Satellite attitude guiding method and system for tracking and imaging cooperative target

Abstract

The invention provides a satellite attitude guiding method and system for tracking and imaging a cooperative target. The method comprises the following steps: an information acquisition step: acquiring parameter information of the cooperative target; the parameter information comprises time information, trajectory longitude, trajectory latitude and trajectory height of the trajectory sequence; and a guidance calculation step: performing high-order polynomial fitting on the trajectory longitude, the trajectory latitude, the trajectory height and the normalized time information, and calculating to obtain a three-axis guidance attitude of the satellite pointing to the cooperative target. Time normalization and high-order polynomial fitting processing are carried out on established trajectory information of a cooperative target, the position of the cooperative target is calculated in real time according to a fitting coefficient on a satellite, and a three-axis guide attitude when the satellite carries out tracking imaging on the cooperative target is solved in combination with a real-time orbit of the satellite. The maneuvering tracking performance of the satellite on the cooperative target can be improved, and the method has practical significance on the dynamic target tracking imaging task of the satellite.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite tracking, imaging and attitude guidance, and in particular to a satellite attitude guidance method and system for tracking and imaging a cooperative target. Background Art

[0002] When a low-orbit satellite camera images a target on the ground, at sea, or in the air, it needs to keep tracking the target through attitude maneuvers due to the existence of the satellite's orbital motion. When a satellite tracks and images a cooperative target, it can agree on a motion trajectory in advance, and the satellite can track and image the cooperative target according to the established trajectory. Existing methods have given some motion trajectory attitude tracking guidance methods, but these methods are no longer applicable when performing high-precision attitude tracking of complex dynamic targets.

[0003] Patent document CN106125745B discloses a satellite attitude control method for tracking and imaging space cooperative targets, but it is aimed at space targets, whose movement trajectories are relatively regular and are not suitable for dynamic cooperative targets on the ground, at sea or in the air targeted by this application.

[0004] Patent document CN107622508A discloses a method for tracking non-cooperative targets by a video satellite, but it is aimed at non-cooperative targets and requires identifying the target and calculating the miss distance relative to the center of the optical axis. The system design is complex and is not suitable for the tracking scenario of cooperative targets in this application.

[0005] Patent document CN104960674A discloses a pointing tracking control method for a moving target, but its input condition is the attitude sequence of the satellite pointing to the target. However, there are errors in determining the attitude sequence or predicting the satellite trajectory in engineering practice, which is not suitable for high-precision attitude pointing.

[0006] Patent document CN114935934A discloses a high-precision pointing and light control method for relative motion of spacecraft based on coordinate binding, which uses a tracking and pointing unit to capture the relative motion optical characteristics of the target, but is easily disturbed by other factors such as weather, affecting the success rate and scene applicability.

[0007] Patent document CN116692028A discloses a small satellite fast gaze pointing tracking control method and device, and introduces a method for real-time calculation of target attitude on the satellite, but it is aimed at fixed targets on the ground and does not involve moving target tracking. Summary of the invention

[0008] In view of the defects in the prior art, the object of the present invention is to provide a satellite attitude guidance method and system for tracking and imaging cooperative targets.

[0009] A satellite attitude guidance method for tracking and imaging a cooperative target provided by the present invention comprises:

[0010] Information collection step: collecting parameter information of the cooperation target; the parameter information includes time information of the trajectory sequence, trajectory longitude, trajectory latitude and trajectory altitude;

[0011] Guidance calculation steps: Perform high-order polynomial fitting on the trajectory longitude, trajectory latitude, trajectory altitude and normalized time information to calculate the three-axis guidance attitude of the satellite pointing to the cooperative target.

[0012] Preferably, the guidance calculation step includes:

[0013] Step S1.0: normalize the time information of the cooperative target trajectory sequence;

[0014] Step S1.1: Perform high-order polynomial fitting on the track longitude, track latitude, track altitude and normalized time information to obtain the corresponding fitting coefficients;

[0015] Step S1.2: Calculate the real-time longitude, latitude and altitude of the cooperation target at the current moment according to the fitting coefficient;

[0016] Step S1.3: Calculate the position of the cooperative target in the earth-fixed coordinate system and the inertial coordinate system according to the obtained real-time information;

[0017] Step S1.4: Based on the position of the cooperative target in the coordinate system, the three-axis guidance attitude of the satellite pointing to the cooperative target is calculated.

