CN108168757B - Space tumbling target electromagnetic derotation micro-derotation force test platform and its test method - Google Patents

Abstract

The invention provides a space tumbling target electromagnetic derotation tiny derotation test platform and a test method thereof, which belong to the technical field of space tumbling target derotation control force testing. Including marble vibration isolation table, industrial robot base, single-degree-of-freedom linear air bearing guide rail, slider, turntable, right limit block, left limit block, target satellite, nozzle, right solar panel, left solar panel , right tension gauge, left tension gauge, right adjustable elastic rod, left adjustable elastic rod, industrial robot and electromagnetic derotation end effector. The turntable above the slider provides two measuring stations. The double tension gauge structure is used to measure the starting friction f ₀ of the air bearing guide rail and the components of the small electromagnetic derotation force in the X and Y directions to realize the measurement of the two-dimensional electromagnetic derotation force. The platform is suitable for installing target satellites of different qualities and sizes. The air-floating guide rails, sliders, turntables and their accessories are all made of granite materials, and are suitable for the measurement of tiny electromagnetic derotation forces in electrostatic and electromagnetic environments.

Description

Space tumbling target electromagnetic derotation micro-derotation force test platform and its test method

technical field

The invention relates to a space tumbling target electromagnetic derotation tiny derotation test platform and a test method thereof, belonging to the technical field of space tumbling target derotation control force testing.

Background technique

With the increase of human space exploration and various space missions, a large amount of space junk left in orbit poses a serious threat to the space environment and the safety of on-orbit spacecraft. The active removal of space debris has become a research focus of major space agencies. Due to the failure of its own attitude control system, space debris will roll under the influence of space perturbation force, so derotation before capture is an essential stage.

In order to ensure the safety of the tumbling space debris de-rotation process, the non-contact de-rotation method becomes the first choice. Rolling targets can usually be derotated by interstellar Coulomb force, electromagnetic force, gas pulse, laser and particle beam bombardment methods. However, these racemization methods will encounter a problem in the ground verification, how to accurately measure the non-contact racemization force? Usually this kind of racemic force is on the order of hundreds of mN. Taking space debris such as failed satellites as an example, its mass is usually tens to hundreds of Kg, and the C1 precision (0.01%) weighing and measuring system is used to achieve mN level force measurement. The accuracy range is only 1Kg, even for small satellites with a mass of a few to tens of Kg, the resolution is difficult to meet the demand. For the measurement of such a large load and small thrust working condition, a new test system is required for measurement.

When the resolution of the sensor is difficult to be greatly improved, the method of mass balance is adopted to offset the mass of the target itself, which is beneficial to the measurement of small forces. Chinese Patent No. ZL201210316957 proposes a magnetic levitation method that uses high-temperature superconductors to levitate the target, and then measures the tiny force acting on the target. However, when it is applied to the measurement of electrostatic derotation and electromagnetic derotation of the tumbling target, the magnetic field of the high-temperature superconductor itself will interfere with the electrostatic and electromagnetic derotation, resulting in distortion of the derotation force, and the use of air floatation can well avoid this. This phenomenon makes the measurement platform universal for various racemization methods. Usually, the friction coefficient of the air flotation system can reach the order of 10 ^-5 , see the literature Rybus T, Seweryn K. Planar air-bearing microgravity simulators: Review of applications, existing solutions and design parameters [J]. Acta Astronautica, 2016, 120: 239-259; When a target of tens of kilograms floats, the friction force is on the order of mN. With the aid of the corresponding test system, it can economically and conveniently realize the measurement of the derotation force without interference in the electric and magnetic environment.

Contents of the invention

The object of the present invention is to solve the above-mentioned problems in the prior art, and further provide a space tumbling target electromagnetic derotation tiny derotation force test platform and a test method thereof.

The purpose of the present invention is achieved through the following technical solutions:

A space tumbling target electromagnetic derotation micro-derotation test platform and its test method, including: marble vibration isolation table, industrial robot base, single-degree-of-freedom linear air-floating guide rail, slider, turntable, right limit block, left limit Bit block, target satellite, nozzle, right solar panel, left solar panel, right tension gauge, left tension gauge, right adjustable elastic rod, left adjustable elastic rod, industrial robot and electromagnetic consumer Rotate the end effector.

