angle of the UAV in each control cycle and the pre-determined maximum horizontal speed, and determine the estimated value of the horizontal speed based on the total horizontal acceleration; Step S120: Determine the unit vector of the line of sight between the projectile and the target in the north-east-earth coordinate system based on the parameters of the camera on the UAV and the attitude of the UAV, and determine the azimuth angle and elevation angle of the line of sight according to the unit vector of the line of sight between the projectile and the target; Specifically, by combining the internal parameters of the camera, the installation attitude of the camera on the UAV, the central pixel coordinates of the image recognition frame, and the attitude of the UAV, the "unit vector of the line of sight between the projectile and the target" in the north-east-earth coordinate system can be calculated. Then, the azimuth angle of the line of sight and the elevation angle of the line of sight can be obtained. After low-pass filtering these two angles (note the processing of low-pass filtering In the case of jumping at ±180°, a stable and can be obtained after filtering. Then, for the and after low-pass filtering, the rate of change of the line-of-sight angle and is obtained.

[0021] Step S130: Based on the horizontal speed estimated value, the line-of-sight azimuth angle, and the line-of-sight elevation angle, the drone impacts the target according to proportional navigation control and / or speed tracking. Preferably, the nose of the drone is always aligned with the target during the impact process.

[0022] Combined with this embodiment, it is realized that the drone can still track and impact the target without GPS signal, and due to the closed-loop control, the impact accuracy on the target is high.

[0023] In some embodiments, the simulation of the formed impact trajectory is shown in Figure 2 and Figure 3 . The lines in Figure 2 are the trajectories flown by the drone, and the right picture in Figure 3 is the picture taken by the camera, and the upper left corner is the third-person view picture, including the linear flight trajectory.

[0024] In some embodiments, an implementation method of horizontal speed estimation is given. In the following formulas of the horizontal speed estimation part, the following characters are used: - The tilt angle of the aircraft, representing the angle between the z-axis of the aircraft body and the plumb line; G - The acceleration due to gravity; - The horizontal acceleration generated by the horizontal component of the propeller thrust acting on the aircraft, and the horizontal component of the propeller thrust is generated due to the tilt of the aircraft; - The horizontal acceleration generated by the air resistance acting on the aircraft; - The horizontal acceleration generated by the air resistance acting on the aircraft due to the current horizontal speed of the aircraft; - The horizontal resultant acceleration of the aircraft; - The true value of the current horizontal speed of the aircraft; - The maximum horizontal speed that the aircraft can generate at a certain fixed tilt angle; - The horizontal speed estimated by the aircraft in the current control cycle; - The current vertical speed of the aircraft, with downward being positive; - The horizontal speed estimated by the aircraft in the previous control cycle; - The time interval between two adjacent control cycles, which is related to the frame rate of image processing.

[0025] Specifically, the current horizontal speed of the UAV is a scalar. If a GPS module is installed on the flight controller and there is a GPS signal, the true horizontal speed (ground speed) of the UAV can be directly obtained from the flight controller. If there is no GPS signal, there is a lack of direct observation of the horizontal speed. However, the horizontal speed of the UAV can be estimated based on the tilt angle and vertical speed of the UAV.

[0026] Therefore, based on the tilt angle of the UAV in each control cycle and the pre-determined maximum horizontal speed, determining the total horizontal acceleration of the UAV, and determining the horizontal speed estimate based on the total horizontal acceleration includes: Determine the horizontal acceleration generated due to the tilt of the UAV according to the relationship between the gravitational acceleration and the tilt angle of the UAV;

[0027] Estimate the maximum horizontal speed of the UAV in each control cycle according to the functional relationship between the tilt angle and the maximum horizontal speed of the UAV determined through pre-tests; Use a simple or refined method to estimate the maximum horizontal speed . Since the proportional navigation algorithm is a closed-loop control, both methods can achieve good impact effects.

[0028] Or

[0029] According to the relationship between the acceleration generated by air resistance and the current tilt angle, horizontal speed, and maximum horizontal speed of the UAV, express the acceleration generated by air resistance in terms of horizontal acceleration, and determine the total horizontal acceleration of the UAV;

[0030] Through integral calculation of the total horizontal acceleration and combining with the horizontal speed of the previous control cycle, obtain the horizontal speed estimate of the current control cycle; .

[0031] According to a specific implementation manner, when the vertical speed of the UAV is 0, the specific derivation process of the formula is as follows: Let be the tilt angle of the UAV. is the magnitude of the horizontal acceleration caused by the tilt. G is the acceleration due to gravity. The calculation method is:

[0032] During the flight at a fixed tilt angle, as the horizontal speed of the drone increases, an increasingly large air resistance will be generated. The calculation formula for the horizontal acceleration caused by the air resistance is as follows.

[0033] In the following formula, is the horizontal acceleration caused by the air resistance. is the air density. is the true value of the current horizontal speed of the drone. is the drag coefficient. A is the frontal area. M is the mass of the drone.

