Deep space probe on-orbit bias system and method

Abstract

The invention provides a deep space probe on-orbit bias system and method. The deep space probe on-orbit bias system comprises deep space probe single-machine layout and on-orbit flight attitude bias design. The solar wing, the orbit control engine, the measurement and control antenna, the star sensor and the camera are optimized in sequence, so that the detection and shooting requirements of a deep space task are met on the premise of ensuring the safe and stable flight of the whole aircraft; in the in-orbit flight attitude offset design, whether the in-orbit of the deep space probe meets constraint conditions or not and whether the camera can shoot the earth or not are judged according to orbit parameters and attitude pointing at the current moment, and if any constraint cannot be met, a three-axis attitude offset angle is used as a variable, and a three-axis attitude offset angle is used as a variable; according to the method, the on-orbit flight attitude offset angle is comprehensively optimized by applying an optimization algorithm, so that the three-axis offset angle which can meet constraint conditions and can enable the earth to appear in the view field range of a camera is solved, design and optimization of the on-orbit attitude offset of the deep space probe can be realized, and the method has extremely high engineering value.

Description

Technical Field

[0001] This invention belongs to the field of attitude control for deep space probes, specifically relating to an on-orbit biasing system and method for deep space probes. Background Technology

[0002] Deep space exploration missions primarily target the Moon and more distant celestial bodies, differing significantly from near-Earth satellite missions. They are characterized by complex flight processes, long flight times, high technical difficulty, and extremely high reliability requirements. Furthermore, these missions demand high levels of precision, further placing stringent demands on the on-orbit autonomous optimization and adaptability capabilities of deep space probes.

[0003] During flight, the angles between the probe and Earth, the Sun, and other celestial bodies vary greatly, and the influence of multiple celestial bodies, including the Sun, the originating planet, and the destination planet, must be comprehensively considered. This complexity makes it extremely difficult to ensure the proper functioning of the solar arrays, orbital control engines, telemetry antennas, star sensors, and cameras throughout the entire flight using ground-based configuration.

[0004] If situations such as insufficient energy (e.g., inadequate solar panel illumination area), telemetry and control interruptions (malfunctioning telemetry and control antennas), or attitude measurement anomalies (unusable star sensors) occur, the reliability and safety of deep space probes will be significantly reduced. Therefore, improving the on-orbit real-time optimization performance of deep space probes has become a critical issue that urgently needs to be addressed.

[0005] For example, patent document CN108820256 discloses a spacecraft offset orbit design method, specifically following these steps: S1: Establish a first mathematical spatial coordinate model by selecting the Earth's center as the origin of the three-dimensional spatial coordinate system; S2: Establish a second mathematical spatial coordinate model by selecting the spacecraft as the origin of the three-dimensional spatial coordinate system, and compare real-time data with the theoretical parameters required for the target orbit; S3: Based on the comparison results, adjust the spacecraft's current attitude and calculate the acceleration required for orbit change, analyzing whether the attitude adjustment can be completed; S4: After orbit change, adjust the spacecraft's attitude based on the comparison results. This invention, by establishing a first and a second mathematical spatial coordinate system, facilitates the digital comparison of the spacecraft's real-time attitude information, enabling precise real-time adjustment of the spacecraft's attitude. Before orbit change, technical analysis allows for pre-judgment of whether orbit change conditions exist, significantly improving the success rate and accuracy of orbit change.

[0006] For example, patent document CN114537715B provides a method and system for adaptive layout of multi-star sensor clusters based on occlusion determination. This includes establishing a parameterized transfer coordinate system with reference to the whole-star coordinate system, and establishing a parameterized coordinate system at the origin of the transfer system; establishing a star sensor mounting coordinate system at the center of the star sensor mounting surface; establishing and assembling an occluded model and an occlusion model; performing position adaptive offset of a single star sensor within the cluster based on occlusion determination, and performing corner adaptive offset of the star sensor based on occlusion determination based on the position adaptive offset; after completing the layout of a single star sensor within the cluster, the already laid-out star sensor model is introduced as a new occlusion model into the layout process of other star sensors within the cluster, and star sensor determination is then performed to achieve adaptive layout of other star sensors within the multi-star sensor cluster; after the adaptive layout of the multi-star sensor cluster is completed, the output result is the offset relationship between each star sensor mounting system, transfer system, X-axis corner system, Y-axis corner system, and Z-axis corner system.

[0007] For example, patent document CN117792461A provides a method and system for offset compensation of the beam pointing to the ground of a spacecraft phased array antenna, including the following steps: S1, calculating the azimuth angle of the satellite pointing to the ground station at the time of the mission based on the satellite orbit parameters and the target ground station position information; S2, selecting the spacecraft attitude rolling offset compensation mode based on the obtained ground station azimuth angle; S3, executing the beam pointing control process of the spaceborne phased array electronically scanned antenna to the ground based on the satellite orbit parameters, attitude information, and target ground station position information. This invention can satisfy the offset compensation function of the beam pointing to the ground of a spacecraft's spaceborne phased array antenna, enhance the beam coverage capability of the edge field of view of the spaceborne phased array antenna, and reduce the beam scanning range of the phased array antenna by means of spacecraft attitude offset compensation, thereby reducing the deterioration of gain and axial ratio after antenna pattern distortion at the edge limit angle, so that the satellite can achieve better overall performance.

