Micro-nano satellite formation multi-target attitude control method and system based on array antenna

Abstract

The invention discloses a micro-nano satellite formation multi-target attitude control method and system based on an array antenna. The method comprises the following steps: firstly, initializing a micro-nano satellite formation model; wherein the micro-nano satellite formation comprises a master spacecraft, a service spacecraft and any slave spacecraft which form a master-slave structure; then calculating a bidirectional LOS vector by using an MIMO communication technology and a CDMA technology; and finally, according to the bidirectional LOS vector and the angular velocity of the spacecraft, calculating control input, so that the control input reaches an expected relative attitude, and completing multi-target attitude control of the micro-nano satellite formation. The method reduces the dependence on a high-precision sensor, reduces the cost, improves the reliability and flexibility of the system, can achieve the precise attitude control of each satellite in the micro-nano satellite formation, and can be widely used in the technical field of micro-nano satellite formation attitude control.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano satellite formation attitude control, and in particular to a micro-nano satellite formation multi-target attitude control method and system based on array antennas. Background Art

[0002] In recent years, micro-nano satellite formation control technology has been widely used in many fields such as commercial aerospace, scientific research, and national defense security. By forming a dynamic network in orbit and exchanging information between satellites, the micro-nano satellite formation can effectively improve the efficiency of mission execution and the fault tolerance of the system, and enhance the overall performance and flexibility of the system. However, there are still many challenges that need to be solved in practical applications, among which the attitude control technology of micro-nano satellite formation is also one of the keys. Traditional navigation and attitude control methods often need to rely on high-precision sensors, such as star sensors, sun sensors, magnetic torque, earth sensors or gyroscopes, etc. These sensors not only increase the load burden of micro-nano satellites, but also increase the control error. Summary of the invention

[0003] The main purpose of the embodiments of the present invention is to propose a multi-target attitude control method and system for a micro-nano satellite formation based on array antennas, so as to realize precise attitude control of each satellite in the micro-nano satellite formation.

[0004] To achieve the above object, an embodiment of the present invention provides a multi-target attitude control method for a micro-nano satellite formation based on an array antenna, comprising the following steps:

[0005] Initialize a micro-nano satellite formation model; wherein the micro-nano satellite formation includes a master spacecraft, a service spacecraft, and any slave spacecraft to form a master-slave structure;

[0006] Calculate the bidirectional LOS vector using MIMO communication technology and CDMA technology;

[0007] According to the bidirectional LOS vector and the spacecraft angular velocity, the control input is calculated so that the control input reaches the desired relative attitude, thereby completing the multi-target attitude control of the micro-nano satellite formation.

[0008] In some embodiments, each slave spacecraft in the micro-nano satellite formation model is assigned a preset orthogonal spread spectrum sequence, and the expression of the orthogonal spread spectrum sequence is:

[0009]

[0010] Among them, a k (τ) represents the spreading sequence of the spacecraft; L represents the length of the sequence; k represents the index of the spacecraft; l represents the index in the sequence; b (k,l)represents the symbol of the lth sequence element of the kth spacecraft; τ represents the time variable; T b Represents cycle;

[0011] The orthogonal spread spectrum sequence is used to modulate the carrier and transmit the signal through the antenna array carried by it;

[0012] The main spacecraft and the service spacecraft act as receiving ends. The received signal is the superposition of the signals transmitted by all the slave spacecraft array elements. Through sliding correlation and two-dimensional joint spectrum peak search technology, the three-dimensional arrival angle and departure angle of all line-of-sight signal propagation paths from the spacecraft to the main spacecraft and the service spacecraft are estimated and identified.

[0013] In some embodiments, in the step of calculating the bidirectional LOS vector using the MIMO communication technology and the CDMA technology, the calculation formula of the bidirectional LOS vector is:

[0014]

[0015] Among them, v k,i represents the LOS vector from the spacecraft to the main and service spacecraft; α k,i represents the projection of the unit LOS vector on the x-axis; β k,i Represents the projection of the unit LOS vector on the y-axis; γ k,i represents the projection of the unit LOS vector on the z-axis; φ k,i Represents the angle between the unit LOS vector and the y-axis; θ k,i represents the angle between the unit LOS vector and the x-axis; k represents the index of the slave spacecraft; i represents the index of the master spacecraft and the service spacecraft, i=1 represents the master spacecraft, and i=2 represents the service spacecraft.