[0018] Preferably, the step S1.0 includes:

[0019] The time information t of the cooperative target trajectory sequence m Normalization is performed as follows:

[0020]

[0021] Where, t m_max and t m_min t m The maximum and minimum values ​​in the sequence.

[0022] Preferably, the step S1.1 comprises:

[0023] Step S1.1.1: Calculate the fitting coefficient lon(i) of longitude, where i = 1, 2, ..., 13;

[0024]

[0025] In the formula, λ m(k), k = 1, 2, ..., n respectively represent the longitudes corresponding to the n trajectory points of the cooperative target trajectory sequence. The calculation method of matrix A is as follows:

[0026]

[0027] Where, T m (k), k = 1, 2, ..., n, respectively represents the normalized time corresponding to the n trajectory points of the cooperative target trajectory sequence;

[0028] Step S1.1.2: Calculate the latitude fitting coefficient lat(i), where i = 1, 2, ..., 13;

[0029]

[0030] In the formula, φ m (k), k = 1, 2, ..., n respectively represent the latitudes corresponding to the n trajectory points of the cooperative target trajectory sequence;

[0031] Step S1.1.3: Calculate the height fitting coefficient alt(i), where i = 1, 2, ..., 13;

[0032]

[0033] In the formula, h m (k), k = 1, 2, ..., n represent the heights corresponding to the n trajectory points of the cooperative target trajectory sequence.

[0034] Preferably, the step S1.2 comprises:

[0035] Step S1.2.1: Calculate the real-time longitude λ of the cooperation target at the current time t according to the longitude fitting coefficient lon(i) noted above:

[0036]

[0037] λ=lon(1)+lon(2)×T+lon(3)×T 2 +...+lon(13)×T 12 ;

[0038] Step S1.2.2: Calculate the real-time latitude φ of the cooperation target at the current time t according to the latitude fitting coefficient lat(i) noted above:

[0039] φ=lat(1)+lat(2)×T+lat(3)×T 2 +...+lat(13)×T 12 ;

[0040] Step S1.2.3: Calculate the real-time height h of the cooperative target at the current time t according to the height fitting coefficient alt(i) noted above:

[0041] h=alt(1)+alt(2)×T+alt(3)×T 2 +...+alt(13)×T 12 .

[0042] Preferably, the step S1.3 comprises:

[0043] Step S1.3.1: Calculate the position projection of the cooperative target in the WGS84 Earth-fixed coordinate system

[0044] In the formula, R e and f e are the Earth's equatorial radius and Earth's oblateness, respectively;

[0045] Step S1.3.2: Calculate the position projection of the cooperative target in the J2000 inertial coordinate system

[0046]

[0047] Where M ecf2eci It is the attitude transformation matrix from WGS84 earth-fixed coordinate system to J2000 inertial coordinate system.

[0048] Preferably, the step S1.4 comprises:

[0049] Calculate the three-axis guidance attitude of the satellite towards the cooperative target

[0050]

[0051] In the formula, i x ,i y ,i z The calculation method is as follows:

[0052]

[0053] in, and They are respectively the projections of the satellite’s position vector and velocity vector in the J2000 inertial coordinate system.

[0054] A satellite attitude guidance system for tracking and imaging a cooperative target provided by the present invention comprises:

[0055] Information collection module: collects parameter information of the cooperation target; the parameter information includes time information of the trajectory sequence, trajectory longitude, trajectory latitude and trajectory altitude;

[0056] Guidance calculation module: Perform high-order polynomial fitting on the trajectory longitude, trajectory latitude, trajectory altitude and normalized time information to calculate the three-axis guidance attitude of the satellite pointing to the cooperative target.