Among them, the industrial robot and the single-degree-of-freedom linear air-floating guide rail are respectively fixed on the independent industrial robot base and the marble vibration isolation table. The other end of the industrial robot is fixedly connected with the electromagnetic derotation end effector. The slider is above the single-degree-of-freedom linear air-floating guide rail, and there are right and left stoppers installed on both sides of the slider. The turntable is fixedly connected with the slider. The target satellite is installed on the turntable. The solar panel and the left side solar panel constitute. The right tension gauge and the left tension gauge are fixed on the single-degree-of-freedom linear air bearing guide rail. The right side tension meter, the left side tension meter and the slide block are fixedly connected by the right side adjustable elastic rod and the left side adjustable elastic rod respectively.

The material of the single-degree-of-freedom linear air-floating guideway includes granite, the length is 500 mm, and the straightness is 1 μm.

The material of the slider and the turntable includes granite, and the stroke of the slider is 200mm.

The target satellite housing includes an aluminum alloy structure.

The right tension gauge and the left tension gauge are IMADA push-pull gauges, the force measuring range is 0-5N, the minimum unit is 1mN, and the overload capacity is 10N.

The industrial robot is a KUKA six-degree-of-freedom industrial robot.

The main steps of the measurement process are as follows:

Step 1. Leveling the marble vibration isolation table. Before the measurement starts, use a level to level the marble vibration isolation table to ensure the least interference to the measurement results during the measurement;

Step 2. Measure the starting friction of the slider as f ₀ , ventilate the single-degree-of-freedom linear air-floating guide rail to make the slider float, adjust the right tension meter, and the position of the left tension meter so that the readings are all reset to zero. At this time Fine-tune the length of the adjustable elastic rod on the left side to generate mN-level tension to act on the slider. Under the action of the starting static friction f ₀ , the position of the slider remains unchanged. The length of the left adjustable elastic rod continues to increase during the fine-tuning process. When the reading on the right tension gauge changes suddenly, the reading on the left tension gauge is the starting friction force f ₀ . You can also use the right adjustable elastic rod to measure the starting friction force f ₀ , the average value after multiple measurements is the starting friction force f ₀ ;

Step 3. Move the target satellite and the electromagnetic derotation end effector to station 1 for measuring the X-direction component of the derotation force, start the electromagnetic derotation end effector, and act on the target satellite body coordinate system O ₁ X ₁ Y ₁ The electromagnetic derotation force F _x in the direction of O ₁ X ₁ can be passed by the average value of the readings of the left and right tension gauges Subtract the starting friction force f ₀ to get;

Step 4. Adjust the target satellite and the electromagnetic derotation end effector to move to station 2 where the Y-direction component of the derotation force is measured, and start the electromagnetic derotation end effector according to the same parameters. At this time, it acts on the target satellite body coordinate system O ₁ X ₁ O ₁ Y ₁ The electromagnetic derotation force F _y in the direction of Y ₁ can pass the average value of the readings of the left tension gauge and the right tension gauge Subtract the starting friction f ₀ to get.

Compared with the prior art, the present invention has the following advantages:

1. The present invention can realize the measurement of large-mass target mN-level force by using the high-precision small-range tension meter by means of the air flotation system. The friction coefficient of the air bearing is on the order of 10 ^-5 , and the force measurement on the order of 10Kg meets the precision of mN level.

2. No interference to the electromagnetic environment. Compared with the superconducting suspension force measuring device, the single-degree-of-freedom linear air-floating guide rail and its related components are made of granite materials, which will not interfere with the external magnetic field, and are suitable for the measurement of electrostatic derotation and electromagnetic derotation force .

3. The two-dimensional force measurement is realized by using the single-degree-of-freedom air-floating guide rail. The electromagnetic derotation force in the directions of O ₁ X ₁ and O ₁ Y ₁ is measured at the first and second stations through the position change of the turntable and the industrial robot, and the measurement of the components of the static derotation force in the X and Y directions is realized.

Description of drawings

Fig. 1 is a structural schematic diagram of a space tumbling target electromagnetic derotation tiny derotation force test platform and its test method.

Fig. 2 is a schematic diagram of a station-position for measuring the X-direction component of the electromagnetic derotation force of a space tumbling target electromagnetic derotation tiny derotation force test platform and its test method.

