Dynamic correction method of angular velocity limitation based on hierarchical saturation control law for maneuvering conditions

Abstract

The present invention discloses a method for dynamically correcting the angular velocity limit of a hierarchical saturation control law based on a maneuvering condition, comprising: calculating the maximum allowable attitude angular velocity ω during the attitude maneuvering process; max ; According to the residual angular momentum H0 of the actuator and the satellite moment of inertia matrix I0 at the initial moment of the attitude maneuver, the residual angular momentum H0 is converted into the initial angular velocity limit constraint vector ω1; according to the current attitude maneuvering task, the maneuvering target angular velocity ω2 is determined, and the sum vector ω3 of the initial angular velocity limit constraint vector ω1 and the maneuvering target angular velocity ω2 is calculated; according to the attitude angular velocity measured by the current gyro combination, the deviation ω between the current attitude angular velocity and the target attitude angular velocity is calculated in real time err , and calculate its unit vector; according to the calculated maximum allowable attitude angular velocity ω max and angular velocity deviation ω err As a result, the current maneuvering attitude angular velocity limit value ω is calculated in real time sat The present invention enhances the adaptability of the control algorithm to different tasks, and improves the satellite's on-orbit autonomy and task execution efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of satellite attitude control, and in particular to a method for dynamically correcting angular velocity limits of a hierarchical saturation control law based on a maneuvering condition. Background Art

[0002] The hierarchical saturation control law is based on the classic PID control law, which artificially limits the output torque and attitude deviation to achieve an improved control algorithm that can obtain near-time optimal dynamic performance without planning the attitude path in advance. Among them, the output torque limit is constrained by the output capacity of the actuator, and the attitude deviation limit indirectly reflects the maneuvering angular velocity deviation limit, which is constrained by the size of the actuator angular momentum envelope and needs to be designed according to the actual product matching and maneuvering conditions.

[0003] Since the angular momentum envelope of the control moment gyro group is actually its singular state, the angular momentum of the control moment gyro group cannot be used to the limit state of the angular momentum envelope during use, and the range of angular momentum use must be strictly limited. Satellites equipped with a control moment gyro group as an actuator have stricter requirements on the angular velocity deviation limit when using a hierarchical saturation control law.

[0004] Most traditional attitude maneuvering tasks belong to the working conditions of maneuvering between two fixed offset attitudes. Since the target angular velocity of this type of task is zero, the angular velocity deviation limit of the hierarchical saturation control law reflects the limit of the actual maneuvering angular velocity. Therefore, the maximum maneuvering angular velocity can be calculated through parameters such as the actuator angular momentum envelope and moment of inertia, and directly used as the angular velocity deviation limit value in the hierarchical saturation control law.

[0005] With the improvement of satellite maneuverability, the on-orbit working modes are becoming more and more diverse, including new working modes such as oblique strip push-scanning and regional strip splicing, which also change the attitude maneuvering conditions. The most obvious difference is that the target attitude is no longer a fixed attitude, but needs to track a certain angular velocity to move. At this time, using the traditional maximum maneuvering angular velocity as the deviation angular velocity limit value for algorithm design will cause the actual maneuvering angular velocity to exceed the allowable value, and may even cause the control torque gyro group to fall into a singular state. Summary of the invention

[0006] The purpose of the present invention is to provide a method for dynamic correction of angular velocity limiting of a hierarchical saturation control law based on maneuvering conditions, so as to realize attitude maneuvering tasks for complex imaging modes, enhance the adaptability of the control algorithm to different tasks, and improve the satellite's on-orbit autonomy and mission execution efficiency.

[0007] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0008] A method for dynamically correcting angular velocity limiting of a hierarchical saturation control law based on a maneuvering condition comprises:

[0009] Step S1: According to the maximum angular momentum H that the actuator can provide in the three-dimensional angular momentum space max and the satellite's maximum moment of inertia I max , calculate the maximum allowable attitude angular velocity ω during attitude maneuvers max .

[0010] Step S2: According to the initial moment of the attitude maneuver, the residual angular momentum H of the actuator 0 and the satellite moment of inertia matrix I 0 , the residual angular momentum H 0 Converted into the initial angular velocity limit constraint vector ω 1 .

[0011] Step S3: Determine the maneuvering target angular velocity ω according to the current attitude maneuvering task 2 , and calculate the initial angular velocity limit constraint vector ω 1 and the maneuvering target angular velocity ω 2 The sum vector ω 3 .

