A simplified method for on-orbit calibration of sub-mN thrust of microthrusters

Abstract

The present invention discloses an on-orbit calibration method and system for thruster force. The present invention adopts two thrusters of the same model, two thrust vectors are located in the orbital plane and deviate from the center of mass, and the thrust vector directions are respectively along the positive and negative directions of the speed. The satellite is always oriented to the ground, and attitude actuators other than the momentum wheel are disabled; secondly, in the same true near-angle range arc segment of adjacent circles, the two thrusters are alternately turned on and work, and the change in the speed of the momentum wheel is recorded; finally, according to the working time of each thruster and the change in the speed of the momentum wheel in two adjacent circles, the thrust estimation value is obtained, and according to all the thrust estimation values, the optimal estimation range of the thruster is obtained. The present invention has the characteristics of fast and high precision for on-orbit calibration of sub-millinewton thrust, and is also of reference value for on-orbit calibration of thrust of other magnitudes.

Description

Technical Field

[0001] The present invention relates to the technical field of space thruster thrust calibration, and in particular to a method and system for on-orbit thrust calibration of a thruster, in particular to a method and system for on-orbit sub-millinewton thrust calibration of a micro-thruster. Background Art

[0002] Nanosatellites are compact in size, consume less power, and have a short development cycle. They have obvious advantages in scientific research and other fields and have attracted much attention. However, there are currently no mature thrusters available for nanosatellites. Although microthrusters such as pulsed plasma thrusters and cathode micro-arc thrusters that match nanosatellites in power consumption and volume have attracted attention, they are currently in the development and testing stage. The thrust performance calibration test of microthrusters is crucial. During the ground calibration test stage, microthrust measurement equipment is used to test in a vacuum system. However, because the thrust or average thrust is small, usually sub-millinewton level, ground testing is easily interfered with. There is also a difference between the simulated space environment on the ground and the real space environment. Microthrusters still need to be calibrated on-orbit in the space environment. Therefore, the on-orbit calibration technology of microthruster thrust performance is a problem that needs to be solved. Summary of the invention

[0003] In view of this, an object of the present invention is to realize on-orbit calibration of thruster thrust and simplify the on-orbit calibration process.

[0004] To achieve the above object, the present invention provides a method for on-orbit calibration of thruster thrust, comprising the steps of:

[0005] Step S100: The first thruster and the second thruster are micro-thrusters of the same model, both of which are installed on the satellite, in the stellar coordinate system O. B X B Y B Z B X B O B Z B In-plane, thrust of the first thruster Direction along +X B Direction, thrust of the second thruster Direction along -X B Direction, the two thrusts are in a straight line, thrust and thrust To X B The distance between axes is L, L>0;

[0006] Step S200: The satellite is in orbit and the first thruster and the second thruster work alternately to measure +Y B The step of the change in the speed of the axis momentum wheel; in this step, the satellite runs 2n circles in total, n = 1, 2..., N, where

[0007] For the 2n-1th turn, the second thruster is turned off, and the first thruster is turned on within the true near-angle range [f1, f2] of this turn. The working time is ΔT, and the thrust magnitude of the working arc is recorded as F i , i = 2n-1, n = 1, 2..., N, according to the start time of the first thruster in each arc segment, the internal +Y B The speed of the shaft momentum wheel ω i1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω i2 , you can get +Y B The speed change Δω generated by the shaft momentum wheel i =ω i2 -ω i1 ;

[0008] For the 2nth round, the first thruster is turned off, and the second thruster is turned on within the true near-angle range [f1, f2] of this round. The working time is ΔT, and the thrust magnitude of the working arc is F j , j = 2n, n = 1, 2..., N, according to the satellite internal +Y when the second thruster is turned on B The speed of the shaft momentum wheel ω j1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω j2 , you can get +Y B The speed change Δω generated by the shaft momentum wheel j =ω j2 -ω j1 ;

[0009] Step S300 is a step of calibrating the thrust of the first thruster or the thrust of the second thruster; in this step,

[0010] When the first thruster is turned on in each working arc, along the satellite +Y B The angular momentum generated by the axis is F i LΔT, momentum wheel along satellite +Y B The angular momentum generated by the axis is JΔω i , J is +Y B Axis momentum wheel rotation inertia; When the second thruster is turned on in each working arc segment, along the satellite +Y B The angular momentum generated by the axis is -F j LΔT, momentum wheel along satellite +Y B The angular momentum generated by the axis is JΔω j ;

