Method and device for identifying thruster failure based on sliding mode observer

Abstract

The application discloses a thruster fault identification method and device based on a sliding mode observer. The method comprises the following steps: designing a sliding mode observer based on a spacecraft dynamics model; calculating real three-axis angular velocities of the spacecraft in a current control period based on gyro outputs of the spacecraft system; estimating estimated three-axis angular velocities of the spacecraft in the current control period based on the sliding mode observer; determining a residual function in the current control period based on the real three-axis angular velocities and the estimated three-axis angular velocities; determining whether a thruster fault exists in the current control period based on a relationship between the residual function and a preset threshold; if the thruster fault exists, calculating an estimated thruster fault matrix in the current control period based on the residual function, and calculating an included angle between the estimated thruster fault matrix in the current control period and each column of a predetermined thruster fault matrix, and determining a thruster corresponding to a column with the minimum included angle as a fault thruster. The application can locate the fault to each thruster.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fault diagnosis, in particular to a thruster fault identification method and device based on a sliding mode observer. BACKGROUND

[0002] As the actuator of the spacecraft orbit and attitude control system, the thruster undertakes the functions of spacecraft orbit and attitude control, orbit and attitude maneuvering, and position keeping. Once a fault occurs, it will seriously affect the completion of the spacecraft mission.

[0003] At present, the related technology mainly determines the state of the thruster by using the cumulative jet time of the thruster, that is, when a thruster frequently jets, it is considered that the thruster may have a fault. However, the fault identification result is relatively rough, and it cannot be determined which thruster has a fault, so the fault disposal can only be realized by switching the entire group of thrusters, causing serious waste of on-board resources.

[0004] Therefore, there is an urgent need for a thruster fault identification method and device based on a sliding mode observer to solve the above problems. SUMMARY

[0005] The present application provides a thruster fault identification method and device based on a sliding mode observer, which can locate the fault to each thruster. The technical scheme is as follows:

[0006] On the one hand, a thruster fault identification method based on a sliding mode observer is provided, the method comprising:

[0007] designing a sliding mode observer based on a spacecraft dynamics model; the sliding mode observer is used to estimate the estimated three-axis angular velocity of the spacecraft;

[0008] calculating the real three-axis angular velocity of the spacecraft in the current control period based on the gyro output of the spacecraft system;

[0009] estimating the estimated three-axis angular velocity of the spacecraft in the current control period based on the sliding mode observer;

[0010] determining the residual function of the current control period based on the real three-axis angular velocity and the estimated three-axis angular velocity;

[0011] determining whether there is a thruster fault in the current control period based on the relationship between the residual function and a preset threshold value; if there is, calculating the estimated thruster fault matrix of the current control period based on the residual function, and calculating the included angle between the estimated thruster fault matrix of the current control period and each column of the pre-determined thruster fault matrix, and determining the thruster corresponding to the column with the smallest included angle as the fault thruster.

[0012] On the other hand, a thruster fault identification device based on a sliding mode observer is provided, the device comprising:

[0013] The design unit is used to design a sliding mode observer based on a spacecraft dynamics model; the sliding mode observer is used to estimate the estimated three-axis angular velocities of the spacecraft.

[0014] The computing unit is used to calculate the true three-axis angular velocity of the spacecraft in the current control cycle based on the gyroscope output of the spacecraft system.

[0015] The estimation unit is used to estimate the estimated three-axis angular velocity of the spacecraft in the current control cycle based on the sliding mode observer;

[0016] The first determining unit is used to determine the residual function of the current control cycle based on the actual triaxial angular velocity and the estimated triaxial angular velocity.

[0017] The second determining unit is used to determine whether there is a thruster fault in the current control cycle based on the relationship between the residual function and the preset threshold.

[0018] The third determining unit is used to calculate the thruster fault matrix estimated in the current control cycle based on the residual function when a thruster fault exists, and to calculate the angle between the thruster fault matrix estimated in the current control cycle and each column of the pre-determined thruster fault matrix, and to determine the thruster corresponding to the column with the smallest angle as the faulty thruster.

[0019] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored therein, and when the computer program is executed by a processor, it implements the steps of the thruster fault identification method based on the sliding mode observer described above.

[0020] On the other hand, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the thruster fault identification method based on a sliding mode observer described above.

