Satellite platform cooperative control method taking load as center

Abstract

The invention provides a load-centered satellite platform cooperative control method, which comprises the following steps of: performing pointing control on a magnetic suspension joint according to attitude deviation and attitude angular velocity deviation of a load platform relative to a load platform rotating coordinate system under a load platform coordinate system; calculating the measurement data of the eddy current sensor of the magnetic suspension joint to obtain the displacement of the magnetic suspension joint so as to control the relative position of the load platform and the satellite platform; according to the expected control moment and the expected control force of the load platform, the output control moment and the output control force of the magnetic suspension joints at different installation positions are determined; calculating an attitude error of the satellite platform relative to the load platform according to the attitude deviation; and controlling the satellite platform according to the attitude deviation, the attitude angular velocity deviation, the displacement, the output control torque, the output control force and the attitude error. According to the scheme, the control precision and the control stability of the load platform are improved, and the control stability of the satellite platform is further improved.

Description

Technical Field

[0001] The present invention relates to the field of satellite control technology, in particular to the field of satellite attitude control technology, and in particular to a payload-centered satellite platform collaborative control method. Background Art

[0002] The ultra-wide coverage high-resolution optical satellite consists of two platforms: a high-speed rotating large payload platform and a satellite platform, forming a complex connected multi-body system consisting of a star body, a rotating joint subsystem, and a payload. The rotating joint subsystem is connected by a magnetic suspension bearing joint. The magnetic suspension bearing joint is a six-degree-of-freedom joint system, including three position degrees of freedom and three attitude degrees of freedom. In this satellite system, the six-degree-of-freedom control of the payload platform relative to the satellite platform is achieved by utilizing the working principle of magnetic levitation, and it has strong anti-interference ability and high reliability; the non-contact eddy current displacement sensor in the magnetic suspension bearing joint is used to obtain high accuracy and measurement precision. Therefore, as the devices carried by satellites become more and more sophisticated, extremely high requirements are placed on the pointing accuracy and stability of the satellite platform. It is urgent to provide a payload-centric satellite platform collaborative control method. Summary of the invention

[0003] The present invention provides a payload-centered satellite platform collaborative control method, which can improve the control accuracy of the payload platform, and further improve the control stability of the satellite platform by stable control of the payload platform.

[0004] In a first aspect, the present invention provides a payload-centric satellite platform collaborative control method, the method comprising:

[0005] According to the attitude deviation and attitude angular velocity deviation of the load platform in the load platform coordinate system relative to the load platform rotation coordinate system, the magnetic levitation joint is controlled in a pointing manner; wherein the load platform and the satellite platform are connected through the magnetic levitation joint;

[0006] Calculating the measurement data of the eddy current sensor of the magnetic levitation joint to obtain the displacement of the magnetic levitation joint to control the relative position of the load platform and the satellite platform;

[0007] Determining the output control torque and output control force of the magnetic suspension joint at different installation positions according to the expected control torque and expected control force of the load platform;

[0008] Calculating an attitude error of the satellite platform relative to the payload platform according to the attitude deviation;

[0009] The satellite platform is controlled according to the attitude deviation, the attitude angular velocity deviation, the displacement, the output control torque, the output control force and the attitude error.

[0010] In a second aspect, the present invention further provides a payload-centric satellite platform collaborative control device, comprising:

[0011] A first computing module is used to control the pointing of the magnetic levitation joint according to the attitude deviation and attitude angular velocity deviation of the load platform in the load platform coordinate system relative to the load platform rotation coordinate system; wherein the load platform and the satellite platform are connected through the magnetic levitation joint;

[0012] A second computing module is used to solve the eddy current sensor measurement data of the magnetic levitation joint to obtain the displacement of the magnetic levitation joint so as to control the relative position of the load platform and the satellite platform;

[0013] A third computing module is used to determine the output control torque and output control force of the magnetic suspension joint at different installation positions according to the expected control torque and expected control force of the load platform;

[0014] A fourth computing module, configured to calculate an attitude error of the satellite platform relative to the payload platform according to the attitude deviation;

[0015] A control module is used to control the satellite platform according to the attitude deviation, the attitude angular velocity deviation, the displacement, the output control torque, the output control force and the attitude error.

[0016] In a third aspect, the present invention further provides a computing device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements any of the above-mentioned payload-centric satellite platform collaborative control methods.

[0017] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute any of the above-mentioned payload-centric satellite platform collaborative control methods.

[0018] In a fifth aspect, an embodiment of the present invention further provides a computer program product, comprising computer instructions, which, when executed by a processor, implement the steps of the method described in any first aspect of this specification.

