Method for estimating and compensating in-orbit disturbance torque of formation satellites

Abstract

The invention relates to a formation satellite on-orbit disturbance torque estimation and compensation method, in particular to a formation satellite on-orbit disturbance torque estimation and compensation method based on angular momentum change, which can calculate the disturbance torque generated in each formation control process in real time through simple operation on the basis of not increasing on-satellite measurement information. And interference compensation is carried out through a feedforward method during next control, so that the attitude control precision and the formation control precision in the formation control process are improved, and the method is small in calculation amount and convenient for engineering implementation.

Description

Technical Field

[0001] The invention relates to an on-orbit disturbance torque estimation and compensation method for formation satellites, belonging to the technical field of satellite control. Background Art

[0002] With the continuous development of satellite control technology, more and more surveying and mapping tasks have put forward very high requirements on the formation control accuracy of formation satellites and the attitude control accuracy during formation control. Traditional formation satellites generally adopt a time-sharing working mode of formation control and payload business. This is mainly because during the formation control process, the interference torque generated by the thruster will seriously affect the attitude control accuracy, making it unable to meet the payload working conditions. On the other hand, when the interference torque causes attitude deviation, it will cause the formation thruster to generate interference force in the non-control direction, affecting the formation control accuracy.

[0003] In order to improve the formation control and attitude control accuracy during the process, on the one hand, the thruster installation can be optimized through the overall satellite layout, or an electric propulsion system with less interference can be selected. On the other hand, the interference torque can be estimated and compensated on orbit through the attitude and orbit control system to reduce the influence of the interference torque on the attitude control accuracy during formation control, thereby achieving the purpose of improving the payload working accuracy and increasing the payload working time.

[0004] Formation satellites need to keep their relative configuration within a certain range when in orbit, which determines that they have the characteristics of small control amount and high control frequency. Since the single control amount of formation control is small, angular momentum exchange actuators are generally used for attitude control in the control process. This is because, on the one hand, the angular momentum change caused by the small control amount is within the control capability of actuators such as flywheels and control force rejection gyroscopes. On the other hand, if attitude control thrusters are used, their control accuracy is low and may generate additional interference forces, which will affect the formation control accuracy. Generally, the attitude control of satellites adopts the method of attitude deviation negative feedback, which leads to a deviation in the attitude under the interference torque of formation control, and then the attitude deviation is controlled to near zero through the adjustment of the negative feedback control system; if the interference torque generated by formation control can be estimated on orbit and feedforward control is performed at the beginning of formation control, the attitude overshoot-stabilization process can be avoided, so that the attitude can always remain stable during the formation control process. Summary of the invention

[0005] The technical problem solved by the present invention is: in view of the problem that traditional attitude control means in the current prior art easily generate additional interference force and affect the formation control accuracy, a method for estimating and compensating the on-orbit interference torque of formation satellites is proposed.

[0006] The present invention solves the above technical problems by the following technical solutions:

[0007] A method for estimating and compensating on-orbit disturbance torque of formation satellites, comprising:

[0008] According to the satellite's on-orbit stability form, the satellite attitude dynamics equation under the interference torque is determined;

[0009] Analyze the preset thruster test data, simplify the interference torque and update the satellite attitude dynamics equation according to the analysis results;

[0010] Record the changes in the total angular momentum and angular velocity of the star during the formation control process, and also record the changes in the angular momentum of the star accumulated by the magnetic unloading torque during the formation control process;

[0011] Perform a Lapse transformation on the updated satellite attitude dynamics equation and substitute the total angular momentum change, angular momentum change and angular velocity change of the satellite during the formation control process to determine the interference torque caused by this formation control.

[0012] The state equation after the La-type transformation and the disturbance torque caused by the current formation control are used to estimate the disturbance torque caused by the next formation control during the next formation control, and the obtained disturbance torque and the preset control torque of the next formation control are used to perform formation feedforward control.

[0013] The method to determine the satellite attitude dynamics equation under the disturbance torque is:

[0014] Obtain the satellite's body dynamics parameters in a stable on-orbit form, including the body's rotational inertia matrix, the angular momentum of the angular momentum exchange actuator, the reaction torque, the magnetic torque, the environmental interference torque, and the thruster interference torque;

[0015] According to the satellite dynamics parameters, the satellite attitude dynamics equation under the interference torque when the satellite is in orbit is determined as follows:

[0016]

[0017] Where, J is the star body moment of inertia matrix; h is the angular momentum of the angular momentum exchange actuator; is the reaction torque generated by the angular momentum exchange actuator on the star, taking the flywheel as an example; M t is the magnetic moment; M d is the environmental disturbance torque, including gravity gradient torque, aerodynamic disturbance torque, sunlight pressure torque, residual magnetic torque, etc., M bd It is the interference torque generated by the thrusters during the jet ejection process during formation control.

