A method and device for controlling the rotation of a circular scanning imaging satellite and a medium

Abstract

The embodiment of the application discloses a kind of ring sweep imaging satellite's rotation control method, device and medium;The method can include: according to the kinematics equation constructed by (w,z) parameter and the dynamics equation constructed by rigid model, the reference value w of parameter w for describing spin axis pointing is obtained by time integration r ;Rotation stage: without introducing the parameter z for describing the rotation angle around spin axis, the parameter w obtained by the first reference value w r Parameter error w e And angular velocity error ω e First control law is designed for rotation control, and is switched to spin angle control stage after rotation stabilizes;Spin angle control stage: the value of parameter z at switching time is used as the initial value of the reference value z r Of parameter z, and according to the kinematics equation constructed by (w,z) parameter and the dynamics equation constructed by rigid model, subsequent reference value z r Is obtained by time integration;According to the reference value z r Of the parameter z, the error z e Of parameter z is introduced, and the second control law for spin angle control is designed according to the error z e Of the parameter z and the first control law.

Description

Technical Field

[0001] This invention relates to the field of spacecraft control technology, and in particular to a method, device and medium for controlling the spin-up of a ring-scan imaging satellite. Background Technology

[0002] Conical Scanning Imaging Satellites (CSIs) are equipped with a tilted optical camera. As the satellite rotates around its nadir axis, the camera's spiral coverage area extends over a wide region, providing a broader image than traditional imaging methods such as pushbroom or multi-band stitched satellites. Unlike traditional spin-stabilized satellites, CSIs often employ a zero-momentum control method for attitude control. Therefore, before performing a CSI mission, a reaction wheel-like angular momentum exchange device is needed to initiate spin-up.

[0003] Conventional satellite attitude control typically uses quaternions as control variables. Since each quaternion must correspond to a specific attitude, using quaternions for synchronous spin control requires explicitly defining a desired quaternion trajectory before spin begins. This desired quaternion trajectory needs to be achieved through trajectory presetting or optimization. However, the preset trajectory may be suboptimal, and trajectory optimization places significant demands on the satellite's computational capabilities. To better describe the attitude motion of a panoramic imaging satellite, a more prominent option is a control strategy using (w,z) parameters as control variables. Compared to quaternions, (w,z) parameters allow for the design of the desired trajectory for parameter z by default, only requiring the design of the desired trajectory for parameter w, thus avoiding the processes of trajectory presetting and optimization.

[0004] Furthermore, since the optical camera is mounted at an angle, the panoramic imaging satellite is typically a non-axisymmetric body. During spin-up, the inertia product generated by the non-axisymmetric body can interfere with attitude control. Traditional control methods based on (w,z) parameters are often applied to spin-stabilized satellites, i.e., the controlled object is an axisymmetric body. Directly applying these control methods to non-axisymmetric satellites will result in a decrease in control accuracy. Therefore, it is necessary to design a spin-up control strategy for non-axisymmetric satellites based on (w,z) parameters. Summary of the Invention

[0005] In view of this, the present invention aims to provide a method, apparatus and medium for controlling the spin-up of a ring-scan imaging satellite; it can accelerate the spin-up speed of the ring-scan imaging satellite in a synchronous spin-up manner without the need for trajectory preset and trajectory optimization, and improve the attitude control accuracy after spin-up.

[0006] The technical solution of this invention is implemented as follows:

[0007] In a first aspect, embodiments of the present invention provide a method for controlling the spin-up of a ring-scan imaging satellite, the method comprising:

[0008] The kinematic equations constructed based on the (w,z) parameters and the dynamic equations constructed using a rigid model are used to obtain a reference value for the parameter w used to describe the spin axis orientation by integrating over time. r ;

[0009] Initiation phase: Without introducing the parameter z to describe the rotation angle about the spin axis, the first reference value w is used. r The obtained parameter w error w e and angular velocity error ω e The first control law is designed for spin initiation control, and the system switches to the spin angle control stage after spin initiation stabilizes.

[0010] Spin angle control stage: The value of parameter z at the time of switching is used as the reference value for parameter z. r The initial value is obtained, and the subsequent reference value z is obtained by integrating over time based on the kinematic equations constructed according to the (w,z) parameters and the dynamic equations constructed with the rigid model. r ;

[0011] Based on the reference value of the parameter z r Introducing the error z of parameter z e According to the error z of the parameter z e And the first control law is designed as a second control law for spin angle control.

[0012] Secondly, embodiments of the present invention provide a spin control device for a ring-scan imaging satellite, the device comprising: a reference value construction section, a spin control section, and a spin angle control section; wherein...

[0013] The reference value construction section is configured to obtain the reference value w for describing the spin axis orientation by integrating the kinematic equations constructed based on the (w,z) parameters and the dynamic equations constructed based on the rigid model over time. r ;

[0014] The spin-starting control section is configured to utilize a first reference value w without introducing a parameter z to describe the rotation angle about the spin axis. r The obtained parameter w error w e and angular velocity error ω e The first control law is designed for spin initiation control, and the system switches to the spin angle control stage after spin initiation stabilizes.

[0015] The spin angle control section is configured to use the value of parameter z during switching as a reference value for parameter z. r The initial value is obtained, and the subsequent reference value z is obtained by integrating over time based on the kinematic equations constructed according to the (w,z) parameters and the dynamic equations constructed with the rigid model. r ;as well as,

[0016] Based on the reference value of the parameter z r Introducing the error z of parameter z e According to the error z of the parameter z e And the first control law is designed as a second control law for spin angle control.