[0019] The present invention provides a satellite platform collaborative control method centered on a load, wherein the magnetic levitation joint uses the attitude deviation and attitude angular velocity deviation of the load platform rotation coordinate system under the load platform coordinate system as input to perform pointing control on the magnetic levitation joint; uses the displacement of the magnetic levitation joint calculated by eddy current sensor measurement data as input to control the relative position of the load platform and the satellite platform; then determines the distribution of the output control torque and output control force of the magnetic levitation joint bearing by the expected control torque and expected control force of the load platform, and determines the attitude error of the satellite platform based on attitude deviation decoupling, thereby performing absolute control on the load platform based on attitude deviation, attitude angular velocity deviation, output control torque, and output control force, and the satellite platform moves with the load platform, and then performs collaborative control on the satellite platform based on the displacement and attitude error on the basis of the satellite platform star sensor. In this way, the present invention controls the load platform by controlling the magnetic levitation joint, and when the satellite platform moves with the load platform, the displacement and attitude error are used to perform attitude correction on the satellite platform, thereby realizing collaborative control of the satellite platform centered on the load, improving the load pointing accuracy, and realizing high-precision and high-stability control of the satellite load platform camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a flow chart of a payload-centric satellite platform collaborative control method provided by one embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of the relationship between a load platform coordinate system and a load platform rotation coordinate system provided by an embodiment of the present invention;

[0023] Figure 3 It is a schematic diagram of the working principle of radial eddy current measurement provided by one embodiment of the present invention;

[0024] Figure 4 It is a schematic diagram of the working principle of axial eddy current measurement provided by one embodiment of the present invention;

[0025] Figure 5 is a schematic diagram of decoupling and calculating displacement in a radial measurement section provided by an embodiment of the present invention;

[0026] Figure 6 It is a schematic diagram of the control force output principle of a magnetic levitation joint provided by an embodiment of the present invention;

[0027] Figure 7 is a hardware architecture diagram of a computing device provided by an embodiment of the present invention;

[0028] Figure 8 It is a structural diagram of a payload-centric satellite platform collaborative control device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] Please refer to Figure 1 The embodiment of the present invention provides a payload-centric satellite platform collaborative control method, including:

[0031] Step 100, according to the attitude deviation and attitude angular velocity deviation of the payload platform in the payload platform coordinate system relative to the payload platform rotation coordinate system, to control the pointing of the magnetic levitation joint; wherein the payload platform and the satellite platform are connected by the magnetic levitation joint;

[0032] Step 102, calculating the measurement data of the eddy current sensor of the magnetic levitation joint to obtain the displacement of the magnetic levitation joint to control the relative position of the load platform and the satellite platform;

[0033] Step 104, determining the output control torque and output control force of the magnetic suspension joints at different installation positions according to the expected control torque and expected control force of the load platform;

[0034] Step 106, calculating the attitude error of the satellite platform relative to the payload platform according to the attitude deviation;

[0035] Step 108, controlling the satellite platform according to the attitude deviation, attitude angular velocity deviation, displacement, output control torque, output control force and attitude error.

[0036] In the present invention, firstly, the magnetic levitation joint takes the attitude deviation and attitude angular velocity deviation of the relative load platform rotation coordinate system under the load platform coordinate system as input, and performs pointing control on the magnetic levitation joint; takes the displacement of the magnetic levitation joint calculated by the eddy current sensor measurement data as input, and controls the relative position of the load platform and the satellite platform; then determines the distribution of the output control torque and output control force of the magnetic levitation joint bearing by the expected control torque and expected control force of the load platform, and determines the attitude error of the satellite platform based on the attitude deviation decoupling, thereby performing absolute control on the load platform based on the attitude deviation, attitude angular velocity deviation, output control torque, and output control force, and the satellite platform moves with the load platform, and then performs collaborative control on the satellite platform based on the displacement and attitude error on the basis of the satellite platform star sensor. In this way, the present invention controls the load platform by controlling the magnetic levitation joint, and when the satellite platform moves with the load platform, the displacement and attitude error are used to perform attitude correction on the satellite platform, thereby realizing collaborative control of the satellite platform centered on the load, improving the load pointing accuracy, and realizing high-precision and high-stability control of the satellite load platform camera.

[0037] Described below Figure 1 How the various steps are performed.

[0038] Specifically, the coordinate systems used in the present invention include: a satellite platform coordinate system, a payload platform coordinate system, a payload platform orbit coordinate system and a payload platform rotation coordinate system:

[0039] In the satellite platform coordinate system, the origin OL is the center of mass of the satellite platform, the Ox axis is along the longitudinal axis of the satellite body, pointing to the payload platform as the positive direction, the positive direction of the z axis points to the I quadrant of the satellite platform (pointing to the center of the earth when there is no attitude deviation), perpendicular to the longitudinal axis, and the y axis, x axis and z axis form a right-handed system;

[0040] In the payload platform coordinate system, the origin OU is the mass center of the payload platform, the uox axis is along the longitudinal axis of the satellite body, pointing to the front end of the payload platform as the positive direction, the positive direction of the uoz axis points to the I quadrant of the payload platform (pointing to the center of the earth when there is no attitude deviation), perpendicular to the longitudinal axis, and the uoy axis, uox and uoz axes form a right-handed system;

[0041] In the payload platform orbit coordinate system, the origin Oi is the center of mass of the payload platform, the xi axis points to the direction of satellite movement, the zi axis points to the center of the earth, and the yi axis, xi, and zi form a right-handed system;

[0042] In the load platform rotating coordinate system, the origin OU is the center of mass of the load platform, which coincides with the load platform orbital coordinate system before the load platform rotates. The rotating coordinate system is the rotating coordinate system after the orbital coordinate system rotates around the rotation axis by an angle;

[0043] In the geocentric inertial coordinate system, with the origin O Eis the center of mass of the Earth, O E X E The axis points to the 2000.0 mean vernal equinox, O E Z E The axis is perpendicular to the 2000.0 flat equatorial plane and is consistent with the direction of the Earth's rotation angular velocity. E Y E Axis and O E X E , O E Z E The axes form a right-hand system.