[0021] This invention provides a thruster fault identification method based on a sliding mode observer. By designing a sliding mode observer, the three-axis angular velocities of the spacecraft can be estimated. Then, by comparing and analyzing the gyroscope output and the sliding mode observer output, a residual function is obtained. Next, the relationship between the residual function and a threshold is used to determine whether a thruster fault exists. If a fault exists, an estimated thruster fault matrix is ​​determined. Finally, based on the angle between the estimated thruster fault matrix and each column of a pre-determined thruster fault matrix, the specific location of the faulty thruster is determined. Therefore, this application can achieve thruster fault detection and accurate location, providing a foundation for improving the accuracy of thruster fault diagnosis and refining fault handling strategies. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of a thruster fault identification method based on a sliding mode observer provided in an embodiment of the present invention;

[0024] Figure 2 This is a structural diagram of a thruster fault identification device based on a sliding mode observer provided in an embodiment of the present invention;

[0025] Figure 3 This is a hardware architecture diagram of a computer device provided in an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] The specific implementation of the above concept is described below.

[0028] Please refer to Figure 1 The present invention provides a thruster fault identification method based on a sliding mode observer, the method comprising:

[0029] Step 100: Based on the spacecraft dynamics model, design a sliding mode observer; the sliding mode observer is used to estimate the estimated three-axis angular velocities of the spacecraft.

[0030] Step 102: Calculate the actual three-axis angular velocity of the spacecraft during the current control cycle based on the gyroscope output of the spacecraft system;

[0031] Step 104: Based on the sliding mode observer, estimate the estimated three-axis angular velocity of the spacecraft in the current control cycle;

[0032] Step 106: Determine the residual function for the current control cycle based on the actual triaxial angular velocity and the estimated triaxial angular velocity;

[0033] Step 108: Based on the relationship between the residual function and the preset threshold, determine whether there is a thruster fault in the current control cycle;

[0034] Step 110: When a thruster fault exists, calculate the thruster fault matrix estimated for the current control cycle based on the residual function, and calculate the angle between the thruster fault matrix estimated for the current control cycle and each column of the predetermined thruster fault matrix. The thruster corresponding to the column with the smallest angle is identified as the faulty thruster.

[0035] In this embodiment, a sliding mode observer is designed to estimate the three-axis angular velocities of the spacecraft. Then, by comparing and analyzing the gyroscope output and the sliding mode observer output, a residual function is obtained. Next, the relationship between the residual function and a threshold is used to determine whether a thruster fault exists; if so, an estimated thruster fault matrix is ​​determined. Finally, based on the angle between the estimated thruster fault matrix and each column of a pre-determined thruster fault matrix, the specific location of the faulty thruster is determined. Therefore, this application can achieve thruster fault detection and accurate location, providing a foundation for improving the accuracy of thruster fault diagnosis and refining fault handling strategies.

[0036] The following description Figure 1 The execution method for each step is shown.

[0037] First, regarding step 100:

[0038] The following spacecraft dynamics model is adopted:

[0039]

[0040] in,

[0041] Based on the above spacecraft dynamics model, the following glide mode observer model is designed:

[0042]

[0043] In the formula, I is the moment of inertia; U = diag(T1, T2, T3) is the desired output torque matrix, where T1, T2, and T3 are the desired output torques along the x-axis, y-axis, and z-axis of the spacecraft, respectively; ω = [ω1 ω2 ω3] T ω1, ω2, and ω3 represent the actual three-axis angular velocities of the spacecraft, with ω1, ω2, and ω3 being the angular velocities along the x, y, and z axes, respectively. The derivative of ω; ω x Let ω be the antisymmetric matrix; D is the thruster fault matrix. This indicates that D is 3 × N thrust A real matrix, N thrust The number of thrusters; ft,i This indicates a fault in thruster i, where i = 1, 2, ..., N. thrust d represents the external disturbance torque, satisfying... The maximum boundary of the external disturbance torque d; ||·|| represents the norm; Let L be the estimated thruster fault matrix; L is a positive definite matrix, L∈R 3×3 ; The estimated three-axis angular velocities of the spacecraft output by the sliding mode observer; for The differential; for An antisymmetric matrix.