[0012] Step S4: Calculate the deviation ω between the current attitude angular velocity and the target attitude angular velocity in real time based on the attitude angular velocity measured by the current gyro combination. err , and calculate its unit vector.

[0013] Step S5: According to the calculated maximum allowable attitude angular velocity ω max and angular velocity deviation ω err As a result, the current maneuvering attitude angular velocity limit value ω is calculated in real time sat .

[0014] Optionally, calculate the maximum allowable attitude angular velocity ω during the attitude maneuver max , calculated as:

[0015]

[0016] Where: The coefficient k is used to adjust the angular momentum margin and is selected between 0.95 and 1.

[0017] Optionally, in order to facilitate the angular velocity limiting correction, the residual angular momentum is converted into a three-axis angular velocity to form an initial angular velocity constraint vector ω 1 , calculated as:

[0018] ω 1 =I -1 *H 0

[0019] Where: I is the satellite moment of inertia matrix, the superscript “-1” indicates the matrix inversion operation, and the symbol “*” indicates the matrix multiplication operation.

[0020] Optionally, the angular velocity deviation ω err is the difference between the target angular velocity and the current actual angular velocity, calculated as

[0021] ω err =ω 2 -ω

[0022] Where: ω is the current real-time angular velocity of the satellite.

[0023] Optionally, according to the geometric relationship, the current maneuvering attitude angular velocity limit value ω sat satisfy

[0024]

[0025] Where: l 1 and l 2 Satisfy

[0026] l 1 =||ω 3 ×<ω err 〉||

[0027] l 2 =-ω 3 ·<ω err >

[0028] Wherein: the symbol “<>” represents the unit vector operation of the orientation quantity, the symbol “×” represents the vector cross multiplication operation, the symbol “|| ||” represents the vector modulus operation, and the symbol “·” represents the vector dot multiplication operation.

[0029] On the other hand, the present invention further provides an electronic device, including a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method described above is implemented.

[0030] In yet another aspect, the present invention further provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0031] The present invention has at least one of the following advantages:

[0032] The present invention provides a method for dynamic correction of angular velocity limiting of a hierarchical saturation control law based on maneuvering conditions. It can solve the attitude angular velocity limiting value in real time according to the actual maneuvering process according to the different requirements of complex imaging modes for maneuvering angular velocity limiting values, realize the comprehensive applicability of the control law to multi-mode maneuvering conditions, solve the problem of preset limiting values ​​and conservatism, and further improve the attitude maneuvering performance.

[0033] That is, the present invention can solve the problem that the conventional preset angular velocity limit value cannot adapt to various complex imaging mode tasks on orbit, reduce the dependence of the control law on pre-set parameters and human intervention, and improve the satellite's on-orbit autonomy and mission execution efficiency. In addition, the preset limit parameters are usually too conservative because they are required to be used in all working conditions. Real-time calculation of the limit value according to the actual maneuvering process can solve this problem and further improve the attitude maneuvering performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flow chart for realizing dynamic correction of attitude angular velocity limit value provided by one embodiment of the present invention;

[0035] Figure 2 A schematic diagram of multiple constraints for attitude angular velocity limiting provided by an embodiment of the present invention;

[0036] Figure 3 A schematic diagram of the calculation principle of the attitude angular velocity limit value provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following is a further detailed description of a dynamic correction method for angular velocity limiting of a hierarchical saturation control law based on a maneuvering condition proposed by the present invention in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation method of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any modification of the structure, change in the proportional relationship or adjustment of the size, without affecting the effect that the present invention can produce and the purpose that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0038] In view of the future multi-mode complex attitude maneuvering mission requirements, it is necessary to improve the satellite's ability to autonomously correct the angular velocity deviation limit of the hierarchical saturation control law in orbit according to the actual maneuvering conditions, so that in any attitude maneuvering mission, the angular momentum of the control moment gyro group is within a reasonable range to ensure that it will not fall into a singular configuration. The present invention achieves the above requirements by providing a dynamic correction method for the angular velocity limit of the hierarchical saturation control law based on the maneuvering conditions.

[0039] like Figure 1 As shown, this embodiment provides a method for dynamically correcting angular velocity limit based on a hierarchical saturation control law of a maneuvering condition, comprising: step S1, according to the maximum angular momentum H that the actuator can provide in the three-dimensional angular momentum space max and the satellite's maximum moment of inertia I max , calculate the maximum allowable attitude angular velocity ω during attitude maneuvers max .