[0008] For example, patent document CN117130384A discloses a full-attitude bias spacecraft imaging mission planning method that is beneficial for aerospace telemetry and control. Considering the strong coupling characteristics between attitude motion channels, and combining geographical information such as the spacecraft's orbit, the installation orientation of the data transmission antenna on the satellite body, the imaging target, and the latitude and longitude of the ground data transmission station, this method ensures that the data transmission antenna is pointed in a direction conducive to tracking by the data transmission station while the spacecraft is imaging the target. Simultaneous imaging and data downlink greatly reduces on-board storage pressure. This invention has high reliability, strong operability, and is easy to promote and use. It can perform long-term imaging of key targets, increasing the available arc duration of on-orbit imaging for spacecraft. This full-attitude bias spacecraft imaging mission planning method is beneficial for aerospace telemetry and control. For example, patent document CN113353291B discloses a method for adjusting the pointing angle of a satellite relative to the Earth. This method corrects the pointing deviation of the altimeter signal transmission beam caused by structural deformation before and after satellite entry into orbit by using a whole-satellite attitude offset. The method includes: designing the direction of the whole-satellite attitude maneuver; analyzing and calculating the angle range of the whole-satellite attitude maneuver; analyzing and calculating the angle step size of the whole-satellite attitude maneuver; designing the path of the whole-satellite attitude maneuver; executing the attitude maneuver and analyzing the altimeter measurement data; and the satellite flying with the adjusted attitude angle offset.

[0009] For example, patent document CN110932768A discloses a polar constellation GEO interference avoidance method based on polar-orbiting satellite attitude offset. It addresses the shortcomings of current polar constellation GEO interference avoidance methods that do not consider constellation coverage continuity, which may lead to service interruption of polar constellations. By continuously offsetting the attitude of polar constellation satellites, frequency interference of GEO satellites is avoided. At the same time, by optimizing the satellite attitude offset pattern, the polar constellation coverage is made continuous and the coverage overlap margin is maximized, thereby ensuring the continuity of polar constellation coverage.

[0010] However, none of the aforementioned existing technologies comprehensively consider the real-time constraints of orbit control, energy, communication, attitude measurement, and imaging targets throughout the flight, nor do they provide methods for optimizing the three-axis attitude offset angle. Furthermore, these patents do not involve the field of deep space control. Summary of the Invention

[0011] To address the shortcomings of existing technologies, the present invention aims to provide an on-orbit offset method for deep space probes, comprising: a single-unit layout stage for the deep space probe and an on-orbit flight attitude offset design stage. Specifically, the single-unit layout stage involves first using the attitude towards the Sun during the relatively long Earth-Mars transfer phase of the flight as the initial attitude, and then sequentially designing the layout of the solar array, orbit control engine, telemetry and control antenna, star sensor, and camera. The on-orbit flight attitude offset design stage involves, based on the design of the single-unit layout stage, and according to the real-time orbital parameters and the three-axis orientation of the attitude at each stage of the flight, optimizing the three-axis attitude offset angles while satisfying real-time constraints on orbit control, energy, communication, and attitude measurement throughout the flight, with the goal of ensuring the Earth appears completely within the camera's field of view.

[0012] Preferably, the layout design of the solar array specifically refers to the solar array's normal direction coinciding with the spacecraft's solar vector during the solar orientation; the layout design of the orbital control engine specifically refers to the orbital control engine's ignition direction being set to the opposite direction of the solar array's normal direction; the layout design of the telemetry and control antenna specifically refers to at least one telemetry and control antenna having an angle between its electrical axis and the spacecraft's ground vector that is less than the telemetry and control antenna's beam angle; the electrical axis of the telemetry and control antenna is not obstructed by the solar array or the orbital control engine's plume components; the layout design of the star sensor specifically refers to ensuring that the angle formed by the optical axis of at least one star sensor with the spacecraft's ground vector, solar vector, and fire vector is greater than the star sensor's protection angle; furthermore, the optical axis of the star sensor is not obstructed by the solar array or the orbital control engine's plume components; the layout design of the camera specifically refers to the camera's optical axis having an angle between its optical axis and the spacecraft's ground vector that is less than the camera's field of view; the camera's optical axis is not obstructed by the solar array or the orbital control engine's plume components.

[0013] Preferably, the on-orbit flight attitude offset design step includes: step S1001: determining whether the current deep space probe can meet the constraints based on the current orbital parameters and attitude orientation; step S1002: if any constraint in step S1001 cannot be met, then an optimization algorithm is used to comprehensively optimize the on-orbit flight attitude offset angle of the deep space probe; the comprehensive optimization includes: optimization variables; the optimization variables specifically refer to optimizing the attitude offset angle of rotation around the three axes of the system.

[0014] Preferably, step S1002 includes: Step S100001: Calculate the normalized vector of the deep space probe in the current orbital position and attitude orientation in the J2000.0 geocentric inertial coordinate system according to the two cases of solar attitude and orbital control attitude; the J2000.0 geocentric inertial coordinate system is an inertial coordinate system with the Earth's center of mass as the origin; Step S100002: Calculate the normalized solar vector, normalized Earth vector, normalized Mars vector, and normalized velocity vector of the deep space probe at the current orbital position; Step S100003: Calculate the three-axis orientation of the deep space probe after offset; Step S100004: Calculate the vectors of the normalized Earth vector, probe solar vector, and probe Mars vector in the offset body coordinate system; Step S100005: Calculate the included angle in the offset body coordinate system.