[0044] By designing the aforementioned sliding mode observer, the three-axis angular velocities of a spacecraft can be estimated based on its output.

[0045] For step 102, based on the gyroscope output of the spacecraft system, calculate the spacecraft's true three-axis angular velocity during the current control cycle, including:

[0046] Determine whether the gyroscope is a gyroscope with three orthogonally mounted axes;

[0047] If so, the three-axis angular velocity output by the gyroscope will be used as the three-axis angular velocity of the spacecraft;

[0048] If not, the three-axis angular velocities of the spacecraft are determined based on the following formula;

[0049]

[0050] In the formula, ω represents the actual three-axis angular velocity of the spacecraft, ω1, ω2, and ω3 are the angular velocities along the x-axis, y-axis, and z-axis, respectively; V is the mounting matrix of the gyroscope; g1, g2, and g... s denoted as ω0 and ωs as the output angular velocities of the gyroscopes, respectively, and s is the number of gyroscopes.

[0051] In this step, each gyroscope is a fault-free gyroscope that can accurately output angular velocity.

[0052] For step 106, the formula for calculating the residual function is:

[0053]

[0054] In the formula, r(t) is the residual function at time t, and ω(t) is the actual triaxial angular velocity of the spacecraft at time t; Let t be the estimated three-axis angular velocity of the spacecraft output by the sliding mode observer.

[0055] In this step, the residual function can be obtained by simultaneously solving the calculation formulas of the spacecraft dynamics model and the sliding mode observer.

[0056] For step 108, based on the relationship between the residual function and the preset threshold, determine whether there is a thruster fault in the current control cycle, including:

[0057] Determine whether the residual function is less than a preset threshold;

[0058] If so, then it is determined that there is no thruster fault in the current control cycle;

[0059] If not, then a thruster malfunction is determined to exist in the current control cycle.

[0060] In some implementations, the preset threshold at each time point is determined using the following formula:

[0061]

[0062] In the formula, J th (t) is a preset threshold at time t, used to represent the upper bound of the residual evaluation function; t is time t; k and λ are positive numbers, and the two parameters satisfy ||e^(-k / λ)||. Λt ||≤ke -λt Λ is a stable matrix; γ1 is the Lipschitz constant with respect to ω, satisfying ε is a constant, satisfying Let I be the moment of inertia; This represents the maximum boundary of the external disturbance torque d.

[0063] In this step, the preset threshold is a time-varying threshold, with different thresholds used at different times; it is a function of time. By using a time-varying threshold, the influence of external interference can be fully considered, thereby reducing the false alarm rate and false alarm rate of thruster fault detection.

[0064] In some implementations, the thruster fault matrix estimated for each control cycle is determined using the following formula:

[0065]

[0066] In the formula, and The thruster fault matrices estimated at time t and time t-1, respectively; γ and δ s Let be a positive real number; r(t) be the residual function at time t; U = diag(T1, T2, T3) be the desired output torque matrix, where T1, T2, and T3 are the desired output torques along the x, y, and z axes of the spacecraft, respectively; P is a symmetric matrix that satisfies the following conditions:

[0067]

[0068] in, Γ=-I -1 L;

[0069] Ω1 and Γ are both intermediate parameters; L is a positive definite matrix, L∈R 3×3 .

[0070] In this step, for any control cycle, as long as the residual function of the control cycle and the thruster fault matrix estimated in the previous control cycle are obtained, the thruster fault matrix estimated in the control cycle can be calculated.

[0071] Finally, in some implementations, the failed thruster is determined using the following formula:

[0072]

[0073] In the formula, i f The number of the thruster that failed; d i The i-th column of the thruster fault matrix D; N represents the estimated thruster fault matrix. thrust The number of thrusters; norm(·) represents modulo; dot(·) represents dot product.

[0074] In this step, the smaller the angle between the estimated thruster fault matrix and the corresponding column in the predetermined thruster fault matrix, the better the calculated i... f The larger the value, the greater the possibility of it having a fault. Therefore, i f The thruster corresponding to the largest column was identified as the faulty thruster.