[0044] First, for step 100, the pointing control of the magnetic suspension joint is performed according to the attitude deviation and attitude angular velocity deviation of the load platform in the load platform coordinate system relative to the load platform rotation coordinate system, including:

[0045] Get the attitude matrix C of the load platform coordinate system relative to the load platform rotation coordinate system pr , the platform angular velocity ω of the load platform XG , the nominal angular velocity ω of the load platform in the load platform rotation coordinate system T and the transformation matrix C of the load platform coordinate system relative to the orbital system bo ;

[0046] The attitude deviation of the non-rotational axis is calculated based on the attitude matrix;

[0047] According to the platform angular velocity, the orbital angular velocity ω is obtained by using the orbital extrapolation algorithm. oi ;

[0048] According to the platform angular velocity, conversion matrix, orbital angular velocity and nominal angular velocity, the attitude angular velocity deviation ω is calculated. r .

[0049] In a preferred embodiment, the posture deviation is determined by the following formula:

[0050] A_Z=arctan(C pr21 / C pr11 )

[0051] A_Y=-arctan(C pr31 / C pr11 )

[0052]

[0053] Where A_Z is the posture deviation of the Z axis; A_Y is the posture deviation of the Y axis; both the Z axis and the Y axis are non-rotational axes; C pr is the attitude matrix.

[0054] Specifically, for attitude deviation, the payload platform is equipped with gyro measurement sensors and star sensors. The inertial attitude C of the payload platform can be obtained by gyro data extrapolation and star sensor data correction. pi , using orbit extrapolation algorithm to determine the precise orbit information of satellite C oi Assuming that the load platform rotates with the X axis as the axis, the angular velocity of the load platform rotation coordinate system relative to the rotation axis of the load platform orbital coordinate system is ω x , the rotation angle around the rotation axis is θ, and the transformation matrix C of the load platform rotation coordinate system relative to the load platform orbital coordinate system is RX The description is as follows:

[0055]

[0056] The transformation matrix C of the load platform rotating coordinate system relative to the geocentric inertial coordinate system ri Description: C ri =C RX ·C oi ;

[0057] The attitude matrix C of the payload platform coordinate system relative to the Earth-centered inertial system is obtained by filtering the star sensor and gyro measurement sensor of the payload platform. pi After that, the attitude matrix C of the load platform coordinate system relative to the load platform rotation coordinate system is further converted. pr The description is as follows:

[0058]

[0059] like Figure 2 As shown in the figure, lox is the x-axis direction of the load platform rotation coordinate system, uox, uoy, uoz are the x, y, z axes of the load platform coordinate system, and the description of lox in the uo_xyz coordinate system is:

[0060]

[0061] The description of the attitude deviation of the load platform coordinate system relative to the non-rotating axis (Y, Z axis) of the load platform rotation coordinate system is calculated as follows:

[0062]

[0063] In a preferred embodiment, the attitude angular velocity deviation is determined by the following formula:

[0064] ω r =ω XG -C bo ω oi -ω T

[0065] Among them, ωr is the attitude angular velocity deviation; ω XG is the platform angular velocity; C bo is the transformation matrix; ω oi is the orbital angular velocity; ω T is the nominal angular velocity.

[0066] Specifically, the platform angular velocity information measured by the gyro sensor configured on the load platform is ω XG , the orbital angular velocity obtained by orbital extrapolation algorithm is ω oi The nominal angular velocity of the load platform in the rotating coordinate system is ω T ,ω T =[ω x ,0,0] T .

[0067] In the present invention, the magnetic levitation joint adopts an absolute pointing control method, and uses the Y-axis and Z-axis posture deviations of the load platform coordinate system relative to the load platform rotation coordinate system as input as pointing control instructions to perform pointing control of the rotating shaft.

[0068] In step 102, the magnetic levitation joint has three translational degrees of freedom, and each translational degree of freedom is equipped with four eddy current displacement sensors;

[0069] The eddy current sensor measurement data of the magnetic levitation joint is solved to obtain the displacement of the magnetic levitation joint, including:

[0070] For each translational degree of freedom of the load platform, perform:

[0071] Obtaining eddy current sensor measurement data collected by each eddy current displacement sensor of the translational degree of freedom;

[0072] The eddy current measurement vector is calculated based on the installation parameters of the eddy current displacement sensor and the relative motion relationship between the satellite platform and the load platform;

[0073] The projection of the eddy current measurement vector within the measurement section of the translational degree of freedom is taken as the relative distance;

[0074] Determine, according to the installation parameters, a first displacement of each eddy current displacement sensor from a bearing geometric center of the magnetic suspension joint in a positive direction;

[0075] The displacement of the magnetic suspension joint at the translational degree of freedom is calculated according to the relative distance between each eddy current displacement sensor and the first displacement.

[0076] In the present invention, the measured end of the eddy current displacement sensor is installed on the stator shaft of the satellite platform; the measuring end of the eddy current displacement sensor is installed on the rotor shaft of the load platform; the magnetic suspension joint includes a stator shaft and a rotor shaft;

[0077] The installation parameters include the first position vector r from the center of mass of the satellite platform to the measured end in the satellite platform coordinate system L_P , the second position vector r from the center of mass of the load platform to the measuring end in the load platform coordinate system U_Q +r I , the third position vector r from the center of mass of the satellite platform to the center of mass of the payload platform in the payload platform orbital coordinate system L_U , eddy current stator direction r in satellite platform coordinate system L_X , eddy current measurement rotor direction r in the load platform coordinate system U_X ;

[0078] The relative motion relationship includes: the transformation matrix C of the satellite platform coordinate system relative to the orbital system LO , the transformation matrix C of the load platform coordinate system relative to the track system UO .

