A method for analyzing the control capability of a satellite magnetic torque converter

Abstract

This invention discloses a method for analyzing the control capability of a satellite magnetic torquer, belonging to the field of satellite attitude and orbit control technology. The method first acquires the three-axis magnetic field strength data of the satellite's own system; then, it iterates through all specified torque directions. For each specified torque direction, it first calculates the average value of the maximum magnetic torque under different magnetic field strengths, and then calculates the corresponding magnetic torquer control capability; finally, based on the magnetic torquer control capability in each specified torque direction, it analyzes whether the magnetic torquer meets the control requirements. This invention can accurately obtain the control capability of the magnetic torquer, providing a decision-making basis for the selection and configuration of magnetic torquers.

Description

Technical Field

[0001] This invention relates to a method for analyzing the control capability of a satellite magnetic torque converter, belonging to the field of satellite attitude and orbit control technology. Background Technology

[0002] Magnetic torquers are commonly used actuators on satellites. The magnetic moment of a magnetic torquer interacts with the Earth's magnetic field to generate a magnetic torque that acts on the satellite, enabling attitude control. Magnetic torquers consume only electrical energy and no fuel. The generated magnetic torque, as an external torque, can change the angular momentum of the entire satellite; therefore, they are often used to unload the angular momentum of a satellite. However, magnetic torquers provide relatively small torques and their output torque is subject to error. When used for direct satellite attitude control, magnetic torquers are only suitable for scenarios where the control torque requirement is not high and the control precision requirement is not stringent.

[0003] The control capability of a magnetic torque converter is a crucial factor in determining its selection and configuration for a satellite. Current techniques for analyzing magnetic torque converter control capability often rely on rough estimations using the magnetic field magnitude or analysis of the maximum control capability of the torque converter on a single axis. These methods lack precision in calculating control capability and fail to consider the mutual influence between the three axes when controlling all three axes simultaneously. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a method for analyzing the control capability of a satellite magnetic torquer. This method introduces a specified torque direction and calculates the control capability of the magnetic torquer based on the average value of the maximum magnetic torque during the on-orbit magnetic field change.

[0005] The technical solution of this invention is:

[0006] A method for analyzing the control capability of a satellite magnetic torque converter includes:

[0007] Acquire three-axis magnetic field strength data within the satellite's own system;

[0008] Iterate through all specified torque directions. For each specified torque direction, first calculate the average value of the maximum magnetic torque under different magnetic field strengths, and then calculate the corresponding magnetic torque controller control capability.

[0009] Based on the control capability of the magnetic torque converter in each specified torque direction, analyze whether the magnetic torque converter meets the control requirements.

[0010] Furthermore, for each specified torque direction, the average value of the maximum magnetic torque is calculated, specifically as follows:

[0011] Calculate the magnetic moment m:

[0012]

[0013] Where B is the magnetic field strength of this system and t0 is the specified torque direction;

[0014] The maximum magnetic torque T is:

[0015] T = km × B

[0016]

[0017] Among them, M limx 、M limy 、M limz These are three-axis magnetic moment limiting devices, determined by the configuration of the magnetic torque converter.

[0018] For multiple magnetic field strengths B, multiple maximum magnetic torques T are calculated. The average value of the maximum magnetic torque is then calculated and denoted as Tmax. mean .

[0019] Furthermore, the method for calculating the control capability of the magnetic torque converter is as follows:

[0020] Based on the obtained average value of the maximum magnetic torque T mean The control capability of a magnetic torquer is described by the angular momentum it can provide within one orbital cycle, i.e., the magnetic torquer control capability H. m for:

[0021]

[0022] Among them, t orbit This is the satellite's orbital period.

[0023] Furthermore, contour plots are used to analyze the control capability of the magnetic torque converter corresponding to each specified torque direction, specifically:

[0024] Using spherical coordinates θ in the direction of the specified torque, Using the x and y axes as the axes, the control capability H of the magnetic torque converter in each specified torque direction is represented. m Using the three components as data, draw a contour map;

[0025] Based on the interference torque experienced by the satellite and the magnetic control requirements, the lower limit of the control capability of the magnetic torque converter on the three axes of the satellite is set, and the contour lines corresponding to the lower limit of the control capability and the area that meets the control capability requirements are marked on the contour map.

[0026] If there is a common area in the region where the three axes meet the control capability requirements, then the magnetic torque device can meet the control requirements.

[0027] Furthermore, for different magnetic torquers, the control capability H of each magnetic torquer is marked on the same contour map. m The three components are compared to determine the merits of each magnetic torquer.

[0028] Furthermore, the direction of the specified torque is expressed as:

[0029]

[0030] Among them, θ, Spherical coordinates specifying the direction of the torque.

[0031] Furthermore, let θ∈[-90°, 90°], Iterate through all possible θ at set intervals. It achieves coverage of all specified torque directions.

[0032] Furthermore, obtain the three-axis magnetic field strength data of the satellite system. The data should cover at least three orbital periods of the satellite, with at least 500 data points in each orbital period.