[0011] The estimated thrust of the first or second thruster in the adjacent turns is i=2n-1,j=2n,n=1,2...,N;

[0012] The optimal estimated thrust of the first thruster or the second thruster is

[0013] The standard deviation of the optimal estimated value of the thrust of the first thruster or the second thruster is

[0014] The optimal estimation range of the thrust of the first thruster or the second thruster is

[0015] Furthermore, the satellite's orbit is a circular orbit, the satellite's attitude is always oriented toward the earth, and attitude actuators other than momentum wheels are disabled.

[0016] Furthermore, the working arc of each circle is within the same true near-angle range [f1, f2], and the working arc range is determined according to the visible arc of the measurement and control and the working time of the first thruster or the second thruster.

[0017] Furthermore, the satellite is a nanosatellite, and the first thruster or the second thruster is a microthruster with a thrust of sub-millinewton order.

[0018] The present invention also provides a thruster thrust on-orbit calibration system, comprising a satellite, a calibration process control module, a calibration data recording module, a calibration calculation module, a first thruster and a second thruster; wherein

[0019] The first thruster and the second thruster are micro-thrusters of the same model, both installed on the satellite, in the stellar coordinate system O B X B Y B Z B X B O B Z B The first thruster is installed in the nozzle direction along +X B The second thruster is installed in the nozzle direction along -X B direction, the two thruster nozzles are in a straight line, the nozzle of the first thruster and the nozzle of the second thruster are to X B The distance between axes is L, L>0;

[0020] The calibration process control module is used to control the first thruster and the second thruster to work alternately when the satellite is in orbit; the satellite runs 2n circles in total, n=1,2...,N, wherein for the 2n-1th circle, the calibration process control module controls the second thruster to shut down, and controls the first thruster to start within the true near angle range [f1,f2] of the circle, and the working time is ΔT; for the 2nth circle, the calibration process control module shuts down the first thruster, and controls the second thruster to start within the true near angle range [f1,f2] of the circle, and the working time is ΔT;

[0021] Calibration data recording module, used to record the satellite internal +Y during calibration B The speed of the axis momentum wheel; wherein, for the 2n-1th lap, the calibration data recording module records the satellite internal +Y at the time when the first thruster of the working arc is turned on B The speed of the shaft momentum wheel ω i1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω i2 For the 2nth lap, the calibration data recording module records the satellite internal +Y at the time when the second thruster is turned on B The speed of the shaft momentum wheel ω j1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω j2 ;

[0022] The calibration calculation module is used to calibrate the thrust of the first thruster or the thrust of the second thruster; wherein the calibration calculation module is based on the satellite internal +Y at the start-up time of each working arc segment of the first thruster recorded by the calibration data recording module B The speed of the shaft momentum wheel ω i1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω i2 , get the first thruster each working arc +Y B The speed change Δω generated by the shaft momentum wheel i =ω i2 -ω i1 ; According to the calibration data recording module, the satellite internal +Y B The speed of the shaft momentum wheel ω j1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω j2 , get the second thruster each working arc +Y B The speed change Δω generated by the shaft momentum wheel j =ω j2 -ω j1 ;

[0023] The calibration calculation module is based on the formula i=2n-1,j=2n,n=1,2...,N calculate the thrust estimate of the first thruster or the second thruster in the adjacent turns According to the formula Calculate the optimal estimated value of the thrust of the first thruster or the second thruster According to the formula The standard deviation of the optimal estimated value of the thrust of the first thruster or the second thruster is calculated to be S; and the optimal estimated range of the thrust of the first thruster or the second thruster is obtained to be

[0024] Furthermore, the satellite's orbit is a circular orbit, the satellite's attitude is always oriented toward the earth, and attitude actuators other than momentum wheels are disabled.

[0025] Furthermore, each working arc segment of each circle is within the same true near-angle range [f1, f2], and the working arc segment range is determined based on the visible arc segment of the measurement and control and the working time of the first thruster or the second thruster.

[0026] Furthermore, the satellite is a nanosatellite, and the first thruster or the second thruster is a microthruster with a thrust of sub-millinewton order.