[0018] The method to simplify the disturbance torque and update the satellite attitude dynamics equation is:

[0019] The preset thruster test data are analyzed to determine the thrust output change process of the thruster within an inference cycle. According to the single jet time of the thruster, the thrust in a single formation control process is simplified to a constant force, the propellant consumption in a single formation control process is ignored, and the satellite center of mass position in a single formation control process is regarded as unchanged. According to the thrust, propellant consumption and satellite center of mass position in a single formation control process, the interference torque in a single formation control process is simplified to a constant and substituted into the satellite body attitude dynamics equation under the interference torque.

[0020] The simplified satellite attitude dynamics equation is:

[0021]

[0022] During each formation control process, the inertia J of the satellite relative to the system records the total angular momentum H0 of the satellite, the angular momentum h0 of the angular momentum actuator, and the inertial angular velocity w0 of the satellite at time t0, H0=h0+Jw0; at time t1, the total angular momentum H1 of the satellite, the angular momentum h1 of the angular momentum actuator, and the inertial angular velocity w1 of the satellite are recorded;

[0023] At the same time, the angular momentum accumulated by magnetic unloading during the jet time period △t of formation control is recorded. M is the magnetic moment instruction calculated by magnetic unloading for each beat, B is the magnetic field strength information measured by the magnetometer for each beat, and hm is the angular momentum change value accumulated by magnetic unloading.

[0024] According to all the recorded information, the simplified satellite attitude dynamics equation is transformed into a state equation form: sH(s) = AH(s) + B, where A is the system matrix and B is the input matrix.

[0025] The change of total angular momentum of the star under different disturbance torques is determined according to the equation of state.

[0026] When the disturbance torque is in a constant form, the undetermined coefficient in the angular momentum state equation is the disturbance torque. The constant disturbance torque generated by formation control can be obtained by substituting the satellite parameters at time t0 and time t1.

[0027] For each formation control process, from the start of jet injection to the end of jet injection, the interference torque is used as the feedforward torque, Tc1 = Tc0 + Tbd;

[0028] Where Tc0 is the control torque calculated according to the attitude deviation, that is, the control torque of the preset formation control, Tbd is the interference torque corresponding to the jet thruster unit, and Tc1 is the control torque actually issued after adding feedforward control.

[0029] The calculation method of the change value of the angular momentum of the star caused by the formation control interference torque during the jet time period △t of the formation control is:

[0030]

[0031] Where wo is the orbital angular velocity.

[0032] The disturbance torque generated by the thruster during the jetting process includes the pitch axis disturbance torque and the combined disturbance torque of the rolling axis and the yaw axis:

[0033] The pitch axis disturbance torque is:

[0034] The combined interference torque of the roll axis and the yaw axis is:

[0035]

[0036] The jet time period △t of the formation control is a preset time period, which is selected by the satellite during the formation control process when it is in orbit. Within the jet time period △t, the total angular momentum, inertial angular velocity, and angular momentum accumulated by magnetic unloading of the satellite are recorded as input data, and the satellite body attitude state equation after the Lapland transformation is input to calculate the formation control interference torque.

[0037] The satellite body attitude state equation after the Lapland transformation calculates the disturbance torque amplitude by solving the differential equation. According to the estimated disturbance torque value, during the next formation control process, control feedforward is performed according to the disturbance torque of different groups of thrusters. The feedforward torque is introduced when the formation control starts and is canceled when the formation control ends, so as to compensate in advance for the satellite attitude overshoot caused by the disturbance torque so as to improve the attitude control accuracy during the formation control.