[0057] Preferably, the guidance calculation module includes:

[0058] Module M1.0: Normalize the time information of the cooperative target trajectory sequence;

[0059] Module M1.1: Perform high-order polynomial fitting on the trajectory longitude, trajectory latitude, trajectory altitude and normalized time information to obtain the corresponding fitting coefficients;

[0060] Module M1.2: Calculate the real-time longitude, latitude and altitude of the cooperation target at the current moment based on the fitting coefficient;

[0061] Module M1.3: Calculate the position of the cooperative target in the earth-fixed coordinate system and the inertial coordinate system based on the real-time information obtained;

[0062] Module M1.4: Based on the position of the cooperative target in the coordinate system, the three-axis guidance attitude of the satellite pointing to the cooperative target is calculated.

[0063] Preferably, the module M1.0 includes:

[0064] The time information t of the cooperative target trajectory sequence m Normalization is performed as follows:

[0065]

[0066] Where, t m_max and t m_min t m The maximum and minimum values ​​in the sequence.

[0067] Preferably, the module M1.1 comprises:

[0068] Module M1.1.1: Calculate the fitting coefficient lon(i) of longitude, where i = 1, 2, ..., 13;

[0069]

[0070] In the formula, λ m (k), k = 1, 2, ..., n respectively represent the longitudes corresponding to the n trajectory points of the cooperative target trajectory sequence. The calculation method of matrix A is as follows:

[0071]

[0072] Where, Tm (k), k = 1, 2, ..., n, respectively represents the normalized time corresponding to the n trajectory points of the cooperative target trajectory sequence;

[0073] Module M1.1.2: Calculate the latitude fitting coefficient lat(i), where i = 1, 2, ..., 13;

[0074]

[0075] In the formula, φ m (k), k = 1, 2, ..., n respectively represent the latitudes corresponding to the n trajectory points of the cooperative target trajectory sequence;

[0076] Module M1.1.3: Calculate the height fitting coefficient alt(i), where i = 1, 2, ..., 13;

[0077]

[0078] In the formula, h m (k), k = 1, 2, ..., n represent the heights corresponding to the n trajectory points of the cooperative target trajectory sequence.

[0079] Preferably, the module M1.2 includes:

[0080] Module M1.2.1: Calculate the real-time longitude λ of the cooperation target at the current time t according to the longitude fitting coefficient lon(i) noted above:

[0081]

[0082] λ=lon(1)+lon(2)×T+lon(3)×T 2 +...+lon(13)×T 12 ;

[0083] Module M1.2.2: Calculate the real-time latitude φ of the cooperation target at the current time t according to the latitude fitting coefficient lat(i) noted above:

[0084] φ=lat(1)+lat(2)×T+lat(3)×T 2 +...+lat(13)×T 12 ;

[0085] Module M1.2.3: Calculate the real-time height h of the cooperative target at the current time t according to the height fitting coefficient alt(i) noted above:

[0086] h=alt(1)+alt(2)×T+alt(3)×T 2 +...+alt(13)×T12 .

[0087] Preferably, the module M1.3 includes:

[0088] Module M1.3.1: Calculate the position projection of the cooperative target in the WGS84 Earth-fixed coordinate system m g :

[0089]

[0090] In the formula, R e and f e are the Earth's equatorial radius and Earth's oblateness, respectively;

[0091] Module M1.3.2: Calculate the position projection of the cooperative target in the J2000 inertial coordinate system

[0092]

[0093] Where M ecf2eci It is the attitude transformation matrix from WGS84 earth-fixed coordinate system to J2000 inertial coordinate system.

[0094] Preferably, the module M1.4 includes:

[0095] Calculate the three-axis guidance attitude of the satellite towards the cooperative target

[0096]

[0097] In the formula, i x ,i y ,i z The calculation method is as follows:

[0098]

[0099] in, and They are respectively the projections of the satellite’s position vector and velocity vector in the J2000 inertial coordinate system.

[0100] Compared with the prior art, the present invention has the following beneficial effects:

[0101] 1. The present invention normalizes the established trajectory information of the cooperative target in time and performs high-order polynomial fitting to process the longitude, latitude and altitude. The position of the cooperative target is calculated in real time on the satellite based on the fitting coefficient, and then combined with the real-time orbit of the satellite, the three-axis guidance attitude of the satellite when tracking and imaging the cooperative target is solved.