[0075] like Figure 2 , Figure 3 As shown, this embodiment of the invention provides a thruster fault identification device based on a sliding mode observer. The device embodiment can be implemented through software, hardware, or a combination of both. From a hardware perspective, such as... Figure 2 The diagram shown is a hardware architecture diagram of a computing device for a thruster fault identification device based on a sliding mode observer, provided in an embodiment of the present invention. (Except for...) Figure 2 In addition to the processor, memory, network interface, and non-volatile memory shown, the computing device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, such as... Figure 3 As shown, a device in a logical sense is formed by the CPU of the computing device in which it is located reading the corresponding computer program from the non-volatile memory into the memory for execution.

[0076] Please refer to Figure 3 This invention provides a thruster fault identification device based on a sliding mode observer, the device comprising:

[0077] Design unit 300 is used to design a sliding mode observer based on a spacecraft dynamics model; the sliding mode observer is used to estimate the estimated three-axis angular velocities of the spacecraft.

[0078] The calculation unit 302 is used to calculate the true three-axis angular velocity of the spacecraft in the current control cycle based on the gyroscope output of the spacecraft system.

[0079] Estimation unit 304 is used to estimate the estimated three-axis angular velocity of the spacecraft in the current control cycle based on the sliding mode observer;

[0080] The first determining unit 306 is used to determine the residual function of the current control cycle based on the actual triaxial angular velocity and the estimated triaxial angular velocity.

[0081] The second determining unit 308 is used to determine whether there is a thruster fault in the current control cycle based on the relationship between the residual function and the preset threshold.

[0082] The third determining unit 310 is used to calculate the thruster fault matrix estimated in the current control cycle based on the residual function when a thruster fault exists, and to calculate the angle between the thruster fault matrix estimated in the current control cycle and each column of the pre-determined thruster fault matrix, and to determine the thruster corresponding to the column with the smallest angle as the faulty thruster.

[0083] In some implementations, the spacecraft dynamics model is as follows:

[0084]

[0085] in,

[0086] The sliding mode observer satisfies the following formula:

[0087]

[0088] In the formula, I is the moment of inertia; U = diag(T1, T2, T3) is the desired output torque matrix, where T1, T2, and T3 are the desired output torques along the x-axis, y-axis, and z-axis of the spacecraft, respectively; ω = [ω1 ω2 ω3] T ω1, ω2, and ω3 represent the actual three-axis angular velocities of the spacecraft, with ω1, ω2, and ω3 being the angular velocities along the x, y, and z axes, respectively. The derivative of ω; ω x Let ω be the antisymmetric matrix; D is the thruster fault matrix. This indicates that D is 3 × N thrust A real matrix, N thrust The number of thrusters; f t,i This indicates a fault in thruster i, where i = 1, 2, ..., N. thrustd represents the external disturbance torque, satisfying... The maximum boundary of the external disturbance torque d; ||·|| represents the norm; Let L be the estimated thruster fault matrix; L is a positive definite matrix, L∈R 3×3 ; The estimated three-axis angular velocities of the spacecraft output by the sliding mode observer; for The differential; for An antisymmetric matrix.

[0089] In some implementations, the computing unit 302 is used to perform the following operations:

[0090] Determine whether the gyroscope is a gyroscope with three orthogonally mounted axes;

[0091] If so, the three-axis angular velocity output by the gyroscope will be used as the three-axis angular velocity of the spacecraft;

[0092] If not, the three-axis angular velocities of the spacecraft are determined based on the following formula;

[0093]

[0094] In the formula, ω represents the actual three-axis angular velocity of the spacecraft, ω1, ω2, and ω3 are the angular velocities along the x-axis, y-axis, and z-axis, respectively; V is the mounting matrix of the gyroscope; g1, g2, and g... s denoted as ω0 and ωs as the output angular velocities of the gyroscopes, respectively, and s is the number of gyroscopes.

[0095] In some implementations, the residual function is calculated using the following formula:

[0096]

[0097] In the formula, r(t) is the residual function at time t, and ω(t) is the actual triaxial angular velocity of the spacecraft; The estimated three-axis angular velocities of the spacecraft are output by the sliding mode observer.

[0098] In some implementations, the existence of a thruster fault in the current control cycle is determined based on the relationship between the residual function and a preset threshold, including:

[0099] Determine whether the residual function is less than a preset threshold;

[0100] If so, then it is determined that there is no thruster fault in the current control cycle;

[0101] If not, then a thruster malfunction is determined to exist in the current control cycle.