[0038] The advantages of the present invention compared with the prior art are:

[0039] (1) The present invention provides a method for estimating and compensating the on-orbit disturbance torque of a formation satellite, which is based on the estimation and compensation of the on-orbit disturbance torque of a stable formation satellite based on angular momentum change. Without increasing the on-board measurement information, the disturbance torque generated during each formation control process can be calculated in real time, and the disturbance compensation can be performed by a feedforward method during the next control, thereby improving the attitude control accuracy and formation control accuracy during the formation control process, and effectively improving the attitude control accuracy during the formation control period:

[0040] (2) This method performs real-time estimation on-orbit, and performs feedforward compensation based on the result of the previous control each time the formation is controlled. It has high estimation accuracy and good compensation effect. At the same time, it does not require additional measurement data on the satellite. It can estimate the size of the formation control interference torque through simple calculation based on the original inertial angular velocity, flywheel angular momentum, magnetic field strength, and magnetic moment command information. It can realize autonomous estimation and compensation on the satellite without ground participation. It has good engineering feasibility and a higher degree of autonomy than traditional attitude control methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A flow chart of the on-orbit disturbance torque estimation and compensation method for formation satellites provided by the invention;

[0042] Figure 2 A schematic diagram of the effect of formation control on posture provided by the invention;

[0043] Figure 3 A schematic diagram of the effect of formation control on attitude after feedforward compensation provided by the invention; DETAILED DESCRIPTION

[0044] The invention discloses an on-orbit disturbance torque estimation and compensation method for formation satellites. The on-orbit disturbance torque estimation and compensation method for stable formation satellites to the earth based on angular momentum change can calculate the disturbance torque generated in each formation control process in real time through simple calculation without adding onboard measurement information, and perform disturbance compensation through a feedforward method in the next control, thereby improving the attitude control accuracy and formation control accuracy in the formation control process. The method has a small amount of calculation and is easy to implement in engineering.

[0045] The method for estimating and compensating the on-orbit disturbance torque of formation satellites has the following steps:

[0046] According to the satellite's on-orbit stability form, the satellite attitude dynamics equation under the interference torque is determined;

[0047] Analyze the preset thruster test data, simplify the interference torque and update the satellite attitude dynamics equation according to the analysis results;

[0048] Record the changes in the total angular momentum and angular velocity of the star during the formation control process, and also record the changes in the angular momentum of the star accumulated by the magnetic unloading torque during the formation control process;

[0049] Perform a Lapse transformation on the updated satellite attitude dynamics equation and substitute the total angular momentum change, angular momentum change and angular velocity change of the satellite during the formation control process to determine the interference torque caused by this formation control.

[0050] The state equation after the La-type transformation and the disturbance torque caused by the current formation control are used to estimate the disturbance torque caused by the next formation control during the next formation control, and the obtained disturbance torque and the preset control torque of the next formation control are used to perform formation feedforward control.

[0051] The method to determine the satellite attitude dynamics equation under the disturbance torque is:

[0052] Obtain the satellite's body dynamics parameters in a stable on-orbit form, including the body's rotational inertia matrix, the angular momentum of the angular momentum exchange actuator, the reaction torque, the magnetic torque, the environmental interference torque, and the thruster interference torque;

[0053] According to the satellite dynamics parameters, the satellite attitude dynamics equation under the interference torque when the satellite is in orbit is determined as follows:

[0054]

[0055] Where, J is the star body moment of inertia matrix; h is the angular momentum of the angular momentum exchange actuator; is the reaction torque generated by the angular momentum exchange actuator on the star, taking the flywheel as an example; M t is the magnetic moment; M d is the environmental disturbance torque, including gravity gradient torque, aerodynamic disturbance torque, sunlight pressure torque, residual magnetic torque, etc. bd It is the interference torque generated by the thrusters during the jet ejection process during formation control.

[0056] The method to simplify the disturbance torque and update the satellite attitude dynamics equation is:

[0057] The preset thruster test data are analyzed to determine the thrust output change process of the thruster within an inference cycle. According to the single jet time of the thruster, the thrust in a single formation control process is simplified to a constant force, the propellant consumption in a single formation control process is ignored, and the satellite center of mass position in a single formation control process is regarded as unchanged. According to the thrust, propellant consumption and satellite center of mass position in a single formation control process, the interference torque in a single formation control process is simplified to a constant and substituted into the satellite body attitude dynamics equation under the interference torque.

[0058] The simplified satellite attitude dynamics equation is:

[0059]

[0060] During each formation control process, the inertia J of the satellite relative to the system records the total angular momentum H0 of the satellite, the angular momentum h0 of the angular momentum actuator, and the inertial angular velocity w0 of the satellite at time t0, H0=h0+Jw0; at time t1, the total angular momentum H1 of the satellite, the angular momentum h1 of the angular momentum actuator, and the inertial angular velocity w1 of the satellite are recorded;

[0061] At the same time, the angular momentum accumulated by magnetic unloading during the jet time period △t of formation control is recorded. M is the magnetic moment instruction calculated by magnetic unloading for each beat, B is the magnetic field strength information measured by the magnetometer for each beat, and hm is the angular momentum change value accumulated by magnetic unloading.