[0102] 2. The present invention can improve the satellite's maneuverability tracking performance for cooperative targets, and has practical significance for the satellite's dynamic target tracking and imaging tasks.

[0103] Other beneficial effects of the present invention will be explained in the specific implementation manner through the introduction of specific technical features and technical solutions. Through the introduction of these technical features and technical solutions, those skilled in the art should be able to understand the beneficial technical effects brought about by the technical features and technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0105] Figure 1 The present invention is a flow chart of the method. DETAILED DESCRIPTION

[0106] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0107] Reference Figure 1 As shown, a satellite attitude guidance method for tracking and imaging a cooperative target includes:

[0108] Step S1: Time information t of cooperative target trajectory sequence m After normalization, we get T m :

[0109] The time information t of the cooperative target trajectory sequence m Normalization is performed as follows:

[0110]

[0111] Where, t m_max and t m_min t m The maximum and minimum values ​​in the sequence.

[0112] Step S2: Set the longitude λ of the cooperative target trajectory m , latitude φ m , height information h m The normalized time Perform high-order polynomial fitting to obtain the fitting coefficients lon(i), lat(i), alt(i):

[0113] The fitting coefficients of longitude, latitude, and altitude are calculated according to the following formulas: lon(i), lat(i), alt(i), where i = 1, 2, ..., 13.

[0114]

[0115] In the formula, λ m (k),φ m (k), h m (k), k = 1, 2, ..., n respectively represent the longitude, latitude, and altitude corresponding to the n trajectory points of the cooperative target trajectory sequence. The calculation method of matrix A is as follows:

[0116]

[0117] Where, T m (k), k = 1, 2, ..., n, respectively represents the normalized time corresponding to the n trajectory points of the cooperative target trajectory sequence.

[0118] Step S3, calculate the real-time longitude λ, latitude φ, and altitude h of the cooperation target at the current time t according to the above-mentioned fitting coefficients lon(i), lat(i), and alt(i):

[0119] According to the above fitting coefficients lon(i), lat(i), alt(i), calculate the real-time longitude λ, latitude φ, and altitude h of the cooperation target at the current time t:

[0120]

[0121] λ=lon(1)+lon(2)×T+lon(3)×T 2 +...+lon(13)×T 12 ;

[0122] φ=lat(1)+lat(2)×T+lat(3)×T 2 +...+lat(13)×T 12 ;

[0123] h=alt(1)+alt(2)×T+alt(3)×T 2 +...+alt(13)×T 12 ;

[0124] Step S4: Calculate the position projection of the cooperative target in the WGS84 Earth-fixed coordinate system and the J2000 inertial coordinate system and

[0125] Position projection of cooperative targets in the WGS84 Earth-fixed coordinate system Calculated as follows:

[0126]

[0127] In the formula, R e and f e are the Earth's equatorial radius and the Earth's oblateness, respectively.

[0128] Position projection of cooperative targets in the J2000 inertial coordinate system Calculated as follows:

[0129]

[0130] Where M ecf2eci It is the attitude transformation matrix from WGS84 earth-fixed coordinate system to J2000 inertial coordinate system.

[0131] Step S5: Calculate the three-axis guidance attitude of the satellite pointing to the cooperative target

[0132] Three-axis guidance attitude of satellite pointing to cooperative target Calculated as follows:

[0133]

[0134] Where i x ,i y ,i z The calculation method is as follows:

[0135]

[0136] in, and They are respectively the projections of the satellite’s position vector and velocity vector in the J2000 inertial coordinate system.

[0137] The present invention performs time normalization and high-order polynomial fitting on the longitude, latitude and altitude of the established trajectory information of the cooperative target, calculates the position of the cooperative target in real time on the satellite according to the fitting coefficient, and then combines the real-time orbit of the satellite to solve the three-axis guidance attitude of the satellite when tracking and imaging the cooperative target. This can improve the satellite's maneuverability tracking performance for the cooperative target and has practical significance for the satellite's dynamic target tracking and imaging tasks.

