Target positioning method, device and system of a tethered airborne device

Abstract

A target positioning method, device and system of a tethered airborne device, comprising: an optoelectronic stabilized platform and an airborne reference transmission device arranged on a tethered unmanned aerial vehicle, a ground reference transmission device and a ground station arranged on the ground, and a positioning solution method embedded in the ground station; the positioning solution method comprises a bias calibration algorithm, a reference transmission algorithm and a target positioning algorithm; the optoelectronic stabilized platform is used for measuring and sensing a surveyed object on a line of sight; the airborne reference transmission device and the ground reference transmission device are used for giving a position and a relative heading reference of two points; and the positioning solution method is used for solving position information of each key point in the system according to a spatial position relationship, so as to realize positioning. The present application does not depend on a high-precision inertial navigation system, and the constant positioning of the system is not affected by the heading drift of the inertial navigation system, and the accuracy of positioning can be ensured.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic technology, and in particular to a target positioning method, device and system for a tethered aerial device. Background Technology

[0002] Tethered unmanned aerial vehicle (UAV) systems rely on tethered fiber optic cables to connect the UAV platform to the ground control station, providing communication, power supply, and interaction functions. Because tethered UAVs have a limited operational range, their reconnaissance range is fixed within a specific area compared to untethered UAVs. However, by increasing flight altitude, tethered UAV systems can provide continuous wide-area reconnaissance and surveillance capabilities within that range, making them more reliable in this scenario. Tethered UAV systems offer good supportability, long loiter time, convenient power supply, and high positioning accuracy. Furthermore, tethered UAVs are mostly rotary-wing UAVs, which, unlike fixed-wing UAVs, do not require airports or runways. Benefiting from this factor, tethered UAV systems also have advantages such as low setup cost, convenient takeoff, easy recovery, and high safety.

[0003] Due to their quasi-static operating characteristics, tethered unmanned aerial vehicle (UAV) systems can achieve functions that are impossible for conventional UAV systems through cleverly designed special devices, systems, and methods. For example, the invention patents filed by Zhang Runzhe et al., namely "A Tethered UAV Optoelectronic Positioning System Without Relying on Satellite Navigation Technology" (Invention Patent Application No.: 202111282148.5) and "A Tethered UAV Optoelectronic Positioning System Without Relying on Satellite Navigation and Ranging Equipment" (Invention Patent Application No.: 202111282905.9), specifically address the positioning problem of tethered UAV systems in situations where differential satellite navigation signals are unavailable and normal ranging is not possible. These inventions are particularly applicable to areas with dense buildings where satellite signals are easily interfered with.

[0004] However, in fields such as maritime search and rescue, forest fire safety, and wide-area continuous surveillance, tethered drone systems generally operate in open environments where satellite guidance signals are less susceptible to interference, but may require constant deployment. For example, in forest fire safety, frequent wildfires both domestically and internationally in recent years have caused enormous economic losses. Establishing tethered drone monitoring systems in advance at open locations could prevent such disasters from occurring.

[0005] Furthermore, the reconnaissance methods and functions of tethered UAV systems are primarily determined by their onboard electro-optical stabilization platform. Positioning typically relies on the satellite navigation system and inertial navigation system mounted on the electro-optical platform. Ensuring high positioning accuracy requires accurate calculation of the aircraft's heading, which in turn depends on a high-precision inertial navigation system. Currently available high-precision inertial navigation systems, such as laser-based and fiber-optic inertial navigation, are characterized by their large size, weight, and high cost, posing a significant challenge to the carrying capacity and cost control of tethered UAV systems. Moreover, current inertial navigation systems are prone to heading drift, which greatly affects the positioning accuracy of the electro-optical platform.

[0006] Therefore, the current tethered UAV electro-optical reconnaissance systems are inadequate in simultaneously achieving payload control, cost savings, and precise positioning. Furthermore, the platform requires intermittent shutdowns to align with the inertial navigation system's heading, increasing the system's inherent risks and failing to meet the requirements for continuous monitoring. Summary of the Invention

[0007] The purpose of this invention is to: (1) overcome the high dependence of current tethered UAV reconnaissance systems on inertial navigation systems and the related heading drift problems; (2) improve the difficulty of alignment, operation, and setup of existing reference transfer schemes; and (3) provide a more cost-effective, convenient, widely applicable, and accurate alternative to current tethered UAV positioning systems. In this regard, this invention proposes a target positioning method, device, and system for tethered launch devices. This invention combines a pair of RTK and optical sight hardware systems with related software algorithms, achieving accurate positioning without relying on inertial navigation systems through the reference transfer process, which is superior to existing alignment schemes.

[0008] This invention proposes a target positioning system for a tethered airborne device, comprising: an optoelectronic stabilization platform and an airborne reference transfer device deployed on the tethered airborne device, and a ground reference transfer device and a ground station deployed on the ground;

[0009] The photoelectric stabilization platform is used to measure the yaw angle of the tethered launch device's airborne platform. Pitch angle and roll attitude angle ;

[0010] The airborne reference transfer device is used to provide RTK satellite navigation coordinates for the airborne reference transfer device. And using an airborne camera to obtain ground laser reference information from a ground reference transfer device;

[0011] The ground reference transfer device is used to provide RTK satellite navigation coordinates for the ground reference transfer device. The ground reference transmission device generates the ground laser reference information to indicate the location of the ground reference transmission device;

[0012] The ground station first performs deviation benchmark calibration: based on RTK satellite navigation coordinates. With RTK satellite navigation coordinates Yaw angle of the tethered lift device airborne platform base Pitch angle and roll attitude angle In addition to ground-based laser reference information, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation ;

[0013] The ground station further performs reference transfer processing: based on the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform. and pitch deviation Calculate the yaw attitude angle of the base of the optoelectronic stabilization platform. And it serves as the angle between the zero-position line of the line of sight of the photoelectric stabilization platform and the true north direction of the geographic coordinate system;

[0014] The ground station further performs target positioning processing: based on the azimuth angle of the pod on the tethered launch platform. and pitch angle Based on the distance measurement value between the tethered launch device and the target object It calculates and locks onto or tracks the location information of the target object located on the line of sight of the visual payload of the optoelectronic platform.

[0015] Preferably, the method for the ground station to perform deviation benchmark calibration includes:

[0016] First, based on the airborne reference transmission end RTK satellite navigation coordinates of the point ground reference transfer end RTK satellite navigation coordinates of the point In addition to local geographic parameters, calculate the geometric key points representing the location of the photoelectric platform in the geographic coordinate system. Point coordinates and coordinates of the point , The point is located at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The point represents the location of the ground-based RTK receiver antenna.

[0017] According to the yaw angle of the launch device Pitch angle and roll attitude angle And the radius of the circle from the center of the pod's top cover to the imaging plane of the airborne camera. d Imaging center of the airborne camera on the tethered launch device's opto-stabilized platform. Point coordinates ;

[0018] Further calculations Point and Spatial distance of points Then calculate the coordinates of the ground reference point in the image coordinate system.

[0019] According to the laser reference array The horizontal coordinate of the ground laser reference in the imaging plane of the airborne camera on the tethered launcher and ordinate Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle ;

[0020] Then, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation .

[0021] Preferably, the step of the ground station performing deviation benchmark calibration specifically includes:

[0022] The calculation of the geographic coordinate system characterizes the geometric key points of the photoelectric platform. Point coordinates and coordinates of the point The specific method is as follows:

[0023]

[0024]

[0025] in, The homogeneous translation transformation matrix is... for The radius of the circle of points (Mao-You circles) for The radius of the circle of points (Mao-You circles) This is the first eccentricity of the Earth's ellipsoidal meridian ellipse. For the roll homogeneous transformation rotation matrix, The homogeneous transformation matrix for heading rotation is... It is a homogeneous translation transformation matrix;

[0026] The imaging center of the onboard camera on the opto-stabilized platform of the computational tethered launch device Point coordinates The specific method is as follows:

[0027]

[0028] in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of;

[0029] Further calculations Point and Spatial distance of points The specific method is as follows:

[0030]

[0031] The specific method for calculating the coordinates of ground reference points in the image coordinate system is as follows:

[0032]

[0033] Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle The specific method is as follows:

[0034]

[0035] Among them, the subscript This is the serial number of the laser source.

[0036] Calibrate the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation The specific method is as follows:

[0037] Based on the above variable values, we can write the following system of equations:

[0038]

[0039] in:

[0040]

[0041] in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of;

[0042] According to equation (3), the pitch deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform is... The value;

[0043] Based on equations (1) and (2), the following non-homogeneous linear equation system is written:

[0044]

[0045] Find the solution vector of this equation. :

[0046]

[0047] Recalculate the heading deviation Value:

[0048]

[0049] in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector;

[0050] When the ground station performs reference transfer processing, it calculates the yaw attitude angle of the optoelectronic stabilization platform base. include:

[0051] Based on the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. .

[0052] Preferably, when the ground station performs reference transfer processing, it determines the yaw attitude angle of the photoelectric stabilization platform base. Specifically, it includes:

[0053] Establish the following equation:

[0054]

[0055] in:

[0056]

[0057] The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation;

[0058] Find the solution vector of this equation. :

[0059]

[0060] Solve based on the following quadrant transformation relationship. :

[0061]

[0062] in, The number in the parentheses is the index value. for The first element of the vector, for The second element of the vector;

[0063] When the When taking north-northeast as the positive direction, the following conversion is performed: When the positive direction is north-northeast The value of .

[0064] Preferably, the target positioning step performed by the ground station specifically includes:

[0065] Based on the pod azimuth of the onboard platform of the tethered launch device and pitch angle Based on the distance measurement value between the tethered launch device and the target object Calculate the target point Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system ;

[0066] The target longitude is calculated based on the Earth's circumpolar radius Rn, the first eccentricity e1 of the Earth's meridian ellipse, and the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system. Target latitude Target height ;

[0067] Based on the radius of gyration r of the center of the imaging plane of the pod's visual sensor, the imaging plane of the pod's visual sensor reaches... The distance h between the points Calculate the value of the target point Given the coordinates in the geographic coordinate system and the principal value of the target's heading angle in the geographic system, calculate the true value of the north-northeast heading angle in the geographic system based on the geographic coordinate system transformation relationship; then, based on the origin... and target point The principal value and true value of the target heading angle in the geodetic coordinate system are calculated using latitude and longitude coordinates.

[0068] Preferably, the ground station calculates the target point. Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system Specifically, it includes:

[0069] in, The distance from the target to the ranging device. The azimuth angle of the pod on the airborne platform for the tethered lift device. The pitch angle of the pod on the airborne platform for the tethered lift device. The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... This is the pitch and rotation homogeneous transformation matrix.

