A non-cooperative spacecraft electromagnetic capture method based on multi-satellite serial release

Abstract

The present invention discloses a non-cooperative spacecraft electromagnetic capture method based on multi-satellite serial release, including: S1, the main spacecraft serially releases the capture satellite; S2, the capture satellite flies to find multiple feature points in the area where the non-cooperative spacecraft is located; S3, the main spacecraft calculates the optimal feature point in each area; S4, the capture satellite flies to each optimal feature point, and completes the successive capture at this point by electromagnetic docking to form a takeover assembly; S5, the takeover assembly is identified for inertial parameters, and the uncertainty of the attitude dynamics system caused by the identification error is attributed to the comprehensive disturbance to form a parameter identification enhancement effect; S6, a controller based on an interference observer is designed, and instructions are sent to each capture satellite actuator through the torque distribution principle, so as to realize the electromagnetic capture takeover of the non-cooperative spacecraft. The present invention can overcome the defects of weak capture capability of a single satellite and easy rigid collision with a non-cooperative spacecraft, and can cope with a variety of complex non-cooperative spacecraft capture tasks.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology, and in particular relates to a non-cooperative spacecraft electromagnetic capture method based on multi-satellite serial release. Background Art

[0002] In recent years, aerospace technology has achieved rapid development and major breakthroughs. Spacecraft with various complex structures have emerged one after another and the number of large spacecraft has increased dramatically. In the future, spacecraft must be flexible, widely used, and have strong anti-interference capabilities when performing non-cooperative spacecraft capture missions.

[0003] Traditional non-cooperative spacecraft capture problems usually adopt the structure of a spacecraft plus a single capture device, such as devices with a robotic arm, a flying net, and a harpoon. These capture methods have their own advantages and disadvantages. The robotic arm device for special components is prone to rigid collision, the flying net device that is not prone to rigid collision has a small application range, and the harpoon device that adapts to targets of various shapes is prone to space debris and plume pollution. Moreover, the above devices can only cope with relatively simple and small-scale capture tasks. At the same time, in actual applications, it is difficult to avoid the failure of a single satellite device. After a failure occurs, the structure of a spacecraft plus a single capture device will make it difficult to continue the capture mission smoothly.

[0004] Therefore, for the on-orbit control of complex non-cooperative spacecraft, multi-satellite collaboration and electromagnetic docking can be used to achieve capture and takeover, which has the advantages of high fault tolerance, no rigid collision, no debris generation, no plume pollution, flexibility and a wide range of applications. Summary of the invention

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides a non-cooperative spacecraft electromagnetic capture method based on multi-satellite serial release, comprising the following steps:

[0006] S1. The main spacecraft releases the captured satellites in series;

[0007] S2, the capture satellite searches for multiple feature points in the area where the non-cooperative spacecraft is located, and feeds the results back to the main spacecraft;

[0008] S3, the main spacecraft calculates the optimal feature points of each area, and generates control instructions based on the results and sends them to the capture satellites of each area;

[0009] S4, after receiving the command, the capture satellite flies to each optimal feature point, and completes the capture one by one at this point by electromagnetic docking to form a takeover assembly;

[0010] S5. Identify the inertial parameters of the take-over assembly, and attribute the uncertainty of the attitude dynamics system caused by the identification error to the comprehensive disturbance to form a parameter identification enhancement effect;

[0011] S6. Design a controller based on interference observer to send instructions to each capture satellite actuator through the torque distribution principle, so as to realize electromagnetic capture takeover of non-cooperative spacecraft;

[0012] The subject spacecraft and the captured satellite in step S1 are as follows: the subject spacecraft is used to carry and release the captured satellite, receive information sent back by the captured satellite, and perform analysis and calculation based on the information obtained, and generate control instructions to send to the captured satellite; the captured satellite is serially released from the subject spacecraft, and is equipped with an electromagnetic coil device, a camera, an orbit / attitude control module and an intersatellite communication module, and is used to find feature points of the assigned area, dock with the non-cooperative spacecraft at the optimal feature point, and complete the takeover of the non-cooperative spacecraft according to the control instructions issued by the subject spacecraft;

[0013] The takeover assembly in step S4 is an assembly formed after a plurality of capture satellites complete the capture and takeover at their respective optimal feature points by electromagnetic docking.