[0034]

[0035] The drone always maintains the tilt angle constant. When the horizontal speed of the drone accelerates to the maximum horizontal speed , and are balanced, and at this time the drone maintains a uniform motion. Therefore,

[0036] Because is positively correlated with , is positively correlated with . So a uniquely corresponds to a .

[0037] If the current tilt angle of the drone is , the corresponding is known, then the acceleration generated by the current air resistance can be calculated based on the current horizontal speed of the drone. Because,

[0038]

[0039] Therefore, when and , and the corresponding are known, the current horizontal resultant acceleration can be obtained:

[0040] The known initial horizontal velocity is 0. In each control cycle, the estimated value of the horizontal velocity in the previous control cycle is accumulated with the velocity change caused , and then the horizontal velocity in each control cycle can be estimated . And it will gradually converge to .

[0041] Therefore, in each control cycle, the following two formulas need to be calculated to obtain :

[0042] .

[0043] It should be noted that it can be obtained in advance through flight tests on drones of various models. Specifically, there are the following two methods for calculating its corresponding : 1) A simple method for calculating its corresponding based on : Install a GPS module on the drone. The GPS can directly observe the horizontal velocity of the drone, so that information such as the horizontal velocity, vertical velocity, and tilt angle of the flight control system can be seen in the flight control log or on the ground station. Control the drone to maintain a certain fixed tilt angle

[0044] and fly at a fixed altitude. When the horizontal velocity value of the drone is stable, a set of corresponding relationships between and can be obtained.

[0045] Test multiple different tilt angles and list them in a table. For example, the following table is generally obtained from simulation tests in a simulation environment. Of course, it can also be obtained through tests in a real environment.

[0046]

[0047] Use the piecewise function or curve fitting method to obtain a function based on the above table. This function can calculate its corresponding according to any . That is

[0048] 2) A refined method for calculating its corresponding based on : [[ID=7N]]Since the horizontal force condition of the drone is affected by the vertical velocity of the drone Therefore, a dimension can be added to this table. It is changed to a group corresponds to one . Thus, a three-dimensional surface function can be fitted, that is . For example, in the following table, tests of 9 inclination angles corresponding to 3 vertical speeds are carried out.

[0049]

[0050] In some embodiments, in step S130, based on the horizontal speed estimate value, the line-of-sight azimuth angle, and the line-of-sight elevation angle, the realization of the impact of the UAV on the target according to proportional guidance control and / or speed tracking includes: Based on the control of the UAV's vertical speed, the impact control of the UAV on the target is divided into multiple stages, including: the stage of yawing the nose towards the target, the stage of reaching the handover point by controlling the line-of-sight elevation angle within the impact range of the target, the stage of speed tracking guidance for the target, and the proportional guidance stage.

[0051] In the formula of the control logic part in step S130, - With " " represents the estimated value (measured value) of x, without " " represents that x is the expected value. represents the derivative of x, and the specific character meanings are described as follows: - The expected value of the horizontal lateral acceleration, with the direction to the right side of the aircraft being positive; - The projection length (scalar) of the aircraft speed on the horizontal plane, if there is no GPS, it comes from the estimation method above; - The speed of the aircraft in the vertical direction, with the downward direction being positive; - The line-of-sight azimuth angle between the projectile and the target, that is, the angle between the projection of the line of sight on the horizontal plane and the due north direction, with the line of sight to the east being +90°; - The line-of-sight elevation angle between the projectile and the target, that is, the angle between the line of sight and the horizontal plane, with the line of sight upward being positive; - The speed azimuth angle, the angle between the projection of the speed vector on the horizontal plane and the due north direction, with the speed to the east being +90°; - The speed elevation angle, that is, the angle between the speed and the horizontal plane, with the speed upward being positive; - The pitch angle in the aircraft attitude, with the aircraft looking up being positive; - The roll angle in the aircraft attitude angle; - Yaw angle in the aircraft attitude, with the nose facing north being 0° and the nose facing east being 90°; - Proportional term of the proportional navigation method in the horizontal plane; - Proportional term of the proportional navigation method in the vertical plane; - Acceleration due to gravity. In some specific embodiments, the control logic executed during the stage of yaw turning the nose towards the target includes at least one of the following: Control the expected yaw angle of the UAV to gradually approach the line-of-sight azimuth angle value, so that the nose of the UAV turns towards the target direction; Control the expected pitch angle of the UAV to gradually approach zero; Control the expected vertical speed of the UAV to approach zero; Control the expected roll angle of the UAV to approach zero.

[0052] Specifically, based on the first stage of vertical speed control: The control logic for yaw turning the nose towards the target object includes: a. The control logic of the expected yaw angle of the UAV is as follows: = , so that the nose turns towards the target object direction. Here, the amplitude of the change rate of the expected yaw angle should be controlled to generate a smooth UAV trajectory.