[0016] In some embodiments, in the step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity, the relative attitude of each slave spacecraft is the rotation of the body coordinate system relative to the body coordinate system, which is represented by a rotation matrix in a special orthogonal group, and the expression is: SO(3) = {R∈R 3×3 ∣R T R=I,det(R)=1},where R 3×3 represents a 3×3 dimensional real matrix, det(R) represents the value of the determinant of the matrix R; SO(3) represents a three-dimensional rotation matrix.

[0017] In some embodiments, the step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity further includes:

[0018] Construct the LOS vector u from the master and service spacecraft to the slave spacecraft in the inertial coordinate system i,k, and the LOS vector v from the spacecraft to the master and service spacecraft k,i The expression is:

[0019]

[0020] Among them, R c,k represents the rotation matrix of the kth slave spacecraft coordinate system relative to the master spacecraft coordinate system; R k represents the rotation matrix of the kth slave spacecraft coordinate system relative to the inertial coordinate system; s k,i Indicates v k,i with u i,k Representation in an inertial coordinate system.

[0021] In some embodiments, the step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity further includes:

[0022] Determine the desired target posture according to the posture requirements;

[0023] The control input is derived so that when time approaches infinity, the rotation matrix of the kth slave spacecraft coordinate system relative to the master spacecraft coordinate system gradually approaches and stabilizes at the desired target attitude. The error equation of this process is expressed as:

[0024]

[0025]

[0026] Among them, Δ k represents the attitude error of the kth slave spacecraft; Δ k,1 ,Δ k,2 Respectively represent MS k Attitude error Δ k Relative to SS 1 ,SS 2 The error component of R b,k represents the desired target posture.

[0027] In some embodiments, an exponential graph is used to represent the infinitesimal change of the rotation matrix, and the expression is:

[0028]

[0029] in, Represents the unit rotation vector; ∈ is an infinitesimal positive number; δR represents the infinitesimal change of the rotation matrix R when ∈ approaches 0; R represents the three-dimensional rotation matrix;

[0030] The expression for each input from the spacecraft control system is:

[0031] uk =-k k Ω k -k k,1 φ k -k k,2 ψ l

[0032] Among them, u k represents the control input vector of the kth slave spacecraft; k k represents the angular velocity control gain of the kth slave spacecraft; Ω k represents the angular velocity vector of the kth slave spacecraft; φ k represents the attitude angle deviation of the kth slave spacecraft in the master spacecraft coordinate system; ψ k The attitude angle deviation of the kth slave spacecraft in the service spacecraft coordinate system.

[0033] In some embodiments, the control system input is subjected to a relevant stability analysis by using a Lyapunov function, and the expression of the process is:

[0034]

[0035] Among them, v is a candidate function of the Lyapunov function; Ω k represents the angular velocity vector of the kth slave spacecraft; J k represents the moment of inertia of the kth slave spacecraft; Δ k,1 represents the attitude error of k slave spacecraft in the master spacecraft coordinate system; Δ k,2 represents the attitude errors of k slave spacecraft in the service spacecraft coordinate system.

[0036] Another aspect of the embodiment of the present invention further provides a micro-nano satellite formation multi-target attitude control system based on array antennas, comprising:

[0037] The first module is used to initialize the micro-nano satellite formation model; wherein the micro-nano satellite formation includes a master spacecraft, a service spacecraft, and any slave spacecraft to form a master-slave structure;

[0038] The second module is used to calculate the bidirectional LOS vector using MIMO communication technology and CDMA technology;

[0039] The third module is used to calculate the control input according to the bidirectional LOS vector and the spacecraft angular velocity, so that the control input reaches the desired relative attitude and completes the multi-target attitude control of the micro-nano satellite formation.

[0040] Another aspect of an embodiment of the present invention further provides an electronic device, including a processor and a memory;

[0041] The memory is used to store programs;

[0042] The processor executes the program to implement the method described above.

[0043] To achieve the above objective, another aspect of an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned method is implemented.

[0044] The embodiment of the present invention also discloses a computer program product or a computer program, which includes a computer instruction stored in a computer-readable storage medium. A processor of a computer device can read the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the above method.