[0138] The above is a basic embodiment of the present invention. The technical solution of the present invention is further described below through a preferred embodiment.

[0139] Example 1

[0140] Due to the existence of satellite orbital motion, it is necessary to maintain target tracking through attitude maneuvers. When a satellite tracks and images a cooperative target, it can agree on a motion trajectory in advance, and the satellite can track and image the cooperative target according to the established trajectory. Existing methods provide some motion trajectory attitude tracking and guidance methods, but these methods are no longer applicable when performing attitude tracking on complex dynamic targets. The present invention provides a satellite attitude guidance method for tracking and imaging cooperative targets, which normalizes the established trajectory information of the cooperative target in time and performs high-order polynomial fitting to process the longitude, latitude, and altitude. The position of the cooperative target is calculated in real time on the satellite according to the fitting coefficient, and then combined with the real-time orbit of the satellite, the three-axis guidance attitude of the satellite when tracking and imaging the cooperative target is solved. The present invention can improve the satellite's maneuvering tracking performance for cooperative targets, and has practical significance for the satellite's dynamic target tracking and imaging tasks.

[0141] As attached Figure 1 As shown, the present invention provides a posture guidance method for tracking and imaging a cooperative target, comprising the following steps:

[0142] Step S1: Time information t of cooperative target trajectory sequence m After normalization, we get T m ;

[0143] Step S2: Set the longitude λ of the cooperative target trajectory m , latitude φ m , height information h m The normalized time

[0144] Perform high-order polynomial fitting to obtain the respective fitting coefficients lon(i), lat(i), alt(i);

[0145] Step S3, calculating the real-time longitude λ, latitude φ, and altitude h of the cooperation target at the current time t according to the above-mentioned fitting coefficients lon(i), lat(i), and alt(i);

[0146] Step S4: Calculate the position projection of the cooperative target in the WGS84 Earth-fixed coordinate system and the J2000 inertial coordinate system and

[0147] Step S5: Calculate the three-axis guidance attitude of the satellite pointing to the cooperative target

[0148] The present invention is based on the established trajectory sequence information of the cooperation target (i.e., n trajectory points forming a time t m and longitude λ m , latitude φ m , height h m), the attitude conversion matrix from the WGS84 earth-fixed coordinate system to the J2000 inertial coordinate system, the projection of the satellite's position vector and velocity vector in the J2000 inertial coordinate system and other parameters, and calculate the three-axis attitude of the satellite in the inertial system when tracking and imaging the cooperative target.

[0149] First, the established trajectory sequence information of the cooperative target needs to be time normalized and fitted with a high-order polynomial.

[0150] 1. The time information t of the cooperative target trajectory sequence m Normalization is performed as follows:

[0151]

[0152] Where, t m_max and t m_min t m The maximum and minimum values ​​in the sequence.

[0153] 2. Calculate the fitting coefficients of longitude, latitude and altitude respectively according to the following formulas: lon(i), lat(i), alt(i), where i = 1, 2, ..., 13:

[0154]

[0155]

[0156] In the formula, λ m (k),φ m (k), h m (k), k = 1, 2, ..., n respectively represent the longitude, latitude, and altitude corresponding to the n trajectory points of the cooperative target trajectory sequence. The calculation method of matrix A is as follows:

[0157]

[0158] Where, T m (k), k = 1, 2, ..., n, respectively represents the normalized time corresponding to the n trajectory points of the cooperative target trajectory sequence.

[0159] Secondly, after the fitting coefficients are injected into the satellite, the satellite can calculate the position of the cooperation target according to the injected fitting coefficients lon(i), lat(i), alt(i) and the current time t.

[0160] 1. Calculate the real-time longitude λ, latitude φ, and altitude h of the cooperation target according to the following formula:

[0161]

[0162] λ=lon(1)+lon(2)×T+lon(3)×T 2 +...+lon(13)×T 12 ;

[0163] φ=lat(1)+lat(2)×T+lat(3)×T 2 +...+lat(13)×T 12 ;

[0164] h=alt(1)+alt(2)×T+alt(3)×T 2 +...+alt(13)×T 12 ;

[0165] 2. Projection of the cooperative target’s position in the WGS84 Earth-fixed coordinate system Calculated as follows:

[0166]

[0167] In the formula, R e and f e are the Earth's equatorial radius and the Earth's oblateness, respectively.