[0040] First, according to the specific model and actual installation configuration of the actuator, determine the maximum angular momentum it can provide in the three-dimensional angular momentum space, denoted as H max , combined with the satellite's maximum moment of inertia I max , calculate the maximum allowable attitude angular velocity ω during attitude maneuvers max , calculated as

[0041]

[0042] Where: The coefficient k is used to adjust the angular momentum margin and can usually be selected between 0.95 and 1.

[0043] Step S2: According to the initial moment of the attitude maneuver, the residual angular momentum H of the actuator 0 and the satellite moment of inertia matrix I 0 , the residual angular momentum H 0 Converted into the initial angular velocity limit constraint vector ω 1 .

[0044] Due to the complex space interference, the angular momentum of the actuator will continue to accumulate when the satellite is in orbit. Even if it is unloaded by thrusters or magnetic torquers, it is still impossible to completely unload the angular momentum to 0. Therefore, each time the maneuver begins, the actuator must have a certain amount of residual angular momentum, which is recorded as vector H. 0 , this residual angular momentum will affect the actual angular momentum usage range of the available angular momentum.

[0045] In order to facilitate the angular velocity limit correction, the residual angular momentum is converted into three-axis angular velocity to form the initial angular velocity constraint vector ω 1 , calculated as

[0046] ω 1 =I-1 *H 0 (2)

[0047] Where: I is the satellite moment of inertia matrix, the superscript “-1” indicates the matrix inversion operation, and the symbol “*” indicates the matrix multiplication operation.

[0048] Step S3: Determine the maneuvering target angular velocity ω according to the current attitude maneuvering task 2 , and calculate the initial angular velocity limit constraint vector ω 1 and the maneuvering target angular velocity ω 2 The sum vector ω 3 .

[0049] like Figure 2 As shown, according to the specific task and working conditions, the maneuvering target angular velocity ω of the current attitude maneuvering task can be determined in advance 2 For each attitude maneuver task, the residual angular momentum of the actuator and the target angular velocity can be determined in advance, that is, the initial angular velocity limit constraint vector ω 1 And the current attitude maneuvering task determines the maneuvering target angular velocity ω 2 Both are known. To facilitate subsequent processing, these two design constraints are combined into a vector, denoted as ω 3 .

[0050] Step S4: Calculate the deviation ω between the current attitude angular velocity and the target attitude angular velocity in real time based on the attitude angular velocity measured by the current gyro combination. err , and calculate its unit vector.

[0051] Under this constraint, the angular velocity deviation ω err Limiting is performed to ensure that the actuator angular momentum does not exceed the maximum envelope.

[0052] Angular velocity deviation ω err is the difference between the target angular velocity and the current actual angular velocity, calculated as

[0053] ω err =ω 2 -ω (3)

[0054] Where: ω is the current real-time angular velocity of the satellite.

[0055] Step S5: According to the calculated maximum allowable attitude angular velocity ω max and angular velocity deviation ω err As a result, the current maneuvering attitude angular velocity limit value ω is calculated in real time sat .

[0056] When the satellite attitude angular velocity reaches its maximum value, vector ω 3 , angular velocity deviation ω errand the maximum permissible angular velocity ω max The relationship between physical quantities is as follows Figure 3 As shown. The angular velocity deviation ω is reflected in the hierarchical saturation control algorithm. err The limit value, that is, to calculate ω in real time sat The value of .

[0057] According to the geometric relationship, ω sat satisfy

[0058]

[0059] Where: l 1 and l 2 Satisfy

[0060] l 1 =||ω 3 ×<ω err >|| (5)

[0061] l 2 =-ω 3 ·<ω err > (6)

[0062] Wherein: the symbol “<>” represents the unit vector operation of the orientation quantity, the symbol “×” represents the vector cross multiplication operation, the symbol “|| ||” represents the vector modulus operation, and the symbol “·” represents the vector dot multiplication operation.

[0063] Substituting the calculation results of equations (5) and (6) into equation (4), the required angular velocity deviation limit value ω can be obtained. sat , and then used for the design of limiting parameters of the hierarchical saturation control algorithm.

[0064] On the other hand, the present invention further provides an electronic device, including a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method described above is implemented.