[0027] The beneficial effects of the present invention are as follows: the calibration method and system of the present invention firstly eliminate the influence of the interference torque, and there is no need to estimate the interference torque separately; secondly, by using two thrusters of the same model with symmetrical installation positions, they are alternately started up and operated in adjacent circles, and through multiple estimates, the optimal estimation range of the thrusters can be obtained; thirdly, the present invention is universal and is applicable to thrusters and satellites of other orders of magnitude. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the installation diagram of the micro-thruster of the present invention.

[0029] Figure 2 The present invention is a block diagram of the thruster thrust on-orbit calibration system.

[0030] In the figure: 1-satellite; 2-microthruster I; 3-microthruster II; 4-satellite orbit. DETAILED DESCRIPTION

[0031] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0032] The inventive concept of the present invention is that the satellite attitude is maintained at a specific attitude, the interference torque in the same arc segment of adjacent circles of the satellite orbit can be approximately equal, two thrusters of the same model are used, the two thrust vectors are located in the orbital plane and deviate from the center of mass, the thrust vector directions are respectively along the positive and negative directions of the speed, the satellite is always oriented to the ground, and attitude actuators other than the momentum wheel are disabled; secondly, in the same true near-angle range arc segment of adjacent circles, the two thrusters are alternately turned on and worked, and the change in the speed of the momentum wheel is recorded; finally, according to the working time of each thruster and the change in the speed of the momentum wheel in two adjacent circles, the thrust estimation value is obtained, and according to all the thrust estimation values, the optimal estimation range of the thruster is obtained.

[0033] The present invention discloses a method and system for on-orbit calibration of thruster force. The present invention has the characteristics of rapidity and high precision for on-orbit calibration of sub-millinewton thrust, and is also referential for on-orbit calibration of thrusts of other magnitudes.

[0034] Example 1

[0035] This embodiment is used for a micro-thruster as an example to describe the thruster thrust on-orbit calibration method of the present invention in detail. In this embodiment, the orbit of the satellite is a circular orbit, the satellite attitude is always oriented to the earth, and the attitude actuators other than the momentum wheel are disabled. The satellite is a nanosatellite, and the first thruster or the second thruster is a micro-thruster with a thrust of sub-millinewton level.

[0036] See also Figure 1 Microthruster I (2) and microthruster II (3) are microthrusters of the same model, both installed in the XBOBZB plane of the satellite (1) star coordinate system OBXBYBZB. The thrust of microthruster I (2) is Direction is along +XB direction, thrust of micro thruster II (3) Direction along -XB direction, two thrust vectors and In a straight line, the thrust and thrust The distance to the XB axis is L. The orbit of the satellite (1) is a circular orbit. During the calibration test, the attitude of the satellite (1) is always oriented to the earth, that is, the stellar coordinate system OBXBYBZB coincides with the same-name axes of the orbital coordinate system OXYZ, and the attitude actuators other than the momentum wheel are disabled.

[0037] Assume that during the entire calibration test process, the satellite (1) runs 2n (n = 1, 2 ..., N) circles in total, for the 2n-1 (n = 1, 2 ..., N)th circle, the microthruster I (2) is turned on and operated, and for the 2n (n = 1, 2 ..., N)th circle, the microthruster II (3) is turned on and operated. During the operation, the satellite (1) will be affected by the residual magnetic torque, gravity gradient torque, aerodynamic torque, solar radiation pressure torque and other interference torques. During the operation time of the microthruster I (2) or microthruster II (3), in order to ensure that the interference torques to which the satellite (1) is subjected in adjacent circles are basically the same, the arc segment of each circle is within the same true near-angle range [f1, f2]. The arc segment range is determined according to the visible arc segment of the measurement and control and the working time of the microthruster I (2) or microthruster II (3). The operating time of the microthruster I (2) or microthruster II (3) within the true near-angle range [f1, f2] is ΔT. Assume that the angular momentum generated by the interference torque to which the satellite (1) is subjected in each circle of the startup arc segment along the +YB axis is H G .