[0017] Thirdly, embodiments of the present invention provide a computing device, the computing device comprising: a communication interface, a memory, and a processor; the various components are coupled together via a bus system, wherein...

[0018] The communication interface is used for receiving and sending signals during the process of sending and receiving information with other external network elements;

[0019] The memory is used to store computer programs that can run on the processor;

[0020] The processor is configured to execute the steps of the rotation control method for the ring-scan imaging satellite described in the first aspect when running the computer program.

[0021] Fourthly, embodiments of the present invention provide a computer storage medium storing a spin control program for a ring-scan imaging satellite. When the spin control program for the ring-scan imaging satellite is executed by at least one processor, it implements the steps of the spin control method for the ring-scan imaging satellite described in the first aspect.

[0022] This invention provides a method, apparatus, and medium for controlling the spin start-up of a circular scanning imaging satellite; by not introducing a parameter z to describe the rotation angle around the spin axis during the spin start-up phase, the method controls the spin start-up based on the parameter w and the error w. e and angular velocity error ω e Design the first control law for initiating spin, and after spin stabilization, determine the error z of parameter z. e The design of a second control law for spin angle control enables the acceleration of the rotation speed of the ring-scan imaging satellite in a synchronous rotation mode without the need for trajectory preset and trajectory optimization, and also improves the attitude control accuracy after rotation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram illustrating the working principle of a ring-scan imaging satellite provided in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of an asynchronous spin-starting method provided in an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the synchronous spinning method provided in an embodiment of the present invention;

[0026] Figure 4 This is a schematic flowchart of a rotation control method for a ring-scan imaging satellite provided in an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram illustrating the definition of parameter z provided in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram illustrating the definition of parameter w provided in an embodiment of the present invention;

[0029] Figure 7 (a) is a schematic diagram of the reference angular velocity trajectory of the quaternion-based spin control strategy provided in an embodiment of the present invention;

[0030] Figure 7 (b) is a schematic diagram of the trajectory of the reference quaternion for the quaternion-based spin control strategy provided in the embodiments of the present invention;

[0031] Figure 8 (a) A schematic diagram of the angular velocity error of the quaternion-based spin control strategy provided in an embodiment of the present invention;

[0032] Figure 8 (b) is a schematic diagram of quaternion error for a quaternion-based spin control strategy provided in an embodiment of the present invention;

[0033] Figure 9 (a) is a schematic diagram of the reference angular velocity trajectory based on the (w,z) parameters provided in an embodiment of the present invention;

[0034] Figure 9 (b) Reference value w for parameter w provided in the embodiments of the present invention r A schematic diagram of the trajectory;

[0035] Figure 10 (a) A schematic diagram of angular velocity error controlled solely by the first control law in a simple control strategy provided in an embodiment of the present invention;

[0036] Figure 10 (b) A schematic diagram of parameter w error in a simple control strategy provided in an embodiment of the present invention, where only the first control law is used for control.

[0037] Figure 10 (c) An error diagram of parameter z in a simple control strategy provided in an embodiment of the present invention, where the parameter z is controlled only by the first control law;

[0038] Figure 11 (a) A schematic diagram of angular velocity error controlled in stages by a first control law and a second control law in a simple control strategy provided in an embodiment of the present invention;

[0039] Figure 11 (b) A schematic diagram of parameter w error in a simple control strategy provided in an embodiment of the present invention, where control is performed in stages by a first control law and a second control law;

[0040] Figure 11 (c) An error diagram of parameter z in a simple control strategy provided in an embodiment of the present invention, in which the first control law and the second control law are used to control the parameters in stages.

[0041] Figure 12 (a) A schematic diagram of a sliding mode where control is performed solely by a first control law in a fixed-time control strategy provided in an embodiment of the present invention;

[0042] Figure 12 (b) A schematic diagram of state variables controlled only by the first control law in the fixed-time control strategy provided in the embodiment of the present invention;

[0043] Figure 12 (c) is a schematic diagram of the angular velocity error controlled only by the first control law in the fixed-time control strategy provided in the embodiment of the present invention;

[0044] Figure 12 (d) is a schematic diagram of the error of parameter w in the fixed-time control strategy provided in the embodiment of the present invention, where only the first control law controls the parameters;

[0045] Figure 12 (e) is a schematic diagram of the error of parameter z in the fixed-time control strategy provided in the embodiment of the present invention, where the parameter z is controlled only by the first control law;

[0046] Figure 13 (a) A schematic diagram of a sliding mode in which control is performed in stages by a first control law and a second control law in a fixed-time control strategy provided in an embodiment of the present invention;

[0047] Figure 13 (b) A schematic diagram of state variables controlled in stages by the first control law and the second control law in the fixed-time control strategy provided in the embodiment of the present invention;

[0048] Figure 13 (c) A schematic diagram of angular velocity error controlled in stages by the first control law and the second control law in the fixed-time control strategy provided in the embodiment of the present invention;

[0049] Figure 13(d) is a schematic diagram of the parameter w error in the fixed-time control strategy provided in the embodiment of the present invention, which is controlled in stages by the first control law and the second control law.