[0102] In some implementations, the preset threshold is a time-varying threshold, and the preset threshold at each time point is determined using the following formula:

[0103]

[0104] In the formula, J th (t) is a preset threshold at time t, used to represent the upper bound of the residual evaluation function; t is time t; k and λ are positive numbers, and the two parameters satisfy ||e^(-k / λ)||. Λt ||≤ke -λt Λ is a stable matrix; γ1 is the Lipschitz constant with respect to ω, satisfying ε is a constant, satisfying Let I be the moment of inertia; This represents the maximum boundary of the external disturbance torque d.

[0105] In some implementations, the thruster fault matrix estimated for each control cycle is determined using the following formula:

[0106]

[0107] In the formula, and The thruster fault matrices estimated at time t and time t-1, respectively; γ and δ s Let be a positive real number; r(t) be the residual function at time t; U = diag(T1, T2, T3) be the desired output torque matrix, where T1, T2, and T3 are the desired output torques along the x, y, and z axes of the spacecraft, respectively; P is a symmetric matrix that satisfies the following conditions:

[0108]

[0109] in,

[0110] Γ=-I -1 L;

[0111] Ω1 and Γ are both intermediate parameters; L is a positive definite matrix, L∈R 3×3 .

[0112] In some implementations, the faulty thruster is determined using the following formula:

[0113]

[0114] In the formula, i f The number of the thruster that failed; d i The i-th column of the thruster fault matrix D; N represents the estimated thruster fault matrix. thrustThe number of thrusters; norm(·) represents modulo; dot(·) represents dot product.

[0115] It should be noted that the thruster fault identification device based on a sliding mode observer provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the thruster fault identification device based on a sliding mode observer provided in the above embodiments and the thruster fault identification method embodiments based on a sliding mode observer belong to the same concept. The specific implementation process is detailed in the method embodiments and will not be repeated here.

[0116] Embodiments of this application also provide a computer device, please refer to... Figure 3 The computer device includes a processor and a memory, the memory storing at least one instruction, at least one program, code set or instruction set, the at least one instruction, at least one program, code set or instruction set being loaded and executed by the processor to implement the thruster fault identification method based on sliding mode observer provided in the above method embodiments.

[0117] Embodiments of this application also provide a computer-readable storage medium storing at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, at least one program, code set, or instruction set is loaded and executed by a processor to implement the thruster fault identification method based on sliding mode observer provided in the above-described method embodiments.

[0118] Embodiments of this application also provide a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium and executes the computer program, causing the computer device to perform any of the thruster fault identification methods based on sliding mode observers described in the above embodiments.

[0119] For ease of description, the above systems or devices are described separately as various modules or units based on their functions. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware components.

[0120] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0121] Finally, it should be noted that in this document, relational terms such as first, second, third, and fourth are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0122] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A thruster fault identification method based on a sliding mode observer, characterized in that, The method includes: A sliding mode observer is designed based on a spacecraft dynamics model; the sliding mode observer is used to estimate the estimated three-axis angular velocities of the spacecraft. Based on the gyroscope output of the spacecraft system, calculate the true three-axis angular velocity of the spacecraft in the current control cycle; Based on the sliding mode observer, estimate the estimated three-axis angular velocity of the spacecraft in the current control cycle; Based on the actual triaxial angular velocity and the estimated triaxial angular velocity, determine the residual function for the current control cycle; Based on the relationship between the residual function and the preset threshold, it is determined whether there is a thruster fault in the current control cycle; if so, the thruster fault matrix estimated for the current control cycle is calculated based on the residual function, and the angle between the thruster fault matrix estimated for the current control cycle and each column of the predetermined thruster fault matrix is ​​calculated. The thruster corresponding to the column with the smallest angle is determined as the faulty thruster. The step of determining whether a thruster fault exists in the current control cycle based on the relationship between the residual function and a preset threshold includes: Determine whether the residual function is less than the preset threshold; If so, then it is determined that there is no thruster fault in the current control cycle; If not, then it is determined that there is a thruster malfunction in the current control cycle; The preset threshold is a time-varying threshold, and the preset threshold at each time point is determined using the following formula: In the formula, for t The preset threshold at time is used to represent the upper bound of the residual evaluation function; t For a specific moment; k and For positive numbers, the two parameters satisfy... , It is a stable matrix; For about The Lipschitz constant satisfies ; It is a constant, satisfying ; I It is the moment of inertia; External disturbance torque d The maximum boundary; The actual three-axis angular velocity of the spacecraft, , and These are the angular velocities along the x-axis, y-axis, and z-axis, respectively. for The antisymmetric matrix; The estimated three-axis angular velocities of the spacecraft output by the sliding mode observer; for The antisymmetric matrix; The thruster fault matrix estimated for each control cycle is determined using the following formula: In the formula, and They are respectively t Time and t The thruster fault matrix estimated at time -1; and It is a positive real number; for t The residual function at time step; To output the torque matrix, , and These represent the desired output torques along the x, y, and z axes of the spacecraft, respectively. P It is a symmetric matrix. P The following conditions must be met: in, , ; and These are all intermediate parameters; It is a positive definite matrix. ; The following formula is used to determine the faulty thruster: In the formula, The serial number of the thruster that failed; thruster fault matrix D The i List; The estimated thruster fault matrix; The number of thrusters; norm() represents modulo; dot() represents dot product.