[0079] It should be noted that the working principle of the eddy current displacement sensor is to drive the magnetic field around the eddy current coil to change through a pulse current of a certain waveform, and generate eddy current at the induction point of the metal parts of the central bearing. The eddy current measurement vector includes the radial eddy current measurement vector and the axial eddy current measurement vector. Figure 3 In the schematic diagram of radial eddy current measurement working principle shown in FIG. 1 , the installation position of the eddy current displacement sensor is r U_X The direction of the rotor shaft parallel to the load platform, and the measurement direction is the load platform rotor shaft axis r U_X The vertical direction of the eddy current stator is related to the vector r L_X The direction is consistent. The vector direction is fixed in the satellite platform coordinate system. The direction is consistent and the vector size is ar L_X ; where a is the coefficient. The direction of the eddy current measurement rotor is related to r U_X The direction is consistent and is the fixed direction of this system.

[0080] Specifically, Figure 3 As shown, the radial eddy current measurement vector r is uniformly expressed in the vector description relationship of the load platform orbital coordinate system as follows:

[0081]

[0082] Because in Figure 3 In the same coordinate system, the radial eddy current measurement vector r and the eddy current installation direction r at a fixed position in the load platform coordinate system are U_X are mutually perpendicular vectors, so Considering the attitude motion of the satellite platform and the payload platform and the relative motion relationship between the platforms, the following expression for the coefficient a can be obtained:

[0083]

[0084] Substitute a into the above radial eddy current measurement vector r to obtain the radial eddy current measurement vector r in the load platform coordinate system. b :

[0085]

[0086] In the present invention, the relative attitude and relative position of the large inertia load platform need to be considered to ensure high measurement accuracy and high control accuracy of the satellite. It should be noted that the large inertia load is preferably such that the mass of the load platform itself is equivalent to the mass of the satellite platform.

[0087] In a preferred embodiment, Figure 4 In the schematic diagram of the axial eddy current measurement working principle shown in FIG, the installation position of the eddy current displacement sensor is perpendicular to the rotor axis of the load platform, and the measurement direction is parallel to the rotor axis of the load platform. Considering that the axial eddy current installation surface is perpendicular to the rotor axis, the measurement direction is consistent with the rotor axis. Since the eddy current is installed on the load platform coordinate system, the installation position vector in this system is expressed as r U_Q +r I From the eddy current measurement, it can be seen that the axial eddy current measurement vector r in the orbital system can be obtained by vector calculation. z :

[0088]

[0089] Because in Figure 4 In the axial eddy current measurement vector r z The central bearing metal part connected to the satellite platform L_X are mutually perpendicular vectors, so Considering the attitude motion of the satellite platform and the payload platform and the relative motion relationship between the platforms, the following expression for the coefficient b can be obtained:

[0090]

[0091] Substitute b into the above axial eddy current measurement vector r z The axial eddy current measurement vector r in the load platform coordinate system is obtained s :

[0092]

[0093] In a preferred embodiment, on the measurement section of each translational degree of freedom, the eddy current displacement sensors are distributed on the upper eddy current surface and the lower eddy current surface, and two eddy current displacement sensors are centrally symmetrically installed on the upper eddy current surface and the lower eddy current surface;

[0094] When the translational degree of freedom is in the direction of the non-rotational axis, the displacement of the magnetic levitation joint is determined by the following formula:

[0095]

[0096] Among them, y r is the displacement of the magnetic suspension joint in the direction of the non-rotation axis; d 1 d 2 are the relative distances between the first eddy current displacement sensor and the second eddy current displacement sensor on the upper eddy current surface within the measurement section; d 3 d 4 are the relative distances between the third eddy current displacement sensor and the fourth eddy current displacement sensor of the lower eddy current surface within the measurement section; L 1 L is the first displacement of the eddy current displacement sensor located on the upper eddy current surface from the bearing geometric center of the magnetic suspension joint in the positive direction; 2 is the first displacement of the eddy current displacement sensor located on the lower eddy current surface from the bearing geometric center of the magnetic suspension joint in the positive direction; L is the displacement of the upper eddy current surface and the lower eddy current surface in the positive direction, L = L 1 -L 2 .

[0097] It should be noted that d 1 d 2 d 3 d 4 When determining the first displacement, it is in the nominal locking state, and the central bearing metal component fixedly connected to the satellite platform is located at the center position of the eddy current measurement.