[0062] According to all the recorded information, the simplified satellite attitude dynamics equation is transformed into a state equation form: sH(s) = AH(s) + B, where A is the system matrix and B is the input matrix.

[0063] The change of total angular momentum of the star under different disturbance torques is determined according to the equation of state.

[0064] When the disturbance torque is in a constant form, the undetermined coefficient in the angular momentum state equation is the disturbance torque. The constant disturbance torque generated by formation control can be obtained by substituting the satellite parameters at time t0 and time t1.

[0065] For each formation control process, from the start of jet injection to the end of jet injection, the interference torque is used as the feedforward torque, Tc1 = Tc0 + Tbd;

[0066] Where Tc0 is the control torque calculated according to the attitude deviation, Tbd is the interference torque corresponding to the jet thruster unit, and Tc1 is the control torque actually issued after adding feedforward control.

[0067] The calculation method of the change of the angular momentum of the star caused by the formation control interference torque during the jet time period △t of the formation control is:

[0068]

[0069] Where wo is the orbital angular velocity.

[0070] The disturbance torque generated by the thruster during the jetting process includes the pitch axis disturbance torque and the combined disturbance torque of the roll axis and yaw axis:

[0071] The pitch axis disturbance torque is:

[0072] The combined interference torque of the roll axis and the yaw axis is:

[0073]

[0074] The jet time period △t of formation control is a preset time period, which is selected by the satellite during the formation control process when it is in orbit. During the jet time period △t, the satellite's total angular momentum, inertial angular velocity, and angular momentum accumulated by magnetic unloading are recorded as input data. The satellite's attitude state equation after the Lagrange transformation is input to calculate the disturbance torque of formation control.

[0075] The satellite body attitude state equation after the Lagrange transformation is used to calculate the disturbance torque amplitude by solving the differential equation. According to the estimated disturbance torque value, in the next formation control process, feedforward control is performed according to the disturbance torque of different groups of thrusters. The feedforward torque is introduced at the beginning of formation control and canceled at the end of formation control. It is used to compensate in advance for the satellite attitude overshoot caused by the disturbance torque to improve the attitude control accuracy during formation control.

[0076] The following is further described in conjunction with the accompanying drawings and preferred embodiments of the specification:

[0077] In the current embodiment, if Figure 1 As shown, the on-orbit disturbance torque estimation and compensation method of formation satellites is implemented by the following steps:

[0078] Step 1: Simplify the attitude dynamics equations according to the satellite's on-orbit operation characteristics and rewritten as Where J is the star's rotational inertia matrix; h is the angular momentum of the angular momentum exchange actuator; is the reaction torque generated by the angular momentum exchange actuator on the star, taking the flywheel as an example; M t is the magnetic moment; M d is the environmental disturbance torque, including gravity gradient torque, aerodynamic disturbance torque, sunlight pressure torque, residual magnetic torque, etc., M bd It is the interference torque generated by the thrusters during the jet ejection process during formation control.

[0079] Step 2: Analyze the thruster test data. In a control cycle, the thrust output of the thruster has a process of rising-stabilizing-decreasing. However, for formation control, the single jet time ranges from a few seconds to hundreds of seconds. Therefore, the thrust in a single formation control process can be regarded as a constant force. Similarly, the propellant consumption of a single formation control can be ignored compared with the whole satellite command, that is, the satellite center of mass can also be regarded as unchanged in this process. Therefore, the interference torque generated by the thruster can be regarded as a constant interference in a single formation control process.

[0080] Step 3: The interference torque generated by the thrusters during formation control is generally much larger than the environmental interference torque, so the environmental interference can be ignored when estimating the formation interference torque; the interference torque generated by formation control will rapidly increase the angular momentum of the angular momentum exchange mechanism, and the unloading torque will also increase accordingly for satellites using magnetic unloading, so the magnetic unloading torque cannot be ignored. At this time, the dynamic equation can be simplified to However, since the magnetic torque is not easy to express directly in analytical form, the magnetic torque can be integrated to compensate for the angular momentum.

[0081] Step 4: Select a suitable period of time △t=t1-t0 during the jet of formation control. The starting time t0 of △t should not be earlier than the start time of the jet, and the ending time t1 should not be later than the end time of the jet. Generally, a period of time with relatively stable intermediate thrust can be selected according to the thruster test results. At the same time, the size of △t should also be appropriate. If △t is too small, the nonlinearity of the thruster output will have a greater impact on the estimation result. If △t is too large, the nonlinearity of the magnetic unloading will have a greater impact on the estimation result.