Fig. 3 is a schematic diagram of the position of station 2 for measuring the Y-direction component of the electromagnetic derotation force of a space tumbling target electromagnetic derotation micro-derotation force test platform and its test method.

Reference numerals in Fig. 1, 1 is the marble vibration isolation table, 2 is the industrial robot base, 3 is the static pressure linear air bearing guide rail, 4 is the slider, 5 is the turntable, 6 is the right limit block, 7 is the left limit Bit block, 8 is the target satellite, 9 is the nozzle, 10 is the right solar panel, 11 is the left solar panel, 12 is the right tension gauge, 13 is the left tension gauge, 14 is the right adjustable elasticity Rod, 15 is an adjustable elastic rod on the left side, 16 is an industrial robot, and 17 is an electromagnetic derotation end effector.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings: the present embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation is provided, but the protection scope of the present invention is not limited to the following embodiments.

As shown in Figure 1, a space tumbling target electromagnetic derotation micro derotation force test platform and its test method involved in this embodiment include: a marble vibration isolation table 1, an industrial robot base 2, and a single-degree-of-freedom linear air flotation Guide rail 3, slider 4, turntable 5, right limit block 6, left limit block 7, target satellite 8, nozzle 9, right solar panel 10, left solar panel 11, right tension gauge 12, Left tension gauge 13, right adjustable elastic rod 14, left adjustable elastic rod 15, industrial robot 16 and electromagnetic derotation end effector 17.

Wherein, the industrial robot 16 and the single-degree-of-freedom linear air-floating guide rail 3 are respectively fixed on the independent industrial robot base 2 and the marble vibration isolation table 1 . The other end of the industrial robot 16 is fixedly connected 17 with the electromagnetic derotation end effector. The slider 4 is above the single-degree-of-freedom linear air bearing guide rail 3, and the right limit block 6 and the left limit block 7 are installed on both sides of the slider 4, the turntable 5 is fixedly connected with the slider 4, and the target satellite is installed on the turntable 5 8. The target satellite 8 is composed of a nozzle 9, a right side solar panel 10 and a left side solar panel 11. The right tension gauge 12 and the left tension gauge 13 are fixed on the single degree of freedom linear air bearing guide rail 3 . The right side tension meter 12, the left side tension meter 13 and the slide block 4 are fixedly connected by a right side adjustable elastic rod 14 and a left side adjustable elastic rod 15 respectively.

The material of the single-degree-of-freedom linear air-floating guideway 3 includes granite, the length is 500 mm, and the straightness is 1 μm.

The material of the slider 4 and the turntable 5 includes granite, and the stroke of the slider 4 is 200mm.

The casing of the target satellite 8 includes an aluminum alloy structure.

The right tension gauge 12 and the left tension gauge 13 are IMADA push-pull gauges, the force measuring range is 0-5N, the minimum unit is 1mN, and the overload capacity is 10N.

The industrial robot 16 is a KUKA six-degree-of-freedom industrial robot.

The main steps of the measurement process are as follows:

Step 1. Leveling the marble vibration isolation table 1. Use a spirit level to level the marble vibration isolation table 1 before the measurement, so as to ensure the minimum interference to the measurement results during the measurement;

Step 2: Measure the starting friction force of the slider 4 as f ₀ , ventilate the single-degree-of-freedom linear air-floating guide rail 3 to float the slider 4, and adjust the positions of the tension gauge 12 on the right and the tension gauge 13 on the left to make the readings uniform. Return to zero. At this time, the length of the adjustable elastic rod 15 on the left side is fine-tuned to generate mN-level tension to act on the slider 4. The position of the slider 4 remains unchanged under the action of the starting static friction force _f0 , and the reading on the right tension gauge 12 is still 0, the reading of the left tension gauge 13 continues to increase with the fine-tuning of the length of the left adjustable elastic rod 15, when the reading of the right tension gauge 12 changes suddenly, the reading of the left tension gauge 13 is the starting friction force f ₀ , also The starting friction force f _{0 can be measured by using the right adjustable elastic rod 14, and the starting friction force f 0 is} obtained by taking the average value after multiple measurements;