[0045] The embodiments of the present invention include at least the following beneficial effects: the present invention provides a method and system for multi-target attitude control of a micro-nano satellite formation based on an array antenna, wherein the method first initializes a micro-nano satellite formation model; wherein the micro-nano satellite formation includes a master spacecraft, a service spacecraft, and any slave spacecraft to form a master-slave structure; then the two-way LOS vector is calculated using MIMO communication technology and CDMA technology; finally, the control input is calculated based on the two-way LOS vector and the angular velocity of the spacecraft, so that the control input reaches the desired relative attitude, and the multi-target attitude control of the micro-nano satellite formation is completed. The present invention reduces the reliance on high-precision sensors, reduces costs, and also improves the reliability and flexibility of the system, and can achieve precise attitude control of each satellite in the micro-nano satellite formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of an implementation environment provided by an embodiment of the present invention;

[0047] Figure 2 is a flow chart of overall steps provided by an embodiment of the present invention;

[0048] Figure 3 is a schematic diagram of a micro-nano satellite formation provided by an embodiment of the present invention;

[0049] Figure 4 It is a schematic diagram of the hardware structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present invention. They are only examples of devices and methods consistent with some aspects of the embodiments of the present invention as detailed in the attached claims.

[0051] It is understood that the terms "first", "second", etc. used in the present invention may be used herein to describe various concepts, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0052] The terms "at least one", "multiple", "each", "any", etc. used in the present invention, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0054] The micro-nano satellite formation multi-target attitude control method and system based on array antenna provided in the embodiment of the present invention relate to the field of micro-nano satellite formation attitude control. The micro-nano satellite formation multi-target attitude control method based on array antenna provided in the embodiment of the present invention can be applied to a terminal, can also be applied to a server, and can also be software running in a terminal or a server. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, a smart speaker, a smart watch, and a vehicle terminal, etc., but is not limited to this; the server side can be configured as an independent physical server, or a server cluster or distributed system composed of multiple physical servers, and can also be configured as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network; the software can be an application that implements a micro-nano satellite formation multi-target attitude control method based on array antennas, etc., but is not limited to the above forms.

[0055] The present invention can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc. The present invention can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present invention can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0056] like Figure 1 FIG. 1 is a schematic diagram of an implementation environment provided by an embodiment of the present invention. Figure 1 The implementation environment includes at least one terminal 102 and a server 101. The terminal 102 and the server 101 can be connected to a network wirelessly or wired to complete data transmission and exchange.

[0057] Server 101 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers. It can also be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), as well as big data and artificial intelligence platforms.

[0058] In addition, the server 101 can also be a node server in the blockchain network. Blockchain is a new application model of computer technologies such as distributed data storage, peer-to-peer transmission, consensus mechanism, and encryption algorithm.

[0059] The terminal 102 may be a smart phone, a tablet computer, a laptop computer, a desktop computer, a smart speaker, a smart watch, etc. The terminal 102 may also be a vehicle-mounted terminal of various device types described above, but is not limited thereto. The terminal 102 and the server 101 may be directly or indirectly connected via wired or wireless communication, which is not limited in this embodiment of the present invention.

[0060] Based on the example Figure 1 In the implementation environment shown, an embodiment of the present invention provides a multi-target attitude control method for a micro-nano satellite formation based on an array antenna. The following is explained using the application of the multi-target attitude control method for a micro-nano satellite formation based on an array antenna in a server 101 as an example. It can be understood that the method can also be applied to a terminal 102.

[0061] Reference Figure 2 , Figure 2 The present invention provides a flowchart of a method for controlling the multi-target attitude of a micro-nano satellite formation based on an array antenna and applied to a server. The execution subject of the method can be any of the aforementioned computer devices (including a server or a terminal). Figure 2 , the method may include the following steps:

[0062] Initialize a micro-nano satellite formation model; wherein the micro-nano satellite formation includes a master spacecraft, a service spacecraft, and any slave spacecraft to form a master-slave structure;

[0063] Calculate the bidirectional LOS vector using MIMO communication technology and CDMA technology;

[0064] According to the bidirectional LOS vector and the spacecraft angular velocity, the control input is calculated so that the control input reaches the desired relative attitude, thereby completing the multi-target attitude control of the micro-nano satellite formation.

[0065] In some embodiments, each slave spacecraft in the micro-nano satellite formation model is assigned a preset orthogonal spread spectrum sequence, and the expression of the orthogonal spread spectrum sequence is:

[0066]

[0067] Among them, a k (τ) represents the spreading sequence of the spacecraft; L represents the length of the sequence; k represents the index of the spacecraft; l represents the index in the sequence; b (k,l) represents the symbol of the lth sequence element of the kth spacecraft; τ represents the time variable; T b Represents cycle;

[0068] The orthogonal spread spectrum sequence is used to modulate the carrier and transmit the signal through the antenna array carried by it;

[0069] The main spacecraft and the service spacecraft act as receiving ends. The received signal is the superposition of the signals transmitted by all the slave spacecraft array elements. Through sliding correlation and two-dimensional joint spectrum peak search technology, the three-dimensional arrival angle and departure angle of all line-of-sight signal propagation paths from the spacecraft to the main spacecraft and the service spacecraft are estimated and identified.