[0168] 3. Position projection of cooperative targets in the J2000 inertial coordinate system Calculated as follows:

[0169]

[0170] Where M ecf2eci It is the attitude transformation matrix from WGS84 earth-fixed coordinate system to J2000 inertial coordinate system.

[0171] Finally, the three-axis attitude of the satellite in the inertial system when tracking and imaging the cooperative target is calculated based on the position information of the cooperative target and the position and velocity information of the satellite.

[0172] 1. Calculate the expected attitude rotation matrix of the satellite pointing to the cooperative target, with the satellite camera axis (+Z axis) pointing to the cooperative target and the satellite +X axis constrained in the orbital plane as the constraint condition, vector i x ,i y ,i z The calculation method is as follows:

[0173]

[0174] in, and They are respectively the projections of the satellite’s position vector and velocity vector in the J2000 inertial coordinate system.

[0175] 2. Calculate the three-axis attitude in the inertial system. Here, we take the Euler angle of 1-2-3 as an example. The roll angle of the satellite under inertia The pitch angle θ and yaw angle ψ are calculated according to the following formula:

[0176]

[0177] The present invention also provides a satellite attitude guidance system for tracking and imaging cooperative targets. The satellite attitude guidance system for tracking and imaging cooperative targets can be implemented by executing the process steps of the satellite attitude guidance method for tracking and imaging cooperative targets, that is, those skilled in the art can understand the satellite attitude guidance method for tracking and imaging cooperative targets as a preferred implementation of the satellite attitude guidance system for tracking and imaging cooperative targets.

[0178] Specifically, a satellite attitude guidance system for tracking and imaging a cooperative target includes:

[0179] Information collection module: collects parameter information of the cooperation target; the parameter information includes time information of the trajectory sequence, trajectory longitude, trajectory latitude and trajectory altitude;

[0180] Guidance calculation module: Perform high-order polynomial fitting on the trajectory longitude, trajectory latitude, trajectory altitude and normalized time information to calculate the three-axis guidance attitude of the satellite pointing to the cooperative target.

[0181] The guidance calculation module includes:

[0182] Module M1.0: Normalize the time information of the cooperative target trajectory sequence;

[0183] Module M1.1: Perform high-order polynomial fitting on the trajectory longitude, trajectory latitude, trajectory altitude and normalized time information to obtain the corresponding fitting coefficients;

[0184] Module M1.2: Calculate the real-time longitude, latitude and altitude of the cooperation target at the current moment based on the fitting coefficient;

[0185] Module M1.3: Calculate the position of the cooperative target in the earth-fixed coordinate system and the inertial coordinate system based on the real-time information obtained;

[0186] Module M1.4: Based on the position of the cooperative target in the coordinate system, the three-axis guidance attitude of the satellite pointing to the cooperative target is calculated.

[0187] The module M1.0 includes:

[0188] The time information t of the cooperative target trajectory sequence m Normalization is performed as follows:

[0189]

[0190] Where, t m_max and t m_min t m The maximum and minimum values ​​in the sequence.

[0191] The module M1.1 comprises:

[0192] Module M1.1.1: Calculate the fitting coefficient lon(i) of longitude, where i = 1, 2, ..., 13;

[0193]

[0194] In the formula, λ m (k), k = 1, 2, ..., n respectively represent the longitudes corresponding to the n trajectory points of the cooperative target trajectory sequence. The calculation method of matrix A is as follows:

[0195]

[0196] Where, T m (k), k = 1, 2, ..., n, respectively represents the normalized time corresponding to the n trajectory points of the cooperative target trajectory sequence;

[0197] Module M1.1.2: Calculate the latitude fitting coefficient lat(i), where i = 1, 2, ..., 13;

[0198]

[0199] In the formula, φ m (k), k = 1, 2, ..., n respectively represent the latitudes corresponding to the n trajectory points of the cooperative target trajectory sequence;

[0200] Module M1.1.3: Calculate the height fitting coefficient alt(i), where i = 1, 2, ..., 13;

[0201]

[0202] In the formula, h m (k), k = 1, 2, ..., n represent the heights corresponding to the n trajectory points of the cooperative target trajectory sequence.