[0053] b. The expected pitch angle of the UAV = 0; c. The expected vertical speed of the UAV = 0; d. Control of the expected roll angle φ: φ = 0; When the difference between the estimated yaw angle of the UAV and the estimated line-of-sight azimuth angle is less than the threshold, it indicates that the yaw angle of the UAV has been aligned with the target, and at this time, it enters the "vertical speed control - second stage: heading to the handover point".

[0054] In some embodiments, the control logic executed during the stage of heading to the handover point while controlling the line-of-sight elevation angle within the impact range of the target includes at least one of the following: Control the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value, and keep the nose of the UAV facing the target; The control of the expected pitch angle of the UAV includes: if the line-of-sight elevation angle is greater than zero, at this time the height of the target is greater than the height of the UAV, then control the expected pitch angle to tend to and even be zero; if the line-of-sight elevation angle is less than the first threshold, at this time the angle between the line of sight and the horizontal plane is too large, then control the expected pitch angle to tend to and even be zero; if the line-of-sight elevation angle is between zero and the second threshold, then control the expected pitch angle to tend to and even be equal to the line-of-sight elevation angle, and control the UAV to fly forward and upward at the same time. The control of the expected vertical speed of the UAV includes: multiplying the difference between the optimal ballistic fall angle and the current line-of-sight elevation angle by the proportional term to obtain the expected line-of-sight elevation angle rate, and by adjusting the expected vertical speed, making the current line-of-sight elevation angle rate gradually approach the expected line-of-sight elevation angle rate: when the expected line-of-sight elevation angle rate is greater than zero, control the expected vertical speed to make the UAV descend in height; when the expected line-of-sight elevation angle rate is less than zero, control the expected vertical speed to make the UAV climb in height. Controlling the expected roll angle of the UAV includes: determining the expected horizontal lateral acceleration according to the product of the estimated value of the line-of-sight azimuth angle rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal speed, determining the vertical acceleration value that meets the straight-line flight expectation according to the expected pitch angle and the gravitational acceleration, and determining the expected roll angle according to the arctangent of the quotient of the expected horizontal lateral acceleration and the expected vertical acceleration.

[0055] The specific logic control of this stage is as follows: Since this guidance method depends on being in a hittable range, between the minimum line-of-sight elevation angle first threshold and the maximum line-of-sight elevation angle second threshold. If is greater than the second threshold of the line-of-sight elevation angle, the impact speed of the UAV will be too slow. If is less than the first threshold of the line-of-sight elevation angle, the UAV will have attitude instability due to too large an inclination angle during the impact. Among them, the value range of the second threshold of the line-of-sight elevation angle is from -12 degrees to -20 degrees, and the value range of the first threshold of the line-of-sight elevation angle is from -40 degrees to -30 degrees.

[0056] "Rushing to the handover point" means that if it is outside the hittable range, then through vertical speed control, make gradually enter the hittable range.

[0057] a. The control logic of the expected yaw angle of the UAV is as follows: In all cases, = ; b. The control logic of the expected pitch angle of the UAV is as follows: if If it is greater than 0°, that is, the target is at a higher altitude than the drone, then: = 0°, the drone will remain horizontal and fly vertically upwards.

[0058] if is less than the first threshold, then: = 0°, the drone will remain horizontal and fly vertically downward.

[0059] if The value is between 0 degrees and the second threshold, then: = , at this time the drone will gradually lower its head and fly forward while flying upward.

[0060] c. Expected vertical speed of the drone The control logic is as follows: The best trajectory angle is generally the average of the first and second thresholds of the sight line height angle. For example, at -26°, the best trajectory angle is the average of the current sight line height angle. The difference is multiplied by the proportional term (such as 0.2) to obtain the expected value of the line of sight high and low angular rate :

[0061] Then adjust the vertical speed setting value by , making the current line of sight high and low angular velocity Gradually approaching .

[0062] Vertical speed control is an integral operation. is the expected value of the vertical velocity in this control cycle. is the expected vertical velocity of the last control cycle. 0.25 is the expected acceleration of climbing or descending, in m / s 2 , you can also fill in other expected acceleration values according to actual conditions. dt is the time interval between two adjacent control cycles, in seconds.

[0063] when When it is greater than 0, it means the drone needs to descend:

[0064] when When it is less than 0, it means the drone needs to climb:

[0065] d. Use the proportional guidance method to control the roll angle so that the angular velocity of the horizontal velocity vector is proportional to the azimuth angular velocity of the line of sight. . is the expected value of the horizontal lateral acceleration, with the right side of the UAV being positive. is the rate of the line-of-sight azimuth angle. is the proportional term of the proportional navigation method in the horizontal plane. is the horizontal velocity estimated above. is the expected value of the pitch angle. is the gravitational acceleration.