[0014] The beneficial effects of the present invention are:

[0015] Compared with the prior art, the beneficial effects of the present invention are that an electromagnetic coil device is installed on the capture satellite, which avoids rigid collision with non-cooperative spacecraft through soft docking, effectively avoids plume contamination and has continuous, reversible and synchronous controllability; in addition, when a capture satellite fails, other capture satellites can be dispatched in time or the torque can be redistributed to make real-time adjustments, which has little impact on the entire capture mission; and the method adopts different schemes for spacecraft of different sizes and structures, and can cope with a variety of complex non-cooperative spacecraft capture missions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A flow chart of a non-cooperative spacecraft electromagnetic capture method based on multi-satellite serial release provided by the present invention;

[0017] Figure 2 This is a schematic diagram of the main spacecraft of the present invention serially releasing and capturing satellites;

[0018] Figure 3 Assign a flow chart for capturing the best feature points of satellites;

[0019] Figure 4 This is the electromagnetic docking device for capturing satellites of the present invention. DETAILED DESCRIPTION

[0020] Combination Figure 1 To illustrate this embodiment, a non-cooperative spacecraft electromagnetic capture method based on multi-satellite serial release includes the following steps:

[0021] S1. The main spacecraft releases the captured satellites in series;

[0022] S2, the capture satellite searches for multiple feature points in the area where the non-cooperative spacecraft is located, and feeds the results back to the main spacecraft;

[0023] S3, the main spacecraft calculates the optimal feature points of each area, and generates control instructions based on the results and sends them to the capture satellites of each area;

[0024] S4, after receiving the command, the capture satellite flies to each optimal feature point, and completes the capture one by one at this point by electromagnetic docking to form a takeover assembly;

[0025] S5. Identify the inertial parameters of the take-over assembly, and attribute the uncertainty of the attitude dynamics system caused by the identification error to the comprehensive disturbance to form a parameter identification enhancement effect;

[0026] S6. Design a controller based on interference observer, and send instructions to each capture satellite actuator through the torque distribution principle to achieve electromagnetic capture takeover of non-cooperative spacecraft.

[0027] In step S1, the main spacecraft releases the captured satellites in series; the specific process is:

[0028] The main spacecraft flies around the non-cooperative spacecraft for one flight, and releases a certain number of captured satellites every time it turns a certain angle, so that the captured satellites are evenly dispersed around the non-cooperative spacecraft;

[0029] Among them, the main spacecraft is used to carry and release the captured satellite, receive the information sent back by the captured satellite, and perform analysis and calculation based on the information obtained, and generate control instructions to send to the captured satellite; the captured satellite is released serially from the main spacecraft, equipped with an electromagnetic coil device, a camera, an orbit / attitude control module and an intersatellite communication module, which is used to find the characteristic points of the assigned area, and dock with the non-cooperative spacecraft at the optimal characteristic point, and complete the takeover of the non-cooperative spacecraft according to the control instructions issued by the main spacecraft.

[0030] In step S2, the satellite searches for multiple feature points in the area where the non-cooperative spacecraft is located, and feeds the result back to the main spacecraft. The specific process is as follows:

[0031] After being released by the main spacecraft, the captured satellite arrives at the assigned working area, searches for all feature points in the area that can be electromagnetically docked with it through a camera, and sends the specific location information of each feature point on the non-cooperative spacecraft to the main spacecraft based on the intersatellite communication module.

[0032] In step S3, the main spacecraft calculates the optimal feature points of each region, and generates control instructions based on the results and sends them to the capture satellites of each region; the specific process is as follows:

[0033] The main spacecraft organizes the multiple feature points received, calculates the optimal feature point distribution suitable for subsequent takeover of non-cooperative spacecraft, and then plans the trajectory of each capture satellite based on the distribution, and generates control instructions based on the results and sends them to capture satellites in each region.

[0034] In step S4, the capture satellite flies to each optimal feature point after receiving the command, and completes the capture one by one at the point by electromagnetic docking to form a takeover assembly; the specific process is:

[0035] After receiving the control command from the main spacecraft, the capture satellite with docking requirements will track the trajectory to the corresponding optimal feature point, and the capture satellite without docking requirements will return to the main spacecraft, or the main spacecraft will dispatch an additional capture satellite to track the trajectory to the corresponding optimal feature point, and at this point, it will conduct electromagnetic docking with the non-cooperative spacecraft through an electromagnetic device to form a takeover combination with it.

[0036] In step S5, the inertial parameters of the take-over assembly are identified, and the uncertainty of the attitude dynamics system caused by the identification error is attributed to the comprehensive disturbance to form a parameter identification enhancement effect; the specific process is:

[0037] The main spacecraft performs parameter identification on the rotational inertia of the takeover assembly composed of multiple captured satellites and non-cooperative spacecraft, and attributes the uncertainty of the attitude dynamics system caused by the identification error, that is, the difference between the parameter identification result and the actual rotational inertia, to the comprehensive disturbance, thereby forming an enhanced effect of parameter identification on the rotational inertia of the takeover assembly.