[0038] When the revolution is the 2n-1th (n=1,2...,N), within the true near-angle range [f1,f2] of each revolution, the thrust generated by the micro-thruster I(2) is F within the working time ΔT of the micro-thruster I(2) when it is turned on. i(i=2n-1,n=1,2...,N), the angular momentum generated by the microthruster I(2) along the +YB axis of the satellite (1) is F i LΔT (i=2n-1, n=1,2...,N). According to the speed ω of the +YB axis momentum wheel inside the satellite when the microthruster I(2) is turned on i1 (i=2n-1,n=1,2...,N) and the speed ω of the +YB axis momentum wheel inside the satellite at the time of shutdown i2 (i=2n-1,n=1,2...,N), the speed change Δω generated by the +YB axis momentum wheel can be obtained i =ω i2 -ω i1 (i=2n-1,n=1,2...,N), then the angular momentum generated by the momentum wheel along the satellite (1)+YB axis is JΔω i (i=2n-1,n=1,2...,N), J is the moment of inertia of the momentum wheel, then there exists

[0039] JΔω i +F i LΔT+H G =0 (i=2n-1,n=1,2...,N) (1)

[0040] Similarly, when the number of turns is 2n (n = 1, 2..., N), within the true near-angle range [f1, f2] of each turn, the thrust generated by the micro-thruster II (3) within the start-up working period ΔT is F j (j=2n,n=1,2...,N), the angular momentum generated by the microthruster II (3) along the +YB axis of the satellite (1) is -F j LΔT. According to the speed ω of the +YB axis momentum wheel inside the satellite when the microthruster II (3) is turned on j1 (j=2n,n=1,2...,N) and the speed ω of the +YB axis momentum wheel inside the satellite at the time of shutdown j2 (j=2n,n=1,2...,N), the speed change Δω generated by the +YB axis momentum wheel can be obtained j =ω j2 -ω j1 (j=2n,n=1,2...,N), then the angular momentum generated by the momentum wheel along the satellite (1)+YB axis is JΔω j (j=2n,n=1,2...,N), then there exists

[0041] JΔω j -F j LΔT+H G =0 (j=2n,n=1,2...,N) (2)

[0042] Assuming that the thrust generated by microthruster I (2) and microthruster II (3) per revolution is the same, both are F, then according to formula (1) and formula (2), the N thrust estimates can be obtained as

[0043]

[0044] Therefore, the optimal estimated thrust of microthruster I (2) or microthruster II (3) is The standard deviation of the thrust optimal estimate is Then the optimal thrust estimation range of micro-thruster I (2) or micro-thruster II (3) is

[0045] It can be seen from the description of the above embodiments that the present invention is universal and applicable to thrusters and satellites of other magnitudes.

[0046] Example 2

[0047] This embodiment is used to explain in detail the thruster thrust on-orbit calibration system of the present invention.

[0048] The thruster thrust on-orbit calibration system of the present invention comprises a satellite, a calibration process control module, a calibration data recording module, a calibration calculation module, a first thruster and a second thruster; wherein

[0049] The first thruster and the second thruster are micro-thrusters of the same model, both installed on the satellite. In the XBOBZB plane of the stellar coordinate system OBXBYBZB, the first thruster is installed at a position along the +XB direction in the nozzle direction, and the second thruster is installed at a position along the -XB direction in the nozzle direction. The nozzles of the two thrusters are in a straight line. The distances from the nozzles of the first thruster and the second thruster to the XB axis are both L, and L>0. In the stellar coordinate system OBXBYBZB, the origin OB is the satellite center of mass, the XB axis is in the tangent direction of the satellite orbit and is positive when pointing to the direction of satellite motion, the ZB axis is in the normal direction of the satellite orbit and is positive when pointing to the inner normal, and the YB axis is in the normal direction of the orbital plane and is positive when pointing to the North Pole;

[0050] The calibration process control module is used to control the first thruster and the second thruster to work alternately when the satellite is in orbit; the satellite runs 2n circles in total, n=1,2...,N, wherein for the 2n-1th circle, the calibration process control module controls the second thruster to shut down, and controls the first thruster to start within the true near angle range [f1,f2] of the circle, and the working time is ΔT; for the 2nth circle, the calibration process control module shuts down the first thruster, and controls the second thruster to start within the true near angle range [f1,f2] of the circle, and the working time is ΔT;

[0051] The calibration data recording module is used to record the rotation speed of the +YB axis momentum wheel inside the satellite during the calibration process; wherein, for the 2n-1th lap, the calibration data recording module records the rotation speed ω of the +YB axis momentum wheel inside the satellite at the time when the first thruster of the working arc is turned on i1 and the speed of the +YB axis momentum wheel inside the satellite at the time of shutdown ω i2 For the 2nth lap, the calibration data recording module records the speed of the +YB axis momentum wheel inside the satellite at the time of the second thruster startup ω j1 and the speed of the +YB axis momentum wheel inside the satellite at the time of shutdown ω j2 ;