[0098] Specifically, since the three translational degrees of freedom correspond to translational motions along the X, Y, and Z axes, respectively, as described in the previous example, the X axis is the rotation axis, and the Y and Z axes are non-rotation axes. For the non-rotation axis, it is necessary to perform decoupling calculations on the radial eddy current measurement vectors measured by the four eddy current displacement sensors of the Y and Z axes respectively; similarly, for the rotation axis, it is necessary to perform decoupling calculations on the axial eddy current measurement vectors measured by the four eddy current displacement sensors of the X axis. Figure 5 The eddy current sensor measurement data within the radial measurement section shown in the figure, four eddy currents are installed as two upper and lower eddy current surfaces in the load platform coordinate system, and two eddy current displacement sensors are symmetrically installed at the center of each eddy current surface. The central bearing metal component that is fixed to the satellite platform in the nominal locked state is located at the center position of the eddy current measurement. After the lock is released, the load platform and the satellite platform produce relative position and posture changes. Among them, the first eddy current displacement sensor D1 and the second eddy current displacement sensor D2 on the upper eddy current surface, the third eddy current displacement sensor D3 and the fourth eddy current displacement sensor D4 on the lower eddy current surface. Ignoring small-order terms, the relative distance information measured by the four eddy current displacement sensors can decouple the calculation of the displacement of the magnetic levitation joint in the direction of the non-rotating axis. As shown Figure 5As shown, the displacement of the eddy current displacement sensor located on the lower eddy current surface from the geometric center of the rotating axis of the magnetic levitation joint in the positive direction is -L 2 ; L = L 1 -(-L 2 ).

[0099] As described in the previous example, for the rotating axis X-axis, the eddy current sensor measurement data in the axial measurement section where the rotating axis is located is used for calculation to obtain the displacement y of the bearing geometric center of the X-axis suspension joint x , the displacement for the Y axis is y y , the displacement for the Z axis is y z The present invention utilizes the displacement of the geometric center of the bearing of the magnetic suspension joint rs = [y x ,y y ,y z ] as input to complete the design of the relative position controller between the payload platform and the satellite platform.

[0100] For step 104, according to the expected control torque and expected control force of the load platform, the output control torque and output control force of the magnetic suspension joints at different installation positions are determined, including:

[0101] Obtaining a desired control torque according to preset attitude information and preset attitude angular velocity of the payload platform;

[0102] According to the displacement of the magnetic levitation joint, the desired control force is obtained;

[0103] Acquire installation information of magnetic levitation joints at different positions, and determine the moment arms of magnetic levitation joints at different positions from the satellite platform according to the installation information;

[0104] Using the control output principle of the magnetic levitation joint, based on the expected control torque, expected control force and lever arm, the output control torque and output control force of the magnetic levitation joint at different installation positions are calculated.

[0105] Specifically, the preset attitude angular velocity ω of the payload platform is obtained according to the camera target pointing x , according to the star sensor and gyro measurement sensor of the payload platform, the preset attitude information is determined, and the payload platform feedforward feedback joint controller is designed using the preset attitude angular velocity and preset attitude information to obtain the expected control torque Design a feedforward-feedback joint controller based on the displacement of the magnetic levitation joint obtained in step 102, and calculate the desired control force In such Figure 6In the schematic diagram of the magnetic levitation joint control force output principle shown, the eddy current and magnetic bearing joints overlap at this time. The upper frame is used to represent the load platform, and the lower frame is used to represent the satellite platform. The position control and torque control output are achieved through the output force distribution of the magnetic levitation joints at different installation positions. Take the control distribution in the Y-axis direction as an example:

[0106]

[0107] in, They are the output control forces of the magnetic suspension joints at installation positions 1 and 2 on the Y axis respectively; for Desired control torque in the Z axis; is the desired control force on the Y axis; l 1y , l 2y Corresponding to The lever arm.

[0108] In step 106, the attitude error is determined by the following formula:

[0109] ψ bm =arcsin(l bx_b2 )

[0110]

[0111] l bx2 / l bx1 =tan(A_Z)

[0112] l bx3 / l bx1 = -tan(A_Y)

[0113] l bx1 2 +l bx2 2 +l bx3 2 =1

[0114] Among them, ψ bm ,θ bm are the yaw direction error and pitch direction error in the attitude error respectively; A_Z is the attitude deviation of the Z axis; A_Y is the attitude deviation of the Y axis; C RX is the transformation matrix of the load platform's rotating coordinate system relative to the orbital system; where the Z axis and the Y axis are both non-rotating axes; and l is an intermediate term.

[0115] In the embodiment of the present invention, as described in the previous example, the X axis is used as the rotation axis, and the Y and Z axes are used as the non-rotation axes. The attitude deviations A_Z and A_Y obtained in step 100 are used to solve the yaw direction error ψ of the satellite platform. bm and the pitch error θbm , specifically:

[0116] make And The normalized l is calculated from this bx ;

[0117] Will l bx Convert to the satellite platform coordinate system to get l bx_b : Consider the output sequence as: Therefore, the attitude error of the satellite platform relative to the payload platform is obtained

[0118] In the present invention, the payload platform adopts a star sensor for absolute control, and the attitude of the satellite platform relative to the payload platform is used as the input of the controller free of charge, so as to complete the attitude correction of the satellite platform centered on the payload platform.

[0119] To ensure the imaging mission requirements of the payload platform and improve the payload pointing accuracy. In the present invention, a satellite platform collaborative control strategy centered on the payload platform is proposed for a complex connected multi-body system with a large inertia and high dynamic payload platform to meet the control accuracy and stability mission requirements of optical satellites. In this strategy, the payload platform adopts absolute pointing control, and the Y and Z axis attitude deviations of the payload platform body coordinate system relative to the nominal rotating coordinate system are used to control the shaft pointing, and the attitude angular velocity deviation of the shaft rotation is used to control the speed. The relative motion between the satellite platform and the payload platform is measured by an eddy current displacement sensor, and the relative displacement of the bearing geometric center of the magnetic levitation joint is calculated using the eddy current sensor measurement data. The relative position control is controlled by the magnetic levitation joint, and the relative pointing is controlled by the satellite platform. The satellite platform integrates the Y and Z axis attitude errors of the satellite platform relative to the payload platform obtained by the eddy current displacement sensor and the attitude deviation information of the X axis relative to the orbit system obtained by the satellite platform star sensor and gyroscope joint filtering, and completes the Y and Z axis relative attitude collaborative control and the absolute attitude stability control of the X axis through a large moment momentum wheel.