[0070] Preferably, the ground station calculates the target longitude. Target latitude Target height The specific method is as follows:

[0071] Based on the coordinate transformation relationship from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system:

[0072]

[0073] For target longitude, For target latitude, For the target height,

[0074] Calculate the target longitude:

[0075]

[0076] Iterative calculation of the target latitude that satisfies the above coordinate transformation relationship and height ;

[0077] Preferably, the specific method by which the ground station calculates the principal value and true value of the target heading angle in the geodetic coordinate system is as follows:

[0078] Calculate the target point Coordinate values ​​in a geographic coordinate system:

[0079]

[0080] in, The radius of gyration is the center of the imaging plane of the pod's vision sensor. To the imaging plane of the pod's visual sensor Distance between points The homogeneous transformation matrix for heading rotation is...

[0081] Target point in computational geography system The specific method for determining the principal value of the heading angle is as follows:

[0082]

[0083] The number in parentheses represents the index value of that coordinate. The first element of this coordinate. This is the second element of that coordinate.

[0084] Calculate the true value of the north-northeast heading angle in the geographic system based on the aforementioned geographic coordinate transformation relationship. :

[0085]

[0086]

[0087]

[0088] Based on the origin and target point The specific method for calculating the principal value of the target heading angle in the geodetic coordinate system using latitude and longitude is as follows:

[0089]

[0090] Calculate the true value of the target heading angle in the geodetic system. The specific method is as follows:

[0091] .

[0092] Preferably, the photoelectric stabilization platform includes:

[0093] A visual sensor is used to perceive the optical environment within the field of view and output an image;

[0094] A ranging device used to measure the straight-line distance from a vision sensor to a distant object on its line of sight;

[0095] Angle measuring equipment is used to measure the yaw angle of the airborne platform of the tethered launch device. Pitch angle ;

[0096] Attitude sensor used to measure the roll attitude angle of the tethered airborne platform. .

[0097] Preferably, the airborne reference transfer device includes:

[0098] An airborne RTK receiver is used to provide RTK satellite navigation coordinates to the airborne reference transfer device. ;

[0099] An airborne camera is used to image the ground-targeting end and the ground reference transfer device to obtain ground laser reference information of the ground reference transfer device.

[0100] Preferably, the ground reference transfer device includes:

[0101] Ground-based RTK receivers are used to provide RTK satellite navigation coordinates from ground-based reference transmission devices. ;

[0102] Ground laser reference is used to indicate the location of the ground reference transfer device in order to generate ground laser reference information for the ground reference transfer device.

[0103] Preferably, the ground station includes: a ground control station, used to control the overall air system and perform deviation benchmark calibration, benchmark transfer and target positioning processing;

[0104] A tethered optical cable is used to connect the tethered airborne device and the ground station;

[0105] Ground power supply, used to provide power to the tethered launch device and the ground station.

[0106] The present invention also discloses a target positioning device for a tethered airborne device, comprising:

[0107] The deviation reference calibration module uses RTK satellite navigation coordinates from the airborne reference transfer end. RTK satellite navigation coordinates with ground reference transfer end Yaw angle of the tethered lift device airborne platform base Pitch angle and roll attitude angle In addition to ground-based laser reference information, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation ;

[0108] The reference transfer module determines the heading deviation between the airborne camera's line of sight and the zero-position line of the optoelectronic stabilization platform. and pitch deviation Calculate the yaw attitude angle of the base of the optoelectronic stabilization platform. And it serves as the angle between the zero-position line of the line of sight of the photoelectric stabilization platform and the true north direction of the geographic coordinate system;

[0109] The target positioning module determines the azimuth of the pod on the tethered launch platform. and pitch angle Based on the distance measurement value between the tethered launch device and the target object It calculates the positioning information of the target object locked or tracked on the line of sight of the visual payload of the optoelectronic platform.

[0110] Preferably, the deviation benchmark calibration module specifically performs the following processing:

[0111] First, based on the airborne reference transmission end RTK satellite navigation coordinates of the point ground reference transfer end RTK satellite navigation coordinates of the point In addition to local geographic parameters, calculate the geometric key points representing the location of the photoelectric platform in the geographic coordinate system. Point coordinates and coordinates of the point , The point is located at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The point represents the location of the ground-based RTK receiver antenna.

[0112] According to the yaw angle of the launch device Pitch angle and roll attitude angle And the radius of the circle from the center of the pod's top cover to the imaging plane of the airborne camera. d Imaging center of the airborne camera on the tethered launch device's opto-stabilized platform. Point coordinates ;

[0113] Further calculations Point and Spatial distance of points Then calculate the coordinates of the ground reference point in the image coordinate system. ;

[0114] According to the laser reference array The horizontal coordinate of the ground laser reference in the imaging plane of the airborne camera on the tethered launcher and ordinate Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle ;

[0115] Then, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation .

[0116] Preferably, the deviation benchmark calibration module specifically performs the following processing:

[0117] The calculation of the geographic coordinate system characterizes the geometric key points of the photoelectric platform. Point coordinates and coordinates of the point The specific method is as follows:

[0118]

[0119]

[0120] in, The homogeneous translation transformation matrix is... for The radius of the circle of points (Mao-You circles) for The radius of the meridian at the point is given by e1, where e1 is the first eccentricity of the Earth's ellipsoidal meridian ellipse. For the roll homogeneous transformation rotation matrix, The homogeneous transformation matrix for heading rotation is... It is a homogeneous translation transformation matrix;

[0121] The imaging center of the onboard camera on the opto-stabilized platform of the computational tethered launch device Point coordinates The specific method is as follows:

[0122]

[0123] in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of;

[0124] Further calculations Point and Spatial distance of points The specific method is as follows:

[0125]

[0126] The specific method for calculating the coordinates of ground reference points in the image coordinate system is as follows:

[0127]

[0128] Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle The specific method is as follows:

[0129]

[0130] Among them, the subscript This is the serial number of the laser source.

[0131] Calibrate the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation The specific method is as follows:

[0132] Based on the above variable values, we can write the following system of equations:

[0133]

[0134] in:

[0135]

[0136] in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of;

[0137] According to equation (3), the pitch deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform is... The value;

[0138] Based on equations (1) and (2), the following non-homogeneous linear equation system is written:

[0139]

[0140] Find the solution vector of this equation. :

[0141]

[0142] Recalculate the heading deviation Value:

[0143]

[0144] in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector.

[0145] Preferably, the reference transfer module calculates the yaw attitude angle of the photoelectric stabilization platform base. include:

[0146] Based on the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. .

[0147] Preferably, the reference transfer module determines the heading deviation between the airborne camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. Specifically, it includes:

[0148] Establish the following equation:

[0149]

[0150] in:

[0151]

[0152] The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation;

[0153] Find the solution vector of this equation. :

[0154]

[0155] Solve based on the following quadrant transformation relationship. :

[0156]

[0157] in, The number in the parentheses is the index value. for The first element of the vector, for The second element of the vector;

[0158] When the When taking north-northeast as the positive direction, the following conversion is performed: When the positive direction is north-northeast The value of .

[0159] Preferably, the target positioning module's target positioning step specifically includes:

[0160] Based on the pod azimuth of the onboard platform of the tethered launch device and pitch angle Based on the distance measurement value between the tethered launch device and the target object Calculate the target point Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system ;

[0161] The target longitude is calculated based on the Earth's circumpolar radius Rn, the first eccentricity e1 of the Earth's meridian ellipse, and the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system. Target latitude Target height ;

[0162] Based on the radius of gyration r of the center of the imaging plane of the pod's visual sensor, the imaging plane of the pod's visual sensor reaches... The distance h between the points Calculate the value of the target point Given the coordinates in the geographic coordinate system and the principal value of the target's heading angle in the geographic system, calculate the true value of the north-northeast heading angle in the geographic system based on the geographic coordinate system transformation relationship; then, based on the origin... and target point The principal value and true value of the target heading angle in the geodetic coordinate system are calculated using latitude and longitude coordinates.

[0163] Preferably, the target positioning module calculates the target point. Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system Specifically, it includes:

[0164] in, The distance from the target to the ranging device. The azimuth angle of the pod on the airborne platform for the tethered lift device. The pitch angle of the pod on the airborne platform for the tethered lift device. The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... This is the pitch and rotation homogeneous transformation matrix.

[0165] Preferably, the target positioning module calculates the target longitude. Target latitude Target height The specific method is as follows:

[0166] Based on the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system:

[0167]

[0168] For target longitude, For target latitude, For the target height,

[0169] Calculate the target longitude:

[0170]

[0171] Iterative calculation of the target latitude that satisfies the transformation relationship and height .

[0172] Preferably, the target positioning module calculates the principal value and true value of the target heading angle in the geodetic coordinate system as follows:

[0173] Calculate the target point Coordinate values ​​in a geographic coordinate system:

[0174]

[0175] in, The radius of gyration is the center of the imaging plane of the pod's vision sensor. To the imaging plane of the pod's visual sensor Distance between points The homogeneous transformation matrix for heading rotation is...

[0176] Target point in computational geography system The specific method for determining the principal value of the heading angle is as follows:

[0177]

[0178] The number in parentheses represents the index value of that coordinate. The first element of this coordinate. This is the second element of that coordinate.

[0179] Calculate the true value of the north-northeast heading angle in the geographic system based on the aforementioned geographic coordinate transformation relationship. :

[0180]

[0181]

[0182]

[0183] Based on the origin and target point The specific method for calculating the principal value of the target heading angle in the geodetic coordinate system using latitude and longitude is as follows:

[0184]

[0185] Calculate the true value of the target heading angle in the geodetic system. The specific method is as follows:

[0186] .

[0187] This invention also proposes a target positioning method for a tethered airborne device, comprising:

[0188] S1. Deviation reference calibration steps: Based on the RTK satellite navigation coordinates from the airborne reference transfer end... RTK satellite navigation coordinates with ground reference transfer end Yaw angle of the tethered lift device airborne platform base Pitch angle and roll attitude angle In addition to ground-based laser reference information, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation ;

[0189] S2, Reference Transfer Steps: Further adjust the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform. and pitch deviation Calculate the yaw attitude angle of the base of the optoelectronic stabilization platform. And it serves as the angle between the zero-position line of the line of sight of the photoelectric stabilization platform and the true north direction of the geographic coordinate system;

[0190] S3. Target Positioning Steps: Further determine the azimuth angle of the pod on the tethered launch platform. and pitch angle Based on the distance measurement value between the tethered launch device and the target object It calculates and locks onto or tracks the location information of the target object located on the line of sight of the visual payload of the optoelectronic platform.

[0191] Preferably, S1, the deviation benchmark calibration step specifically includes:

[0192] First, based on the airborne reference transmission end RTK satellite navigation coordinates of the point ground reference transfer end RTK satellite navigation coordinates of the point In addition to local geographic parameters, calculate the geometric key points representing the location of the photoelectric platform in the geographic coordinate system. Point coordinates and coordinates of the point , The point is located at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The point represents the location of the ground-based RTK receiver antenna.

[0193] According to the yaw angle of the launch device Pitch angle and roll attitude angle And the radius of the circle from the center of the pod's top cover to the imaging plane of the airborne camera. d Imaging center of the airborne camera on the tethered launch device's opto-stabilized platform. Point coordinates ;

[0194] Further calculations Point and Spatial distance of points Then calculate the coordinates of the ground reference point in the image coordinate system. ;

[0195] According to the laser reference array The horizontal coordinate of the ground laser reference in the imaging plane of the airborne camera on the tethered launcher and ordinate Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle ;

[0196] Then, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation .

[0197] Preferably, S1, the deviation benchmark calibration step specifically includes:

[0198] The calculation of the geographic coordinate system characterizes the geometric key points of the photoelectric platform. Point coordinates and coordinates of the point The specific method is as follows:

[0199]

[0200]

[0201] in, The homogeneous translation transformation matrix is... for The radius of the circle of points (Mao-You circles) for The radius of the meridian at the point is given by e1, where e1 is the first eccentricity of the Earth's ellipsoidal meridian ellipse. For the roll homogeneous transformation rotation matrix, The homogeneous transformation matrix for heading rotation is... It is a homogeneous translation transformation matrix;

[0202] The imaging center of the onboard camera on the opto-stabilized platform of the computational tethered launch device Point coordinates The specific method is as follows:

[0203]

[0204] in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of;

[0205] Further calculations Point and Spatial distance of points The specific method is as follows:

[0206]

[0207] The specific method for calculating the coordinates of ground reference points in the image coordinate system is as follows:

[0208]

[0209] Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle The specific method is as follows:

[0210]

[0211] Among them, the subscript This is the serial number of the laser source.

[0212] Calibrate the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation The specific method is as follows:

[0213] Based on the above variable values, we can write the following system of equations:

[0214]

[0215] in:

[0216]

[0217] in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of;

[0218] According to equation (3), the pitch deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform is... The value;

[0219] Based on equations (1) and (2), the following non-homogeneous linear equation system is written:

[0220]

[0221] Find the solution vector of this equation. :

[0222]

[0223] Recalculate the heading deviation Value:

[0224]

[0225] in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector.

[0226] Preferably, in step S2, the calculation of the yaw attitude angle of the photoelectric stabilization platform base... include:

[0227] Based on the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. .

[0228] Preferably, in step S2, the heading deviation between the airborne camera's line of sight and the zero-position line of the photoelectric stabilization platform is considered. and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. Specifically, it includes:

[0229] Establish the following equation:

[0230]

[0231] in:

[0232]

[0233] The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation;

[0234] Find the solution vector of this equation. :

[0235]

[0236] Solve based on the following quadrant transformation relationship. :

[0237]

[0238] in, The number in the parentheses is the index value. for The first element of the vector, for The second element of the vector;

[0239] When the When taking north-northeast as the positive direction, the following conversion is performed: When the positive direction is north-northeast The value of .

[0240] Preferably, S3, the target localization step specifically includes:

[0241] Based on the pod azimuth of the onboard platform of the tethered launch device and pitch angle Based on the distance measurement value between the tethered launch device and the target object Calculate the target point Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system ;

[0242] The target longitude is calculated based on the Earth's circumpolar radius Rn, the first eccentricity e1 of the Earth's meridian ellipse, and the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system. Target latitude Target height ;

[0243] Based on the radius of gyration r of the center of the imaging plane of the pod's visual sensor, the imaging plane of the pod's visual sensor reaches... The distance h between the points Calculate the value of the target point Given the coordinates in the geographic coordinate system and the principal value of the target's heading angle in the geographic system, calculate the true value of the north-northeast heading angle in the geographic system based on the geographic coordinate system transformation relationship; then, based on the origin... and target point The principal value and true value of the target heading angle in the geodetic coordinate system are calculated using latitude and longitude coordinates.

[0244] Preferably, in S3, the calculated target point Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system Specifically, it includes:

[0245] in, The distance from the target to the ranging device. The azimuth angle of the pod on the airborne platform for the tethered lift device. The pitch angle of the pod on the airborne platform for the tethered lift device. The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... This is the pitch and rotation homogeneous transformation matrix.

[0246] Preferably, in S3, the target longitude is calculated. Target latitude Target height The specific method is as follows:

[0247] Based on the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system:

[0248]

[0249] For target longitude, For target latitude, For the target height,

[0250] Calculate the target longitude:

[0251]

[0252] Iterative calculation of the target latitude that satisfies the transformation relationship and height .

[0253] Preferably, the specific method for determining the principal value of the target heading angle and the true value of the target heading angle in the geodetic coordinate system in S3 is as follows:

[0254] Calculate the target point Coordinate values ​​in a geographic coordinate system:

[0255]

[0256] in, The radius of gyration is the center of the imaging plane of the pod's vision sensor. To the imaging plane of the pod's visual sensor Distance between points The homogeneous transformation matrix for heading rotation is...

[0257] Target point in computational geography system The specific method for determining the principal value of the heading angle is as follows:

[0258]

[0259] The number in parentheses represents the index value of that coordinate. The first element of this coordinate. This is the second element of that coordinate.

[0260] Calculate the true value of the north-northeast heading angle in the geographic system based on the aforementioned geographic coordinate transformation relationship. :

[0261]

[0262]

[0263]

[0264] Based on the origin and target point The specific method for calculating the principal value of the target heading angle in the geodetic coordinate system using latitude and longitude is as follows:

[0265]

[0266] Calculate the true value of the target heading angle in the geodetic system. The specific method is as follows:

[0267] .

[0268] The advantages of this invention compared to the prior art are:

[0269] (1) The present invention reduces the dependence on the inertial navigation system. The present invention locks the relative heading information in the deviation angle between the airborne camera line of sight and the zero line of the photoelectric stabilization platform through the air-to-ground reference transfer technology. After the deviation is calibrated, the system equipped with attitude sensor can be completely independent of the inertial navigation system, avoiding the defects of the inertial navigation technology solution that is easily affected by heading drift and cannot achieve high-precision positioning at constant time.

[0270] (2) The present invention is less affected by environmental factors such as light intensity and fog. It uses a high-definition camera with a laser source. By adjusting the camera's exposure time, the laser point can be clearly positioned on the phase plane under any circumstances. It has high visibility and strong protection, and can ensure that the system can work under strong daylight, night and adverse weather conditions.

[0271] (3) By adopting a combination system of a pair of RTK and optical sights and using its related algorithms, the present invention significantly increases the practicality of the system. Compared with other reference transfer schemes in the prior art, this scheme uses unidirectional alignment instead of mutual aiming, which makes deployment more convenient and alignment easier.

[0272] (4) The positioning algorithm in the system of the present invention takes into account the spatial position relationship and the geometric model of the specific equipment, so that the positioning algorithm has a wider range of applications and higher accuracy.

[0273] (5) The present invention uses a tethering system weighing tens of kilograms, which can complete the mission at a lower cost. This is of great significance for saving costs, reducing space, and ensuring constant reconnaissance for tethered UAV systems. The system of the present invention replaces the high-precision inertial navigation system required in conventional optoelectronic stabilization platforms with airborne and ground reference transmission devices, providing a better solution for reducing the load, space, and cost of tethered UAV systems. Attached Figure Description

[0274] Figure 1 This is the overall system block diagram of the present invention;

[0275] Figure 2 This is a schematic diagram of the photoelectric stabilization platform of the present invention;

[0276] Figure 3 This is a schematic diagram of the system setup of the present invention;

[0277] Figure 4 This invention is a mathematical model of coordinate system relationships considering spatial location;

[0278] Figure 5 This is a schematic diagram of laser target imaging according to the present invention;

[0279] Figure 6 This is a diagram showing the dynamic experimental positioning results of this invention;

[0280] Figure 7 This is a comparison between the deviation calibration input and the reference transfer output in the simulation analysis of this invention;

[0281] Figure 8 This is a spatial scatter plot of the solution results and true values ​​of the target localization algorithm in the simulation analysis of this invention;

[0282] Figure 9 It is the difference between the solution result of the target localization algorithm in the simulation analysis of this invention and the true value;

[0283] Figure 10 This is a comparison between the deviation calibration input and the reference transmission output in the error transmission of this invention;

[0284] Figure 11 This is a spatial scatter plot of the solution results and true values ​​of the target localization algorithm in the error propagation of this invention;

[0285] Figure 12 It is the difference between the solution result of the target localization algorithm in the error propagation of this invention and the true value.

[0286] 1. Tethered Unmanned Aerial Vehicle (UAV) System; 2. Optoelectronic Stabilization Platform; 3. Airborne Reference Transfer Device; 4. Ground Reference Transfer Device; 5. Ground Station; 6. Other Supporting Systems; 7. Aerial System; 8. Ground System; 9. Balancing Ring Frame; 10. Visual Sensor; 11. Ranging Device; 12. Angle Measuring Device; 13. Attitude Sensor; 14. Airborne RTK Receiver; 15. Airborne Camera; 16. Ground RTK Receiver; 17. Ground Laser Reference; 18. Ground Control Station; 19. Tethered Control Box; 20. Ground Power Supply Detailed Implementation

[0287] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments. The present invention proposes a target positioning method, device, and system for a tethered aerial device. The target positioning method and system of the present invention can utilize reference information on the tethered UAV to obtain information between the UAV, the airborne reference transmission device, and the ground control station, and obtain accurate target positioning information through calculation and transformation of the information captured by the airborne reference transmission device.

[0288] The key modules of the system include: an optoelectronic stabilization platform and an airborne reference transfer device deployed on a tethered UAV; a ground-based reference transfer device and a ground control station deployed on the ground; and a positioning calculation method embedded in the ground control station. The optoelectronic stabilization platform includes a balance ring frame, a visual sensor, a ranging device, an angle measuring device, and an attitude sensor. The airborne reference transfer device includes an airborne camera and an airborne RTK receiver. The ground transfer device includes a ground laser reference and a ground RTK receiver. The positioning calculation method includes a deviation calibration algorithm, a reference transfer algorithm, and a target positioning algorithm.

[0289] An optoelectronic stabilization platform is used to sense the surrounding environment and objects, provide stable reconnaissance images, and give the azimuth, pitch, and attitude angle of the line of sight axis relative to the platform's zero-position line, or the attitude of the line of sight axis relative to the inertial coordinate system. It also measures the straight-line distance of the object being detected relative to the stabilization platform for positioning and calculation applications.

[0290] Optionally, the visual sensor in the photoelectric stabilization platform can be a visible light camera, a short-wave, medium-wave, or long-wave visual sensor, or others, or even a combination of multiple cameras. The specific choice depends on the specific application of the equipment. Optionally, the ranging device in the photoelectric stabilization platform can be a laser rangefinder, an infrared rangefinder, or others. The specific choice depends on the requirements for positioning accuracy and cost. Optionally, the angle measuring device in the photoelectric stabilization platform can be a magnetic moment meter, a photoelectric encoder, a rotary transformer, or others. The specific choice also depends on the requirements for positioning accuracy and cost.

[0291] The airborne reference transfer device is used to image the ground laser reference with an airborne camera at a certain angle to the ground, obtain the coordinate value of the ground laser reference on the imaging plane of the airborne camera, and also to provide the RTK satellite navigation coordinate value of the current airborne camera for positioning and calculation.