[0050] Figure 13 (e) is a schematic diagram of the error of parameter z in the fixed-time control strategy provided in the embodiment of the present invention, which is controlled in stages by the first control law and the second control law;

[0051] Figure 14 This is a schematic diagram of the composition of an apparatus provided in an embodiment of the present invention;

[0052] Figure 15 This is a schematic diagram of the specific hardware structure of a computing device provided in an embodiment of the present invention. Detailed Implementation

[0053] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0054] See Figure 1 It illustrates the working principle of a ring-scan imaging satellite applicable to the technical solutions of embodiments of the present invention. Figure 1 In the figure, a ring-scanning imaging satellite carrying an inclined optical camera payload operates in a circular orbit, with the direction of travel indicated by the arrow in the figure. As the satellite travels, it rotates around the nadir axis at an angular velocity Ω, and the spiral footprint of the optical camera payload covers a wide area. The angle between the nadir axis and the optical axis of the optical camera is the skew angle.

[0055] For remote sensing satellites, especially small ones, imaging tasks can only be performed for short periods. Their external solar panels face the sun during idle times, a process known as sun-pointing mode. Before operation, they switch their attitude to working mode; this maneuver is called spin-up. Currently, two common spin-up methods are used: one is... Figure 2 As shown, the satellite first switches from sun-pointing mode to earth-pointing mode, then, after stabilizing its Earth-orientation attitude, it begins to spin, achieving a set angular velocity around its Earth-axis. In this method, the pointing control of the spin axis and the spin angular velocity control are performed step by step; therefore, this method can be called asynchronous spin-on. Secondly, as... Figure 3As shown, the satellite starts directly from its initial attitude, simultaneously initiating rotation and adjusting its spin axis direction until it reaches a set angular velocity around its Earth-axis. This method can be called synchronous spin-on. Clearly, asynchronous spin-on is easier to control but prolongs the spin-on time; synchronous spin-on requires higher satellite attitude control capabilities but shortens the spin-on time. It should be noted that the technical solutions in this embodiment can all be executed in synchronous spin-on mode, aiming to accelerate the spin-on speed of the panoramic imaging satellite without requiring trajectory pre-setting and optimization, and improving the attitude control accuracy after spin-on.

[0056] Based on this, see Figure 4 This illustrates a method for controlling the spin-up of a ring-scan imaging satellite according to an embodiment of the present invention. The method may include:

[0057] S401: The reference value w for the parameter w describing the spin axis orientation is obtained by integrating the kinematic equations constructed based on the (w,z) parameters and the dynamic equations constructed based on the rigid model over time. r ;

[0058] S402: Spinning Phase: Without introducing the parameter z to describe the rotation angle about the spin axis, the first reference value w is used. r The obtained parameter w error w e and angular velocity error ω e The first control law is designed for spin initiation control, and the system switches to the spin angle control stage after spin initiation stabilizes.

[0059] S403: Spin Angle Control Stage: Utilizing the value of parameter z at the time of switching as a reference value for parameter z. r The initial value is obtained, and the subsequent reference value z is obtained by integrating over time based on the kinematic equations constructed according to the (w,z) parameters and the dynamic equations constructed with the rigid model. r ;

[0060] S404: Based on the reference value z of the parameter z r Introducing the error z of parameter z e According to the error z of the parameter z e And the first control law is designed as a second control law for spin angle control.

[0061] for Figure 4 It should be noted that, since there is no requirement for the rotation angle of the satellite around the spin axis during the spin-on process, compared with using quaternions as control variables for synchronous spin-on control, the (w,z) parameters used in this embodiment of the invention can avoid the process of trajectory preset and trajectory optimization by designing only the expected trajectory of parameter w without introducing the design of the expected trajectory of parameter z.

[0062] for Figure 4 The technical solution shown, combined with Figure 5 and Figure 6 The (w,z) parameters used to describe the kinematic equations are defined as follows:

[0063] For parameter z, such as Figure 5 As shown, it represents Figure 5 The rotation angle about the i3 axis in the coordinate system shown is given by the coordinate system (i′1, i′2, i′3).

[0064] For parameters The definition of is: Where point (a,b,c) is a unit sphere Stereoscopic projection, such as Figure 6 As shown, it represents the direction of the i3′ axis relative to the coordinate system (b1,b2,b3).

[0065] Based on the above definition of the (w,z) parameters, for Figure 4 In some possible implementations of the technical solution shown, the kinematic equations constructed based on the (w,z) parameters and the dynamic equations constructed using a rigid model are used to obtain a reference value w for the parameter w describing the spin axis orientation by integrating over time. r ,include:

[0066] Based on the assumption that a rigid spacecraft can withstand limited disturbances, the dynamic equations are constructed as follows:

[0067]

[0068] in, The moment of inertia of the satellite is represented by ω = [ω1, ω2, ω3]. T This represents the angular velocity of the satellite in the volume coordinate system; This represents the angular momentum of the satellite flywheel; This represents the control torque, which is equal to... T d It represents the disturbance torque; the operator (·) × Representing a 3×3 cross-product matrix, in this embodiment of the invention,

[0069] The kinematic equations constructed based on the (w,z) parameters are shown below:

[0070]

[0071] Where ω=ω1+iω2, Denotes the complex conjugate of ω;

[0072] Let the satellite's position vector and velocity vector in the inertial frame at the initial moment of rotation be R0 and V0, respectively. The attitude transformation matrix of the orbital coordinate system relative to the satellite's inertial coordinate system is shown in the following equation:

[0073]