[0120] It should be noted that the superscript T in the above formulas is used to indicate the transpose of the matrix.

[0121] like Figure 7 , Figure 8 As shown, the embodiment of the present invention provides a satellite platform collaborative control device centered on payload. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 7 As shown, it is a hardware architecture diagram of a computing device where a payload-centric satellite platform collaborative control device is located according to an embodiment of the present invention. Figure 7In addition to the processor, memory, network interface, and non-volatile memory shown in the figure, the computing device in which the device is located in the embodiment may also generally include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 8 As shown, as a device in a logical sense, the CPU of the computing device in which it is located reads the corresponding computer program in the non-volatile memory into the memory and runs it. This embodiment provides a satellite platform collaborative control device centered on a payload, including:

[0122] The first computing module 800 is used to control the pointing of the magnetic levitation joint according to the attitude deviation and attitude angular velocity deviation of the payload platform in the payload platform coordinate system relative to the payload platform rotation coordinate system; wherein the payload platform and the satellite platform are connected through the magnetic levitation joint;

[0123] The second operation module 802 is used to solve the eddy current sensor measurement data of the magnetic levitation joint to obtain the displacement of the magnetic levitation joint to control the relative position of the load platform and the satellite platform;

[0124] The third operation module 804 is used to determine the output control torque and output control force of the magnetic suspension joints at different installation positions according to the expected control torque and expected control force of the load platform;

[0125] A fourth calculation module 806 is used to calculate the attitude error of the satellite platform relative to the payload platform according to the attitude deviation;

[0126] The control module 808 is used to control the satellite platform according to the attitude deviation, attitude angular velocity deviation, displacement, output control torque, output control force and attitude error.

[0127] In some specific embodiments, the first operation module 800 can be used to execute the above step 100, the second operation module 802 can be used to execute the above step 102, the third operation module 804 can be used to execute the above step 104, the fourth operation module 806 can be used to execute the above step 106, and the control module 808 can be used to execute the above step 108.

[0128] In some specific implementations, the first operation module 800 is further configured to perform the following operations:

[0129] Obtain the attitude matrix of the load platform coordinate system relative to the load platform rotation coordinate system, the platform angular velocity of the load platform, the nominal angular velocity of the load platform in the load platform rotation coordinate system, and the transformation matrix of the load platform coordinate system relative to the orbital system;

[0130] The attitude deviation of the non-rotating axis is calculated based on the attitude matrix; the attitude deviation is determined by the following formula:

[0131] A_Z=arctan(C pr21 / C pr11 )

[0132] A_Y=-arctan(C pr31 / C pr11 )

[0133]

[0134] Where A_Z is the posture deviation of the Z axis; A_Y is the posture deviation of the Y axis; both the Z axis and the Y axis are non-rotational axes; C pr is the posture matrix;

[0135] According to the platform angular velocity, the orbital angular velocity is obtained by using the orbital extrapolation algorithm;

[0136] According to the platform angular velocity, conversion matrix, orbital angular velocity and nominal angular velocity, the attitude angular velocity deviation is calculated; the attitude angular velocity deviation is determined by the following formula:

[0137] ω r =ω XG -C bo ω oi -ω T

[0138] Among them, ω r is the attitude angular velocity deviation; ω XG is the platform angular velocity; C bo is the transformation matrix; ω oi is the orbital angular velocity; ω T is the nominal angular velocity.

[0139] In some specific embodiments, the magnetic levitation joint has three translational degrees of freedom, and each translational degree of freedom is equipped with four eddy current displacement sensors;

[0140] The second operation module 802 is further configured to perform the following operations:

[0141] For each translational degree of freedom of the load platform, perform:

[0142] Acquire eddy current sensor measurement data collected by each eddy current displacement sensor of the translational degree of freedom; on the measurement section of each translational degree of freedom, the eddy current displacement sensors are distributed on the upper eddy current surface and the lower eddy current surface, and two eddy current displacement sensors are centrally symmetrically installed on the upper eddy current surface and the lower eddy current surface;

[0143] The eddy current measurement vector is calculated based on the installation parameters of the eddy current displacement sensor and the relative motion relationship between the satellite platform and the load platform;

[0144] The projection of the eddy current measurement vector within the measurement section of the translational degree of freedom is taken as the relative distance;

[0145] Determine, according to the installation parameters, a first displacement of each eddy current displacement sensor from a bearing geometric center of the magnetic suspension joint in a positive direction;

[0146] The displacement of the magnetic suspension joint in the translational degree of freedom is calculated according to the relative distance of each eddy current displacement sensor and the first displacement;

[0147] When the translational degree of freedom is in the direction of the non-rotational axis, the displacement of the magnetic levitation joint is determined by the following formula:

[0148]

[0149] Among them, y r is the displacement of the magnetic suspension joint in the direction of the non-rotation axis; d 1 d 2 are the relative distances between the first eddy current displacement sensor and the second eddy current displacement sensor on the upper eddy current surface within the measurement section; d 3 d 4 are the relative distances between the third eddy current displacement sensor and the fourth eddy current displacement sensor of the lower eddy current surface within the measurement section; L 1 L is the first displacement of the eddy current displacement sensor located on the upper eddy current surface from the bearing geometric center of the magnetic suspension joint in the positive direction; 2 is the first displacement of the eddy current displacement sensor located on the lower eddy current surface from the bearing geometric center of the magnetic suspension joint in the positive direction; L is the displacement of the upper eddy current surface and the lower eddy current surface in the positive direction, L = L 1 -L 2 .