[0065] In yet another aspect, the present invention further provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0066] In summary, the present embodiment provides a method for dynamically correcting the angular velocity limit of the hierarchical saturation control law based on maneuvering conditions. On the one hand, the initial residual angular momentum of the actuator is converted into the attitude angular velocity limit constraint for the situation where the angular momentum is constantly accumulated during frequent agile attitude maneuvers. On the other hand, the angular velocity limit is dynamically corrected for maneuvering conditions where the target angular velocity is non-zero, effectively avoiding the saturation of the angular momentum of the actuator during the continuous execution of complex maneuvering tasks, and realizing the full applicability of the control law to multi-mode frequent maneuvering conditions. Compared with the prior art, the beneficial effects are: for complex and continuous maneuvering control tasks of satellites on orbit, there is no need to set in advance or manually intervene to switch the angular velocity limit value, which improves the efficiency and reliability of satellite on-orbit mission execution. Real-time updating of the angular velocity limit value according to the actual maneuvering conditions can also solve the problem of the preset limit value being too conservative, and further improve the attitude maneuvering performance.

[0067] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0068] It should be noted that the devices and methods disclosed in the embodiments of this article can also be implemented in other ways. The device implementation described above is only schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of this article. In this regard, each box in the flowchart or block diagram can represent a part of a module, program or code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented by a dedicated hardware-based system for performing a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0069] In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0070] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A method for dynamic correction of angular velocity limit based on hierarchical saturation control law of maneuvering conditions, characterized in that: include: Step S1: According to the maximum angular momentum H that the actuator can provide in the three-dimensional angular momentum space max and the satellite's maximum moment of inertia I max , calculate the maximum allowable attitude angular velocity ω during attitude maneuvers max ; Step S2, according to the residual angular momentum H0 of the actuator and the satellite moment of inertia matrix I0 at the initial moment of the attitude maneuver, the residual angular momentum H0 is converted into the initial angular velocity limit constraint vector ω1; Step S3, determining the maneuvering target angular velocity ω2 according to the current attitude maneuvering task, and calculating the sum vector ω3 of the initial angular velocity limit constraint vector ω1 and the maneuvering target angular velocity ω2; Step S4: Calculate the deviation ω between the current attitude angular velocity and the target attitude angular velocity in real time based on the attitude angular velocity measured by the current gyro combination. err , and calculate its unit vector; Step S5: According to the calculated maximum allowable attitude angular velocity ω max and angular velocity deviation ω err As a result, the current maneuvering attitude angular velocity limit value ω is calculated in real time sat .

2. The method for dynamic correction of angular velocity limitation of hierarchical saturation control law based on maneuvering conditions according to claim 1, characterized in that: Calculate the maximum allowable attitude angular velocity ω during attitude maneuvers max , calculated as: Where: The coefficient k is used to adjust the angular momentum margin and is selected between 0.95 and 1.

3. The method for dynamic correction of angular velocity limitation of hierarchical saturation control law based on maneuvering conditions according to claim 1, characterized in that: In order to facilitate the angular velocity limit correction, the residual angular momentum is converted into three-axis angular velocity to form the initial angular velocity constraint vector ω1, which is calculated as follows: ω1=I -1 *H0 Where: I is the satellite moment of inertia matrix, the superscript "-1" represents the matrix inversion operation, and the symbol "*" represents the matrix multiplication operation.

4. The method for dynamic correction of angular velocity limitation of hierarchical saturation control law based on maneuvering conditions according to claim 1, characterized in that: Angular velocity deviation ω err is the difference between the target angular velocity and the current actual angular velocity, calculated as oh err =ω2-ω Where: ω is the current real-time angular velocity of the satellite.

5. The method for dynamic correction of angular velocity limitation of hierarchical saturation control law based on maneuvering conditions according to claim 1, characterized in that: According to the geometric relationship, the current maneuvering attitude angular velocity limit value ω sat satisfy Where: l1 and l2 satisfy l1=||ω3×<ω err , <h2 style=";text-align:left;direction:ltr">l2 = -ω3 · <ω<h2 style=";text-align:left;direction:ltr"> err <h2 style=";text-align:left;direction:ltr"> > Wherein: the symbol "<>" represents the unit vector operation of the orientation quantity, the symbol "×" represents the vector cross multiplication operation, the symbol "|| ||" represents the vector modulus operation, and the symbol "·" represents the vector dot multiplication operation.

6. An electronic device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method according to any one of claims 1 to 5 is implemented.

7. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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