[0292] Optionally, the airborne camera uses a CMOS or CCD sensor, and its operating frame rate is not less than a preset threshold. Preferably, the integration time of the airborne camera should be as short as possible to facilitate the camera's field of view in highlighting the position of the ground laser reference and reduce interference from other objects in the field of view in determining the location.

[0293] The ground reference transfer device is used to provide RTK satellite navigation coordinate values ​​for ground laser reference points imaged in the airborne camera, for positioning calculation applications.

[0294] Optionally, the ground reference transmission device uses two laser sources, which are equally distributed on both sides of the geometric center of the ground RTK receiver antenna, and the line connecting the emission points of the two laser sources passes through the geometric center of the ground RTK receiver antenna; preferably, the ground reference transmission device uses three laser sources, which are equally distributed on the circumference of the geometric center of the ground RTK receiver antenna, and the connection image of the three points forms an equilateral triangle, the center of which is the geometric center of the RTK receiver antenna.

[0295] When the system is in operation, the tethered UAV system, equipped with an optoelectronic stabilization platform, hovers in the air. The system can perform positioning by adjusting the attitude of the tethered UAV so that the ground reference image is projected onto the airborne camera. This alignment scheme only requires unidirectional alignment, making it easy to set up and operate. Therefore, preferably, using an airborne camera with a larger field of view and setting a greater distance between the ground reference and the tethered UAV will make system alignment easier and positioning more accurate.

[0296] The positioning calculation method is used to calculate the optical geometric relationship based on the four-dimensional homogeneous matrix transformation. It calculates the deviation between the airborne camera's line of sight and the zero line of the optoelectronic stabilization platform from the RTK satellite navigation coordinates in the air and on the ground. Using this deviation value, it further calculates the heading of the pod's line of sight axis, and then calculates the heading of the target object locked in the center of the visual sensor's field of view on the optoelectronic platform, thereby achieving positioning.

[0297] The positioning solution method considers the positioning problem at near, medium, and far distances within the range from the shortest detection distance to the farthest line-of-sight. All observable and measurable objects within the line-of-sight range can be located using this method. The specific processing procedure is as follows:

[0298] Select a reference ellipsoid that conforms to the local geography, and establish an origin with the center of the Earth's reference ellipsoid as the longitude. ,latitude as high as the earth Geodetic coordinate system with coordinate parameters Any coordinate within this coordinate system can be used Description; Establish an origin with the center of the Earth's reference ellipsoid as the reference point. The axis points to the geographic North Pole. Pointing to the intersection of the Prime Meridian and the Equator, The axis is located on the equatorial plane and is parallel to the equatorial plane. shaft and The axes form a right-handed rectangular coordinate system, a geocentric coordinate system. Any coordinate within this coordinate system can be represented using rectangular coordinates. To describe this, establish the origin at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The axis points due east geographically. The axis points to due north. Geographic coordinate system with axes perpendicular to the Earth's surface Any coordinate within this coordinate system can be represented using rectangular coordinates. To describe this, establish the origin at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The axis points to the right within the circular surface of the photoelectric platform base, forming a 90-degree angle with the zero-position line of the photoelectric stabilization platform. The axis points to the zero-position line of the photoelectric stabilization platform. The axis is perpendicular to the disk surface of the photoelectric stabilization platform base and faces upwards in the carrier coordinate system. Any coordinate within this coordinate system can be represented using rectangular coordinates. To describe; establish an origin with the center of the airborne camera's imaging plane as the origin, The axis lies within the imaging plane and points to the direct right of the imaging plane. The axis points to the line of sight of the airborne camera. The airborne camera's line-of-sight coordinate system, located within the imaging plane and pointing directly above it. Any coordinate within this coordinate system can be represented using rectangular coordinates. To describe; establish an origin with the center of the airborne camera's imaging plane as the origin, The axis points to the target appearing in the image captured by the airborne camera. shaft and The shaft is located at Airborne camera image coordinate system to the right and up of the axis Any coordinate within this coordinate system can be represented using rectangular coordinates. To describe; establish the imaging center of the visual payload within the photoelectric stabilization platform as the origin, The axis lies within the imaging plane and points to the direct right of the imaging plane. The axis points to the visual sensor's line of sight. The visual sensor's line-of-sight coordinate system is located within the imaging plane and points directly above it. Any coordinate within this coordinate system can be represented using rectangular coordinates. To describe.

[0299] Receive the The horizontal coordinate of the ground laser reference in the imaging plane of the airborne camera and ordinate Let i be a natural number. Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle .

[0300] Receive RTK satellite navigation coordinates from the airborne reference transfer unit RTK satellite navigation coordinates with ground reference transfer end .

[0301] Receives platform base yaw, pitch, and roll attitudes calculated from the opto-stabilized platform attitude sensors. and .

[0302] The deviation calibration algorithm is based on the received information above, specifically the heading and pitch deviations between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and Since the airborne camera is rigidly connected to the base of the optoelectronic stabilization platform via a rigid structure, the yaw and pitch deviations between the airborne camera's line of sight and the zero-position line of the optoelectronic stabilization platform are... and Once installed, the quantity is fixed, so this step only needs to be performed once after assembly.

[0303] The reference transfer algorithm is based on the RTK satellite navigation coordinates received from the airborne reference transfer terminal. RTK satellite navigation coordinates with ground reference transfer end Based on the pitch and roll attitude of the platform base calculated from the attitude sensors of the opto-stabilized platform. and The matrix rotation angle is calculated based on the coordinates of the laser array on the imaging plane of the airborne camera. and And based on the calibrated heading and pitch deviations between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and Calculate the yaw attitude of the platform base This value is also the angle between the zero line of the line of sight of the optoelectronic platform and the true north direction of the geographic coordinate system. This step, through the relative deviation between the line of sight of the airborne camera and the zero line of the optoelectronic stabilization platform, transfers the absolute north reference calculated by the RTK satellite navigation coordinate group to the line of sight of the optoelectronic stabilization platform, providing a heading reference for subsequent positioning steps.

[0304] The target localization algorithm uses RTK satellite navigation coordinates received from the airborne reference transmitter. RTK satellite navigation coordinates with ground reference transfer end Based on the calculated yaw attitude of the platform base The platform base pitch and roll attitudes calculated by the self-electro-stabilized platform attitude sensor received. and The matrix rotation angle is calculated based on the coordinates of the laser array on the imaging plane of the airborne camera. and Based on the calibrated heading and pitch deviations between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform... and According to the azimuth angle of the pod given by the self-optical stabilization platform angle measuring device and pitch angle Based on the distance measured by the ranging device after the receiver is aligned with the object. It calculates the positioning information of a target object locked or tracked on the line-of-sight axis of the visual payload of the optoelectronic platform. The positioning information specifically includes the longitude, latitude, and altitude of the target object and its heading relative to the platform.

[0305] Preferably, the deviation calibration algorithm can be replaced by calibration in the laboratory using more precise measurement methods. This description is for the convenience of introducing and verifying the algorithm, so the heading information of the attitude sensor is not required in actual use.

[0306] The present invention will be described in detail below with reference to the embodiments.

[0307] Example

[0308] like Figure 1 As shown, embodiments of the present invention propose a target positioning method and system for a tethered aerial device. The system includes: a tethered aerial device (such as a tethered unmanned aerial vehicle system) 1, an electro-optical stabilization platform 2, an airborne reference transmission device 3, a ground reference transmission device 4, a ground station 5, and other cooperating systems 6. The tethered unmanned aerial vehicle system 1, the electro-optical stabilization platform 2, and the airborne reference transmission device 3 constitute an aerial system 7, while the ground reference transmission device 4, the ground station 5, and the other cooperating systems 6 constitute a ground system 8. The tethered unmanned aerial vehicle system 1 carries the electro-optical stabilization platform 2 and the airborne reference transmission device 3, and provides communication and power supply between the subsystems. The electro-optical stabilization platform 2 performs the main reconnaissance and positioning functions of the system. The airborne reference transmission device 3 and the ground reference transmission device 4 transmit a north-facing reference in ground space. The ground station 5 is used for detecting, powering, and controlling the overall system. The other cooperating systems 6 are responsible for signal processing, signal conversion, and power transmission.

[0309] like Figure 2As shown, the photoelectric stabilization platform 2 specifically includes: a balance ring frame 9, a vision sensor 10, a ranging device 11, an angle measuring device 12, and an attitude sensor 13. The balance ring frame 9 is used to control and stabilize the load; the vision sensor 10 is used to sense the optical environment within the field of view and output an image; the ranging device 11 is used to measure the straight-line distance from the vision sensor 10 to a distant object on its line of sight axis; the angle measuring device 12 is used to measure the azimuth and pitch angles of the platform frame; and the attitude sensor 13 is used to measure the attitude of the platform, and before the system is initialized with deviation calibration, it should also provide the heading angle of the platform relative to the inertial coordinate system.

[0310] The airborne reference transmission device 3 includes an airborne RTK receiver 14 and an airborne camera 15; wherein the airborne RTK receiver 14 is used to provide real-time differential satellite navigation coordinate values ​​of the airborne reference transmission device 3; the airborne camera 15 is used to image the ground laser reference 17 and calculate the coordinate values ​​of the antenna of the ground RTK receiver 16 in the imaging plane.

[0311] Since the airborne camera 15 needs to aim at the ground, its lens and line-of-sight axis should form a certain angle with its horizontal reference plane. The size of the angle depends on the system's daily operating altitude and the ground environment. In this embodiment, the airborne camera 15's lens and line-of-sight axis are at an angle... Angle; in addition, for easy alignment, the field of view of the airborne camera should be large enough and have sufficient resolution.

[0312] The ground reference transmission device 4 includes a ground RTK receiver 16 and a ground laser reference 17; wherein the ground RTK receiver 16 is used to provide real-time differential satellite navigation coordinate values ​​of the ground reference transmission device 4; and the ground laser reference is used to indicate the location of the ground RTK receiver 16 to the airborne camera 15 in real time.

[0313] The ground reference transmission device 4 can be supported by a tripod for camera equipment or fixed to the ground by means of a fixed connection; for convenience, the orientation of the ground laser reference 17 should be able to be adjusted in azimuth and elevation at any time, but the antenna of the ground RTK receiver 16 should always be located at the geometric center of the array light source of the ground laser reference 17.

[0314] Ground station 5 includes ground control station 18, tethered control box 19 and ground power supply 20; ground control station 18 is used to control real-time monitoring and control the overall air system 7; tethered control box 19 is used to store tethered optical cable 21; ground power supply 20 provides power to the entire air system 7 and ground system 8 to ensure the normal operation of the overall system.

[0315] The specific configuration steps of the optoelectronic system for the tethered unmanned aerial vehicle of the present invention are as follows:

[0316] Step 1: System Assembly

[0317] Deploy aerial system 7, equipped with tethered unmanned aerial vehicle system 1, airborne reference transfer device 3, and electro-optical stabilization platform 2; to facilitate deviation calibration, the azimuth deviation angle between the line-of-sight axis of airborne reference transfer device 3 and the zero-position line of electro-optical stabilization platform 2 is as close as possible. , , and Nearby; special attention should be paid to ensuring that the base of the airborne reference transfer device 3 and the photoelectric stabilization platform 2 are firmly connected.