[0052] A calibration calculation module is used to calibrate the thrust of the first thruster or the thrust of the second thruster; wherein the calibration calculation module is based on the speed ω of the +YB axis momentum wheel inside the satellite at the start-up time of each working arc segment of the first thruster recorded by the calibration data recording module. i1 and the speed of the +YB axis momentum wheel inside the satellite at the time of shutdown ω i2 , and obtain the speed change Δω generated by the YB axis momentum wheel in each working arc segment of the first thruster i =ω i2 -ω i1 ; According to the calibration data recording module, the speed of the satellite internal +YB axis momentum wheel at the start time of each working arc segment of the second thruster is recorded j1 and the speed of the +YB axis momentum wheel inside the satellite at the time of shutdown ω j2 , and obtain the speed change Δω generated by the momentum wheel of the YB axis in each working arc segment of the second thruster j =ω j2 -ω j1 ;

[0053] The calibration calculation module is based on the formula i=2n-1,j=2n,n=1,2...,N calculate the thrust estimate of the first thruster or the second thruster in the adjacent turns According to the formula Calculate the optimal estimated value of the thrust of the first thruster or the second thruster According to the formula The standard deviation of the optimal estimated value of the thrust of the first thruster or the second thruster is calculated to be S; and the optimal estimated range of the thrust of the first thruster or the second thruster is obtained to be

[0054] In summary, the calibration method and system of the present invention firstly eliminate the influence of the interference torque, and there is no need to estimate the interference torque separately; secondly, two thrusters of the same type with symmetrical installation positions are started alternately in adjacent circles, and the optimal estimation range of the thrusters can be obtained through multiple estimates; thirdly, the present invention has the characteristics of fast and high precision for the on-orbit calibration of sub-millinewton thrust, and is also referential for the on-orbit calibration of thrusts of other magnitudes.

[0055] The present application is not limited to the contents defined in the specification and claims. Any modifications and changes known in the art fall within the scope of the present application. The specific embodiments of the specification are only exemplary descriptions of the present invention, not specific limitations of the present invention.

Claims

1. A method for on-orbit thrust calibration of a thruster, characterized in that Includes steps: Step S100: The first thruster and the second thruster are of the same type and are both installed on the satellite in the stellar coordinate system O. B X B Y B Z B X B O B Z B In-plane, thrust of the first thruster Direction along +X B Direction, thrust of the second thruster Direction along -X B Direction, the two thrusts are in a straight line, thrust and thrust To X B The distance between axes is L, L>0; Step S200: The satellite is in orbit and the first thruster and the second thruster work alternately to measure +Y B The step of the change in the speed of the axis momentum wheel; in this step, the satellite runs a total of 2n circles, n = 1, 2..., N, where, For the 2n-1th turn, the second thruster is turned off, and the first thruster is turned on within the true near-angle range [f1, f2] of this turn. The working time is ΔT, and the thrust magnitude of the working arc is recorded as F i , i = 2n-1, n = 1, 2..., N, according to the start time of the first thruster in each arc segment, the internal +Y B The speed of the shaft momentum wheel ω i1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω i2 , you can get +Y B The speed change Δω generated by the shaft momentum wheel i =ω i2 -ω i1 ; For the 2nth round, the first thruster is turned off, and the second thruster is turned on within the true near-angle range [f1, f2] of this round. The working time is ΔT, and the thrust magnitude of the working arc is F j , j = 2n, n = 1, 2..., N, according to the satellite internal +Y when the second thruster is turned on B The speed of the shaft momentum wheel ω j1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω j2 , you can get +Y B The speed change Δω generated by the shaft momentum wheel j =ω j2 -ω j1 ; Step S300 is a step of calibrating the thrust of the first thruster or the thrust of the second thruster; in this step, When the first thruster is turned on in each working arc, along the satellite +Y B The angular momentum generated by the axis is F i LΔT, momentum wheel along satellite +Y B The angular momentum generated by the axis is JΔω i , J is +Y B Axis momentum wheel rotation inertia; When the second thruster is turned on in each working arc segment, along the satellite +Y B The angular momentum generated by the axis is -F j LΔT, momentum wheel along satellite +Y B The angular momentum generated by the axis is JΔω j ; The estimated thrust of the first or second thruster in the adjacent turns is The optimal estimated thrust of the first thruster or the second thruster is The standard deviation of the optimal estimated value of the thrust of the first thruster or the second thruster is The optimal estimation range of the thrust of the first thruster or the second thruster is 2. The thruster thrust on-orbit calibration method according to claim 1, characterized in that: The satellite's orbit is a circular orbit, and the satellite attitude is always oriented toward the earth. At the same time, attitude actuators except for the momentum wheels are disabled.