[0066]

[0067]

[0068] Because at this stage, the target is far from the UAV, and at the same time, the flight speed of the UAV is slow during this stage, the horizontal line-of-sight angle rate is very small, resulting in the expected value of the roll angle calculated by the formula being almost 0.

[0069] When enters the impact range, the line-of-sight elevation angle is between the first threshold and the second threshold, that is, reaches the intersection point, and at this time, it enters "Vertical Velocity Control - Stage 3: Control Based on the Velocity Tracking Algorithm".

[0070] In some embodiments, the control logic executed in the stage of performing velocity tracking guidance on the target includes at least one of the following: Control the expected value of the yaw angle of the UAV to be equal to the line-of-sight azimuth angle value, and keep the nose of the UAV facing the target; Control the expected value of the pitch angle of the UAV to be equal to the line-of-sight elevation angle value; Control the expected value of the vertical velocity of the UAV to include: determining the expected value of the vertical velocity according to the product of the tangent value of the negative line-of-sight elevation angle and the estimated value of the horizontal velocity; Control the expected value of the roll angle of the UAV to include: determining the expected value of the horizontal lateral acceleration according to the product of the estimated values of the line-of-sight azimuth angle rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal velocity, determining the vertical acceleration value that conforms to the straight flight expectation according to the expected value of the pitch angle and the gravitational acceleration, and determining the expected value of the roll angle according to the arctangent of the quotient of the expected value of the horizontal lateral acceleration and the expected value of the vertical acceleration.

[0071] The principle of velocity tracking control is to direct the three-dimensional velocity vector of the UAV towards the target, so as to achieve the tracking of the target. The variables relied on include the estimated value of the horizontal velocity, the line-of-sight azimuth angle rate, and the line-of-sight elevation angle. The specific control logic includes: a. The control logic of the expected value of the yaw angle of the UAV is as follows: =

[0072] b. Expected pitch angle of the UAV The control logic is as follows: = At this time, the UAV will lower its head and fly downward while flying forward.

[0073] c. Expected vertical speed of the UAV The control logic is as follows is the estimated value of the current line-of-sight elevation angle between the missile and the target. is the estimated value (scalar) of the UAV's horizontal speed. is the expected elevation angle of speed in this control cycle. Then,

[0074]

[0075] d. Refer to the control logic of the second stage for the control of the expected roll angle of the UAV.

[0076] Because when the UAV first enters the "Vertical Speed Control - Third Stage", the distance between the UAV and the target is relatively far, so the line-of-sight elevation angle rate is close to 0, and at this time, the condition for switching to proportional navigation is not met. When the distance between the UAV and the target gradually approaches, the line-of-sight elevation angle rate begins to become relatively large, and at this time, proportional navigation control can be performed. Therefore, when the line-of-sight elevation angle rate is greater than the threshold, it enters the "Vertical Speed Control - Fourth Stage: Impact Control Based on Proportional Navigation Algorithm".

[0077] In some embodiments, the control logic executed in the proportional navigation stage includes at least one of the following: Control the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value to keep the nose of the UAV facing the target; Control the expected pitch angle of the UAV to be equal to the line-of-sight elevation angle value; Control the expected vertical speed of the UAV to include: the expected elevation angle of speed in the previous control cycle, plus the product of the proportional term of the proportional navigation algorithm in the vertical plane, the line-of-sight elevation angle rate, and the time interval between two adjacent control cycles, to obtain the expected elevation angle of speed in the current control cycle. Then, determine the expected vertical speed according to the product of the tangent value of the negative value of the expected elevation angle of speed in the current control cycle and the estimated horizontal speed; The expected roll angle value for controlling the drone includes: determining the expected horizontal lateral acceleration value based on the product of the estimated value of the line-of-sight azimuth angle rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal speed; determining the expected vertical acceleration value that conforms to the straight flight expectation based on the expected pitch angle and the gravitational acceleration; and determining the expected roll angle value based on the arctangent of the quotient of the expected horizontal lateral acceleration value and the expected vertical acceleration value.

[0078] The principle of proportional navigation control is to conduct guidance control through the proportional relationship between the rotational angular velocity of the drone's velocity vector and the line-of-sight angle rate. The parameters relied on include the estimated value of the horizontal speed, the line-of-sight azimuth angle rate, and the line-of-sight pitch angle rate. The specific control logic includes: a. The control logic of the expected yaw angle value of the drone is as follows: =

[0079] b. The control logic of the expected pitch angle value of the drone is as follows: = At this time, the drone will lower its head and fly downward while flying forward.

[0080] c. The control logic of the expected vertical speed value of the drone is as follows: is the expected speed elevation angle value in this control cycle, is the expected speed elevation angle value in the previous control cycle, is the proportional term of the proportional navigation method in the vertical plane. is the line-of-sight elevation angle rate between the missile and the target. dt is the time interval between two adjacent control cycles, and the time interval is related to the frame rate of image processing.