[0015] Preferably, the constraints in step S1001 specifically refer to whether the constraints of orbit control, energy, communication, and attitude measurement can be met in orbit, and whether the camera can capture images of the Earth. Further, the constraints include: ensuring orbit control, ensuring energy, ensuring communication, and ensuring attitude measurement. Ensuring orbit control specifically means that, in the case of orbital maneuvering attitude, the ignition direction of the orbit control engine coincides with the velocity increment direction. Ensuring energy specifically means that the solar array current is greater than or equal to a threshold. Ensuring communication specifically means that at least one telemetry and control antenna's electrical axis has an angle with the Earth smaller than the beam angle. Ensuring attitude measurement specifically means that at least one star sensor's optical axis has an angle greater than the star sensor's protection angle when it forms an angle with the detector and the Earth's edge, an angle with the vector formed by the detector and the Sun, and an angle with the detector and the Martian edge. Further, the constraints include: optimizing the objective function so that the Earth appears completely in the camera's field of view, as shown in the following formula:

[0016] in, To maximize processing; The angle between the camera's optical axis and the Earth's center; The angle between the ground vector and the horizon.

[0017] Preferably, the three-axis orientation of the deep space probe body after offsetting in step S100003 is calculated according to the following formula:

[0018]

[0019]

[0020]

[0021] in, Let be the transformation matrix for rotation about the +Xb axis of this system; The transformation matrix is ​​the rotation around the +Yb axis of this system; Let be the transformation matrix for rotation about the +Zb axis of this system; The +Xb axis orientation of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The orientation of the +Yb axis of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The orientation of the +Zb axis of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; These are the attitude offset angles for rotation around the three axes of the system.

[0022] Preferably, the normalized ground vector, solar vector, and fire vector in step S100004 are calculated in the offset body coordinate system as shown in the following formula:

[0023]

[0024]

[0025] in, This is the normalizer day vector in the offset detector body coordinate system; This is the normalizer ground vector in the offset detector body coordinate system; The normalized fire vector in the offset detector body coordinate system; The normalizer day vector in the J2000.0 geocentric inertial coordinate system; This is the normalizer ground vector in the J2000.0 geocentric inertial coordinate system; The normalizer fire vector is defined in the J2000.0 geocentric inertial coordinate system.

[0026] Preferably, the included angles in step S100005 include: the angle between the ignition direction of the orbital control engine and the velocity increment direction, the angle between the solar array normal and the solar vector, the angle between the electrical axis of the telemetry and control antenna and the ground vector, the angle between the star-sensor optical axis and the solar vector, the angle between the star-sensor optical axis and the ground edge, the angle between the star-sensor optical axis and the solar-fire edge, the angle between the camera optical axis and the Earth's center, and the angle between the ground vector and the horizon.

[0027] This invention proposes an on-orbit offset system for a deep space probe, comprising: a single-unit layout module for the deep space probe and an on-orbit flight attitude offset design module. Specifically, the single-unit layout module first uses the attitude towards the Sun during the relatively long Earth-Mars transfer phase of the flight as the initial attitude, and then sequentially designs the layout of the solar array, orbit control engine, telemetry and control antenna, star sensor, and camera. The on-orbit flight attitude offset design module, based on the design of the single-unit layout module and according to the real-time orbital parameters and the three-axis orientation of the attitude at each stage of the flight, optimizes the attitude offset angles of the three axes while satisfying the constraints of real-time orbit control, power, communication, and attitude measurement throughout the flight, with the goal of ensuring the Earth appears completely within the camera's field of view.

[0028] This invention proposes an on-orbit offset device for deep space probes. By employing the on-orbit offset method for deep space probes and optimizing the on-orbit flight attitude offset angle of the deep space probes, the reliability of the deep space probes throughout their flight and the display accuracy of their imaging missions are effectively improved.

[0029] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention can quickly and in real time calculate the three-axis attitude offset angle, enabling deep space probes to take pictures of the Earth at different distances at any time during deep space flight and transmit the pictures back to Earth in real time.

[0030] 2. This invention effectively improves the reliability of deep space probes throughout their flight and the accuracy of their imaging missions. The method is simple, efficient, and has strong engineering value. Attached Figure Description

[0031] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart illustrating an on-orbit biasing method for a deep space probe proposed in this invention. Figure 2 This is a schematic diagram of the attitude of a deep space probe toward the sun, based on an on-orbit biasing method for a deep space probe proposed in this invention. Figure 3 This is a schematic diagram of the orbital maneuvering attitude of a deep space probe, based on the on-orbit biasing method for a deep space probe proposed in this invention. Figure 4 This is a schematic diagram of the deep space probe layout for an on-orbit biasing method for a deep space probe proposed in this invention. Figure 5 This is a schematic diagram showing the relationship between the camera optical axis and the Earth in a deep space probe on-orbit biasing method proposed in this invention. The diagram shows: +X b This is represented as the X-axis direction in the coordinate system of the deep space probe. +Y b This is represented by the Y-axis direction in the coordinate system of the deep space probe. +Z b This is represented by the Z-axis direction in the coordinate system of the deep space probe. +O b This is represented as the origin of the deep space probe's body coordinate system; + This is represented as the normal direction of solar panel 1; + This is represented as the normal direction of Solar Panel 2; + This is indicated by the optical axis direction of StarSense 1; + This is indicated by the optical axis direction of StarSense 2; + This is indicated by the optical axis direction of StarSense 3; + This is indicated by the optical axis direction of StarSense 4; + This is indicated by the electrical axis direction of the telemetry and control antenna 1; + This is indicated by the electrical axis direction of the telemetry and control antenna 2; + This is indicated by the electrical axis direction of the telemetry and control antenna 3; + This is indicated by the electrical axis direction of the telemetry and control antenna 4; + This indicates the ignition direction of the rail-controlled engine; + Indicated as the direction of the camera's optical axis; P represents the detector; Represented as the angle between the instrument's ground vector and the horizon; This is expressed as the angle between the camera's optical axis and the horizon. Re represents the Earth's radius; h represents the height; E represents Earth; M represents the point of tangency between the probe and the Earth's radius; It is represented as the angle between the camera's optical axis and the Earth's center. Detailed Implementation

[0032] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0033] This invention proposes an on-orbit offset method for deep space probes, including: the layout of a single deep space probe and the on-orbit flight attitude offset design.