[0318] Step 2: Power-on test

[0319] Deploy ground station 5, connect tethered optical cable 21 in tethered control box 19 to tethered UAV system 1, and connect ground power supply 20 to UAV system 1 using power medium; verify whether the functions of the system are normal, and test the power supply, communication and monitoring functions of ground station 5 and the air system 7 that has not yet taken off.

[0320] Step 3: System Setup

[0321] The tethered unmanned aerial vehicle (UAV) system 1 takes off and hovers at a certain altitude; the azimuth angle of the UAV and the position, pitch, and azimuth of the ground reference transmission device are coordinated and adjusted so that the airborne camera 15 is aligned with the ground laser reference 17; the integration time is adjusted to make the laser array clearly and accurately visible; the overall system setup effect is as follows. Figure 3 As shown.

[0322] After the system is configured, subsequent positioning functions can be performed, namely the tethered UAV photoelectric positioning method, which is mainly divided into three main stages: I. Deviation calibration, II. Reference transfer and III. Target positioning.

[0323] I Deviation Calibration

[0324] Step 1: Initialize the coordinate system

[0325] According to a specific embodiment, establish as follows Figure 4 The coordinate system relationship mathematical model is shown; in the legend, The point is located at the intersection of the vertical line perpendicular to the center of the pod's top cover and the plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. This point is the origin of both the geographic coordinate system and the carrier coordinate system. Point 1 is the imaging center of the airborne camera, and it is the origin of both the airborne camera's line-of-sight coordinate system and its image coordinate system. Point 1 is the imaging center of the airborne vision sensor, and this point is also the origin of the visual axis coordinate system of the optoelectronic stabilization platform vision sensor. The point represents the location of the ground-based RTK receiver antenna. The point represents the target location that needs to be located. , , , and The geometric distance between points can be calculated or obtained from structural parameters, ranging equipment, and RTK point values. It is equal to the radius of the circle from the center of the pod's top cover to the imaging plane of the airborne camera. To the imaging plane of the pod's visual sensor Distance between points The radius of gyration is the center of the imaging plane of the pod's vision sensor. The distance from the target to the ranging device. for Point and Spatial distance between points.

[0326] Step 2: Solve for the coordinate system representation of key points of the airborne reference transfer device and the ground reference transfer device.

[0327] For ease of representation, the mathematical representations of rotation and translation of a four-dimensional homogeneous matrix are defined as follows:

[0328]

[0329] Let be the homogeneous transformation matrix for heading rotation, where the variables are... It is the counterclockwise heading rotation angle; Let be the pitch and rotation homogeneous transformation matrix, where the variables are... It is the counterclockwise pitch rotation angle; Let be the roll homogeneous transformation rotation matrix, where the variables are... This is the counterclockwise roll angle. Homogeneous transformations are known mathematical transformations.

[0330]

[0331] Let be the homogeneous translation transformation matrix, where the variables are... , and This represents the translation in the three axial directions.

[0332] The homogeneous coordinates are defined as follows: The upper right subscript indicates the location of the point, and the lower right subscript indicates the coordinate system in which the point is located, such as... express The homogeneous coordinates of a point in a geographic coordinate system; based on coordinate system transformation relationships, the coordinates in the geographic coordinate system can be solved. Points and Point coordinate representation:

[0333]

[0334] .

[0335] in, and Known real-time differential GPS point values ​​(longitude, latitude, geodetic height) are obtained in real time from the airborne RTK receiver 14 and the ground RTK receiver 16. In this particular embodiment, the airborne RTK receiver 14 is located at... point; This is the first eccentricity of the Earth's ellipsoidal meridian ellipse. The radius of the circle is given by the formula:

[0336] .

[0337] in, Use the semi-major axis of the reference ellipsoid; , and These are all parameters of the Earth reference ellipsoid, and their settings should be determined based on the local geographical location where the system operates, with reference to international standards; The point coordinates can be further calculated. Point coordinates:

[0338]

[0339] in, , and The attitude angle of the photoelectric stabilized platform 2 relative to the geographic coordinate system is given by the attitude sensor 13; [the following is specified] To determine the heading deviation between the zero position of the opto-stabilized platform 2 and the line of sight of the airborne camera 15, The pitch deviation between the zero position of the optoelectronic stabilization platform 2 and the line of sight of the airborne camera 15, and To estimate the heading deviation, only the closest approximation needs to be substituted. It can be an integer multiple of; furthermore, Dot and The distance between points can be calculated as follows:

[0340]

[0341] The numbers within the parentheses represent the indices of the coordinate array. Furthermore, The representation of a point in a geographic coordinate system can be extended to an image coordinate system:

[0342]

[0343] in and The matrix azimuth and pitch angles of the airborne camera image coordinate system and the airborne camera line-of-sight coordinate system are derived from the image received from the ground laser reference 17. As mentioned earlier, the centroid of the laser array reflects the position of the ground RTK receiver 16, so the spatial matrix rotation angles are calculated after considering geometric relationships and coupling effects. and for:

[0344]

[0345] in The number of sources in the laser array. For the first The x-coordinate of each laser source, For the first The vertical coordinate of each laser source.

[0346] Because the object appears in the image coordinate system of the airborne camera. If the axis is used, then the position of the ground RTK receiver 16 in this coordinate system is expressed as follows:

[0347] .

[0348] Step 3: Establish a mathematical equation based on the point calculation relationship and the actual RTK point values.

[0349] Based on positional relationship Point calculation to The coordinates of the point should be the same as those in the previous sentence. If the RTK point values ​​are equal, the following formula establishes the relationship between the two points:

[0350]

[0351] For convenience, let:

[0352]

[0353] in, and All are constants, and are the substitution results calculated through the left side of the equation; therefore, the equation can be transformed into the following system of equations through mathematical derivation:

[0354]

[0355] Step 4: Solve for pitch installation deviation using an iterative algorithm.

[0356] Equation (3) can be solved independently. Solving equation (3) is mathematically equivalent to finding the zeros of the following function:

[0357]

[0358] In the formula For the function argument being rewritten, and To find the points where the function equals zero, the following method is designed to iteratively solve for this function:

[0359] Let the initial value be:

[0360]

[0361] The iterative formula is:

[0362]

[0363] Where k is the iteration number, iterating to: ,but The iteration ends; It can be set to any small quantity that meets the accuracy requirements. The solution is complete.

[0364] Step 5: Solve for heading installation deviation using a system of non-homogeneous linear equations.

[0365] The solution has been found. As known quantities, we can continue to solve for the unknown quantities in equations (1) and (2). Then the following equation can be established:

[0366]

[0367] This equation can be viewed as a set of non-homogeneous linear equations. Obviously, the constant coefficient matrix It is neither strange nor unusual. and The solution can be obtained directly from the following formula:

[0368]

[0369] and The solution can then be found using the following quadrant transformation relationship:

[0370]

[0371] in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector. The solution is then complete; once the airborne reference transfer device 3 and the photoelectric stabilization platform 2 are assembled, the deviation... and It should be kept at a constant value; therefore, the deviation calibration process only needs to be performed once after assembly.

[0372] As already mentioned, the given calibration method is only a simple calibration method for on-site use; product deviations can be calibrated in the laboratory using precision measuring instruments. In this case, this step can be skipped and is completely independent of the heading angle, making it a more mature solution suitable for product manufacturing.

[0373] After the deviation calibration is completed, the benchmark transfer and target positioning steps should be performed every time positioning is required.

[0374] II. Reference Transfer

[0375] Step 1: Solve for the coordinate system representation of key points of the airborne reference transfer device and the ground reference transfer device.

[0376] The coordinate system and matrix settings for the reference deviation calibration step of the benchmark transfer; based on the coordinate system transformation relationship, the solution is obtained in the geographic coordinate system. Points and The coordinates of the point:

[0377]

[0378] It is worth noting that deviation calibration only needs to be performed once, while reference transfer must be performed whenever positioning is required; therefore Point and The coordinates of a point change with the movement of the object, meaning that any computation is performed by collecting data within the same frame.

[0379] Step 2: Establish a mathematical equation based on the point calculation relationship and the actual RTK point values.

[0380] Similarly, it can be listed about Point RTK dot values ​​and from Estimated to The equation for the theoretical value:

[0381] Unlike deviation calibration, at this time It is the unknown quantity that needs to be solved, while the other variables are known quantities.

[0382] Step 3: Solve for the zero-position line heading of the photoelectric platform using a system of non-homogeneous linear equations.

[0383] For convenience, the known quantities are set as follows:

[0384] This can then be transformed into the following system of linear equations:

[0385]

[0386] Similarly, it has a non-homogeneous linear system of equations ( In the form of ); obviously If it is non-singular, then the solution vector is:

[0387]

[0388] and The solution can then be found using the following quadrant transformation relationship:

[0389]

[0390] in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector. When When taking north-northeast as the positive direction, the following conversion is performed:

[0391]

[0392] The zero-axis heading angle of the photoelectric stabilization platform 2 is calculated, and this value is the reference for reference transfer. Relying on this process, the heading angle provided by the attitude sensor 13 will no longer be needed, so that the positioning accuracy will not be affected by heading drift.

[0393] III. Target Positioning

[0394] Step 1: Calculate the coordinates of the target point in the geodetic coordinate system.

[0395] During target localization, the object to be located should be locked in the center of the field of view of the vision sensor 10 of the photoelectric stabilization platform 2. Then, the coordinates of the target in the visual sensor's line-of-sight coordinate system should be:

[0396]

[0397] in This is the distance measurement output value from the object to the photoelectric stabilized platform 2; based on the coordinate transformation relationship, the target point can be calculated. Coordinates in the Earth-centered, Earth-fixed coordinate system:

[0398]

[0399] The transition from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system can be solved in the following way:

[0400] The following mathematical relationship for coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system is used:

[0401]

[0402] Longitude can be calculated directly:

[0403]

[0404] Latitude and altitude can be solved through iterative calculations. The initial value for latitude is:

[0405]

[0406] The iterative formulas for the radius, latitude, and altitude of the circumpolar region are as follows:

[0407]

[0408] Iterate to:

[0409]

[0410] but:

[0411]

[0412] , Both can be set to any small quantity that does not affect accuracy; thus, through the above method, the latitude, longitude, and altitude of the target point can be determined. It can be solved.

[0413] Step 2: Calculate the heading angle of the target point in the geographic coordinate system.

[0414] There are two ways to define the target heading. One is the angle of north-east relative to the electro-optical stabilized platform 2 in a geographic rectangular coordinate system; this definition is suitable for medium- to short-range positioning. The other is the heading angle of the target's latitude and longitude relative to the platform's latitude and longitude on the Earth's curved surface, i.e., the heading angle in a geodetic coordinate system; this angle expression is more suitable for long-range positioning. For the heading angle in the geographic coordinate system, the coordinates of the target point in the geographic coordinate system should be calculated first.