[0081]

[0082] is the expected vertical speed value (positive when the speed is downward), is the estimated value of the drone's horizontal speed (scalar).

[0083] =

[0084] d. Refer to the control logic in the second stage for the control of the expected roll angle value of the drone.

[0085] According to the above embodiments of the present application, during the process of the UAV hitting the target, especially in the later stage, the nose of the UAV is always aligned with or pointed at the target while guidance is completed. The benefits brought by such strict alignment of the nose with the target include: First, it is not easy for the target to get out of the camera's field of view, and the line-of-sight angle is less affected by the imaging distortion of the camera. Second, when the roll angle of the UAV changes, the imaging position of the target object does not change, which is conducive to the stable tracking of the image tracking algorithm. Third, it can ensure that the nose of the UAV always faces the target during flight, which is conducive to the operation of some loadings that act directionally, such as the fire extinguishing spraying device.

[0086] Combined with Figure 4 As shown, the present application also protects a rotor UAV impact device 400, and the rotor UAV impact device 400 includes: A horizontal velocity estimation module 410, adapted to determine the total horizontal acceleration of the UAV based on the tilt angle of the UAV in each control period and a pre-determined maximum horizontal velocity, and determine the horizontal velocity estimated value based on the total horizontal acceleration; A line-of-sight angle determination module 420, adapted to determine the missile-to-target line-of-sight unit vector in the north-east-earth coordinate system based on the parameters of the camera on the UAV and the attitude of the UAV, and determine the line-of-sight azimuth angle and the line-of-sight elevation angle; A target impact control module 430, adapted to impact the target by the UAV based on at least one of the horizontal velocity estimated value, the line-of-sight azimuth angle or the line-of-sight elevation angle, according to proportional navigation control and / or speed tracking.

[0087] Through the above embodiments, the UAV can achieve precise impact on the target without GPS signal.

[0088] In some embodiments, the horizontal velocity estimation module 410 is adapted to: Determine the horizontal acceleration generated due to the tilt of the UAV according to the relationship between the gravitational acceleration and the tilt angle of the UAV; Estimate the maximum horizontal velocity of the UAV in each control period according to the functional relationship between the tilt angle and the maximum horizontal velocity of the UAV determined through pre-tests; Express the acceleration generated by air resistance in terms of horizontal acceleration according to the relationship between the acceleration generated by air resistance and the current tilt angle, horizontal velocity and maximum horizontal velocity of the UAV, and determine the total horizontal acceleration of the UAV; By integrating the total horizontal acceleration and combining with the horizontal velocity of the previous control period, obtain the horizontal velocity estimated value of the current control period.

[0089] In some embodiments, the target impact control module 430 is adapted to: Based on the control of the vertical speed of the UAV, divide the impact control of the UAV on the target into multiple stages, including: the stage of yawing the nose towards the target, the stage of rushing to the handover point with the line-of-sight elevation angle controlled within the impact range of the target, the stage of speed tracking and guiding the target, and / or the proportional guidance stage.

[0090] In some embodiments, the control logic executed in the stage of yawing the nose towards the target in the target impact control module 430 includes at least one of the following: Control the expected yaw angle of the UAV to gradually tend towards the line-of-sight azimuth angle value, so that the nose of the UAV turns towards the target direction; Control the expected pitch angle of the UAV to gradually tend towards zero; Control the expected vertical speed of the UAV to tend towards zero; Control the expected roll angle of the UAV to tend towards zero.

[0091] In some embodiments, the control logic executed in the stage of rushing to the handover point with the line-of-sight elevation angle controlled within the impact range of the target in the target impact control module 430 includes at least one of the following: Control the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value, and keep the nose of the UAV facing the target; The control of the expected pitch angle of the UAV includes: if the line-of-sight elevation angle is greater than zero, at this time the height of the target is greater than the height of the UAV, then control the expected pitch angle to tend towards and even be zero; if the line-of-sight elevation angle is less than the first threshold, then control the expected pitch angle to tend towards and even be zero; if the line-of-sight elevation angle is between zero and the second threshold, then control the expected pitch angle to tend towards and even be equal to the line-of-sight elevation angle, and control the UAV to fly forward and upward at the same time; The control of the expected vertical speed of the UAV includes: multiply the difference between the optimal ballistic fall angle and the current line-of-sight elevation angle by the proportional term to obtain the expected line-of-sight elevation angle rate, and by adjusting the expected vertical speed, make the current line-of-sight elevation angle rate gradually approach the expected line-of-sight elevation angle rate: when the expected line-of-sight elevation angle rate is greater than zero, control the expected vertical speed to make the UAV descend in height; when the expected line-of-sight elevation angle rate is less than zero, control the expected vertical speed to make the UAV climb in height; The control of the expected roll angle of the UAV includes: determine the expected horizontal lateral acceleration value according to the product of the estimated value of the line-of-sight azimuth angle rate, the proportional term of the proportional guidance algorithm in the horizontal plane and the horizontal speed, determine the expected vertical acceleration value that conforms to the straight flight expectation according to the expected pitch angle and the gravitational acceleration, and determine the expected roll angle according to the arctangent of the quotient of the expected horizontal lateral acceleration value and the expected vertical acceleration value.