[0070] In some embodiments, in the step of calculating the bidirectional LOS vector using the MIMO communication technology and the CDMA technology, the calculation formula of the bidirectional LOS vector is:

[0071]

[0072] Among them, v k,i represents the LOS vector from the spacecraft to the main and service spacecraft; α k,i represents the projection of the unit LOS vector on the x-axis; β k,i Represents the projection of the unit LOS vector on the y-axis; γ k,i represents the projection of the unit LOS vector on the z-axis; φ k,i Represents the angle between the unit LOS vector and the y-axis; θ k,i represents the angle between the unit LOS vector and the x-axis; k represents the index of the slave spacecraft; i represents the index of the master spacecraft and the service spacecraft, i=1 represents the master spacecraft, and i=2 represents the service spacecraft.

[0073] In some embodiments, in the step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity, the relative attitude of each slave spacecraft is the rotation of the body coordinate system relative to the body coordinate system, which is represented by a rotation matrix in a special orthogonal group, and the expression is: SO(3) = {R∈R 3×3 ∣R T R=I,det(R)=1},where R3×3 represents a 3×3 dimensional real matrix, det(R) represents the value of the determinant of the matrix R; SO(3) represents a three-dimensional rotation matrix.

[0074] In some embodiments, the step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity further includes:

[0075] Construct the LOS vector u from the master and service spacecraft to the slave spacecraft in the inertial coordinate system i,k , and the LOS vector v from the spacecraft to the master and service spacecraft k,i The expression is:

[0076]

[0077] Among them, R c,k represents the rotation matrix of the kth slave spacecraft coordinate system relative to the master spacecraft coordinate system; R k represents the rotation matrix of the kth slave spacecraft coordinate system relative to the inertial coordinate system; s k,i Indicates v k,i with u i,k Representation in an inertial coordinate system.

[0078] In some embodiments, the step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity further includes:

[0079] Determine the desired target posture according to the posture requirements;

[0080] The control input is derived so that when time approaches infinity, the rotation matrix of the kth slave spacecraft coordinate system relative to the master spacecraft coordinate system gradually approaches and stabilizes at the desired target attitude. The error equation of this process is expressed as:

[0081]

[0082] Among them, Δ k represents the attitude error of the kth slave spacecraft; Δ k,1 ,Δ k,2 Respectively represent MS k Attitude error Δ k Relative to SS 1 ,SS 2 The error component of R d,k represents the desired target posture.

[0083] In some embodiments, an exponential graph is used to represent the infinitesimal change of the rotation matrix, and the expression is:

[0084]

[0085] in, Represents the unit rotation vector; ∈ is an infinitesimal positive number; δR represents the infinitesimal change of the rotation matrix R when ∈ approaches 0; R represents the three-dimensional rotation matrix;

[0086] The expression for each input from the spacecraft control system is:

[0087] u k =-k k Ω k -k k,1 φ k -k k,2 ψ k

[0088] Among them, u k represents the control input vector of the kth slave spacecraft; k k represents the angular velocity control gain of the kth slave spacecraft; Ω k represents the angular velocity vector of the kth slave spacecraft; φ k represents the attitude angle deviation of the kth slave spacecraft in the master spacecraft coordinate system; ψ k The attitude angle deviation of the kth slave spacecraft in the service spacecraft coordinate system.

[0089] In some embodiments, the control system input is subjected to a relevant stability analysis by using a Lyapunov function, and the expression of the process is:

[0090]

[0091] Where v is a candidate function of the Lyapunov function; Ω k represents the angular velocity vector of the kth slave spacecraft; J k represents the moment of inertia of the kth slave spacecraft; Δ k,1 represents the attitude error of k slave spacecraft in the master spacecraft coordinate system; Δ k,2 represents the attitude errors of k slave spacecraft in the service spacecraft coordinate system.