[0074] in,

[0075] According to the attitude transformation matrix C oi0 Obtain the initial reference value of parameter w. Among them, a r0 =C oi0 (1,3), C oi0 (1,3) represents the element value in the 1st row and 3rd column of the attitude transformation matrix; b r0 =C oi0 (2,3), C oi0 (2,3) represents the element value in the 2nd row and 3rd column of the attitude transformation matrix; c r0 =C oi0 (3,3), C oi0 (3,3) represents the element value in the 3rd row and 3rd column of the attitude transformation matrix;

[0076] Setting C 20 =C2(w r0 ),in,

[0077] according to The initial reference values ​​for parameter z are determined as follows:

[0078]

[0079] Where, ζ r0 =atan2(C 10 (1,2),C 10 (1,1)), atan2 represents the arctangent function;

[0080] Using the initial reference values ​​of the parameters w and z, and performing time integration based on the kinematic and dynamic equations, the reference value w of parameter w is obtained. r .

[0081] Regarding the above implementation method, it should be noted that the parameter w determines the direction of the satellite's spin axis. When there is no requirement for the angle of the satellite around the spin axis, the parameter z does not need to be considered, and the control law design for the spin-on stage can be based solely on the parameter w. After the spin-on stage stabilizes, the control can be switched to the spin angle control stage, thereby improving the control accuracy.

[0082] For the spin initiation stage and the spin angle control stage, this embodiment of the invention provides two exemplary control strategies. The first is that when the system convergence time requirement is not high, a simple control strategy can be used to adapt to most application scenarios. The second is a control strategy based on fixed time, in order to achieve stability within a stable time.

[0083] Based on this, regarding a simple control strategy that can adapt to most application scenarios, in some examples, for the spin-on phase, the first reference value w is used without introducing a parameter z to describe the rotation angle around the spin axis. r The obtained parameter w error w e and angular velocity error ω e The first control law is designed for spin initiation control, and after spin stabilization, it switches to the spin angle control stage, including:

[0084] Define angular velocity error ω e And the error value w of the (w,z) parameter. e With z e As shown below:

[0085] ω e =ω-C br ω r

[0086]

[0087]

[0088] in, C is the attitude transformation matrix between the satellite body coordinate system and the reference attitude coordinate system. ri C represents the transformation matrix from the inertial coordinate system relative to the reference attitude coordinate system. bi ω represents the transformation matrix from the inertial coordinate system to the volume coordinate system. r Indicates the reference angular velocity; a e ,b e ,c e It can be done Calculated; ζ e =atan2(C e1 (1,2),C e1 (1,1)), C e2 =C2(w e );

[0089] Based on angular velocity error ω e and parameter w error w e Spin control is achieved using the first control law shown in the following formula:

[0090]

[0091] Among them, J b0 This represents the initial value of the satellite's moment of inertia. Let K represent the first derivative of the reference angular velocity with respect to time, Θ represent the estimated value of the lumped disturbance, and K represent the first derivative of the reference angular velocity with respect to time. ω =diag(k) ω1 ,k ω2 ,k ω3 ), k w and k ωi (i = 1, 2, 3) are variable parameters greater than 0; sgn(ω e ) represents the vector ω e The sign function;

[0092] When the spin-on control is performed according to the first control law and stabilized, switch to the spin angle control stage.

[0093] In the example above, it should be noted that the expression for the reference angular velocity with respect to time can be ω. r =[-ω0sin(θ0+Ωt),-ω0cos(θ0+Ωt),Ω] T ω0 represents the angular velocity of the orbit, θ0 represents the initial rotation angle at t = 0, and Ω represents the reference rotation angular velocity. The analytical expression for the first derivative of the reference angular velocity with respect to time is: The estimated value of the lumped disturbance is Θ = diag(Θ1,Θ2,Θ3). e =[w e1 ,w e2 ,0] T For vector ω e The sign function sgn(ω) e )=[sgn(ω e1 ),sgn(ω e2 ),sgn(ω e3 )] T ,and Understandably, when spin control is performed according to the first control law described above, and the index satisfies ||w e ||≤ε w And ||ω e ||≤ε ω When this occurs, it indicates that the spin control is stable, allowing switching to the spin angle control stage. It is worth noting that ε... w and ε ω It is a small constant used to represent the spin-starting control accuracy and to characterize the spin-starting stable state.

[0094] Based on the above example, in the spin angle control stage, preferably, the step is based on the reference value z of the parameter z. r Introducing the error z of parameter ze According to the error z of the parameter z e And the first control law is designed to be used as a second control law for spin angle control, including:

[0095] Based on the error z of parameter z e And the first control law, through the second control law shown in the following formula, performs self-selected angle control:

[0096]

[0097] Where, k z For a variable parameter greater than 0, use bold italics. e Represents a three-dimensional vector, and z e =[0,0,z e ] T .

[0098] For the above preferred example, it should be noted that the spin-starting stage has already ensured that the spin axis pointing error and angular velocity error meet a certain accuracy, and this accuracy is also retained in the spin angle control stage.

[0099] The first and second control laws in the above example have only three adjustable parameters in total, which are suitable for most application scenarios and can ensure accuracy performance regardless of whether the satellite is symmetrical or asymmetrical.