[0092] In some embodiments, the control logic executed during the stage of speed tracking and guiding the target in the target impact control module 430 includes at least one of the following: Controlling the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value to keep the nose of the UAV facing the target; Controlling the expected pitch angle of the UAV to be equal to the line-of-sight elevation angle value; Controlling the expected vertical speed of the UAV includes: determining the expected vertical speed according to the product of the tangent value of the negative line-of-sight elevation angle and the estimated horizontal speed; Controlling the expected roll angle of the UAV includes: determining the expected horizontal lateral acceleration according to the product of the line-of-sight azimuth rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the estimated horizontal speed, determining the expected vertical acceleration that conforms to the straight flight expectation according to the expected pitch angle and the gravitational acceleration, and determining the expected roll angle according to the arctangent of the quotient of the expected horizontal lateral acceleration and the expected vertical acceleration.

[0093] In some embodiments, the control logic executed during the proportional navigation stage in the target impact control module 430 includes at least one of the following: Controlling the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value to keep the nose of the UAV facing the target; Controlling the expected pitch angle of the UAV to be equal to the line-of-sight elevation angle value; Controlling the expected vertical speed of the UAV includes: the expected elevation angle of the speed in the previous control cycle, plus the product of the proportional term of the proportional navigation algorithm in the vertical plane, the line-of-sight elevation rate, and the time interval between two adjacent control cycles, to obtain the expected elevation angle of the speed in the current control cycle, and then determining the expected vertical speed according to the product of the tangent value of the negative expected elevation angle of the speed in the current control cycle and the estimated horizontal speed; Controlling the expected roll angle of the UAV includes: determining the expected horizontal lateral acceleration according to the product of the line-of-sight azimuth rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the estimated horizontal speed, determining the expected vertical acceleration that conforms to the straight flight expectation according to the expected pitch angle and the gravitational acceleration, and determining the expected roll angle according to the arctangent of the quotient of the expected horizontal lateral acceleration and the expected vertical acceleration. <http: / / www.w3.org / 2000 / svg>

[0094] It should be noted that the specific implementation manners of the above device embodiments may refer to the specific implementation manners of the corresponding method embodiments described above, and will not be elaborated herein.

[0095] In summary, the embodiments of the present application have the following features or beneficial effects: 1. The multi-rotor UAV realizes hitting the target based on image guidance in a GPS-free environment.

[0096] 2. Without relying on a pod, simply installing a low-cost strap-down camera horizontally on the UAV can achieve the function of vision-guided impact.

[0097] 3. During the image-guided flight, the nose of the aircraft is always aligned with the target, and the target object is always at the center of the image. This has three advantages: First, the target object is not easily out of the camera's field of view, and the line-of-sight angle is less affected by the imaging distortion of the camera. Second, when the roll angle of the UAV changes, the imaging position of the target object does not change, which is conducive to the stable tracking of the image tracking algorithm. Third, it can ensure that the nose of the aircraft always faces the target object during flight, which is conducive to the operation of some payloads that work directionally, such as fire extinguishing spraying devices.

[0098] It should be noted that: The algorithms and displays provided herein are not inherently related to any particular computer, virtual device, or other equipment. Various general-purpose devices can also be used in conjunction with the teachings herein. The structure required to construct such devices is obvious from the above description. In addition, this application is not directed to any particular programming language. It should be understood that the content of this application described herein can be implemented using various programming languages, and the above description of specific languages is for the purpose of disclosing the best mode of this application.

[0099] In the specification provided herein, a large number of specific details are set forth. However, it can be understood that the embodiments of this application can be practiced without these specific details. In some instances, well-known methods, structures, and technologies have not been shown in detail so as not to obscure the understanding of this specification.

[0100] Similarly, it should be understood that, in order to streamline this application and assist in understanding one or more of the various aspects of this application, in the above description of the exemplary embodiments of this application, the various features of this application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting the intention that the claimed application requires more features than are expressly recited in each claim.

[0101] Those skilled in the art can understand that the modules in the devices in the embodiments can be adaptively changed and arranged in one or more devices different from those of the embodiments. The modules or units or components in the embodiments can be combined into one module or unit or component, and in addition, they can be divided into multiple sub-modules or sub-units or sub-components. Except that at least some of such features and / or processes or units are mutually exclusive, any combination can be adopted to combine all the features disclosed in this specification (including the accompanying claims, abstract and drawings) and all the processes or units of any method or device thus disclosed. Unless otherwise explicitly stated, each feature disclosed in this specification (including the accompanying claims, abstract and drawings) can be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0102] In addition, those skilled in the art can understand that although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of this application and forms different embodiments.