[0415]

[0416] Based on the geometric positional relationships, the principal value of the target's heading angle can be solved as follows:

[0417]

[0418] The truth value needs to be solved through quadrant transformation and transgression transformation:

[0419]

[0420]

[0421] Finally, change the positive direction to north-northeast:

[0422]

[0423] Heading angle under the geography department Solution complete.

[0424] Step 3: Calculate the heading angle of the target point in the geodetic coordinate system

[0425] For the heading angle below the Earth's curved surface, the principal value is calculated first:

[0426]

[0427] The truth value also needs to be solved through quadrant transformation:

[0428]

[0429] The heading angle under the Earth system The solution is complete; the longitude, latitude, altitude, and heading angle of the target point have now been determined, and positioning has been achieved.

[0430] Simulation verification analysis

[0431] Given simulation conditions: Assume the longitude of the tethered UAV. ,latitude ,high Ground reference is located at ;latitude ;high Assuming the attitude of the tethered drone undergoes sinusoidal and cosine-like changes, such as Figure 6 As shown; under the given conditions above, first verify the correctness of the deviation calibration algorithm and the reference transfer algorithm. Since these two algorithms are inverse problems, i.e., one input... One output The algorithm can be verified simply by examining the difference between the two.

[0432] Figure 7 Give the heading and attitude of the deviation calibration input under given conditions. Heading attitude calculated from the reference transfer In comparison, the absolute value of the difference between the two is no greater than The results proved the correctness of the deviation calibration algorithm and the reference transfer algorithm;

[0433] Given simulation conditions: Assume the longitude of the tethered UAV. ,latitude ,high To visually assess the effectiveness of the positioning algorithm, the real target was set as a series of points located on a spatial circular trajectory. This spatial circular trajectory was horizontal and its height was [missing information]. , radius is (That is, the distance between the target and the tethered drone is) The center of the circle is the projection of the tethered drone onto its plane; Figure 8 The actual target location and the target trajectory calculated by the target localization algorithm are given, and the degree of overlap between the two can be seen. Figure 9 The deviations between the solved point and the original target point in three directions are given, and it can be seen that the maximum deviation is less than 1 / 3. The results demonstrate the correctness of the target localization algorithm.

[0434] Error propagation analysis

[0435] Based on the simulation assumptions of verifying the deviation calibration algorithm and the reference transfer algorithm, noise is added to each parameter, specifically as follows: the attitude sensor error follows... The normal distribution, the RTK point deviation follows (That is, the fluctuation range of RTK deviation is about 2cm. This value is set with reference to "Analysis of RTK Positioning Accuracy of Network Based on Beidou Compatible GPS+GLONASS", article number: 2096-4390(2020)25-0105-03), and the average RTK error may be less than 2cm following a normal distribution. The calculated deviation can be seen in...) Figure 10 This can cause The course calculation deviation is on the order of magnitude, and this error will be propagated to the target positioning calculation. However, since this value is so small, it can be almost ignored.

[0436] Based on the simulation assumptions used to verify the target localization algorithm, additive noise is added to each parameter, as follows: the attitude sensor error follows... The normal distribution, the RTK point deviation follows The ranging deviation follows Under these conditions, the trajectory deviation between the current location and the original location can be observed in... Figure 11 ; Figure 12 The waveforms for the deviations in longitude, latitude, and altitude are given. It can be seen that under these conditions, the deviations in longitude and latitude are no greater than [value missing]. The height deviation is no greater than .

[0437] Numerical Analysis

[0438] (1) To illustrate more specifically how the positioning results respond to different parameters and different magnitudes of deviation, the table below provides the numerical and statistical results of the above simulation under various conditions.

[0439]

[0440] The results in the table show that the attitude sensor error has the greatest impact on the positioning results. This is achieved while ensuring that the attitude sensor error is within a certain range. The order of magnitude, RTK error is within The range measurement error is on the order of magnitude. Magnitude The maximum target deviation within the range shall not exceed Maintaining the above error magnitude unchanged, we re-examined the algorithm's localization performance for targets at different distances, as shown in the table below:

[0441]

[0442] It is evident that, under given assumptions, the algorithm can achieve meter-level positioning of targets within a distance of 20km.

[0443] Simulation verification analysis and error propagation analysis demonstrate the effectiveness and error range of the algorithm, and the results are highly competitive among current tethered UAV positioning solutions.

[0444] Accordingly, the present invention also proposes a positioning device for a tethered airborne device, comprising:

[0445] The deviation reference calibration module uses RTK satellite navigation coordinates from the airborne reference transfer end. RTK satellite navigation coordinates with ground reference transfer end and the yaw angle of the tethered launch device airborne platform base Pitch angle and roll attitude angle Calibrate the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation .

[0446] The reference transfer module measures the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform. and pitch deviation Calculate the yaw attitude angle of the base of the optoelectronic stabilization platform. It also serves as the angle between the zero-position line of the line of sight of the photoelectric stabilization platform and the true north direction of the geographic coordinate system.

[0447] The target positioning module determines the azimuth of the pod on the tethered launch platform. and pitch angle Based on the distance measurement value between the tethered launch device and the target object It calculates the positioning information of the target object locked or tracked on the line of sight of the visual payload of the optoelectronic platform.

[0448] Furthermore, the deviation benchmark calibration module performs the following processing:

[0449] First, based on the airborne reference transmission end RTK satellite navigation coordinates of the point ground reference transfer end RTK satellite navigation coordinates of the point In addition to local geographic parameters, calculate the geometric key points representing the location of the photoelectric platform in the geographic coordinate system. Point coordinates and coordinates of the point , The point is located at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The point represents the location of the ground-based RTK receiver antenna.

[0450]

[0451]

[0452] in, The homogeneous translation transformation matrix is... for The radius of the circle of points (Mao-You circles) for The radius of the circle of points (Mao-You circles) For Earth's reference ellipsoid parameters, For the roll homogeneous transformation rotation matrix, The homogeneous transformation matrix for heading rotation is... It is a homogeneous translation transformation matrix.

[0453] According to the yaw angle of the launch device Pitch angle and roll attitude angle and pod geometric measurements , The radius of the circle extending from the center of the pod's top cover to the imaging plane of the airborne camera is equal to the radius of the circle containing the image center of the airborne camera on the photoelectric stabilization platform of the ascent device. Point coordinates :

[0454]

[0455] in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of.

[0456] Further calculations Point and Spatial distance of points :

[0457]

[0458] Next, calculate the coordinate representation of the ground reference point in the image coordinate system:

[0459]

[0460] According to the laser reference array The horizontal coordinate of the ground laser reference in the imaging plane of the airborne camera on the tethered launcher and ordinate Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle :

[0461]

[0462] Where the subscript 'i' represents the serial number of the laser source,

[0463] Based on the above variable values, we can write the following system of equations:

[0464]

[0465] in:

[0466]

[0467] in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of.

[0468] According to equation (3), the pitch deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform is... The value of .

[0469] Based on equations (1) and (2), the following non-homogeneous linear equation system is written:

[0470]

[0471] The solution vector of the equation It can be solved directly:

[0472]

[0473] Recalculate the heading deviation Value:

[0474]

[0475] in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector.

[0476] Furthermore, the reference transfer module performs the following specific processing:

[0477] Establish the following equation:

[0478]

[0479] in:

[0480]

[0481] The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... This is the homogeneous transformation matrix for the heading rotation.

[0482] The solution vector of the equation It can be solved directly:

[0483]

[0484] The final The solution is obtained based on the following quadrant transformation relationship:

[0485]

[0486] in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector.

[0487] When the When taking north-northeast as the positive direction, the following conversion is performed: When the positive direction is north-northeast The value of .

[0488] Furthermore, the target localization module specifically performs the following processing:

[0489] Calculate the target point Coordinates in the Earth-centered, Earth-fixed coordinate system:

[0490] Where L is the distance from the target to the ranging device, A is the azimuth angle of the pod on the airborne platform of the tethered launch device, and B is the pitch angle of the pod on the airborne platform of the tethered launch device. The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... This is the pitch and rotation homogeneous transformation matrix.

[0491] Based on the mathematical relationship of coordinate transformation from a geodetic coordinate system to a geocentric coordinate system:

[0492]

[0493] For target longitude, H represents the target latitude, and H represents the target altitude.

[0494] Calculate the target longitude:

[0495]

[0496] Iterative calculation of the target latitude that satisfies the transformation relationship and height .

[0497] First, calculate the target point. Coordinate values ​​in a geographic coordinate system:

[0498]

[0499] in, The radius of gyration is the center of the imaging plane of the pod's vision sensor. To the imaging plane of the pod's visual sensor Distance between points The homogeneous transformation matrix for heading rotation is...

[0500] Then, the principal value of the target's heading angle in the geographic frame is determined:

[0501]

[0502] The number in parentheses represents the index value of that coordinate. The first element of this coordinate. It is the second element of that coordinate.

[0503] The true value of the heading angle of north by east in the final geographic system is obtained by the following calculation and transformation relationship:

[0504]

[0505]

[0506]

[0507] Based on the calculated origin and target point Calculate the principal value of the heading angle in the geodetic coordinate system using latitude and longitude:

[0508]

[0509] The true value of the heading angle under the final Earth system is obtained by the following transformation relationship:

[0510] .

[0511] The present invention also proposes a target positioning system for a tethered airborne device, comprising: an optoelectronic stabilization platform 2 and an airborne reference transfer device 3 deployed on the tethered airborne device 1, and a ground reference transfer device 4 and a ground station 5 deployed on the ground.

[0512] The photoelectric stabilization platform 2 is used to measure the yaw angle of the airborne platform base of the tethered launch device. Pitch angle and roll attitude angle ;

[0513] The airborne reference transfer device 3 is used to provide RTK satellite navigation coordinates from the airborne reference transfer end. And to use its airborne camera 15 to image the ground laser reference 17 to obtain ground laser reference information;

[0514] Ground reference transfer device 4 is used to provide RTK satellite navigation coordinates from the ground reference transfer end. The ground reference transmission device 4 also includes a ground laser reference 17, which is used to indicate the location of the ground reference transmission device 4.

[0515] Ground station 5 receives RTK satellite navigation coordinates With RTK satellite navigation coordinates Yaw angle of the tethered lift device airborne platform base Pitch angle and roll attitude angle In addition to ground-based laser reference information, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform 2 is then determined. and pitch deviation ;

[0516] Ground station 5 further performs reference transfer processing: based on the heading deviation between the airborne camera's line of sight and the zero-position line of the electro-optical stabilization platform. and pitch deviation Calculate the yaw attitude angle of the base of the optoelectronic stabilization platform. And it serves as the angle between the zero-position line of the line of sight of the photoelectric stabilization platform and the true north direction of the geographic coordinate system;

[0517] Ground station 5 further performs target positioning processing: based on the azimuth angle of the pod on the airborne platform of the tethered launch device. and pitch angle Based on the distance measurement value between the tethered launch device and the target object It calculates the positioning information of the target object locked or tracked on the line of sight of the visual payload of the optoelectronic platform.