Step 3. Move the target satellite 8 and the electromagnetic derotation end effector 17 to station 1 for measuring the X-direction component of the derotation force, start the electromagnetic derotation end effector 17, and act on the body coordinate system O of the target satellite ₈ at this time. The electromagnetic derotation force F _x passable force in the direction O ₁ X ₁ of X ₁ Y ₁ is the average value of the readings of the left tension gauge 13 and the right tension gauge 12 Subtract the starting friction force f ₀ to get;

Step 4. Adjust the target satellite 8 and the electromagnetic derotation end effector 17 to move to the station 2 where the Y-direction component of the derotation force is measured, and start the electromagnetic derotation end effector 17 according to the same parameters. At this time, it acts on the body coordinates of the target satellite 8 The electromagnetic derotation force F _y in the direction of O ₁ Y ₁ of O ₁ X ₁ Y ₁ can pass the average value of the readings of the tension gauge 13 on the left side and the tension gauge 12 on the right side Subtract the starting friction f ₀ to get.

In this embodiment, as shown in Figure 1, the industrial robot 16 and the single-degree-of-freedom linear air-floating guide rail 3 are respectively fixed on the independent industrial robot base 2 and the marble vibration isolation table 1, and are moved by the electromagnetic derotation end effector 17 The influence of time vibration on the force measurement process. The single-degree-of-freedom linear air-floating guide rail 3 is a static pressure air-floating guide rail, and is installed on the marble vibration isolation table 1 . The single-degree-of-freedom linear air-floating guideway 3 has a rectangular structure, and the material is granite, which has no interference to the electromagnetic environment. The guide rail length is 500mm, and the straightness is 1μm. Slide block 4 stroke is 200mm. The air supply method is a small hole throttling air supply, the air supply pressure is 0.5MPa, and the mass of the target satellite 8 module that can be carried is 50Kg. A right limiter 6 and a left limiter 7 are installed on both sides of the slide block 4 to prevent damage to the dynamometer caused by external forces exceeding the range of the dynamometer. The slider 4 and the turntable 5 constitute a carrying module for installing the target satellite module 8 . An air film is formed between the slider 4 and the single-degree-of-freedom linear air-bearing guide rail 3 through the gas supplied from the outside, and the slider 4 can realize approximately frictionless sliding in the X direction of the single-degree-of-freedom linear air-bearing guide rail 3 . The turntable 5 is fixedly connected with the slider 4, and the turntable 5 has mounting holes and T-shaped slots for installing the target satellite 8 module. Use the turntable 5 to turn the module of the target satellite 8 to two stations perpendicular to each other, as shown in Fig. 2 and Fig. 3, so that the measurement of force in the X and Y directions can be realized. In order to avoid disturbing the racemic electromagnetic field environment, the materials of the slider 4 and the turntable 5 are granite.

The target satellite 8 module is composed of an electromagnetic derotation target—space failure satellite. The shell of the target satellite 8 is an aluminum alloy structure, which is composed of a nozzle 9 , a right solar panel 10 and a left solar panel 11 . The target satellite 8 has a cubic structure, and when its conductive shell interacts with the electromagnetic derotation end effector 17 , an electromagnetic force acting on the target satellite 8 will be generated. The electromagnetic force is transmitted to the turntable 5 and the slider 4 through the body of the target satellite 8, causing the slider 4 to move slightly, and this mN level is measured by the right tension meter 12 and the left tension meter 13 connected to the slider 4. Electromagnetic force.

The right tension gauge 12 and the left tension gauge 13 are fixed on the single-degree-of-freedom linear air bearing guide rail 3, and the right adjustable elastic rod 14 and the slider 4 are respectively used between the right tension gauge 12 and the left tension gauge 13 The left side adjustable elastic bar 15 is fixedly connected. When the slider is directly transmitted to the right tension gauge 12 and the left tension gauge 13 when the slider is subjected to electromagnetic force, the transmitted electromagnetic force is measured by using the small-scale high-precision right tension gauge 12 and the left tension gauge 13. The selected right tension gauge 12 and left tension gauge 13 are IMADA push-pull gauges, the force measuring range is 0-5N, the minimum unit is 1mN, and the overload capacity is 10N. The overload capacity of the right limiter 6 of the guide rail, the left limiter limiter 7, the right side tension gauge 12 and the left side tension gauge 13 itself ensures that the right side tension gauge 12 and the left side tension gauge 13 will not be damaged during the measurement process. cause damage.