[0203] The module M1.2 includes:

[0204] Module M1.2.1: Calculate the real-time longitude λ of the cooperation target at the current time t according to the longitude fitting coefficient lon(i) noted above:

[0205]

[0206] λ=lon(1)+lon(2)×T+lon(3)×T 2 +...+lon(13)×T 12 ;

[0207] Module M1.2.2: Calculate the real-time latitude φ of the cooperation target at the current time t according to the latitude fitting coefficient lat(i) noted above:

[0208] φ=lat(1)+lat(2)×T+lat(3)×T 2 +...+lat(13)×T 12 ;

[0209] Module M1.2.3: Calculate the real-time height h of the cooperative target at the current time t according to the height fitting coefficient alt(i) noted above:

[0210] h=alt(1)+alt(2)×T+alt(3)×T 2 +...+alt(13)×T 12 .

[0211] The module M1.3 includes:

[0212] Module M1.3.1: Calculate the position projection of cooperative targets in the WGS84 Earth-fixed coordinate system

[0213]

[0214] In the formula, R e and f e are the Earth's equatorial radius and Earth's oblateness, respectively;

[0215] Module M1.3.2: Calculate the position projection of the cooperative target in the J2000 inertial coordinate system

[0216]

[0217] Where M ecf2eci It is the attitude transformation matrix from WGS84 earth-fixed coordinate system to J2000 inertial coordinate system.

[0218] The module M1.4 includes:

[0219] Calculate the three-axis guidance attitude of the satellite towards the cooperative target

[0220]

[0221] In the formula, i x ,i y,i z The calculation method is as follows:

[0222]

[0223] in, and They are respectively the projections of the satellite’s position vector and velocity vector in the J2000 inertial coordinate system.

[0224] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, the system and its various devices, modules, and units provided by the present invention can be completely realized in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps to realize the same functions. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0225] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0226] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A satellite attitude guidance method for tracking and imaging a cooperative target, characterized in that: include: Information collection step: Collect parameter information of cooperation targets; The parameter information includes time information of the trajectory sequence, trajectory longitude, trajectory latitude and trajectory altitude; Guidance calculation steps: Perform high-order polynomial fitting on the trajectory longitude, trajectory latitude, trajectory altitude and normalized time information to calculate the three-axis guidance attitude of the satellite pointing to the cooperative target.

2. The satellite attitude guidance method for tracking and imaging a cooperative target according to claim 1, characterized in that: The guiding calculation step comprises: Step S1.0: normalize the time information of the cooperative target trajectory sequence; Step S1.1: Perform high-order polynomial fitting on the track longitude, track latitude, track altitude and normalized time information to obtain the corresponding fitting coefficients; Step S1.2: Calculate the real-time longitude, latitude and altitude of the cooperation target at the current moment according to the fitting coefficient; Step S1.3: Calculate the position of the cooperative target in the earth-fixed coordinate system and the inertial coordinate system according to the obtained real-time information; Step S1.4: Based on the position of the cooperative target in the coordinate system, the three-axis guidance attitude of the satellite pointing to the cooperative target is calculated.

3. The satellite attitude guidance method for tracking and imaging a cooperative target according to claim 2, characterized in that: The step S1.0 comprises: The time information t of the cooperative target trajectory sequence m Normalization is performed as follows: Where, t m_max and t m_min t m The maximum and minimum values ​​in the sequence.