[0100] If stability needs to be achieved within a fixed time, sliding mode control can be introduced into the control law. Based on this, in some examples, for the spin-on phase, the first reference value w is used without introducing a parameter z to describe the rotation angle about the spin axis. r The obtained parameter w error w e and angular velocity error ω e The first control law is designed for spin initiation control, and after spin stabilization, it switches to the spin angle control stage, including:

[0101] Based on angular velocity error ω e and parameter w error w e Design the first state variable as shown in the following equation:

[0102] x A =ω e +μ1w e +μ2sgn(w e )

[0103] Where μ1 and μ2 are variable parameters greater than 0;

[0104] The first sliding mode variable is defined based on the first state variable as shown in the following formula:

[0105]

[0106] Where, μ5=diag(μ 51 ,μ 52 ,μ 53 ), μ6=diag(μ 61 ,μ 62 ,μ 63 ), μ 5i and μ 6i (i = 1, 2, 3) are variable parameters greater than 0, 0 < α3 < 1, α4 > 1;

[0107] Based on the first sliding mode variable, spin control is performed using the first control law shown in the following formula:

[0108]

[0109] Where, μ7=diag(μ 71 ,μ 72 ,μ 73 ), μ8=diag(μ 81 ,μ 82 ,μ 83 ), μ 7i and μ 8i (i = 1, 2, 3) are variable parameters greater than 0, α5 > 1, and Θ is an estimate of the ensemble uncertainty.

[0110] For the first control law described in the example above, it can be guaranteed that the system converges within a fixed time, and the convergence time satisfies:

[0111]

[0112] in, Understandably, when spin control is performed according to the first control law described above, and the index satisfies ||w e ||≤ε w And ||ω e ||≤ε ω When this occurs, it indicates that the spin control is stable, allowing switching to the spin angle control stage. It is worth noting that ε... w and ε ω It is a small constant used to represent the spin-starting control accuracy and to characterize the spin-starting stable state.

[0113] Based on the above example, in the spin angle control stage, preferably, the step is based on the reference value z of the parameter z. r Introducing the error z of parameter z e According to the error z of the parameter z e And the first control law is designed to be used as a second control law for spin angle control, including:

[0114] Based on the error z of parameter z e The first state variable is designed as shown in the following formula, and the second state variable is as follows:

[0115]

[0116] Where μ3 and μ4 are variable parameters greater than 0, 0 < α1 < 1, α2 > 1;

[0117] It should be noted that during the spin angle control phase, z r The initial value is the value of parameter z when switching to the spin angle control stage. This is because in this stage, it is only necessary to ensure the spin angle is stable, and thus the stability of the ring scan imaging trajectory can be ensured under the premise that the spin control is stable.

[0118] The second sliding mode variable is defined according to the second state variable as shown in the following formula:

[0119]

[0120] Where, μ5=diag(μ 51 ,μ 52 ,μ 53 ), μ6=diag(μ 61 ,μ 62 ,μ 63 ), μ 5i and μ 6i (i = 1, 2, 3) are variable parameters greater than 0, 0 < α3 < 1, α4 > 1;

[0121] Based on the second sliding mode variable, the self-selected angle control is performed using the second control law shown in the following formula:

[0122]

[0123] Among them, μ3 and μ4 are variable parameters greater than 0.

[0124] For the second control law described in the example above, it can be guaranteed that the system converges within a fixed time, and the convergence time satisfies:

[0125]

[0126] Where, θ2=min{e|e=Θ i -|D i |i,=1,2},;D i Let D be a component of the lumped uncertainty D, and ΔJ b This represents the unknown portion of the satellite's rotational inertia.

[0127] As can be seen from the above examples and their preferred examples, the convergence time is related to the variable parameters. Therefore, by designing variable parameters to control the convergence time, convergence within a fixed time can be achieved, making it possible for the system to converge quickly.

[0128] Based on the foregoing technical solution, the embodiments of the present invention verify the effectiveness of the technical solution through the following numerical simulation experiments. The simulation conditions are as follows:

[0129] The satellite parameters are: J b0 =diag(10,9,8)kg·m 2 The parameters of the triaxial actuator are: angular momentum boundary magnitude of 4.8 Nm, control torque boundary magnitude of 1.2 Nm; considering the disturbance torque T composed of aerodynamic torque, solar pressure torque, and gravitational gradient torque. d Satisfying ||T d ||≤1e-5Nm.

[0130] The initial values ​​for the satellite are set as follows:

[0131] Angular velocity ω(0)=[0,0,0] T ° / s; attitude parameters w(0) = 0.366 + i0.366, z(0) = 0.611; orbital parameters R(0) = [7535.137, 0, 0] T km, V(0)=[0,4.223,6.031] T km / s; the actuator's angular momentum is 0, and the reference spin rate is 10° / s.

[0132] Based on the above simulation conditions, simulations were performed on the simple control strategy and the fixed-time control strategy described in the aforementioned technical solution, and the quaternion-based spin-starting control strategy was compared. In detail,

[0133] First, for the quaternion-based spin-starting control strategy, its control law is as follows:

[0134]

[0135] Where, q e Let represent the error quaternion, and define it as follows: K p =diag(K) p1 ,K p2 ,K p3 ) and K d =diag(K) d1 ,K d2 ,K d3 All are positive definite matrices. Before the Earth is pointed to, ω rThe angular velocity is equal to that of the orbit. Then the satellite begins to rotate, at which point ω... r =[-ω0sin(θ0+Ωt),-ω0cos(θ0+Ωt),Ω] T Set K p =diag(800,800,800), K d =diag(250,250,250), under the spin-starting control strategy, the trajectories of the reference angular velocity and quaternion are as follows: Figure 7 (a) and Figure 7 As shown in (b), it can be seen that the satellite will begin to rotate at 35 seconds, and in combination with Figure 8 (a) and Figure 8 (b) As shown in the angular velocity error and quaternion error respectively, it can be seen that the attitude stabilizes after 60 seconds, and the angular velocity control accuracy is better than 5*10. -3 ° / s, quaternion control accuracy better than 2×10 -4 Equivalent to 4×10 -4 rad, or 2.3 × 10 -2 °.