[0034] The single-unit layout of the deep space probe includes: designing the layout of the solar array, orbit control engine, telemetry and control antenna, star sensor, and camera based on the orbital characteristics and energy attitude constraints during the relatively long Earth-Mars transfer phase of the flight. This ensures that the deep space probe has sufficient energy, uninterrupted communication with Earth, and at least one star sensor is available during flight, while maintaining the Earth's position relative to the Sun during the Earth-Mars transfer phase. It also ensures that the Earth appears in the camera's field of view during flight, allowing for the taking of photographs of the Earth.

[0035] Furthermore, the single-unit layout of the deep space probe specifically refers to optimizing the layout in the order of solar array, orbit control engine, telemetry and control antenna, star sensor, and camera, while ensuring the exploration and imaging requirements of the deep space mission and the overall flight safety and stability of the probe. The layout optimization process is carried out based on the solar attitude during the Earth-Mars transfer phase, which takes a long time during the entire flight of the deep space probe, and the pointing relationship of the deep space probe to Earth, Sun, and Mars is relatively fixed.

[0036] The layout design of the solar array specifically refers to the requirement that, in order to ensure the energy safety of the deep space probe, the normal of the solar array must coincide with the probe's solar vector when in solar orientation.

[0037] The layout design of the orbit control engine specifically refers to the fact that, because the orbit control speed increment is large, in order to ensure the safety of the deep space probe when the orbit control engine is ignited, the ignition direction of the orbit control engine is set to be the opposite direction of the solar array normal.

[0038] The layout design of the telemetry and control antenna specifically refers to the fact that the angle between the electrical axis of at least one telemetry and control antenna and the ground vector is smaller than the beam angle of the telemetry and control antenna; and the electrical axis of the telemetry and control antenna is not blocked by the solar array or the plume component of the orbital control engine.

[0039] The layout design of the star sensor specifically refers to ensuring that the angle formed by the optical axis of at least one star sensor with the spacecraft-to-ground vector, spacecraft-to-sun vector, and spacecraft-to-Mars vector is greater than the star sensor protection angle; furthermore, the optical axis of the star sensor is not obstructed by the solar array or the plume components of the orbital control engine.

[0040] Specifically, the camera layout design means that the angle between the camera's optical axis and the ground vector is smaller than the camera's field of view; and the camera's optical axis is not obstructed by the solar array or the plume components of the orbital control engine.

[0041] The aforementioned on-orbit flight attitude offset design specifically refers to the comprehensive optimization of the attitude offset angles of the three axes based on the design of the deep space probe's single-unit layout and according to the real-time orbital parameters and attitude three-axis pointing at each stage of the flight, while meeting the constraints of real-time orbit control, energy, communication, and attitude measurement throughout the flight, with the goal of ensuring that the Earth appears completely in the camera's field of view. This optimization enables the deep space probe to capture images of the Earth at different distances at any moment during its deep space flight and to transmit the images back to Earth in real time.

[0042] The on-orbit flight attitude offset design process includes: Step S1001: Based on the current orbital parameters and attitude orientation, determine whether the current deep space probe can meet the constraints. Specifically, the constraints in step S1001 refer to whether the constraints of orbit control, energy, communication, and attitude measurement can be met in orbit, and whether the camera can capture images of the Earth. Furthermore, the constraints include: ensuring orbit control, ensuring power supply, ensuring communication, and ensuring attitude measurement. Specifically, ensuring track control means that, in the case of track maneuvering attitude, the ignition direction of the track control engine coincides with the direction of velocity increment. The guaranteed energy specifically refers to the solar panel current being greater than or equal to a threshold; the formula for calculating the solar panel current is as follows:

[0043] in, The magnitude of the solar array current; The magnitude of the current when the solar array vertical rotor is in the daytime vector; The angle between the solar array normal and the solar vector; The guarantee of communication specifically means, as shown in the following formula, that at least one telemetry and control antenna has an electrical axis angle with the Earth that is smaller than the beam angle.

[0044] in, The angle between the electrical axis of the telemetry and control antenna and the Earth; Beam angle; The aforementioned attitude measurement guarantee specifically refers to the existence of at least one star sensor whose optical axis has angles greater than the star sensor's protection angle, including the angles formed by the probe and the edge of Earth, the angle formed by the vector formed by the probe and the Sun, and the angle formed by the probe and the edge of Mars. This is illustrated by the following formula:

[0045] in, The angle between the instrument and the sun vector; Protect the star's angle; The angle between the star sensor's optical axis and the edge of the device ground; The angle between the edges of the Mars probe.

[0046] Furthermore, the constraints include: an optimization objective function; as shown in the following formula, the optimization objective function ensures that the Earth appears completely in the camera's field of view;

[0047] in, To maximize processing; The angle between the camera's optical axis and the Earth's center; The angle between the ground vector and the horizon.