[0033] The advantages of this invention compared to the prior art are:

[0034] This invention improves upon existing technologies by proposing an algorithm for calculating the maximum magnetic torque in a specified torque direction. It calculates the control capability of the magnetic torquer by obtaining the average maximum magnetic torque across multiple tracks and traversing the specified torque direction. The control capability is then visually illustrated using contour plots. This method comprehensively reflects the three-axis control capability of the magnetic torquer, particularly highlighting the mutual influence and constraints among the three axes, thus providing a basis for magnetic torquer configuration decisions. Attached Figure Description

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0036] Figure 1 A schematic diagram illustrating the calculation of the maximum magnetic torque in a specified direction according to an embodiment of the present invention;

[0037] Figure 2 This is a flowchart of the satellite magnetic torque converter control capability analysis method according to an embodiment of the present invention;

[0038] Figure 3 This is a contour plot of the control capability of the magnetic torquer under the first magnetic torque configuration in the embodiments of the present invention;

[0039] Figure 4 This is a contour plot of the control capability of the magnetic torquer under the second magnetic torque configuration in an embodiment of the present invention. Detailed Implementation

[0040] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0041] This invention proposes a method for analyzing the control capability of a satellite magnetic torque converter, such as... Figure 2 As shown, it includes the following steps:

[0042] Step S1: Obtain the three-axis magnetic field strength data of the satellite's own system.

[0043] The three-axis magnetic field strength data of the satellite's intrinsic system under long-term on-orbit operation are obtained by using on-orbit measurement data or calculations based on magnetic field theory formulas. To ensure the accuracy of subsequent calculation results, the data should cover at least three orbital periods of the satellite, with at least 500 data points collected in each orbital period.

[0044] Step S2: Determine the direction of the specified torque.

[0045] The specified torque direction t0 can be expressed as a unit vector in spherical coordinates:

[0046]

[0047] Select θ, θ represents the spherical coordinates specifying the direction of the torque. For specific values, please refer to step S4.

[0048] Step S3: Calculate the control capability of the magnetic torquer in the specified torque direction.

[0049] Using the specified torque direction t0 determined in step S2, the magnetic field strength B is calculated by taking the data from each set obtained in step S1, and then calculating the maximum magnetic torque T:

[0050] The magnetic torque T is obtained by the cross product of the magnetic moment M and the magnetic field strength B. Therefore, the magnetic torque must lie in the plane β perpendicular to B. (See attached diagram) Figure 1 As shown, when the specified torque direction t0 is not perpendicular to B, the actual magnetic torque direction will differ from the specified torque direction. In this case, if the projection of the actual magnetic torque along t0 onto the β plane is t1 = (B × t0) × B, the error between the actual magnetic torque direction and the specified torque direction is minimized. Here, B × t0 can be considered as the magnetic moment. By scaling it proportionally according to the magnetic moment limit, the control capability of the magnetic torquer under the current specified torque direction and configuration can be calculated. Therefore, given the known magnetic field strength B and the specified torque direction t0 of the system, the following calculations are performed sequentially:

[0051]

[0052] The maximum magnetic torque is:

[0053] T = km × B

[0054] Among them, M limx 、M limy 、M limz These are three-axis magnetic moment limits, determined by the configuration of the magnetic torque generator.

[0055] For each magnetic field strength B, the corresponding maximum magnetic torque T can be calculated. Step S1 obtains magnetic field strength data containing multiple magnetic field strengths B, calculates multiple maximum magnetic torques T for each, and calculates the average value of these maximum magnetic torques, denoted as Tmax. mean .

[0056] The control capability of a magnetic torquer is described by the angular momentum it can provide within one orbital cycle; that is, the control capability of the magnetic torquer is:

[0057]

[0058] Among them, t orbit This is the satellite's orbital period.

[0059] Step S4: Traverse the specified torque directions

[0060] When calculating the specified torque direction t0 in step S2, θ∈[-90°,90°] is taken. It can cover all possible specified torque directions. It iterates through all possible θ directions at regular intervals. Repeat steps S2 to S3 to calculate the control capability H of the magnetic torque converter for different specified torque directions. m .

[0061] Step S5: Draw a contour map

[0062] After step S4, each group of θ, All have corresponding magnetic torque control capabilities H m . respectively with θ, The x and y axes are represented by H, respectively. m The three components H mx 、H my 、H mz Draw contour maps on the same plot of data.

[0063] Step S6: Data Analysis

[0064] Data is analyzed based on contour maps. According to the interference torque experienced by the satellite and magnetic control requirements, lower limits for the control capability of the magnetic torque converters on the three axes of the satellite are set, and the corresponding contour lines and the areas meeting the control capability requirements are marked on the contour map. If there is a common area among the areas meeting the control capability requirements on all three axes, the magnetic torque converter can meet the control needs, and the larger the common area, the more sufficient the control capability margin. Different three-axis magnetic moment limits are set for different magnetic torque converter configurations and analyzed separately to compare the advantages and disadvantages of each configuration.