[0092] The following describes the implementation process of the method of the embodiment of the present invention in detail by taking a specific scenario as an example:

[0093] The present invention provides a multi-target control method for a micro-nano satellite formation based on array signal detection. The method aims to achieve precise attitude control of each satellite in a micro-nano satellite formation through modularization of communication and attitude control.

[0094] Based on the existing communication system and antenna array, the present invention proposes an attitude control algorithm for master-slave micro-nano satellite formation using existing communication modules. The bidirectional LOS vector between spacecraft is calculated by combining MIMO communication technology with cellular code division multiple access (CDMA). Then, an error equation is established to obtain the control input of the micro-nano satellite attitude control so that it reaches the desired attitude. The stability of this attitude control method is proved by establishing the Lyapunov function. This multi-target micro-nano satellite attitude control method based on array signal detection uses the existing communication module on the spacecraft, combines communication and navigation technology, and provides a new solution for micro-nano satellite formation control.

[0095] The technical solution adopted in the embodiment of the present invention is:

[0096] Each satellite in the micro-nano satellite formation is equipped with an array antenna, and a micro-nano satellite relative attitude positioning model based on the LOS vector is established as an observation device for the attitude control algorithm.

[0097] Through array signal detection, the bidirectional LOS vector between the master satellite and the slave satellite is obtained simultaneously using the same communication link. Since the dual-vector LOS is obtained based on the same communication link, no additional parallel calibration is required, avoiding estimation errors caused by non-parallel LOS vectors.

[0098] The LOS vector observation value output by the array antenna device is used as a part of the control input in this control system through the attitude control algorithm. This control algorithm is used to control the spacecraft to achieve a stable desired attitude.

[0099] Specifically, the implementation process in this application scenario includes the following three parts:

[0100] 1. Identification of multiple micro-nano satellites:

[0101] In this embodiment, Figure 3 As shown in the figure, a micro-nano satellite formation is constructed. The satellite formation is based on the master-slave satellite formation. By designating one of the spacecraft as the master spacecraft (SS 1 ), one spacecraft is a service spacecraft (SS 2 ), the rest of the spacecraft are slave spacecraft (MS k ), forming a master-slave structure. Multi-target recognition technology mainly relies on cellular code division multiple access (CDMA) and multiple input multiple output (MIMO) communication technology. First, each slave spacecraft is assigned a preset orthogonal spread spectrum sequence as follows:

[0102]

[0103] In the above formula, the period is T b ,power Rectangular pulse. The duration of this spread spectrum sequence is T s =T b The spread spectrum sequence a of any two different spacecraft k1 (τ) and a k2 (τ) are perpendicular to each other, and the autocorrelation function is an impulse function. These sequences ensure the orthogonality of signals from different spacecraft, so that the master spacecraft and the service spacecraft can distinguish and identify these signals through CDMA technology. The slave spacecraft uses these spread spectrum sequences to modulate the carrier and transmit the signal through its antenna array. The master spacecraft and the service spacecraft act as the receiving end. The received signal is the superposition of the signals transmitted by all the slave spacecraft array elements. Through sliding correlation and two-dimensional joint spectrum peak search technology, the three-dimensional arrival angle and departure angle of all the line-of-sight signal propagation paths from the slave spacecraft to the master spacecraft and the service spacecraft are accurately estimated and identified.

[0104] 2. Calculation of unit LOS vector between micro-nano satellites:

[0105] The unit LOS vector is defined as the three-dimensional coordinate value of a unit vector, which can be obtained from the relationship between the wave arrival angle or wave departure angle and the LOS vector, where α k,i is the projection of the unit LOS vector on the x-axis, β k,i is the projection of the unit LOS vector on the y-axis, γ k,i is the projection of the unit LOS vector on the z-axis, θ is the angle between the unit LOS vector and the x-axis, and φ is the angle between the unit LOS vector and the y-axis.

[0106]

[0107] 3. Posture control algorithm:

[0108] For each slave spacecraft, its relative attitude R is the coordinate system of the body relative to SS 1 Rotation of the body coordinate system. It is represented by the rotation matrix in the special orthogonal group, that is,

[0109] SO(3)={R∈R 3×3 ∣R T R=I,det(R)=1}

[0110] In the formula, R 3×3 represents a 3×3 dimensional real matrix, and det(R) represents the value of the determinant of the matrix R.