[0048] Step S1002: If any of the constraints cannot be satisfied, an optimization algorithm is used to comprehensively optimize the on-orbit flight attitude offset angle of the deep space probe; the comprehensive optimization includes: optimization variables; the optimization variables include: attitude offset angles rotating around the three axes of the system; Step S1002 includes: Step S100001: For both the attitude towards the sun and the orbital control attitude, calculate the localized vector of the deep space probe under its current orbital position and attitude orientation in the J2000.0 geocentric inertial coordinate system; the J2000.0 geocentric inertial coordinate system is an inertial coordinate system with the Earth's center of mass as the origin; Step S100002: Calculate the normalizer sun vector, normalizer earth vector, normalizer fire vector, and normalized velocity vector of the deep space probe at its current orbital position. Step S100003: Calculate the three-axis orientation of the deep space probe body after offset; Further, the three-axis orientation of the deep space probe body after offset is calculated according to the following formula in step S100003;

[0049]

[0050]

[0051]

[0052] in, Let be the transformation matrix for rotation about the +Xb axis of this system; The transformation matrix is ​​the rotation around the +Yb axis of this system; Let be the transformation matrix for rotation about the +Zb axis of this system; The +Xb axis orientation of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The orientation of the +Yb axis of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The orientation of the +Zb axis of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The attitude offset angle is the rotation around the three axes of this system; Step S100004: Calculate the vectors of the normalizer ground vector, the device sun vector, and the device fire vector in the offset body coordinate system; Further, according to the following formula, calculate the vectors of the normalizer ground vector, device sun vector, and device fire vector in the offset body coordinate system in step S100004;

[0053]

[0054]

[0055] in, This is the normalizer day vector in the offset detector body coordinate system; This is the normalizer ground vector in the offset detector body coordinate system; The normalized fire vector in the offset detector body coordinate system; The normalizer day vector in the J2000.0 geocentric inertial coordinate system; This is the normalizer ground vector in the J2000.0 geocentric inertial coordinate system; The normalized fire vector in the J2000.0 geocentric inertial coordinate system; Step S100005: Calculate the included angle in the offset body coordinate system; The calculation in step S100005 includes: calculating and optimizing based on constraints to solve for the three-axis offset angle that satisfies the constraints and maximizes the area of ​​the Earth covered by the camera's field of view.

[0056] Furthermore, as shown in the appendix Figure 4 As shown, the included angles in step S100005 include: the angle between the ignition direction of the orbital control engine and the velocity increment direction, the angle between the solar array normal and the spacecraft's solar vector, the angle between the electrical axis of the telemetry and control antenna and the spacecraft's ground vector, the angle between the star sensor optical axis and the spacecraft's solar vector, the angle between the star sensor optical axis and the spacecraft's ground edge, the angle between the star sensor optical axis and the spacecraft's Mars edge, the angle between the camera optical axis and the Earth's center, and the angle between the spacecraft's ground vector and the horizon; the included angles in step S100005 are calculated according to the following formula;

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] in, The angle between the ignition direction of the track control engine and the velocity increment direction; This refers to the ignition direction of the rail-controlled engine; The direction of velocity increment in the J2000.0 geocentric inertial coordinate system; The angle between the solar array normal and the solar vector; Normal to the solar array; This is the normalizer day vector in the offset detector body coordinate system; The angle between the electrical axis of the telemetry and control antenna and the ground vector. The electrical axis of the telemetry and control antenna is pointed in the direction of the antenna. This is the normalizer ground vector in the offset detector body coordinate system; The angle between the star-sensitive optical axis and the instrument solar vector; The direction of the star-sensitive optical axis; This is the normalizer day vector in the offset detector body coordinate system; The angle between the star sensor's optical axis and the edge of the device ground; The radius of the Earth; The angle between the star-sensitive optical axis and the edge of the Martian surface of the instrument; The normalized fire vector in the offset detector body coordinate system; The radius of Mars; The angle between the camera's optical axis and the Earth's center; The direction of the camera's optical axis; The horizon; This invention proposes an on-orbit biasing system for a deep space probe, comprising: a single-unit layout module for the deep space probe and an on-orbit flight attitude biasing design module.

[0065] The deep space probe's single-unit layout module includes: designing the layout of the solar array, orbit control engine, telemetry and control antenna, sensing equipment, and image acquisition equipment based on the orbital characteristics and energy attitude constraints during the relatively long Earth-Mars transfer phase of flight. This ensures that the deep space probe has sufficient energy, uninterrupted communication with Earth, and at least one star sensor is available during flight, while maintaining the Earth's position relative to the Sun during the Earth-Mars transfer phase. It also ensures that the Earth appears in the camera's field of view during flight, allowing for Earth photography.

[0066] Furthermore, the aforementioned deep space probe single-unit layout module specifically refers to the layout optimization performed in the order of solar array, orbit control engine, telemetry and control antenna, star sensor, and camera, based on the premise of meeting the exploration and imaging requirements of deep space missions while ensuring the overall flight safety and stability of the probe. The layout optimization process is carried out based on the solar attitude during the Earth-Mars transfer phase, which takes a long time during the entire flight of the deep space probe, and the pointing relationship of the deep space probe to Earth, Sun, and Mars is relatively fixed.

[0067] The layout design of the solar array specifically refers to the requirement that, in order to ensure the energy safety of the deep space probe, the normal of the solar array must coincide with the probe's solar vector when in solar orientation.