[0136] Next, a simulation is performed on the control strategy proposed in the embodiments of the present invention, with reference angular velocity ω. r The trajectory is as follows Figure 9 As shown in (a), the reference value of parameter w is w r The trajectory is as follows Figure 9 As shown in (b), with Figure 7 (a) and Figure 7 (b) The difference is that, since there is no need to switch control modes, Figure 9 (a) and Figure 9 The trajectory shown in (b) is continuous.

[0137] A simulation was performed on the simple control strategy described in the embodiments of the present invention, with the parameters set as follows:

[0138] Θ = diag(3.5, 3.5, 3.5) × 10 -5 K ω =diag(5,5,2.5), k w =5,k z =2.5

[0139] Control is achieved solely through the first control law, such as Figure 10 The errors in angular velocity, parameter w, and parameter z shown in (a), (b), and (c) respectively indicate that during the initial spinning phase, the spin stabilizes after 50 seconds, and the angular velocity error ω after stabilization... e Parameter w error w e And the error z of parameter z e Better than 10 respectively-3 ° / s, 5×10 -5 1.5×10 -4 ;

[0140] The control simulation is performed in stages using the first and second control laws. The errors in angular velocity, parameter w, and parameter z are respectively as follows: Figure 11 As shown in (a), (b), and (c), it can be seen that under the control of the first control law, the system converges within 37 seconds, after which the second control law is switched on. Figure 11 The step change in (c) represents the switching time. According to the partially enlarged diagram, after the switching, the angular velocity error ω... e and parameter w error w e and Figure 10 The results in (a) and (b) are consistent, but the error of parameter z is different. e Less than 5×10 -5 Superior Figure 10 The result shown in (c).

[0141] A simulation was performed on the fixed-time control strategy described in the embodiments of the present invention, with the parameters set as follows:

[0142] Θ = diag(3.5, 3.5, 3.5) × 10 -5 , μ1=0.25, μ2=0.2, μ3=μ4=3, μ5=μ6=diag(0.4,0.4,0.4), μ7=diag(8,8,8), μ8=diag(5,5,5), α1=0.6, α2=1.5, α3=0.7, α4=2.5, α5=2.

[0143] Substituting the above parameters into the convergence times of the first and second control laws described in the previous example, we can see that the overall convergence time of the first control law is less than 50 seconds, and the convergence time of the second control law is less than 45 seconds.

[0144] Control simulation using only the first control law, the errors in slip mode, state variables, angular velocity, parameter w, and parameter z are respectively as follows: Figure 12 As shown in (a), (b), (c), (d), and (e), it can be seen that the sliding variable takes approximately 20 seconds to reach the sliding surface, and then the state variable slides on the sliding surface. See also... Figure 12 In (c), (d), and (e), the system stabilizes after 40 seconds, which is significantly faster than the convergence speed of the simple control strategy. Furthermore, after convergence and stabilization, the angular velocity error ω... e Parameter w error w e And the error z of parameter z e Better than 2×10 -3 ° / s, 10-4 6×10 -4 .

[0145] The control simulation is performed in stages using the first and second control laws. The errors in the sliding mode, state variables, angular velocity, parameter w, and parameter z are respectively as follows: Figure 13 As shown in (a), (b), (c), (d), and (e), it can be seen that the state variable and the sliding mode variable will exhibit a sudden pulse, while Figure 13 The angular velocity errors ω shown in (c) and (d) e Error with parameter w e and Figure 12 The results in (c) and (d) are consistent, but the error precision of parameter z is better than 10. -5 It significantly outperforms all the simulation results mentioned above.

[0146] Based on the simulation results above, the simple control strategy proposed in the aforementioned technical solution is simple and effective for spin initiation control, while the fixed-time control strategy, although complex, enables faster convergence, and the second control law enables the spin angle to remain stable after spin initiation.

[0147] Based on the same inventive concept as the aforementioned technical solution, see [link to inventive concept]. Figure 14 This invention illustrates a spin control device 140 for a ring-scan imaging satellite, comprising: a reference value construction section 1401, a spin control section 1402, and a spin angle control section 1403; wherein,

[0148] The reference value construction section 1401 is configured to obtain a reference value w for describing the spin axis orientation by integrating the kinematic equations constructed based on the (w,z) parameters and the dynamic equations constructed based on the rigid model over time. r ;

[0149] The spin-starting control section 1402 is configured to utilize a first reference value w without introducing a parameter z to describe the rotation angle about the spin axis. r The obtained parameter w error w e and angular velocity error ω e The first control law is designed for spin initiation control, and the system switches to the spin angle control stage after spin initiation stabilizes.

[0150] The spin angle control section 1403 is configured to use the value of parameter z during switching as a reference value for parameter z. r The initial value is obtained, and the subsequent reference value z is obtained by integrating over time based on the kinematic equations constructed according to the (w,z) parameters and the dynamic equations constructed with the rigid model. r ;as well as,

[0151] Based on the reference value of the parameter z r Introducing the error z of parameter z e According to the error z of the parameter z e And the first control law is designed as a second control law for spin angle control.