The industrial robot 16 is a KUKA six-degree-of-freedom industrial robot, one end is fixedly connected to the base 2 of the industrial robot, and the other end is fixedly connected to the electromagnetic derotation end effector 17 . The electromagnetic derotation end effector 17 is driven by the power supply of the industrial robot 16 . When simulating the space electromagnetic derotation process on the ground, the six-degree-of-freedom mechanical arm of the industrial robot 16 drives the electromagnetic derotation end effector 17 to move to a certain position from the target to simulate the relative pose relationship in the initial derotation state.

Since the single-degree-of-freedom air-floating guide rail 3 can only measure the force in one direction, the force in two directions can be measured by changing the positions of the turntable 5 and the industrial robot 16 during actual force measurement. Measure the electromagnetic derotation force F _x in the direction of O ₁ X ₁ at station 1, then turn the turntable 90° clockwise to reach station 2, and at the same time, the six-degree-of-freedom mechanical arm of the industrial robot 16 drives the electromagnetic derotation end effector 17 to move To the new position after rotating 90° around O ₁ from the initial position. The electromagnetic derotation end effector 17 is driven according to the same parameters, and the electromagnetic derotation force F _y in the O ₁ Y ₁ direction is measured to realize the measurement of the electromagnetic derotation force components in two directions.

Example 1

In this embodiment, the main steps of mN-level two-dimensional electromagnetic force measurement during the electromagnetic derotation process of the target satellite 8 are as follows:

Step 1. Leveling the marble vibration isolation table 1. Use a spirit level to level the marble vibration isolation table 1 before the measurement, so as to ensure the minimum interference to the measurement results during the measurement;

Step 2: Measure the starting friction force of the slider 4 as f ₀ , ventilate the single-degree-of-freedom linear air-floating guide rail 3 to float the slider 4, and adjust the positions of the tension gauge 12 on the right and the tension gauge 13 on the left to make the readings uniform. Return to zero. At this time, the length of the adjustable elastic rod 15 on the left side is fine-tuned to generate mN-level tension to act on the slider 4. The position of the slider 4 remains unchanged under the action of the starting static friction force _f0 , and the reading on the right tension gauge 12 is still 0, the reading of the left tension gauge 13 continues to increase with the fine-tuning of the length of the left adjustable elastic rod 15. When the reading of the right tension gauge 12 changes suddenly, the reading of the left tension gauge 13 is the starting friction force f ₀ , also The starting friction force f _{0 can be measured by the right adjustable elastic rod 14, and the starting friction force f 0 is} obtained by taking the average value after multiple measurements;

Step 3. Move the target satellite 8 and the electromagnetic derotation end effector 17 to station 1 for measuring the X-direction component of the derotation force, start the electromagnetic derotation end effector 17, and act on the body coordinate system O of the target satellite ₈ at this time. The electromagnetic derotation force F _x passable force in the direction O ₁ X ₁ of X ₁ Y ₁ is the average value of the readings of the left tension gauge 13 and the right tension gauge 12 Subtract the starting friction force f ₀ to get;

Step 4: Adjust the target satellite 8 and the electromagnetic derotation end effector 17 to move to the station 2 for measuring the Y-direction component of the derotation force, start the electromagnetic derotation end effector 17 according to the same parameters, and act on the body coordinates of the target satellite 8 at this time The electromagnetic derotation force F _y in the direction of O ₁ Y ₁ of O ₁ X ₁ Y ₁ can pass the average value of the readings of the tension gauge 13 on the left side and the tension gauge 12 on the right side Subtract the starting friction f ₀ to get.

In this embodiment, the large-mass target satellite 8 is floated on the static pressure air-floating guide rail, and the mN-level electromagnetic force acting on the large-mass target in the electromagnetic environment is measured by using a high-precision small-range tension gauge. The measurement platform is capable of measuring 2-degree-of-freedom electromagnetic derotation force, and the target installation turntable is suitable for measuring targets of different masses and sizes.