[0068] The layout design of the orbit control engine specifically refers to the fact that, due to the large increase in orbit control speed, in order to ensure the safety of the deep space probe at the moment of orbit control engine ignition, the ignition direction of the orbit control engine is set to be the opposite direction of the solar array normal.

[0069] The layout design of the telemetry and control antenna specifically refers to the fact that the angle between the electrical axis of at least one telemetry and control antenna and the ground vector is smaller than the beam angle of the telemetry and control antenna; and the electrical axis of the telemetry and control antenna is not blocked by the solar array or the plume component of the orbital control engine.

[0070] The layout design of the star sensor specifically refers to ensuring that the angle formed by the optical axis of at least one star sensor with the spacecraft-to-ground vector, spacecraft-to-sun vector, and spacecraft-to-Mars vector is greater than the star sensor protection angle; furthermore, the optical axis of the star sensor is not obstructed by the solar array or the plume components of the orbital control engine. Specifically, the camera layout design means that the angle between the camera's optical axis and the ground vector is smaller than the camera's field of view; and the camera's optical axis is not obstructed by the solar array or the plume components of the orbital control engine.

[0071] The on-orbit flight attitude offset design module specifically refers to the comprehensive optimization of the attitude offset angles of the three axes based on the real-time orbital parameters and the three-axis orientation of the attitude at each stage of the flight, while meeting the constraints of real-time orbit control, energy, communication, and attitude measurement throughout the flight, with the goal of ensuring that the Earth appears completely in the camera's field of view. This enables the deep space probe to capture images of the Earth at different distances at any moment during its deep space flight and to transmit the images back to Earth in real time.

[0072] The on-orbit flight attitude offset design module includes: Module M1001: Based on the current orbital parameters and attitude orientation, determine whether the current deep space probe can meet the constraints. Specifically, the constraints in module M1001 refer to whether the constraints of orbit control, energy, communication, and attitude measurement can be met in orbit, and whether the camera can capture images of the Earth. Furthermore, the constraints include: ensuring orbit control, ensuring power supply, ensuring communication, and ensuring attitude measurement. Specifically, ensuring track control means that, in the case of track maneuvering attitude, the ignition direction of the track control engine coincides with the direction of velocity increment. The guaranteed energy specifically refers to the solar panel current being greater than or equal to a threshold; the formula for calculating the solar panel current is as follows:

[0073] in, The magnitude of the solar array current; The magnitude of the current when the solar array vertical rotor is in the daytime vector; The angle between the solar array normal and the solar vector; The guarantee of communication specifically means, as shown in the following formula, that at least one telemetry and control antenna has an electrical axis angle with the Earth that is smaller than the beam angle.

[0074] in, The angle between the electrical axis of the telemetry and control antenna and the Earth; Beam angle; The aforementioned attitude measurement guarantee specifically refers to the existence of at least one star sensor whose optical axis has angles greater than the star sensor's protection angle, including the angles formed by the probe and the edge of Earth, the angle formed by the vector formed by the probe and the Sun, and the angle formed by the probe and the edge of Mars. This is illustrated by the following formula:

[0075] in, The angle between the instrument and the sun vector; Protect the star's angle; The angle between the star sensor's optical axis and the edge of the device ground; The angle between the edges of the Mars probe.

[0076] Furthermore, the constraints include: an optimization objective function; as shown in the following formula, the optimization objective function ensures that the Earth appears completely in the camera's field of view;

[0077] in, To maximize processing; The angle between the camera's optical axis and the Earth's center; The angle between the ground vector and the horizon.

[0078] Module M1002: If any of the constraints cannot be met, an optimization algorithm is used to comprehensively optimize the on-orbit attitude offset angle of the deep space probe; the comprehensive optimization includes: optimization variables; the optimization variables include: attitude offset angles rotating around the three axes of the system; The module M1002 includes: Module M100001: For both solar attitude and orbit control attitude scenarios, calculate the localized vector of the deep space probe under its current orbital position and attitude orientation in the J2000.0 geocentric inertial coordinate system; the J2000.0 geocentric inertial coordinate system is an inertial coordinate system with the Earth's center of mass as its origin; Module M100002: Calculates the normalized solar vector, normalized ground vector, normalized fire vector, and normalized velocity vector of the deep space probe at its current orbital position. Module M100003: Calculates the three-axis orientation of the deep space probe body after biasing; Further, the three-axis orientation of the biased deep space probe body in module M100003 is calculated according to the following formula;

[0079]

[0080]

[0081]

[0082] in, Let be the transformation matrix for rotation about the +Xb axis of this system; The transformation matrix is ​​the rotation around the +Yb axis of this system; Let be the transformation matrix for rotation about the +Zb axis of this system; The +Xb axis orientation of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The orientation of the +Yb axis of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The orientation of the +Zb axis of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The attitude offset angle is the rotation around the three axes of this system; Module M100004: Calculates the vectors of the normalizer's ground vector, solar vector, and fire vector in the offset body coordinate system; Further, according to the following formula, the vectors of the normalizer ground vector, device sun vector, and device fire vector in the module M100004 are calculated in the offset body coordinate system;

[0083]

[0084]

[0085] in, This is the normalizer day vector in the offset detector body coordinate system; This is the normalizer ground vector in the offset detector body coordinate system; The normalized fire vector in the offset detector body coordinate system; The normalizer day vector in the J2000.0 geocentric inertial coordinate system; This is the normalizer ground vector in the J2000.0 geocentric inertial coordinate system; The normalized fire vector in the J2000.0 geocentric inertial coordinate system; Module M100005: Calculates the included angle in the offset body coordinate system; The calculations in module M100005 include: calculating and optimizing based on constraints to solve for the three-axis offset angle that satisfies the constraints and maximizes the area of ​​the Earth covered by the camera's field of view.