[0150] In some specific implementations, the third operation module 804 is further configured to perform the following operations:

[0151] Obtaining a desired control torque according to preset attitude information and preset attitude angular velocity of the payload platform;

[0152] According to the displacement of the magnetic levitation joint, the desired control force is obtained;

[0153] Acquire installation information of magnetic levitation joints at different positions, and determine the moment arms of magnetic levitation joints at different positions from the satellite platform according to the installation information;

[0154] Using the control output principle of the magnetic levitation joint, based on the expected control torque, expected control force and lever arm, the output control torque and output control force of the magnetic levitation joint at different installation positions are calculated.

[0155] In some specific implementations, the posture error is determined by the following formula:

[0156] ψ bm =arcsin(l bx_b2 )

[0157]

[0158] l bx2 / l bx1 =tan(A_Z)

[0159] l bx3 / l bx1 = -tan(A_Y)

[0160] l bx1 2 +l bx2 2 +l bx3 2 =1

[0161] Among them, ψ bm ,θ bm are the yaw direction error and pitch direction error in the attitude error respectively; A_Z is the attitude deviation of the Z axis; A_Y is the attitude deviation of the Y axis; C RX is the transformation matrix of the load platform's rotating coordinate system relative to the orbital system; where the Z axis and the Y axis are both non-rotating axes; and l is an intermediate term.

[0162] It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on a payload-centric satellite platform collaborative control device. In other embodiments of the present invention, a payload-centric satellite platform collaborative control device may include more or fewer components than shown in the figure, or combine certain components, or split certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0163] The information interaction, execution process and other contents between the modules in the above-mentioned device are based on the same concept as the embodiment of the method of the present invention. For the specific contents, please refer to the description in the embodiment of the method of the present invention, and no further description is given here.

[0164] An embodiment of the present invention further provides a computing device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, a payload-centric satellite platform collaborative control method in any embodiment of the present invention is implemented.

[0165] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes a payload-centric satellite platform collaborative control method in any embodiment of the present invention.

[0166] An embodiment of the present application also provides a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium, and the processor executes the computer program, so that the computer device executes a payload-centric satellite platform collaborative control method described in any of the above embodiments.

[0167] Specifically, a system or device equipped with a storage medium can be provided, on which software program code that implements the functions of any of the above-mentioned embodiments is stored, and a computer (or CPU or MPU) of the system or device can be enabled to read and execute the program code stored in the storage medium.

[0168] In this case, the program code itself read from the storage medium can realize the function of any one of the above-mentioned embodiments, and thus the program code and the storage medium storing the program code constitute a part of the present invention.

[0169] The storage medium embodiments for providing the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a non-volatile memory card, and a ROM. Alternatively, the program code can be downloaded from a server computer by a communication network.

[0170] In addition, it should be clear that the functions of any of the above embodiments can be implemented not only by executing the program code read by the computer, but also by enabling an operating system operating on the computer to complete part or all of the actual operations based on instructions from the program code.

[0171] In addition, it can be understood that the program code read from the storage medium is written to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion module connected to the computer, and then based on the instructions of the program code, a CPU installed on the expansion board or expansion module is enabled to perform part or all of the actual operations, thereby realizing the functions of any of the above-mentioned embodiments.

[0172] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical factors in the process, method, article or device including the elements.

[0173] A person of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc., various media that can store program codes.

[0174] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A payload-centric satellite platform collaborative control method, characterized in that: include: According to the attitude deviation and attitude angular velocity deviation of the load platform in the load platform coordinate system relative to the load platform rotation coordinate system, the magnetic levitation joint is controlled in a pointing manner; wherein the load platform and the satellite platform are connected through the magnetic levitation joint; Calculating the measurement data of the eddy current sensor of the magnetic levitation joint to obtain the displacement of the magnetic levitation joint to control the relative position of the load platform and the satellite platform; Determining the output control torque and output control force of the magnetic suspension joint at different installation positions according to the expected control torque and expected control force of the load platform; Calculating an attitude error of the satellite platform relative to the payload platform according to the attitude deviation; The satellite platform is controlled according to the attitude deviation, the attitude angular velocity deviation, the displacement, the output control torque, the output control force and the attitude error.

2. The method according to claim 1, characterized in that The method of controlling the pointing direction of the magnetic suspension joint according to the attitude deviation and attitude angular velocity deviation of the load platform in the load platform coordinate system relative to the load platform rotation coordinate system includes: Obtaining the attitude matrix of the load platform coordinate system relative to the load platform rotation coordinate system, the platform angular velocity of the load platform, the nominal angular velocity of the load platform in the load platform rotation coordinate system, and the transformation matrix of the load platform coordinate system relative to the orbital system; Calculate the attitude deviation of the non-rotational axis according to the attitude matrix; According to the platform angular velocity, the orbital angular velocity is obtained by using an orbital extrapolation algorithm; The attitude angular velocity deviation is calculated according to the platform angular velocity, the conversion matrix, the orbital angular velocity and the nominal angular velocity.