The above are only preferred specific implementations of the present invention. These specific implementations are all based on different implementations under the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field Within the technical scope disclosed in the present invention, any changes or substitutions that can be easily conceived by a skilled person shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (5)

1. a kind of small racemization power test platform of space Tum bling Target electromagnetism racemization, comprising: marble vibration isolation table (1), industrial machine Device people pedestal (2), single-degree-of-freedom straight line air-float guide rail (3), sliding block (4), turntable (5), right limit block (6), left limit block (7), Target satellite (8), jet pipe (9), right side solar array (10), left side solar array (11), right side tensiometer (12), left side pulling force (13), right side adjustable elastic bar (14), left side adjustable elastic bar (15), industrial robot (16) and electromagnetism racemization end is counted to execute Device (17)；

It is characterized in that, industrial robot (16) and single-degree-of-freedom straight line air-float guide rail (3) are separately fixed at mutually independent work On industry robot base (2) and marble vibration isolation table (1), industrial robot (16) other end and electromagnetism racemization end effector (17) it is connected, sliding block (4) is equipped with right limit block (6) in sliding block (4) two sides above single-degree-of-freedom straight line air-float guide rail (3) With left limit block (7), turntable (5) and sliding block (4) are connected, and are equipped on turntable (5) target satellite (8), target satellite (8) is by spraying It manages (9), right side solar array (10) and left side solar array (11) to constitute, right side tensiometer (12), left side tensiometer (13) are solid It is scheduled on single-degree-of-freedom straight line air-float guide rail (3), between right side tensiometer (12), left side tensiometer (13) and sliding block (4) respectively It is connected using right side adjustable elastic bar (14) and left side adjustable elastic bar (15)；

Single-degree-of-freedom straight line air-float guide rail (3) material includes granite, and length 500mm, straightness is 1 μm；

Sliding block (4) and turntable (5) material include granite, and sliding block (4) stroke is 200mm.

2. a kind of small racemization power test platform of space Tum bling Target electromagnetism racemization according to claim 1, feature exist In target satellite (8) shell is aluminium alloy structure.

3. a kind of small racemization power test platform of space Tum bling Target electromagnetism racemization according to claim 1, feature exist In right side tensiometer (12) and left side tensiometer (13) are IMADA pull and push dynamometer, and dynamometry range is 0~5N, and minimum unit is 1mN, overload capacity 10N.

4. a kind of small racemization power test platform of space Tum bling Target electromagnetism racemization according to claim 1, feature exist In industrial robot (16) is library card Six-DOF industrial robot.

5. a kind of small racemization power survey of space Tum bling Target electromagnetism racemization described in a kind of Claims 1 to 4 any claim Try the test method of platform, which is characterized in that measurement process key step is as follows:

Step 1: marble vibration isolation table (1) levels, marble vibration isolation table (1) is adjusted using horizontal ruler before measurement starts It is flat, guarantee to interfere measurement result when measurement minimum；

Step 2: measurement sliding block (4) starting frictional force is f₀, ventilate to single-degree-of-freedom straight line air-float guide rail (3), keep sliding block (4) floating It rises, the position of adjustment right side tensiometer (12) and left side tensiometer (13) makes its reading be zeroed, at this time the adjustable bullet in fine tuning left side Property bar (15) length, generate mN grade pulling force effects on sliding block (4), starting stiction f₀Act on sliding block (4) position not Become, right side tensiometer (12) registration is still 0, and tensiometer (13) registration in left side is with left side adjustable elastic bar (15) length trim process In continue growing, when right side tensiometer (12) registration mutation when left side tensiometer (13) reading be start frictional force f₀, or Person utilizes right side adjustable elastic bar (14) to measure starting frictional force f₀, repeatedly average after measurement as starting frictional force f₀；

Step 3: target satellite (8) and electromagnetism racemization end effector (17) to be moved to the work of measurement racemization power X-direction component Position one starts electromagnetism racemization end effector (17), acts on target satellite (8) body coordinate system O at this time₁X₁Y₁O₁X₁Direction Electromagnetism racemization power F_xThe average value read by left side tensiometer (13) and right side tensiometer (12)Subtract starting frictional force f₀ It obtains；

Step 4: adjustment target satellite (8) and electromagnetism racemization end effector (17) are moved to measurement racemization power Y-direction component Station two starts electromagnetism racemization end effector (17) by identical parameters, acts on target satellite (8) body coordinate system at this time O₁X₁Y₁O₁Y₁The electromagnetism racemization power F in direction_yThe average value read by left side tensiometer (13) and right side tensiometer (12) Subtract starting frictional force f₀It obtains.