[0086] Furthermore, the included angles in module M100005 include: the angle between the ignition direction of the orbital control engine and the velocity increment direction; the angle between the solar array normal and the spacecraft's solar vector; the angle between the electrical axis of the telemetry and control antenna and the spacecraft's ground vector; the angle between the star sensor optical axis and the spacecraft's solar vector; the angle between the star sensor optical axis and the spacecraft's ground edge; the angle between the star sensor optical axis and the spacecraft's Mars edge; the angle between the camera optical axis and the Earth's center; and the angle between the spacecraft's ground vector and the horizon. The included angles in module M100005 are calculated according to the following formula.

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] in, The angle between the ignition direction of the track control engine and the velocity increment direction; This refers to the ignition direction of the rail-controlled engine; The direction of velocity increment in the J2000.0 geocentric inertial coordinate system; The angle between the solar array normal and the solar vector; Normal to the solar array; This is the normalizer day vector in the offset detector body coordinate system; The angle between the electrical axis of the telemetry and control antenna and the ground vector. The electrical axis of the telemetry and control antenna is pointed in the direction of the antenna. This is the normalizer ground vector in the offset detector body coordinate system; The angle between the star-sensitive optical axis and the instrument solar vector; The direction of the star-sensitive optical axis; This is the normalizer day vector in the offset detector body coordinate system; The angle between the star sensor's optical axis and the edge of the device ground; The radius of the Earth; The angle between the star-sensitive optical axis and the edge of the Martian surface of the instrument; The normalized fire vector in the offset detector body coordinate system; The radius of Mars; The angle between the camera's optical axis and the Earth's center; The direction of the camera's optical axis; The horizon; Preferably, as shown in the appendix Figure 1 As shown, this invention proposes an on-orbit biasing method for deep space probes, comprising: S200001: Execute the start procedure and optimize the single-unit layout of the probe based on the Earth-Mars transfer phase; S200002: Calculate the three-axis pointing based on the current orbit and attitude; S200003: Determine whether the constraints of orbit control, energy, communication, and attitude measurement can be met, and whether the camera can capture images of the Earth. If the result is "Yes (Y)", proceed to S200008; if the result is "No (N)", proceed to S200004. S200004: Calculate the three-axis orientation of the detector body after biasing; S200005: Calculate the included angle in the offset body coordinate system; S200006: Perform offset angle optimization solution operation; S200007: Obtain the optimal offset angle that satisfies the constraints at the current moment; S200008: Determine if the current time is the end of the time period. If it is "Yes (Y)", proceed to S200009; if it is "No (N)", return to S200002 to perform "next time point calculation" and repeat the process. S200009: Execution terminated; Preferably, as shown in the appendix Figure 2 Appendix Figure 3 and attached Figure 5As shown, the present invention proposes an on-orbit biasing method for a deep space probe, which involves the solar attitude of the deep space probe, the positional relationship between the camera optical axis and the Earth, and the orbital maneuvering attitude of the deep space probe. Furthermore, the engine of the deep space probe can provide a certain speed increment during orbit control.

[0095] Preferably, the present invention proposes an on-orbit offset device for deep space probes. By adopting the on-orbit offset method for deep space probes, the offset angle of the on-orbit flight attitude of deep space probes is optimized, which effectively improves the reliability of deep space probes throughout their flight and the display accuracy of their imaging missions.

[0096] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An on-orbit biasing method for a deep space probe, characterized in that, include: The deep space probe's single-unit layout and on-orbit flight attitude offset design stages are as follows: The single-unit layout stage specifically refers to first designing the initial attitude based on the Earth-Mars transfer phase, which constitutes a significant portion of the flight, and then sequentially designing the layout of the solar array, orbit control engine, telemetry and control antenna, star sensor, and camera. The on-orbit flight attitude offset design stage specifically refers to, based on the single-unit layout design, and taking into account the real-time orbital parameters and the three-axis orientation of the attitude throughout the flight, while satisfying real-time constraints on orbit control, energy, communication, and attitude measurement throughout the flight, optimizing the complete appearance of the Earth in the camera's field of view, and processing the attitude offset angles of the three axes.

2. The on-orbit biasing method for deep space probes according to claim 1, characterized in that, The solar array layout design specifically refers to the solar array's normal direction coinciding with the spacecraft's solar vector during solar orientation. The orbital control engine layout design specifically refers to the orbital control engine's ignition direction being set opposite to the solar array's normal direction. The telemetry and control antenna layout design specifically refers to at least one telemetry and control antenna having an angle between its electrical axis and the spacecraft's ground vector that is less than the antenna's beam angle; the telemetry and control antenna's electrical axis is not obstructed by the solar array or the orbital control engine's plume components. The star sensor layout design specifically refers to ensuring that the angle formed by the optical axis of at least one star sensor and the spacecraft's ground vector, solar vector, and fire vector is greater than the star sensor's protection angle; furthermore, the star sensor's optical axis is not obstructed by the solar array or the orbital control engine's plume components. The camera layout design specifically refers to the camera's optical axis having an angle between its optical axis and the spacecraft's ground vector that is less than the camera's field of view; the camera's optical axis is not obstructed by the solar array or the orbital control engine's plume components.