[0103] Each component embodiment of this application can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) can be used in practice to implement some or all of the functions of some or all of the components in the rotor UAV impact device according to the embodiments of this application. This application can also be implemented as a device or device program (such as a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0104] The embodiment of this application provides a non-volatile computer storage medium, and the computer storage medium stores at least one executable instruction, and the computer executable instruction can execute the rotor UAV impact method in any of the above method embodiments.

[0105] Figure 5 The structural schematic diagram of the embodiment of the UAV (flight control system) of this application is shown, and the specific embodiments of this application do not limit the specific structure of the UAV.

[0106] As Figure 5As shown in the figure, the flight control system of the drone may include: a processor 502, a communications interface 504, a memory 506, and a communication bus 508.

[0107] Among them: the processor 502, the communications interface 504, and the memory 506 communicate with each other through the communication bus 508. The communications interface 504 is used to communicate with network elements of other devices such as clients or other servers. The processor 502 is used to execute the program 510, and specifically can execute the relevant steps in the above-mentioned rotor drone impact method embodiments for the drone.

[0108] Specifically, the program 510 may include program code, and the program code includes computer operation instructions.

[0109] The processor 502 may be a central processing unit CPU, or a specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application. One or more processors included in the drone may be of the same type of processor, such as one or more CPUs; or may be of different types of processors, such as one or more CPUs and one or more ASICs.

[0110] The memory 506 is used to store the program 510. The memory 506 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk memory.

[0111] The program 510 is specifically used to cause the processor 502 to execute the operations corresponding to the above-mentioned rotor drone impact method embodiments.

[0112] It should be noted that the above embodiments illustrate the present application rather than limit the present application, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present application can be implemented by means of hardware including several different elements and by means of a properly programmed computer. In the unit claims listing several devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

Claims

1. A method for a rotary-wing unmanned aerial vehicle to impact a target, which is used to utilize the flight control system on the unmanned aerial vehicle to conduct target impact in the case of GPS signal loss, and is characterized in that, The method comprises: determining a total horizontal acceleration of the UAV based on a tilt angle of the UAV in each control cycle and a predetermined maximum horizontal velocity, and determining a horizontal velocity estimate based on the total horizontal acceleration; Based on the parameters of the camera on the UAV and the attitude of the UAV, the unit vector of the missile-target line of sight in the north-east coordinate system is determined, and the azimuth and elevation angle of the line of sight are determined based on the unit vector of the missile-target line of sight. Based on at least one of the horizontal velocity estimate, the line of sight azimuth angle, or the line of sight elevation angle, the UAV is brought into collision with the target according to proportional guidance control and / or speed tracking control.

2. The method according to claim 1, characterized in that, The total horizontal acceleration of the UAV is determined based on the tilt angle of the UAV in each control cycle and the predetermined maximum horizontal velocity. The horizontal velocity estimation value is determined based on the total horizontal acceleration, including: Determine the horizontal acceleration caused by the tilt of the drone based on the relationship between the acceleration of gravity and the tilt angle of the drone; According to the functional relationship between the tilt angle and the maximum horizontal speed of the UAV determined in advance through testing, the maximum horizontal speed of the UAV in each control cycle is estimated; Based on the relationship between the acceleration caused by air resistance and the current tilt angle, horizontal velocity, and maximum horizontal velocity of the UAV, the acceleration caused by air resistance is expressed as horizontal acceleration, and the total horizontal acceleration of the UAV is determined. The estimated value of the horizontal velocity of the current control cycle is obtained by integrating the total horizontal acceleration and combining it with the horizontal velocity of the previous control cycle.

3. The method according to claim 1 or 2, characterized in that, Based on at least one of the horizontal velocity estimate, the line of sight azimuth, or the line of sight elevation angle, achieving collision of the UAV with the target using proportional guidance control and / or speed tracking control includes: Based on the control of the vertical speed of the UAV, the impact control of the UAV on the target is divided into multiple stages, including: the stage of yaw-turning the nose toward the target, the stage of running to the intersection point to control the elevation angle of the line of sight within the impact range of the target, the stage of speed tracking and guidance of the target, and / or the stage of proportional guidance.

4. The method according to claim 3, characterized in that, The control logic executed during the nose yaw steering phase includes at least one of the following: The desired value of the yaw angle of the UAV is controlled to gradually approach the line of sight azimuth value, so that the UAV's nose turns towards the target direction; The desired value of the pitch angle of the drone is controlled to gradually approach zero; The expected vertical velocity of the drone is controlled to be zero; The expected value of the roll angle of the drone is controlled to be zero.