[0152] It should be noted that for the specific implementation of the functions configured in each "part" of the above-mentioned device, please refer to the aforementioned... Figure 4 The implementation methods and examples of the corresponding steps in the rotation control method of the ring-scan imaging satellite shown are not repeated here.

[0153] Understandably, in this embodiment, "part" can be a part of a circuit, a part of a processor, a part of a program or software, etc., or it can be a unit, a module, or a non-modular one.

[0154] Furthermore, in this embodiment, the components can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional module.

[0155] If the integrated unit is implemented as a software functional module and not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the method described in this embodiment. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0156] Therefore, this embodiment provides a computer storage medium storing a rotation control program for a ring-scan imaging satellite. When the rotation control program for the ring-scan imaging satellite is executed by at least one processor, it implements the steps of the rotation control method for the ring-scan imaging satellite described in the above technical solution.

[0157] Based on the aforementioned swivel control device 140 of the ring-scan imaging satellite and the computer storage medium, see [link to relevant documentation]. Figure 15This illustration shows the specific hardware structure of a computing device 150 capable of implementing the aforementioned swivel control device 140 for a ring-scan imaging satellite, according to an embodiment of the present invention. The computing device 150 can be a wireless device, mobile or cellular phone (including so-called smartphones), personal digital assistant (PDA), video game console (including video display, mobile video game device, mobile video conferencing unit), laptop computer, desktop computer, set-top box, tablet computing device, e-book reader, fixed or mobile media player, etc. The computing device 150 includes: a communication interface 1501, a memory 1502, and a processor 1503; the various components are coupled together through a bus system 1504. It is understood that the bus system 1504 is used to realize the connection and communication between these components. In addition to a data bus, the bus system 1504 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 15 The general designated all buses as Bus System 1504.

[0158] The communication interface 1501 is used for receiving and sending signals during the process of sending and receiving information with other external network elements;

[0159] The memory 1502 is used to store computer programs that can run on the processor 1503;

[0160] The processor 1503 is used to execute the steps of the rotation control method for the ring-scan imaging satellite described in the foregoing technical solution when running the computer program.

[0161] It is understood that the memory 1502 in the embodiments of the present invention can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate Synchronous DRAM (DDRSDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 1502 of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0162] The processor 1503 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the processor 1503 or by instructions in software form. The processor 1503 can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 1502. Processor 1503 reads the information in memory 1502 and completes the steps of the above method in conjunction with its hardware.

[0163] It is understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described herein, or combinations thereof.

[0164] For software implementation, the techniques described herein can be achieved through modules (e.g., procedures, functions, etc.) that perform the functions described herein. The software code can be stored in memory and executed by a processor. The memory can be implemented within the processor or externally.

[0165] It is understood that the exemplary technical solutions of the above-described ring-scan imaging satellite spin control device 140 and computing device 150 belong to the same concept as the aforementioned ring-scan imaging satellite spin control method. Therefore, all details not described in detail above regarding the technical solutions of the ring-scan imaging satellite spin control device 140 and computing device 150 can be found in the description of the aforementioned ring-scan imaging satellite spin control method. This embodiment of the invention will not elaborate further on these details.

[0166] It should be noted that the technical solutions described in the embodiments of the present invention can be combined arbitrarily without conflict.

[0167] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method of spin-up control for a circular scanning imaging satellite, characterized by, The method comprises: According to The kinematic equations constructed from the parameters and the dynamic equations constructed from the rigid model are integrated over time to obtain parameters for describing the spin axis orientation The reference values ; Precession phase: without introducing a parameter for describing the angle of rotation around the spin axis z , the parameter resulting from the first reference value error and angular velocity error is used. A first control law for precession control is designed and switched to the spin angle control phase after precession stabilization. Spin angle control phase: the values of the parameters at the switch are used as reference values for the initial values of the parameters of the model z z z r The subsequent reference values are obtained by time integration of the kinematic equations constructed from the parameters of the model and the dynamic equations constructed from the rigid model z r ;​​​ according to said parameter z of reference z r introducing a parameter z of error z e , according to said parameter z of error z e and said first control law a second control law designed for spin angle control Wherein, the parameter for describing the rotation angle around the spin axis is not introduced z , the first reference value is used to obtain the parameter , the error , and the angular velocity error Design a first control law for spin-up control, and switch to a spin angle control phase after spin-up stabilization, including: defining an angular velocity error and an error value of a parameter with z e as follows: wherein is a transformation matrix of the satellite body coordinate system relative to the reference attitude coordinate system, denotes a transformation matrix from the inertial coordinate system relative to the reference attitude coordinate system, denotes a transformation matrix from the inertial coordinate system relative to the body coordinate system, denotes a reference angular velocity; by is calculated; , , ; According to the angular velocity error and the parameters error , the spin-up control is performed by a first control law shown by the following equation: wherein denotes an initial value of the moment of inertia of the satellite, denotes the first derivative of the reference angular velocity with respect to time, denotes an estimate of the collective disturbance, , and is a variable parameter greater than 0, wherein ; denotes the sign function for the vector ; When the spin-up control is stable according to the first control law, switching to a spin angle control phase.