3. The on-orbit biasing method for deep space probes according to claim 1, characterized in that, The on-orbit flight attitude offset design process includes: Step S1001: Based on the current orbital parameters and attitude orientation, determine whether the current deep space probe can meet the constraints. Step S1002: If any constraint in step S1001 cannot be satisfied, an optimization algorithm is used to comprehensively optimize the on-orbit flight attitude offset angle of the deep space probe; the comprehensive optimization includes: optimization variables; the optimization variables specifically refer to optimizing the attitude offset angle of rotation around the three axes of the system.

4. The on-orbit biasing method for deep space probes according to claim 3, characterized in that, Step S1002 includes: Step S100001: Based on the two cases of solar attitude and orbital control attitude, calculate the localized vector of the deep space probe under the current orbital position and attitude orientation in the J2000.0 geocentric inertial coordinate system; the J2000.0 geocentric inertial coordinate system is an inertial coordinate system with the Earth's center of mass as the origin; Step S100002: Calculate the normalizer sun vector, normalizer earth vector, normalizer fire vector, and normalized velocity vector of the deep space probe at its current orbital position. Step S100003: Calculate the three-axis orientation of the deep space probe body after offset; Step S100004: Calculate the vectors of the normalizer ground vector, the device sun vector, and the device fire vector in the offset body coordinate system; Step S100005: Calculate the included angle in the offset body coordinate system.

5. The on-orbit biasing method for deep space probes according to claim 3, characterized in that, The constraints in step S1001 specifically refer to whether the constraints of orbit control, energy, communication, and attitude measurement can be met in orbit, and whether the camera can capture images of the Earth. Further, the constraints include: ensuring orbit control, ensuring energy, ensuring communication, and ensuring attitude measurement. Ensuring orbit control specifically means that, in the case of orbital maneuvering attitude, the ignition direction of the orbit control engine coincides with the velocity increment direction. Ensuring energy specifically means that the solar array current is greater than or equal to a threshold. Ensuring communication specifically means that at least one telemetry and control antenna's electrical axis has an angle with the Earth smaller than the beam angle. Ensuring attitude measurement specifically means that at least one star sensor's optical axis has an angle greater than the star sensor's protection angle when its angles with the detector and the Earth's edge, the vector formed by the detector and the Sun, and the vector formed by the detector and the Martian edge are all greater than the star sensor's protection angle. Further, the constraints include: optimizing the objective function, which ensures that the Earth appears completely in the camera's field of view, as shown in the following formula: in, To maximize processing; The angle between the camera's optical axis and the Earth's center; The angle between the ground vector and the horizon.

6. The on-orbit biasing method for deep space probes according to claim 4, characterized in that, The three-axis pointing of the deep space probe body after offsetting in step S100003 is calculated according to the following formula: in, Let be the transformation matrix for rotation about the +Xb axis of this system; The transformation matrix is ​​the rotation around the +Yb axis of this system; Let be the transformation matrix for rotation about the +Zb axis of this system; The +Xb axis orientation of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The orientation of the +Yb axis of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; The orientation of the +Zb axis of the deep space probe body after offset in the J2000.0 geocentric inertial coordinate system; These are the attitude offset angles for rotation around the three axes of the system.

7. The on-orbit biasing method for deep space probes according to claim 4, characterized in that, The normalized ground vector, solar vector, and fire vector in step S100004 are calculated in the offset body coordinate system as shown in the following formula: in, This is the normalizer day vector in the offset detector body coordinate system; This is the normalizer ground vector in the offset detector body coordinate system; The normalized fire vector in the offset detector body coordinate system; The normalizer day vector in the J2000.0 geocentric inertial coordinate system; This is the normalizer ground vector in the J2000.0 geocentric inertial coordinate system; The normalizer fire vector is defined in the J2000.0 geocentric inertial coordinate system.

8. The on-orbit biasing method for deep space probes according to claim 4, characterized in that, The included angles in step S100005 include: the angle between the ignition direction of the orbital control engine and the velocity increment direction, the angle between the solar array normal and the solar vector, the angle between the electrical axis of the telemetry and control antenna and the ground vector, the angle between the star sensor optical axis and the solar vector, the angle between the star sensor optical axis and the ground edge, the angle between the star sensor optical axis and the solar flare edge, the angle between the camera optical axis and the Earth's center, and the angle between the ground vector and the horizon.

9. An on-orbit biasing system for a deep space probe, characterized in that, include: The deep space probe consists of a single-unit layout module and an on-orbit flight attitude offset design module. Specifically, the single-unit layout module first uses the attitude towards the Sun during the relatively long Earth-Mars transfer phase of the flight as the initial attitude, and then sequentially designs the layout of the solar array, orbit control engine, telemetry and control antenna, star sensor, and camera. The on-orbit flight attitude offset design module, based on the design of the single-unit layout module and taking into account the real-time orbital parameters and the three-axis orientation of the attitude at each stage of the flight, optimizes the attitude offset angles of the three axes while meeting the constraints of real-time orbit control, energy, communication, and attitude measurement throughout the flight, with the goal of ensuring the Earth appears completely within the camera's field of view.

10. A device for on-orbit biasing of a deep space probe, characterized in that, The method of on-orbit offsetting of deep space probes according to any one of claims 1 to 8 effectively improves the reliability of deep space probes throughout their flight and the display accuracy of imaging missions by optimizing the on-orbit flight attitude offset angle of deep space probes.

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