[0082] Step 5: During each formation control, at time t0, record the satellite's total angular momentum H0, the angular momentum h0 of the angular momentum actuator (e.g., flywheel, control torque gyro, etc.), and the satellite's inertial angular velocity w0, H0=h0+Jw0; at time t1, record the satellite's total angular momentum H1, the angular momentum h1 of the angular momentum actuator (e.g., flywheel, control torque gyro, etc.), and the satellite's inertial angular velocity w1, H1=h1+Jw1, where J is the satellite's inertia relative to the system.

[0083] Step 6: Record the angular momentum accumulated during magnetic unloading in △t Where M is the magnetic moment instruction calculated by magnetic unloading in each beat, B is the magnetic field strength information measured by the magnetometer in each beat, and hm is the angular momentum change value accumulated by magnetic unloading.

[0084] Step 7: Perform a Lasik transformation on the simplified kinetic equation and write it in the form of a state equation, where X = (sI-A) -1 B can solve the differential equation, and then we can get the analytical form of the change of the total angular momentum of the star under different interference force rectangular potentials.

[0085] Step 8: For the disturbance torque in constant form, the undetermined coefficient in the angular momentum expression is the magnitude of the disturbance torque. The equation can be solved by substituting the data at times t0 and t1 to obtain the magnitude of the constant disturbance torque generated by formation control.

[0086] Step 9: For each jet, if the thruster is used, it is necessary to estimate and record them separately. When performing attitude control, from the start of the jet to the end of the jet, add feedforward control. The feedforward torque is the interference torque of the thruster corresponding to this jet, that is, Tc1=Tc0+Tbd, where Tc0 is the control torque calculated based on the attitude deviation, Tbd is the interference torque corresponding to the thruster unit of this jet, and Tc1 is the control torque actually issued after adding feedforward control.

[0087] Specifically, calculate the change in the star's angular momentum caused by the formation control interference torque from the ignition time to the ignition start △t Where wo is the orbital angular velocity.

[0088] The disturbance torque of the pitch axis can be estimated separately Joint estimation of disturbance torques on the roll and yaw axes

[0089] For each jet, if the thruster is used, it is necessary to estimate and record it separately. When performing attitude control, from the start of the jet to the end of the jet, feedforward control is added. The feedforward torque is the interference torque of the thruster corresponding to this jet, that is, Tc1 = Tc0 + Td, where Tc0 is the control torque calculated based on the attitude deviation, Td is the interference torque of the thruster of this jet, and Tc1 is the actual control torque issued after adding feedforward control. The attitude changes in the formation control process before and after adding feedforward are as follows: Figure 2 , Figure 3 shown.

[0090] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0091] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for estimating and compensating for the on-orbit disturbance torque of a formation satellite, characterized in that include: According to the satellite's on-orbit stability form, the satellite attitude dynamics equation under the interference torque is determined; Analyze the preset thruster test data, simplify the interference torque and update the satellite attitude dynamics equation according to the analysis results; Record the changes in the total angular momentum and angular velocity of the star during the formation control process, and also record the changes in the angular momentum of the star accumulated by the magnetic unloading torque during the formation control process; Perform a Lapse transformation on the updated satellite attitude dynamics equation and substitute the total angular momentum change, angular momentum change and angular velocity change of the satellite during the formation control process to determine the interference torque caused by this formation control. The state equation after the La-type transformation and the disturbance torque caused by the current formation control are used to estimate the disturbance torque caused by the next formation control during the next formation control, and the obtained disturbance torque and the preset control torque of the next formation control are used to perform formation feedforward control.

2. The method for estimating and compensating for on-orbit disturbance torque of formation satellites according to claim 1, characterized in that: The method to determine the satellite attitude dynamics equation under the disturbance torque is: Obtain the satellite's body dynamics parameters in a stable on-orbit form, including the body's rotational inertia matrix, the angular momentum of the angular momentum exchange actuator, the reaction torque, the magnetic torque, the environmental interference torque, and the thruster interference torque; According to the satellite dynamics parameters, the satellite attitude dynamics equation under the interference torque when the satellite is in orbit is determined as follows: Where, J is the star body moment of inertia matrix; h is the angular momentum of the angular momentum exchange actuator; is the reaction torque generated by the angular momentum exchange actuator on the star, taking the flywheel as an example; M t is the magnetic moment; M d is the environmental disturbance torque, including gravity gradient torque, aerodynamic disturbance torque, sunlight pressure torque, residual magnetic torque, etc., M bd It is the interference torque generated by the thrusters during the jet ejection process during formation control.