[0518] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A target positioning system for a tethered aerial device, characterized in that, include: The photoelectric stabilization platform (2) and airborne reference transfer device (3) are deployed on the tethered airborne device (1), and the ground reference transfer device (4) and ground station (5) are deployed on the ground. The photoelectric stabilization platform (2) is used to measure the yaw angle of the tethered airborne platform. Pitch angle and roll attitude angle ; The airborne reference transfer device (3) is used to provide the RTK satellite navigation coordinates of the airborne reference transfer device. , and use the airborne camera to obtain ground laser reference information of the ground reference transfer device (4); The ground reference transfer device (4) is used to provide the RTK satellite navigation coordinates of the ground reference transfer device (4). The ground reference transmission device (4) generates the ground laser reference information to indicate the location of the ground reference transmission device (4); The ground station (5) first performs deviation benchmark calibration: based on RTK satellite navigation coordinates With RTK satellite navigation coordinates Yaw angle of the tethered lift device airborne platform base Pitch angle and roll attitude angle And ground laser reference information, to calibrate the zero-position line heading deviation of the computer-mounted camera line of the photoelectric stabilization platform (2). and pitch deviation ; The ground station (5) further performs reference transfer processing: based on the heading deviation between the airborne camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation Calculate the yaw attitude angle of the base of the optoelectronic stabilization platform. And it serves as the angle between the zero-position line of the line of sight of the photoelectric stabilization platform and the true north direction of the geographic coordinate system; The ground station (5) further performs target positioning processing: based on the azimuth angle of the pod of the tethered launch device airborne platform. and pitch angle Based on the distance measurement value between the tethered launch device and the target object It calculates and locks onto or tracks the location information of the target object located on the line of sight of the visual payload of the optoelectronic platform.

2. The system according to claim 1, characterized in that, The methods for deviation benchmark calibration processing of the ground station (5) include: First, based on the airborne reference transmission end RTK satellite navigation coordinates of the point ground reference transfer end RTK satellite navigation coordinates of the point In addition to local geographic parameters, calculate the geometric key points representing the location of the photoelectric platform in the geographic coordinate system. Point coordinates and coordinates of the point , The point is located at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The point represents the location of the ground-based RTK receiver antenna. According to the yaw angle of the launch device Pitch angle and roll attitude angle And the radius of the circle from the center of the pod's top cover to the imaging plane of the airborne camera. d Imaging center of the airborne camera on the tethered launch device's opto-stabilized platform. Point coordinates ; Further calculations Point and Spatial distance of points Then calculate the coordinates of the ground reference point in the image coordinate system. ; According to the laser reference array The horizontal coordinate of the ground laser reference in the imaging plane of the airborne camera on the tethered launcher and ordinate Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle ; Then, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation .

3. The system according to claim 2, characterized in that, The specific steps for the deviation benchmark calibration process performed by the ground station (5) include: The calculation of the geographic coordinate system characterizes the geometric key points of the photoelectric platform. Point coordinates and coordinates of the point The specific method is as follows: in, The homogeneous translation transformation matrix is... for The radius of the circle of points Maoyou. for The radius of the circle of points (Mao-You circles) This is the first eccentricity of the Earth's ellipsoidal meridian ellipse. For the roll homogeneous transformation rotation matrix, The homogeneous transformation matrix for heading rotation is... It is a homogeneous translation transformation matrix; The imaging center of the onboard camera on the opto-stabilized platform of the computational tethered launch device Point coordinates The specific method is as follows: in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of; Further calculations Point and Spatial distance of points The specific method is as follows: The specific method for calculating the coordinates of ground reference points in the image coordinate system is as follows: Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle The specific method is as follows: Among them, the subscript This is the serial number of the laser source. Calibrate the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation The specific method is as follows: Based on the above variable values, we can write the following system of equations: in: in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of; According to equation (3), the pitch deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform is... The value; Based on equations (1) and (2), the following non-homogeneous linear equation system is written: Find the solution vector of this equation. : Recalculate the heading deviation Value: in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector.

4. The system according to claim 2, characterized in that, When the ground station (5) performs reference transfer processing, it calculates the yaw attitude angle of the photoelectric stabilization platform base. include: Based on the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. .

5. The system according to claim 4, characterized in that, When the ground station (5) performs reference transfer processing, it determines the yaw attitude angle of the photoelectric stabilization platform base. Specifically, it includes: Establish the following equation: in: The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation; Find the solution vector of this equation. : Solve based on the following quadrant transformation relationship. : in, The number in the parentheses is the index value. for The first element of the vector, for The second element of the vector; When the When taking north-northeast as the positive direction, the following conversion is performed: When the positive direction is north-northeast The value of .

6. The system according to claim 4, characterized in that, The target positioning steps performed by the ground station (5) specifically include: Based on the pod azimuth of the onboard platform of the tethered launch device and pitch angle Based on the distance measurement value between the tethered launch device and the target object Calculate the target point Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system ; The target longitude is calculated based on the Earth's circumpolar radius Rn, the first eccentricity e1 of the Earth's meridian ellipse, and the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system. Target latitude Target height ; Based on the radius of gyration r of the center of the imaging plane of the pod's visual sensor, the imaging plane of the pod's visual sensor reaches... The distance h between the points Calculate the value of the target point Given the coordinates in the geographic coordinate system and the principal value of the target's heading angle in the geographic system, calculate the true value of the north-northeast heading angle in the geographic system based on the geographic coordinate system transformation relationship; then, based on the origin... and target point The principal value and true value of the target heading angle in the geodetic coordinate system are calculated using latitude and longitude coordinates.

7. The system according to claim 6, characterized in that, The ground station (5) calculates the target point. Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system Specifically, it includes: in, The distance from the target to the ranging device. The azimuth angle of the pod on the airborne platform for the tethered lift device. The pitch angle of the pod on the airborne platform for the tethered lift device. The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... This is the pitch and rotation homogeneous transformation matrix.

8. The system according to claim 6, characterized in that, The ground station (5) calculates the target longitude. Target latitude Target height The specific method is as follows: Based on the coordinate transformation relationship from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system: For target longitude, For target latitude, For the target height, Calculate the target longitude: Iterative calculation of the target latitude that satisfies the above coordinate transformation relationship and height .

9. The system according to claim 6, characterized in that, The specific method by which the ground station (5) calculates the principal value and true value of the target heading angle in the geodetic coordinate system is as follows: Calculate the target point Coordinate values ​​in a geographic coordinate system: in, The radius of gyration is the center of the imaging plane of the pod's vision sensor. To the imaging plane of the pod's visual sensor Distance between points The homogeneous transformation matrix for heading rotation is... Target point in computational geography system The specific method for determining the principal value of the heading angle is as follows: The number in parentheses represents the index value of that coordinate. The first element of this coordinate. This is the second element of that coordinate. Calculate the true value of the north-northeast heading angle in the geographic system based on geographic coordinate transformation relationships. : Based on the origin and target point The specific method for calculating the principal value of the target heading angle in the geodetic coordinate system using latitude and longitude is as follows: Calculate the true value of the target heading angle in the geodetic system. The specific method is as follows: 。 10. The system according to claim 1, characterized in that, The photoelectric stabilization platform (2) includes: A visual sensor (10) is used to sense the optical environment within the field of view and output an image; A ranging device (11) is used to measure the straight-line distance from the vision sensor (10) to a distant object on its line of sight; Angle measuring device (12) is used to measure the yaw angle of the airborne platform of the tethered launch device. Pitch angle ; Attitude sensor (13) is used to measure the roll attitude angle of the tethered airborne platform. .

11. The system according to claim 1, characterized in that, The airborne reference transfer device (3) includes: An airborne RTK receiver (14) is used to provide RTK satellite navigation coordinates from the airborne reference transfer device (3). ; An airborne camera (15) is used to image the ground-targeting end and the ground reference transmission device (4) to obtain ground laser reference information of the ground reference transmission device (4).

12. The system according to claim 11, characterized in that, The ground reference transfer device (4) includes: Ground RTK receiver (16) is used to provide RTK satellite navigation coordinates of ground reference transfer device (4). ; Ground laser reference (17) is used to indicate the location of ground reference transmission device (4) to generate ground laser reference information of ground reference transmission device (4).

13. The system according to claim 12, characterized in that, The ground station (5) includes: The ground control station (18) is used to control the overall air system (7) and to perform deviation benchmark calibration, benchmark transfer and target positioning processing; A tethered optical cable (21) is used to connect the tethered airborne device (1) and the ground station (5). Ground power supply (20) is used to provide power to the tethered launch device (1) and the ground station (5).

14. A target positioning device for a tethered aerial device, characterized in that, include: The deviation reference calibration module uses RTK satellite navigation coordinates from the airborne reference transfer end. RTK satellite navigation coordinates with ground reference transfer end Yaw angle of the tethered lift device airborne platform base Pitch angle and roll attitude angle In addition to ground-based laser reference information, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation ; The reference transfer module determines the heading deviation between the airborne camera's line of sight and the zero-position line of the optoelectronic stabilization platform. and pitch deviation Calculate the yaw attitude angle of the base of the optoelectronic stabilization platform. And it serves as the angle between the zero-position line of the line of sight of the photoelectric stabilization platform and the true north direction of the geographic coordinate system; The target positioning module determines the azimuth of the pod on the tethered launch platform. and pitch angle Based on the distance measurement value between the tethered launch device and the target object It calculates and locks onto or tracks the location information of the target object located on the line of sight of the visual payload of the optoelectronic platform.

15. The device according to claim 14, characterized in that, The deviation benchmark calibration module specifically performs the following processing: First, based on the airborne reference transmission end RTK satellite navigation coordinates of the point ground reference transfer end RTK satellite navigation coordinates of the point In addition to local geographic parameters, calculate the geometric key points representing the location of the photoelectric platform in the geographic coordinate system. Point coordinates and coordinates of the point , The point is located at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The point represents the location of the ground-based RTK receiver antenna. According to the yaw angle of the launch device Pitch angle and roll attitude angle And the radius of the circle from the center of the pod's top cover to the imaging plane of the airborne camera. d Imaging center of the airborne camera on the tethered launch device's opto-stabilized platform. Point coordinates ; Further calculations Point and Spatial distance of points Then calculate the coordinates of the ground reference point in the image coordinate system. ; According to the laser reference array The horizontal coordinate of the ground laser reference in the imaging plane of the airborne camera on the tethered launcher and ordinate Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle ; Then, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation .

16. The device according to claim 15, characterized in that, The deviation benchmark calibration module specifically performs the following processing: The calculation of the geographic coordinate system characterizes the geometric key points of the photoelectric platform. Point coordinates and coordinates of the point The specific method is as follows: in, The homogeneous translation transformation matrix is... for The radius of the circle of points (Mao-You circles) for The radius of the meridian at the point is given by e1, where e1 is the first eccentricity of the Earth's ellipsoidal meridian ellipse. For the roll homogeneous transformation rotation matrix, The homogeneous transformation matrix for heading rotation is... It is a homogeneous translation transformation matrix; The imaging center of the onboard camera on the opto-stabilized platform of the computational tethered launch device Point coordinates The specific method is as follows: in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of; Further calculations Point and Spatial distance of points The specific method is as follows: The specific method for calculating the coordinates of ground reference points in the image coordinate system is as follows: Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle The specific method is as follows: Among them, the subscript This is the serial number of the laser source. Calibrate the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation The specific method is as follows: Based on the above variable values, we can write the following system of equations: in: in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of; According to equation (3), the pitch deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform is... The value; Based on equations (1) and (2), the following non-homogeneous linear equation system is written: Find the solution vector of this equation. : Recalculate the heading deviation Value: in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector.

17. The device according to claim 14, characterized in that, The reference transfer module calculates the yaw attitude angle of the photoelectric stabilization platform base. include: Based on the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. .

18. The device according to claim 17, characterized in that, The reference transfer module calculates the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform. and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. Specifically, it includes: Establish the following equation: in: The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation; Find the solution vector of this equation. : Solve based on the following quadrant transformation relationship. : in, The number in the parentheses is the index value. for The first element of the vector, for The second element of the vector; When the When taking north-northeast as the positive direction, the following conversion is performed: When the positive direction is north-northeast The value of .

19. The device according to claim 14, characterized in that, The target localization steps of the target localization module specifically include: Based on the pod azimuth of the onboard platform of the tethered launch device and pitch angle Based on the distance measurement value between the tethered launch device and the target object Calculate the target point Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system ; The target longitude is calculated based on the Earth's circumpolar radius Rn, the first eccentricity e1 of the Earth's meridian ellipse, and the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system. Target latitude Target height ; Based on the radius of gyration r of the center of the imaging plane of the pod's visual sensor, the imaging plane of the pod's visual sensor reaches... The distance h between the points Calculate the value of the target point Given the coordinates in the geographic coordinate system and the principal value of the target's heading angle in the geographic system, calculate the true value of the north-northeast heading angle in the geographic system based on the geographic coordinate system transformation relationship; then, based on the origin... and target point The principal value and true value of the target heading angle in the geodetic coordinate system are calculated using latitude and longitude coordinates.

20. The device according to claim 19, characterized in that, The target localization module calculates the target point. Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system Specifically, it includes: in, The distance from the target to the ranging device. The azimuth angle of the pod on the airborne platform for the tethered lift device. The pitch angle of the pod on the airborne platform for the tethered lift device. The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... This is the pitch and rotation homogeneous transformation matrix.

21. The device according to claim 19, characterized in that, The target positioning module calculates the target longitude. Target latitude Target height The specific method is as follows: Based on the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system: For target longitude, For target latitude, For the target height, Calculate the target longitude: Iterative calculation of the target latitude that satisfies the transformation relationship and height .

22. The device according to claim 19, characterized in that, The specific method by which the target positioning module calculates the principal value and true value of the target heading angle in the geodetic coordinate system is as follows: Calculate the target point Coordinate values ​​in a geographic coordinate system: in, The radius of gyration is the center of the imaging plane of the pod's vision sensor. To the imaging plane of the pod's visual sensor Distance between points The homogeneous transformation matrix for heading rotation is... Target point in computational geography system The specific method for determining the principal value of the heading angle is as follows: The number in parentheses represents the index value of that coordinate. The first element of this coordinate. This is the second element of that coordinate. Calculate the true value of the north-northeast heading angle in the geographic system based on geographic coordinate transformation relationships. : Based on the origin and target point The specific method for calculating the principal value of the target heading angle in the geodetic coordinate system using latitude and longitude is as follows: Calculate the true value of the target heading angle in the geodetic system. The specific method is as follows: 。 23. A target positioning method for a tethered aerial device, characterized in that, include: S1. Deviation reference calibration steps: Based on the RTK satellite navigation coordinates from the airborne reference transfer end... RTK satellite navigation coordinates with ground reference transfer end Yaw angle of the tethered lift device airborne platform base Pitch angle and roll attitude angle In addition to ground-based laser reference information, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation ; S2, Reference Transfer Steps: Further adjust the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform. and pitch deviation Calculate the yaw attitude angle of the base of the optoelectronic stabilization platform. And it serves as the angle between the zero-position line of the line of sight of the photoelectric stabilization platform and the true north direction of the geographic coordinate system; S3. Target Positioning Steps: Further determine the azimuth angle of the pod on the tethered launch platform. and pitch angle Based on the distance measurement value between the tethered launch device and the target object It calculates and locks onto or tracks the location information of the target object located on the line of sight of the visual payload of the optoelectronic platform.

24. The method according to claim 23, characterized in that, S1. The deviation benchmark calibration step specifically includes: First, based on the airborne reference transmission end RTK satellite navigation coordinates of the point ground reference transfer end RTK satellite navigation coordinates of the point In addition to local geographic parameters, calculate the geometric key points representing the location of the photoelectric platform in the geographic coordinate system. Point coordinates and coordinates of the point , The point is located at the intersection of a vertical line perpendicular to the center of the pod's top cover and a plane parallel to the pod's top cover, passing through the center of the airborne camera's imaging surface. The point represents the location of the ground-based RTK receiver antenna. According to the yaw angle of the launch device Pitch angle and roll attitude angle And the radius of the circle from the center of the pod's top cover to the imaging plane of the airborne camera. d Imaging center of the airborne camera on the tethered launch device's opto-stabilized platform. Point coordinates ; Further calculations Point and Spatial distance of points Then calculate the coordinates of the ground reference point in the image coordinate system. ; According to the laser reference array The horizontal coordinate of the ground laser reference in the imaging plane of the airborne camera on the tethered launcher and ordinate Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle ; Then, the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform was calibrated. and pitch deviation .

25. The method according to claim 24, characterized in that, S1. The deviation benchmark calibration step specifically includes: The calculation of the geographic coordinate system characterizes the geometric key points of the photoelectric platform. Point coordinates and coordinates of the point The specific method is as follows: in, The homogeneous translation transformation matrix is... for The radius of the circle of points (Mao-You circles) for The radius of the meridian at the point is given by e1, where e1 is the first eccentricity of the Earth's ellipsoidal meridian ellipse. For the roll homogeneous transformation rotation matrix, The homogeneous transformation matrix for heading rotation is... It is a homogeneous translation transformation matrix; The imaging center of the onboard camera on the opto-stabilized platform of the computational tethered launch device Point coordinates The specific method is as follows: in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of; Further calculations Point and Spatial distance of points The specific method is as follows: The specific method for calculating the coordinates of ground reference points in the image coordinate system is as follows: Calculate the spatial heading matrix rotation angle from the airborne camera image coordinate system to the airborne camera line-of-sight coordinate system. and pitch matrix rotation angle The specific method is as follows: Among them, the subscript This is the serial number of the laser source. Calibrate the heading deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform. and pitch deviation The specific method is as follows: Based on the above variable values, we can write the following system of equations: in: in, The homogeneous transformation matrix for heading rotation is... The pitch and rotation homogeneous transformation matrix is... The homogeneous translation transformation matrix is... For the closest heading deviation of Integer multiples of; According to equation (3), the pitch deviation between the computer-mounted camera's line of sight and the zero-position line of the photoelectric stabilization platform is... The value; Based on equations (1) and (2), the following non-homogeneous linear equation system is written: Find the solution vector of this equation. : Recalculate the heading deviation Value: in, The number in the parentheses is the index value, i.e. for The first element of the vector, for The second element of the vector.

26. The method according to claim 23, characterized in that, In step S2, the calculation of the yaw attitude angle of the photoelectric stabilization platform base is described. include: Based on the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. .

27. The method according to claim 26, characterized in that, In step S2, the heading deviation between the airborne camera's line of sight and the zero-position line of the opto-stabilized platform is calculated. and pitch deviation A homogeneous transformation and correction calculation are performed to determine the yaw attitude angle of the photoelectric stabilization platform base. Specifically, it includes: Establish the following equation: in: The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation is... The homogeneous transformation matrix for heading rotation; Find the solution vector of this equation. : Solve based on the following quadrant transformation relationship. : in, The number in the parentheses is the index value. for The first element of the vector, for The second element of the vector; When the When taking north-northeast as the positive direction, the following conversion is performed: When the positive direction is north-northeast The value of .

28. The method according to claim 26, characterized in that, S3. The target localization step specifically includes: Based on the pod azimuth of the onboard platform of the tethered launch device and pitch angle Based on the distance measurement value between the tethered launch device and the target object Calculate the target point Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system ; The target longitude is calculated based on the Earth's circumpolar radius Rn, the first eccentricity e1 of the Earth's meridian ellipse, and the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system. Target latitude Target height ; Based on the radius of gyration r of the center of the imaging plane of the pod's visual sensor, the imaging plane of the pod's visual sensor reaches... The distance h between the points Calculate the value of the target point Given the coordinates in the geographic coordinate system and the principal value of the target's heading angle in the geographic system, calculate the true value of the north-northeast heading angle in the geographic system based on the geographic coordinate system transformation relationship; then, based on the origin... and target point The principal value and true value of the target heading angle in the geodetic coordinate system are calculated using latitude and longitude coordinates.

29. The method according to claim 28, characterized in that, In S3, the target point for calculation Coordinate values ​​in the Earth-centered and Earth-fixed coordinate system Specifically, it includes: in, The distance from the target to the ranging device. The azimuth angle of the pod on the airborne platform for the tethered lift device. The pitch angle of the pod on the airborne platform for the tethered lift device. The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... For the roll homogeneous transformation rotation matrix, The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... The homogeneous translation transformation matrix is... The homogeneous transformation matrix for heading rotation is... This is the pitch and rotation homogeneous transformation matrix.

30. The method according to claim 28, characterized in that, In S3, calculate the target longitude. Target latitude Target height The specific method is as follows: Based on the mathematical relationship of coordinate transformation from the geodetic coordinate system to the Earth-centered Earth-fixed coordinate system: For target longitude, For target latitude, For the target height, Calculate the target longitude: Iterative calculation of the target latitude that satisfies the transformation relationship and height .

31. The method according to claim 28, characterized in that, In S3, the specific methods for determining the principal value and true value of the target heading angle in the geodetic coordinate system are as follows: Calculate the target point Coordinate values ​​in a geographic coordinate system: in, The radius of gyration is the center of the imaging plane of the pod's vision sensor. To the imaging plane of the pod's visual sensor Distance between points The homogeneous transformation matrix for heading rotation is... Target point in computational geography system The specific method for determining the principal value of the heading angle is as follows: The number in parentheses represents the index value of that coordinate. The first element of this coordinate. This is the second element of that coordinate. Calculate the true value of the north-northeast heading angle in the geographic system based on geographic coordinate transformation relationships. : Based on the origin and target point The specific method for calculating the principal value of the target heading angle in the geodetic coordinate system using latitude and longitude is as follows: Calculate the true value of the target heading angle in the geodetic system. The specific method is as follows: 。

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