[0111] LOS vector u from the master and service spacecraft to the slave spacecraft i,k , the LOS vector v from the spacecraft to the main and service spacecraft k,i , k represents the vector related to the kth slave spacecraft, i=1, i=2 represent the vectors related to the master spacecraft and the service spacecraft respectively.i,k With v k,i Relationship and v k,i with u i,k Representation in inertial coordinate system k,i The relationship is as follows:

[0112]

[0113] In the formula, R c,k R represents the rotation matrix of the kth slave spacecraft coordinate system relative to the master spacecraft coordinate system. k represents the rotation matrix of the kth slave spacecraft coordinate system relative to the inertial coordinate system. The desired target attitude R d,k Given the attitude requirement, the control input u needs to be derived k , when time approaches infinity, R c,k Gradually tend to and stabilize at the desired target posture R d,k . The error equation is defined as follows:

[0114]

[0115] In the above formula, Δ k represents the attitude error of the kth slave spacecraft. k,1 ,Δ k，2 Respectively represent MS k Attitude error Δ k Relative to SS 1 ,SS 2 The error component.

[0116] Infinitesimal changes to the rotation matrix can be represented using an exponential graph as follows:

[0117]

[0118] Where η∈R 3 , for Δ k Find the value of R k The derivative of . According to the above formula, Δ k The infinitesimal changes are as follows:

[0119]

[0120] Let φ k =R d,k v k,1 ×u 1,k ,ψ k =R d,k v k,1 ×u 1,k , the above formula can be simplified to:

[0121]

[0122] For each slave spacecraft, the control system input is as follows:

[0123] u k =-k k Ω k -k k,1 φ k -k k,2 ψ k

[0124] In the above equation, the first term corresponds to the angular velocity of the spacecraft, and the last two terms minimize the error equation. The control system input can be directly represented by the LOS vector and the target attitude. The relevant stability analysis is as follows:

[0125] The Lyapunov function is defined as:

[0126]

[0127] In the formula, J k represents the moment of inertia of the kth slave spacecraft, since And from the above, we can know that k k,1 Δ k，1 +k k,2 Δ k，2 >0, so ν>0. Derivative of the above formula with respect to the Lyapunov function yields:

[0128]

[0129] will u k Substituting into the above formula, we can get:

[0130]

[0131] In the above formula, So it can be simplified to:

[0132]

[0133] Obviously, the derivative of the Lyapunov function is strictly non-positive. According to LaSalle's theorem, this system is globally asymptotically stable, that is, when time tends to infinity, the angular velocity tends to 0, and the attitude of each slave spacecraft converges to the maximum invariant set M:

[0134] M={R k ∈SO(3)|k k,1 φ k +k k,2 ψ k =0}

[0135] In the above formula, it can be proved that k k,1 φ k +k k,2 ψk = 0 is equivalent to (φ k =0)&(ψ k =0), that is, the maximum invariant set M:

[0136] M={R k ∈SO(3)|(φ k =0)&(ψ k =0)}

[0137] That is, when time tends to infinity, the attitude error approaches 0, and the control system makes the relative attitude converge to the target attitude. And the control input in this control system is represented by the angular velocity and LOS vector observation value. There is no need to solve the relative attitude. This makes the controller design more concise and efficient, and more suitable for the attitude control task of micro-nano satellite formation.

[0138] In summary, the present invention utilizes the existing communication modules and antenna arrays on each satellite in the micro-nano satellite formation, and realizes the bidirectional LOS vector measurement between satellites by combining MIMO communication technology with cellular code division multiple access (CDMA). Using the obtained bidirectional LOS vector, the control input required to control the satellite to achieve the desired attitude is further obtained by designing an error function, and then a control strategy is designed to achieve precise control of the attitude of the entire formation. This method not only reduces the dependence on high-precision sensors and reduces costs, but also improves the reliability and flexibility of the system.

[0139] Another aspect of the embodiment of the present invention further provides a micro-nano satellite formation multi-target attitude control system based on array antennas, comprising:

[0140] The first module is used to initialize the micro-nano satellite formation model; wherein the micro-nano satellite formation includes a master spacecraft, a service spacecraft, and any slave spacecraft to form a master-slave structure;

[0141] The second module is used to calculate the bidirectional LOS vector using MIMO communication technology and CDMA technology;

[0142] The third module is used to calculate the control input according to the bidirectional LOS vector and the spacecraft angular velocity, so that the control input reaches the desired relative attitude and completes the multi-target attitude control of the micro-nano satellite formation.

[0143] It can be understood that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0144] The embodiment of the present invention further provides an electronic device, the electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the above-mentioned micro-nano satellite formation multi-target attitude control method based on array antenna when executing the computer program. The electronic device can be any intelligent terminal including a tablet computer, a vehicle-mounted computer, etc.