3. The method for estimating and compensating for on-orbit disturbance torque of formation satellites according to claim 2, characterized in that: The method to simplify the disturbance torque and update the satellite attitude dynamics equation is: The preset thruster test data are analyzed to determine the thrust output change process of the thruster within an inference cycle. According to the single jet time of the thruster, the thrust in a single formation control process is simplified to a constant force, the propellant consumption in a single formation control process is ignored, and the satellite center of mass position in a single formation control process is regarded as unchanged. According to the thrust, propellant consumption and satellite center of mass position in a single formation control process, the interference torque in a single formation control process is simplified to a constant and substituted into the satellite body attitude dynamics equation under the interference torque.

4. The method for estimating and compensating for on-orbit disturbance torque of formation satellites according to claim 2, characterized in that: The simplified satellite attitude dynamics equation is: During each formation control process, the inertia J of the satellite relative to the system records the total angular momentum H0 of the satellite, the angular momentum h0 of the angular momentum actuator, and the inertial angular velocity w0 of the satellite at time t0, H0=h0+Jw0; at time t1, the total angular momentum H1 of the satellite, the angular momentum h1 of the angular momentum actuator, and the inertial angular velocity w1 of the satellite are recorded; At the same time, the angular momentum accumulated by magnetic unloading during the jet time period △t of formation control is recorded. M is the magnetic moment instruction calculated by magnetic unloading for each beat, B is the magnetic field strength information measured by the magnetometer for each beat, and hm is the angular momentum change value accumulated by magnetic unloading.

5. The method for estimating and compensating the on-orbit disturbance torque of formation satellites according to claim 4, characterized in that: According to all the recorded information, the simplified satellite attitude dynamics equation is transformed into a state equation form: sH(s) = AH(s) + B, where A is the system matrix and B is the input matrix. The change of total angular momentum of the star under different disturbance torques is determined according to the equation of state.

6. The method for estimating and compensating on-orbit disturbance torque of formation satellites according to claim 4, characterized in that: When the disturbance torque is in a constant form, the undetermined coefficient in the angular momentum state equation is the disturbance torque. The constant disturbance torque generated by formation control can be obtained by substituting the satellite parameters at time t0 and time t1. For each formation control process, from the start of jet injection to the end of jet injection, the interference torque is used as the feedforward torque, Tc1 = Tc0 + Tbd; Where Tc0 is the control torque calculated according to the attitude deviation, that is, the control torque of the preset formation control, Tbd is the interference torque corresponding to the jet thruster unit, and Tc1 is the control torque actually issued after adding feedforward control.

7. The method for estimating and compensating for on-orbit disturbance torque of formation satellites according to claim 4, characterized in that: The calculation method of the change value of the angular momentum of the star caused by the formation control interference torque during the jet time period △t of the formation control is: Where wo is the orbital angular velocity.

8. The method for estimating and compensating the on-orbit disturbance torque of formation satellites according to claim 4, characterized in that: The disturbance torque generated by the thruster during the jetting process includes the pitch axis disturbance torque and the combined disturbance torque of the rolling axis and the yaw axis: The pitch axis disturbance torque is: The combined interference torque of the roll axis and the yaw axis is:

9. The method for estimating and compensating the on-orbit disturbance torque of formation satellites according to claim 7, characterized in that: The jet time period △t of the formation control is a preset time period, which is selected by the satellite during the formation control process when it is in orbit. Within the jet time period △t, the total angular momentum, inertial angular velocity, and angular momentum accumulated by magnetic unloading of the satellite are recorded as input data, and the satellite body attitude state equation after the Lapland transformation is input to calculate the formation control interference torque.

10. The method for estimating and compensating the on-orbit disturbance torque of formation satellites according to claim 9, characterized in that: The satellite body attitude state equation after the Lapland transformation calculates the disturbance torque amplitude by solving the differential equation. According to the estimated disturbance torque value, during the next formation control process, control feedforward is performed according to the disturbance torque of different groups of thrusters. The feedforward torque is introduced when the formation control starts and is canceled when the formation control ends, so as to compensate in advance for the satellite attitude overshoot caused by the disturbance torque so as to improve the attitude control accuracy during the formation control.

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