3. The thruster thrust on-orbit calibration method according to claim 1, characterized in that: The working arc of each circle is within the same true near-angle range [f1, f2], and the working arc range is determined by the visible arc of measurement and control and the working time of the first thruster or the second thruster.

4. The thruster thrust on-orbit calibration method according to claim 1, characterized in that: The satellite is a nanosatellite, and the first thruster or the second thruster is a microthruster with a thrust of sub-millinewton order.

5. A thruster thrust on-orbit calibration system, characterized in that It includes a satellite, a calibration process control module, a calibration data recording module, a calibration calculation module, a first thruster and a second thruster; wherein The first thruster and the second thruster are of the same type and are both installed on the satellite. B X B Y B Z B X B O B Z B The first thruster is installed in the nozzle direction along +X B The second thruster is installed in the nozzle direction along -X B direction, the two thruster nozzles are in a straight line, the nozzle of the first thruster and the nozzle of the second thruster are to X B The distance between axes is L, L>0; The calibration process control module is used to control the first thruster and the second thruster to work alternately when the satellite is in orbit; the satellite runs 2n circles in total, n=1,2...,N, wherein for the 2n-1th circle, the calibration process control module controls the second thruster to shut down, and controls the first thruster to start within the true near angle range [f1,f2] of the circle, and the working time is ΔT; for the 2nth circle, the calibration process control module shuts down the first thruster, and controls the second thruster to start within the true near angle range [f1,f2] of the circle, and the working time is ΔT; Calibration data recording module, used to record the satellite internal +Y during calibration B The speed of the axis momentum wheel; wherein, for the 2n-1th lap, the calibration data recording module records the satellite internal +Y at the time when the first thruster of the working arc is turned on B The speed of the shaft momentum wheel ω i1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω i2 For the 2nth lap, the calibration data recording module records the satellite internal +Y at the time when the second thruster is turned on B The speed of the shaft momentum wheel ω j1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω j2 ; The calibration calculation module is used to calibrate the thrust of the first thruster or the thrust of the second thruster; wherein the calibration calculation module is based on the satellite internal +Y at the start-up time of each working arc segment of the first thruster recorded by the calibration data recording module B The speed of the shaft momentum wheel ω i1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω i2 , get the first thruster each working arc +Y B The speed change Δω generated by the shaft momentum wheel i =ω i2 -ω i1 ; According to the calibration data recording module, the satellite internal +Y B The speed of the shaft momentum wheel ω j1 And the satellite internal +Y at shutdown time B The speed of the shaft momentum wheel ω j2 , get the second thruster each working arc +Y B The speed change Δω generated by the shaft momentum wheel j =ω j2 -ω j1 ; The calibration calculation module is based on the formula Calculate the estimated thrust value of the first thruster or the second thruster in adjacent circles According to the formula Calculate the optimal estimated value of the thrust of the first thruster or the second thruster According to the formula The standard deviation of the optimal estimated value of the thrust of the first thruster or the second thruster is calculated to be S; and the optimal estimated range of the thrust of the first thruster or the second thruster is obtained to be 6. The thruster thrust on-orbit calibration system according to claim 5, characterized in that: The satellite's orbit is a circular orbit, and the satellite attitude is always oriented toward the earth. At the same time, attitude actuators except for the momentum wheels are disabled.

7. The thruster thrust on-orbit calibration system according to claim 5, characterized in that: The working arc of each circle is within the same true near-angle range [f1, f2], and the range of the working arc is determined by the visible arc of the measurement and control and the working time of the first thruster or the second thruster.

8. The thruster thrust on-orbit calibration system according to claim 5, characterized in that: The satellite is a nanosatellite, and the first thruster or the second thruster is a microthruster with a thrust of sub-millinewton order.

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