[0065] The present invention will be further illustrated below through specific embodiments:

[0066] Taking a satellite in a sun-synchronous orbit at an altitude of 700km that operates for a long time as an example, in step S1, the three-axis magnetic field strength of the satellite's own system is calculated at 10-second intervals, obtaining a total of 2000 sets of data; in step S2, based on θ, Determine the direction of the specified torque; in step S3, calculate the maximum magnetic torque T using 2000 sets of magnetic field strengths sequentially, and calculate the control capability H of the magnetic torque converter. m In step S4, steps S2 to S3 are repeated, and different θ values ​​are calculated at 1° intervals. Combined magnetic torque converter control capability H m Step S5 is used to draw a contour map.

[0067] Triaxial magnetic moment limiting M limx =30A·m 2 、M limy =60A·m 2 、M limz =30A·m 2 The contour map drawn at that time is as follows Figure 3 As shown, the triaxial magnetic moment limiting M limx =60A·m 2 、M limy =30A·m 2 、M limz =30A·m 2 The contour map drawn at that time is as follows Figure 4 As shown, the units for the horizontal and vertical axes of both contour maps are degrees, and the units for the data in the maps are Nms / track.

[0068] If the satellite's requirements for magnetor control capabilities are at least -2 Nms / track for roll axis, at least 6 Nms / track for pitch axis, and at least 2 Nms / track for yaw axis, then mark the corresponding contour lines on the contour map (already marked). Figure 3 and Figure 4 (Indicated by bold lines) and the areas that meet the control capability requirements, by Figure 3 and Figure 4It can be seen that both types of magnetic torquers have common areas in the three-axis configurations that meet the control capability requirements, and both can meet the control needs.

[0069] If the constant disturbance torque on the satellite's pitch axis is much greater than that on the other two axes, then the magnetic torque converter needs to have stronger control capability on the pitch axis, thus requiring comparison. Figure 3 and Figure 4 The two corresponding magnetic torquer configurations are attached. Figure 4 The magnetic torquer configuration is superior, ensuring that while the pitch axis magnetic torquer control capability is 10 Nms / rail, the roll axis and yaw axis can simultaneously have a control capability of at least ±1 Nms / rail.

[0070] The embodiments described above are merely preferred embodiments of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for analyzing the control capability of a satellite magnetor, characterized in that, include: Acquire three-axis magnetic field strength data within the satellite's own system; Iterate through all specified torque directions. For each specified torque direction, first calculate the average value of the maximum magnetic torque under different magnetic field strengths, and then calculate the corresponding magnetic torque controller control capability. Based on the control capability of the magnetic torque converter in each specified torque direction, this paper analyzes whether the magnetic torque converter meets the control requirements. Contour plots are used to analyze the control capability of the magnetic torque converter in each specified torque direction, specifically: Using spherical coordinates θ in the direction of the specified torque, Using the x and y axes as the axes, the control capability H of the magnetic torque converter in each specified torque direction is represented. m Using the three components as data, draw a contour map; Based on the interference torque experienced by the satellite and the magnetic control requirements, the lower limit of the control capability of the magnetic torque converter on the three axes of the satellite is set, and the contour lines corresponding to the lower limit of the control capability and the area that meets the control capability requirements are marked on the contour map. If there is a common area in the region where the three axes meet the control capability requirements, then the magnetic torque device can meet the control requirements.

2. The satellite magnetor control capability analysis method according to claim 1, characterized in that, For each specified torque direction, the average value of the maximum magnetic torque is calculated using the following method: Calculate the magnetic moment m: Where B is the magnetic field strength of this system and t0 is the specified torque direction; The maximum magnetic torque T is: T = km × B Among them, M limx 、M limy 、M limz These are three-axis magnetic moment limiting devices, determined by the configuration of the magnetic torque converter. For multiple magnetic field strengths B, multiple maximum magnetic torques T are calculated. The average value of the maximum magnetic torque is then calculated and denoted as Tmax. mean .

3. The satellite magnetor control capability analysis method according to claim 1, characterized in that, The method for calculating the control capability of a magnetic torque converter is as follows: Based on the obtained average value of the maximum magnetic torque T mean The control capability of a magnetic torquer is described by the angular momentum it can provide within one orbital cycle, i.e., the magnetic torquer control capability H. m for: Among them, t orbit This is the satellite's orbital period.

4. The satellite magnetor control capability analysis method according to claim 1, characterized in that, For different magnetic torquers, the control capability H of each magnetic torquer is marked on the same contour map. m The three components are compared to determine the merits of each magnetic torquer.

5. The satellite magnetor control capability analysis method according to claim 1, characterized in that, The direction of the specified torque is represented as: Among them, θ, Spherical coordinates specifying the direction of the torque.

6. The satellite magnetor control capability analysis method according to claim 5, characterized in that, Take θ∈[-90°,90°], Iterate through all possible θ at set intervals. It achieves coverage of all specified torque directions.

7. The satellite magnetor control capability analysis method according to claim 1, characterized in that, To obtain the three-axis magnetic field strength data of the satellite system, the data should cover at least three orbital periods of the satellite, with at least 500 data points in each orbital period.

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