5. The method according to claim 3, wherein The control logic executed during the run-to-joint point phase to control the sight elevation angle within the target's impact range includes at least one of the following: Control the desired yaw angle of the drone to be equal to the line of sight azimuth angle, keeping the drone's nose facing the target; The control of the desired value of the pitch angle of the drone includes: if the sight elevation angle is greater than zero, and the height of the target is greater than the height of the drone, then the desired value of the pitch angle is controlled to tend toward or even be zero; if the sight elevation angle is less than a first threshold, then the desired value of the pitch angle is controlled to tend toward or even be zero; if the sight elevation angle is between zero and a second threshold, then the desired value of the pitch angle is controlled to tend toward or even be equal to the sight elevation angle, and the drone is controlled to fly upward simultaneously; The control of the expected vertical speed of the UAV includes: multiplying the difference between the optimal ballistic fall angle and the current line-of-sight elevation angle by a proportional term to obtain the expected line-of-sight elevation angle rate, and adjusting the expected vertical speed so that the current line-of-sight elevation angle rate gradually approaches the expected line-of-sight elevation angle rate: when the expected line-of-sight elevation angle rate is greater than zero, controlling the expected vertical speed to make the UAV descend in height; when the expected line-of-sight elevation angle rate is less than zero, controlling the expected vertical speed to make the UAV climb in height. The control of the expected roll angle of the UAV includes: determining the expected horizontal lateral acceleration based on the product of the estimated value of the line-of-sight azimuth angle rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal speed, determining the expected vertical acceleration that conforms to the straight-line flight expectation based on the expected pitch angle and the gravitational acceleration, and determining the expected roll angle based on the arctangent of the quotient of the expected horizontal lateral acceleration and the expected vertical acceleration.

6. The method according to claim 3, characterized in that, The control logic executed in the stage of speed tracking and guidance for the target includes at least one of the following: Controlling the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value to keep the nose of the UAV facing the target; Controlling the expected pitch angle of the UAV to be equal to the line-of-sight elevation angle value; The control of the expected vertical speed of the UAV includes: determining the expected vertical speed based on the product of the tangent value of the negative line-of-sight elevation angle and the estimated horizontal speed; The control of the expected roll angle of the UAV includes: determining the expected horizontal lateral acceleration based on the product of the estimated value of the line-of-sight azimuth angle rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal speed, determining the expected vertical acceleration that conforms to the straight-line flight expectation based on the expected pitch angle and the gravitational acceleration, and determining the expected roll angle based on the arctangent of the quotient of the expected horizontal lateral acceleration and the expected vertical acceleration.

7. The method according to claim 3, wherein The control logic executed in the proportional navigation stage includes at least one of the following: Controlling the expected yaw angle of the UAV to be equal to the line-of-sight azimuth angle value to keep the nose of the UAV facing the target; Controlling the expected pitch angle of the UAV to be equal to the line-of-sight elevation angle value; The control of the expected vertical speed of the UAV includes: adding the expected elevation angle rate of speed in the previous control cycle to the product of the proportional term of the proportional navigation algorithm in the vertical plane, the line-of-sight elevation angle rate between the missile and the target, and the time interval between two adjacent control cycles to obtain the expected elevation angle rate of speed in the current control cycle, and then determining the expected vertical speed based on the product of the tangent value of the negative expected elevation angle rate of speed in the current control cycle and the estimated horizontal speed; The control of the expected roll angle of the UAV includes: determining the expected horizontal lateral acceleration based on the product of the estimated value of the line-of-sight azimuth angle rate, the proportional term of the proportional navigation algorithm in the horizontal plane, and the horizontal speed, determining the expected vertical acceleration that conforms to the straight-line flight expectation based on the expected pitch angle and the gravitational acceleration, and determining the expected roll angle based on the arctangent of the quotient of the expected horizontal lateral acceleration and the expected vertical acceleration.

8. A rotor UAV impact device for using the flight control system on the UAV to perform target impact in the case of GPS signal loss, characterized in that, The device includes: A horizontal speed estimation module, adapted to determine the total horizontal acceleration of the UAV based on the tilt angle of the UAV in each control cycle and a pre-determined maximum horizontal speed, and determine the estimated horizontal speed based on the total horizontal acceleration; A line-of-sight angle determination module, adapted to determine a missile-to-target line-of-sight unit vector in the north-east-earth coordinate system based on the parameters of a camera on an unmanned aerial vehicle (UAV) and the attitude of the UAV, and determine a line-of-sight azimuth angle and a line-of-sight elevation angle according to the missile-to-target line-of-sight unit vector; A target impact control module, adapted to implement the impact of the UAV on the target based on at least one of an estimated horizontal velocity value, a line-of-sight azimuth angle, or a line-of-sight elevation angle, according to proportional navigation control and / or velocity tracking control.

9. A drone, characterized in that, Comprising a processor and a memory arranged to store computer-executable instructions, the executable instructions, when executed, cause the processor to execute the rotor UAV impact method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores one or more programs, which, when executed by a processor, implement the rotor UAV impact method according to any one of claims 1-7.

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