3. The method according to claim 2, characterized in that The posture deviation is determined by the following formula: A_Z=arctan(C pr21 / C pr11 ) A_Y=-arctan(C pr31 / C pr11 ) Where A_Z is the posture deviation of the Z axis; A_Y is the posture deviation of the Y axis; both the Z axis and the Y axis are non-rotational axes; C pr is the posture matrix; and / or, The attitude angular velocity deviation is determined by the following formula: oh r =ω XG -C bo oh oi -oh T Among them, ω r is the attitude angular velocity deviation; ω XG is the platform angular velocity; C bo is the transformation matrix; ω oi is the orbital angular velocity; ω T is the nominal angular velocity.

4. The method according to claim 1, characterized in that: The magnetic levitation joint has three translational degrees of freedom, and each translational degree of freedom is equipped with four eddy current displacement sensors; The step of calculating the eddy current sensor measurement data of the magnetic levitation joint to obtain the displacement of the magnetic levitation joint includes: For each translational degree of freedom of the load platform, perform: Acquire the eddy current sensor measurement data collected by each eddy current displacement sensor of the translational degree of freedom; Calculating an eddy current measurement vector according to installation parameters of the eddy current displacement sensor and a relative motion relationship between the satellite platform and the load platform; Taking the projection of the eddy current measurement vector within the measurement section of the translational degree of freedom as the relative distance; Determine, according to the installation parameters, a first displacement of each of the eddy current displacement sensors from a bearing geometric center of the magnetic levitation joint in a positive direction; The displacement of the magnetic suspension joint in the translational degree of freedom is calculated according to the relative distance of each of the eddy current displacement sensors and the first displacement.

5. The method according to claim 4, characterized in that On the measurement section of each translational degree of freedom, the eddy current displacement sensors are distributed on the upper eddy current surface and the lower eddy current surface, and two eddy current displacement sensors are centrally symmetrically installed on the upper eddy current surface and the lower eddy current surface; When the translational degree of freedom is in the direction of the non-rotational axis, the displacement of the magnetic levitation joint is determined by the following formula: Among them, y r is the displacement of the magnetic levitation joint in the direction of the non-rotating axis; d1 and d2 are the relative distances between the first eddy current displacement sensor and the second eddy current displacement sensor of the upper eddy current surface in the measuring section; d3 and d4 are the relative distances between the third eddy current displacement sensor and the fourth eddy current displacement sensor of the lower eddy current surface in the measuring section; L1 is the first displacement of the eddy current displacement sensor located on the upper eddy current surface from the bearing geometric center of the magnetic levitation joint in the positive direction; L2 is the first displacement of the eddy current displacement sensor located on the lower eddy current surface from the bearing geometric center of the magnetic levitation joint in the positive direction; L is the displacement of the upper eddy current surface and the lower eddy current surface in the positive direction, L=L1-L2.

6. The method according to claim 1, characterized in that The step of determining the output control torque and output control force of the magnetic suspension joint at different installation positions according to the expected control torque and expected control force of the load platform includes: Obtaining the desired control torque according to the preset attitude information and preset attitude angular velocity of the load platform; Obtaining the desired control force according to the displacement of the magnetic levitation joint; Acquire installation information of the magnetic levitation joints at different positions, and determine the moment arms of the magnetic levitation joints at different positions from the satellite platform according to the installation information; The output control torque and output control force of the magnetic suspension joint at different installation positions are calculated based on the expected control torque, the expected control force and the lever arm by utilizing the output control principle of the magnetic suspension joint.

7. The method according to any one of claims 1 to 6, characterized in that: The attitude error is determined by the following formula: ψ bm =arcsin(l bx_b2 ) l bx2 / l bx1 =tan(A_Z) l bx3 / l bx1 =-tan(A_Y) l bx1 2 +l bx2 2 +l bx3 2 ＝1 Among them, ψ bm ,θ bm are the yaw direction error and pitch direction error in the attitude error respectively; A_Z is the attitude deviation of the Z axis; A_Y is the attitude deviation of the Y axis; C RX is the transformation matrix of the load platform rotation coordinate system relative to the orbital system; wherein the Z axis and the Y axis are both non-rotational axes; and l are all intermediate items.

8. A payload-centered satellite platform collaborative control device, characterized in that: include: A first computing module is used to control the pointing of the magnetic levitation joint according to the attitude deviation and attitude angular velocity deviation of the load platform in the load platform coordinate system relative to the load platform rotation coordinate system; wherein the load platform and the satellite platform are connected through the magnetic levitation joint; A second computing module is used to solve the eddy current sensor measurement data of the magnetic levitation joint to obtain the displacement of the magnetic levitation joint so as to control the relative position of the load platform and the satellite platform; A third computing module is used to determine the output control torque and output control force of the magnetic suspension joint at different installation positions according to the expected control torque and expected control force of the load platform; A fourth computing module, used for calculating the attitude error of the satellite platform relative to the payload platform according to the attitude deviation; A control module is used to control the satellite platform according to the attitude deviation, the attitude angular velocity deviation, the displacement, the output control torque, the output control force and the attitude error.

9. A computing device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 7.

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