2. The method of claim 1, wherein, The parameters The kinematic equations constructed from the parameters and the dynamic equations constructed from the rigid model are integrated over time to obtain parameters for describing the spin axis orientation The reference values , comprising: Based on the fact that the rigid spacecraft can withstand limited disturbances, the dynamic equation is constructed as: wherein denotes the moment of inertia of the satellite; denotes the angular velocity of the satellite in the body coordinate system; denotes the flywheel angular momentum of the satellite; denotes the control torque, which is equal to ; is the disturbance torque; the operator denotes the cross product matrix of ; Based on The kinematic equation constructed based on the parameters is shown in the following equation: wherein , denotes the conjugate complex of The position vector and the velocity vector of the satellite at the initial moment of the start of rotation in the inertial system are respectively set as and The attitude conversion matrix of the orbit coordinate system relative to the satellite inertial coordinate system is as follows: wherein , ; According to the attitude conversion matrix , a reference value initial value of a parameter is obtained; wherein, , represents an element value of the first row and the third column of the attitude conversion matrix; , represents an element value of the second row and the third column of the attitude conversion matrix; , represents an element value of the third row and the third column of the attitude conversion matrix; Setting wherein According to , the reference value initial value of the parameter z is as follows: wherein , denotes the arctangent function; using said parameters and reference values for the initial values of the parameters z and based on said kinematic equations and on dynamic equations, time integrations are performed to obtain reference values for the parameters .​ 3. The method of claim 1, wherein, said parameter z a reference value z r an error z of said parameter z e an error z of said parameter z e and said first control law is designed for a second control law for spin angle control. According to the parameters z of the error z e and the first control law, spin angle control is performed by a second control law shown by the following equation ​ wherein is a variable parameter greater than 0, in bold denotes a three-dimensional vector, and .

4. The method of claim 3, wherein, the parameter for describing the angle of rotation around the spin axis is not introduced z with the first reference value the resulting parameter error and the angular velocity error a first control law is designed for the roll control, and after the roll is stabilized, it is switched to the spin angle control stage, including: According to the angular velocity error and parameters error The first state variable is designed as follows: wherein and is a variable parameter greater than 0; According to the first state variable, a first sliding mode variable is defined as shown in the following formula: wherein , , and are variable parameters greater than 0, wherein , , ; According to the first sliding mode variable, the spin-up control is performed through a first control law shown in the following formula: wherein , , and is a variable parameter greater than 0, , is an estimate of the lumped uncertainty.

5. The method of claim 4, wherein, said parameter z z r introducing an error z z e , according to said parameter z z e and said first control law a second control law designed for spin angle control.​​​ According to the parameters z of the error z e and the first state variable is designed as the second state variable as follows: wherein and is a variable parameter greater than 0, , ; According to the second state variable, a second sliding mode variable is defined as shown in the following formula: wherein , , and are variable parameters greater than 0, wherein , , ; According to the second sliding mode variable, the spin angle control is performed through a second control law shown in the following formula: wherein and is a variable parameter greater than 0.

6. A spin-up control apparatus for a circular scanning imaging satellite, characterized by comprising: The device comprises a reference value construction part, a spin-up control part and a spin angle control part; wherein, The reference value construction part is configured to construct the reference value according to The kinematic equation constructed by the parameter and the dynamic equation constructed by the rigid model are obtained by time integration to obtain a parameter for describing the spin axis pointing The reference value of the parameter ; The spin-up control part is configured to use a first reference value z without introducing a parameter for describing the rotation angle around the spin axis The resulting parameter error and angular velocity error A first control law for spin-up control is designed, and after spin-up stabilization, it is switched to a spin angle control phase; The spin angle control section is configured to use as a parameter the value of the parameter at the time of switching z as a reference value for the initial value of the parameter z z r and to obtain a subsequent reference value by time-integrating a kinematics equation constructed from the parameter and a dynamics equation constructed from the rigid model z r ; and,​ according to said parameter z a reference value z r introducing a parameter z an error z e , according to said parameter z an error z e and said first control law a second control law designed for spin angle control The spin-up control part is configured to: defining an angular velocity error and an error value of a parameter and z e as follows: wherein is a transformation matrix of the satellite body coordinate system relative to the reference attitude coordinate system, is a transformation matrix of the inertial coordinate system relative to the reference attitude coordinate system, is a transformation matrix of the inertial coordinate system relative to the body coordinate system, is a reference angular velocity; is calculated by is calculated by , , ; According to the angular velocity error and the parameters error the spin-up control is performed by a first control law shown by the following equation: wherein denotes an initial value of the moment of inertia of the satellite, denotes the first derivative of the reference angular velocity with respect to time, denotes an estimate of the collective disturbance, , and is a variable parameter greater than 0, wherein ; denotes the sign function for the vector ; When the spin-up control is stable according to the first control law, switching to a spin angle control phase.

7. A computing device, comprising: The computing device comprises a communication interface, a memory and a processor; each component is coupled together through a bus system, wherein, The communication interface is used for receiving and sending signals in the process of transmitting information with other external network elements; The memory is used for storing a computer program capable of running on the processor; The processor is used for executing the steps of the spin-up control method of the ring-scan imaging satellite in any one of claims 1 to 5 when running the computer program.

8. A computer storage medium, characterized in that, The computer storage medium stores a spin-up control program of a ring-scan imaging satellite, and the spin-up control program of the ring-scan imaging satellite, when executed by at least one processor, implements the steps of the spin-up control method of the ring-scan imaging satellite in any one of claims 1 to 5.

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