[0145] It can be understood that the contents of the above method embodiments are all applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0146] See also Figure 4 , Figure 4 The hardware structure of an electronic device of another embodiment is illustrated, and the electronic device includes:

[0147] The processor 401 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present invention;

[0148] The memory 402 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 402 can store an operating system and other application programs. When the technical solution provided in the embodiment of this specification is implemented by software or firmware, the relevant program code is stored in the memory 402, and the processor 401 calls and executes the multi-target attitude control method of micro-nano satellite formation based on array antenna according to the embodiment of the present invention;

[0149] Input / output interface 403, used to implement information input and output;

[0150] Communication interface 404, used to realize communication interaction between the device and other devices, which can be realized by wired mode (such as USB, network cable, etc.) or wireless mode (such as mobile network, WIFI, Bluetooth, etc.);

[0151] Bus 405 , which transmits information between various components of the device (e.g., processor 401 , memory 402 , input / output interface 403 , and communication interface 404 );

[0152] The processor 401 , the memory 402 , the input / output interface 403 and the communication interface 404 are connected to each other in communication within the device via the bus 405 .

[0153] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-mentioned multi-target attitude control method for a micro-nano satellite formation based on an array antenna.

[0154] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiments, the functions specifically implemented by the present storage medium embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0155] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0156] The embodiments described in the embodiments of the present invention are intended to more clearly illustrate the technical solutions of the embodiments of the present invention, and do not constitute a limitation on the technical solutions provided by the embodiments of the present invention. Those skilled in the art can appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present invention are also applicable to similar technical problems.

[0157] Those skilled in the art will appreciate that the technical solutions shown in the figures do not limit the embodiments of the present invention and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0158] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0159] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0160] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0161] It should be understood that in the present invention, "at least one (item)" refers to one or more, and "plurality" refers to two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can represent: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0162] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0163] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0164] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0165] If the integrated unit is implemented in the form of a software functional unit and 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 the present invention, 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. The computer software product is stored in a storage medium, including multiple instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store programs.

[0166] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the embodiments of the present invention is not limited thereby. Any modification, equivalent substitution and improvement made by those skilled in the art without departing from the scope and essence of the embodiments of the present invention shall be within the scope of the rights of the embodiments of the present invention.

Claims

1. A multi-target attitude control method for micro-nano satellite formation based on array antenna, characterized in that: The following steps are involved: Initialize a micro-nano satellite formation model; wherein the micro-nano satellite formation includes a master spacecraft, a service spacecraft, and any slave spacecraft to form a master-slave structure; Calculate the bidirectional LOS vector using MIMO communication technology and CDMA technology; According to the bidirectional LOS vector and the spacecraft angular velocity, the control input is calculated so that the control input reaches the desired relative attitude, thereby completing the multi-target attitude control of the micro-nano satellite formation.

2. The multi-target attitude control method of a micro-nano satellite formation based on an array antenna according to claim 1, characterized in that: Each slave spacecraft in the micro-nano satellite formation model is assigned a preset orthogonal spread spectrum sequence, and the expression of the orthogonal spread spectrum sequence is: Among them, a k (τ) represents the spreading sequence of the spacecraft; L represents the length of the sequence; k represents the index of the spacecraft; l represents the index in the sequence; b (k,l) represents the symbol of the lth sequence element of the kth spacecraft; τ represents the time variable; T b Represents cycle; The orthogonal spread spectrum sequence is used to modulate the carrier and transmit the signal through the antenna array carried by it; The main spacecraft and the service spacecraft act as receiving ends. The received signal is the superposition of the signals transmitted by all the slave spacecraft array elements. Through sliding correlation and two-dimensional joint spectrum peak search technology, the three-dimensional arrival angle and departure angle of all line-of-sight signal propagation paths from the spacecraft to the main spacecraft and the service spacecraft are estimated and identified.

3. The multi-target attitude control method of a micro-nano satellite formation based on array antenna according to claim 1, characterized in that: In the step of calculating the bidirectional LOS vector using the MIMO communication technology and the CDMA technology, the calculation formula of the bidirectional LOS vector is: Among them, v k,i represents the LOS vector from the spacecraft to the main and service spacecraft; α k,i represents the projection of the unit LOS vector on the x-axis; β k,i Represents the projection of the unit LOS vector on the y-axis; γ k,i represents the projection of the unit LOS vector on the z-axis; φ k,i Represents the angle between the unit LOS vector and the y-axis; θ k,i represents the angle between the unit LOS vector and the x-axis; k represents the index of the slave spacecraft; i represents the index of the master spacecraft and the service spacecraft, i=1 represents the master spacecraft, and i=2 represents the service spacecraft.