2. The method according to claim 1, characterized in that, The spacecraft dynamics model is as follows: in, The sliding mode observer satisfies the following formula: In the formula, I It is the moment of inertia; To output the torque matrix, , and These represent the desired output torques along the x, y, and z axes of the spacecraft, respectively. The actual three-axis angular velocity of the spacecraft, , and These are the angular velocities along the x-axis, y-axis, and z-axis, respectively. for The differential; for The antisymmetric matrix; D For the thruster fault matrix, ,express D 3× A real matrix, The number of thrusters; , Indicates thruster i The fault, i =1,2,... ; d For external disturbance torque, satisfy , External disturbance torque d The maximum boundary; Represents the norm; The estimated thruster fault matrix; It is a positive definite matrix. ; The estimated three-axis angular velocities of the spacecraft output by the sliding mode observer; for The differential; for An antisymmetric matrix.

3. The method according to claim 1, characterized in that, The calculation of the spacecraft's true three-axis angular velocity during the current control cycle, based on the gyroscope output of the spacecraft system, includes: Determine whether the gyroscope is a gyroscope with three orthogonally mounted axes; If so, the three-axis angular velocity output by the gyroscope will be used as the three-axis angular velocity of the spacecraft; If not, the three-axis angular velocities of the spacecraft are determined based on the following formula; In the formula, The actual three-axis angular velocity of the spacecraft, , and These are the angular velocities along the x-axis, y-axis, and z-axis, respectively. V This is the mounting matrix for the gyroscope; , to These are the output angular velocities of the gyroscope. s The number of spinning tops.

4. The method according to claim 1, characterized in that, The formula for calculating the residual function is as follows: In the formula, for t The residual function at time t, for t The actual three-axis angular velocity of the spacecraft at any given moment; for t The estimated three-axis angular velocities of the spacecraft are output by the sliding mode observer at any given time.

5. A thruster fault identification device based on a sliding mode observer, characterized in that, The apparatus for implementing the method according to any one of claims 1-4 comprises: The design unit is used to design a sliding mode observer based on a spacecraft dynamics model; the sliding mode observer is used to estimate the estimated three-axis angular velocities of the spacecraft. The computing unit is used to calculate the true three-axis angular velocity of the spacecraft in the current control cycle based on the gyroscope output of the spacecraft system. The estimation unit is used to estimate the estimated three-axis angular velocity of the spacecraft in the current control cycle based on the sliding mode observer; The first determining unit is used to determine the residual function of the current control cycle based on the actual triaxial angular velocity and the estimated triaxial angular velocity. The second determining unit is used to determine whether there is a thruster fault in the current control cycle based on the relationship between the residual function and the preset threshold. The third determining unit is used to calculate the thruster fault matrix estimated in the current control cycle based on the residual function when a thruster fault exists, and to calculate the angle between the thruster fault matrix estimated in the current control cycle and each column of the pre-determined thruster fault matrix, and to determine the thruster corresponding to the column with the smallest angle as the faulty thruster.

6. A computer device, characterized in that, The computer device includes a memory and a processor. The memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory to implement the steps of the method according to any one of claims 1-4.

Images