4. The satellite attitude guidance method for tracking and imaging a cooperative target according to claim 3, characterized in that: The step S1.1 comprises: Step S1.1.1: Calculate the fitting coefficient lon(i) of longitude, where i = 1, 2, ..., 13; In the formula, λ m (k), k = 1, 2, ..., n respectively represent the longitudes corresponding to the n trajectory points of the cooperative target trajectory sequence. The calculation method of matrix A is as follows: Where, T m (k), k = 1, 2, ..., n, respectively represents the normalized time corresponding to the n trajectory points of the cooperative target trajectory sequence; Step S1.1.2: Calculate the fitting coefficient of latitude lat(i), where i = 1, 2, ..., 13; In the formula, φ m (k), k = 1, 2, ..., n respectively represent the latitudes corresponding to the n trajectory points of the cooperative target trajectory sequence; Step S1.1.3: Calculate the height fitting coefficient alt(i), where i = 1, 2, ..., 13; In the formula, h m (k), k = 1, 2, ..., n represent the heights corresponding to the n trajectory points of the cooperative target trajectory sequence.

5. The satellite attitude guidance method for tracking and imaging a cooperative target according to claim 4, characterized in that: The step S1.2 comprises: Step S1.2.1: Calculate the real-time longitude λ of the cooperation target at the current time t according to the longitude fitting coefficient lon(i) noted above: λ=day(1)+day(2)×T+day(3)×T 2 +…+day(13)×T 12 ; Step S1.2.2: Calculate the real-time latitude φ of the cooperation target at the current time t according to the latitude fitting coefficient lat(i) noted above: φ=lat(1)+lat(2)×T+lat(3)×T 2 +...+years(13)×T 12 ; Step S1.2.3: Calculate the real-time height h of the cooperative target at the current time t according to the height fitting coefficient alt(i) noted above: h=all(1)+all(2)×T+all(3)×T 2 +...+all(13)×T 12 。 6. The satellite attitude guidance method for tracking and imaging a cooperative target according to claim 5, characterized in that: The step S1.3 comprises: Step S1.3.1: Calculate the position projection of the cooperative target in the WGS84 Earth-fixed coordinate system In the formula, R e and f e are the Earth's equatorial radius and Earth's oblateness, respectively; Step S1.3.2: Calculate the position projection of the cooperative target in the J2000 inertial coordinate system Where M ecf2eci It is the attitude transformation matrix from WGS84 earth-fixed coordinate system to J2000 inertial coordinate system.

7. The satellite attitude guidance method for tracking and imaging a cooperative target according to claim 6, characterized in that: The step S1.4 comprises: Calculate the three-axis guidance attitude of the satellite towards the cooperative target In the formula, i x ,i y ,i z The calculation method is as follows: in, and They are respectively the projections of the satellite’s position vector and velocity vector in the J2000 inertial coordinate system.

8. A satellite attitude guidance system for tracking and imaging cooperative targets, characterized in that: include: Information collection module: collects parameter information of cooperation targets; The parameter information includes time information of the trajectory sequence, trajectory longitude, trajectory latitude and trajectory altitude; Guidance calculation module: Perform high-order polynomial fitting on the trajectory longitude, trajectory latitude, trajectory altitude and normalized time information to calculate the three-axis guidance attitude of the satellite pointing to the cooperative target.

9. The satellite attitude guidance system for tracking and imaging cooperative targets according to claim 8, characterized in that: The guidance calculation module includes: Module M1.0: Normalize the time information of the cooperative target trajectory sequence; Module M1.1: Perform high-order polynomial fitting on the trajectory longitude, trajectory latitude, trajectory altitude and normalized time information to obtain the corresponding fitting coefficients; Module M1.2: Calculate the real-time longitude, latitude and altitude of the cooperation target at the current moment based on the fitting coefficient; Module M1.3: Calculate the position of the cooperative target in the earth-fixed coordinate system and the inertial coordinate system based on the real-time information obtained; Module M1.4: Based on the position of the cooperative target in the coordinate system, the three-axis guidance attitude of the satellite pointing to the cooperative target is calculated.

10. The satellite attitude guidance system for tracking and imaging cooperative targets according to claim 9, characterized in that: The module M1.0 includes: The time information t of the cooperative target trajectory sequence m Normalization is performed as follows: Where, t m_max and t m_min t m The maximum and minimum values ​​in the sequence.

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