4. The multi-target attitude control method of a micro-nano satellite formation based on an array antenna according to claim 1, characterized in that: In the step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity, the relative attitude of each slave spacecraft is the rotation of the body coordinate system relative to the body coordinate system, which is represented by the rotation matrix in the special orthogonal group, and the expression is: SO(3) = {R∈R 3×3 ∣R T R=I,det(R)=1},where R 3×3 represents a 3×3 dimensional real matrix, det(R) represents the value of the determinant of the matrix R; SO(3) represents a three-dimensional rotation matrix.

5. The multi-target attitude control method of micro-nano satellite formation based on array antenna according to claim 4 is characterized in that: The step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity also includes: Construct the LOS vector u from the master and service spacecraft to the slave spacecraft in the inertial coordinate system i,k , and the LOS vector v from the spacecraft to the master and service spacecraft k,i The expression is: Among them, R c,k represents the rotation matrix of the kth slave spacecraft coordinate system relative to the master spacecraft coordinate system; R k represents the rotation matrix of the kth slave spacecraft coordinate system relative to the inertial coordinate system; s k,i Indicates v k,i with u i,k Representation in an inertial coordinate system.

6. The method for multi-target attitude control of a micro-nano satellite formation based on array antenna according to claim 5, characterized in that: The step of calculating the control input according to the bidirectional LOS vector and the spacecraft angular velocity also includes: Determine the desired target posture based on the posture requirements; The control input is derived so that when time approaches infinity, the rotation matrix of the kth slave spacecraft coordinate system relative to the master spacecraft coordinate system gradually approaches and stabilizes at the desired target attitude. The error equation of this process is expressed as: Among them, Δ k represents the attitude error of the kth slave spacecraft; Δ k,1 ,Δ k,2 Respectively represent MS k Attitude error Δ k Error component relative to SS1, SS2; R d,k represents the desired target posture.

7. The multi-target attitude control method of micro-nano satellite formation based on array antenna according to claim 6 is characterized in that: The infinitesimal change of the rotation matrix is ​​represented by an exponential graph, and the expression is: in, Represents the unit rotation vector; ∈ is an infinitesimal positive number; δR represents the infinitesimal change of the rotation matrix R when ∈ approaches 0; R represents the three-dimensional rotation matrix; The expression for each input from the spacecraft control system is: you k =-k k Oh k -k k,1 f k -k k,2 ψ l Among them, u k represents the control input vector of the kth slave spacecraft; k k represents the angular velocity control gain of the kth slave spacecraft; Ω k represents the angular velocity vector of the kth slave spacecraft; φ k represents the attitude angle deviation of the kth slave spacecraft in the master spacecraft coordinate system; ψ k The attitude angle deviation of the kth slave spacecraft in the service spacecraft coordinate system.

8. The multi-target attitude control method of micro-nano satellite formation based on array antenna according to claim 7 is characterized in that: The Lyapunov function is used to perform relevant stability analysis on the control system input. The expression of this process is: Among them, v is a candidate function of the Lyapunov function; Ω k represents the angular velocity vector of the kth slave spacecraft; J k represents the moment of inertia of the kth slave spacecraft; Δ k,1 represents the attitude error of k slave spacecraft in the master spacecraft coordinate system; Δ k,2 represents the attitude errors of k slave spacecraft in the service spacecraft coordinate system.

9. A multi-target attitude control system for micro-nano satellite formation based on array antenna, characterized in that: include: The first module is used to initialize the micro-nano satellite formation model; wherein the micro-nano satellite formation includes a master spacecraft, a service spacecraft, and any slave spacecraft to form a master-slave structure; The second module is used to calculate the bidirectional LOS vector using MIMO communication technology and CDMA technology; The third module is used to calculate the control input according to the bidirectional LOS vector and the spacecraft angular velocity, so that the control input reaches the desired relative attitude and completes the multi-target attitude control of the micro-nano satellite formation.

10. An electronic device, characterized in that: including a processor and a memory; The memory is used to store programs; The processor executes the program to implement the method according to any one of claims 1 to 8.

Images