[0038] In step S6, a controller based on an interference observer is designed to send instructions to each capture satellite actuator through the torque distribution principle, so as to achieve electromagnetic capture and takeover of the non-cooperative spacecraft; the specific process is:

[0039] A disturbance observer is designed to reduce the impact of the comprehensive disturbance, observe the equivalent disturbance and introduce equivalent compensation when designing the controller. Then, the torque of the takeover assembly is distributed according to the torque distribution principle, and control instructions are generated and sent to the actuators of each capture satellite, so as to realize the electromagnetic capture takeover of non-cooperative spacecraft.

[0040] Combination Figure 2 , the main spacecraft serially releases captured satellites, the main spacecraft circles the non-cooperative spacecraft once, and releases two captured satellites every ninety degrees, that is, releases at points 1, 2, 3 and 4 in the figure; the area where the two captured satellites search for characteristic points is the area of ​​one eighth of a circle from the current release position to the next release point on both sides of the main spacecraft orbit;

[0041] Among them, the angle of the serial release interval can be adjusted according to the size and structure of the non-cooperative spacecraft.

[0042] Combination Figure 3 , the capture satellite optimal feature point allocation flow chart, the specific process is as follows:

[0043] The main spacecraft sorts out all the feature points received in each area, calculates the optimal feature point distribution suitable for subsequent takeover of the non-cooperative spacecraft, considers the distance, time and energy optimization principles, and plans the trajectory of the captured satellite for the following three different situations:

[0044] When the number of optimal feature points is less than the current number of captured satellites, the captured satellites that need to further complete the docking mission are found according to the optimal principle and the trajectory is planned so that the captured satellites with docking requirements can track the trajectory to the corresponding optimal feature points, and the captured satellites without docking requirements can return to the main spacecraft;

[0045] When the number of optimal feature points is equal to the current number of captured satellites, the trajectory is planned according to the optimal principle so that each captured satellite tracking trajectory flies to the corresponding optimal feature point;

[0046] When the number of optimal feature points is greater than the current number of captured satellites, the trajectory is planned according to the optimal principle so that each captured satellite tracks the trajectory to reach the corresponding optimal feature point, and additional capture satellites are dispatched from the main spacecraft to fly to other optimal feature points.

[0047] Combination Figure 4 The electromagnetic docking device for capturing satellites, each device consists of four energized solenoids a1 (b1 or c1), a2 (b2 or c2), a3 (b3 or c3), and a4 (b4 or c4) with iron cores. The current is provided by an external solar panel. The distances between adjacent solenoids are equal and symmetrical about the center of mass of the captured satellite.

[0048] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such special statements and embodiments. Those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all belong to the protection scope of the claims attached to the present invention.

Claims

1. A non-cooperative spacecraft electromagnetic capture method based on multi-satellite serial release, characterized in that: The method comprises the following steps: S1. The main spacecraft releases the captured satellites in series; S2, the capture satellite searches for multiple feature points in the area where the non-cooperative spacecraft is located, and feeds the results back to the main spacecraft; S3, the main spacecraft calculates the optimal feature points of each area, and generates control instructions based on the results and sends them to the capture satellites of each area; S4, after receiving the command, the capture satellite flies to each optimal feature point, and completes the capture one by one at the optimal feature point by electromagnetic docking to form a takeover assembly; S5. Identify the inertial parameters of the take-over assembly, and attribute the uncertainty of the attitude dynamics system caused by the identification error to the comprehensive disturbance to form a parameter identification enhancement effect; S6. Design a controller based on interference observer to send instructions to each capture satellite actuator through the torque distribution principle, so as to realize electromagnetic capture takeover of non-cooperative spacecraft; In step S1, the main spacecraft releases the captured satellites in series; the specific process is: The main spacecraft flies around the non-cooperative spacecraft for one flight, and releases a certain number of captured satellites every time it turns a certain angle, so that the captured satellites are evenly dispersed around the non-cooperative spacecraft; The main spacecraft is used to carry and release the captured satellite, receive the information sent back by the captured satellite, analyze and calculate based on the information obtained, generate control instructions and send them to the captured satellite; the captured satellite is serially released from the main spacecraft, equipped with an electromagnetic coil device, a camera, an orbit / attitude control module and an intersatellite communication module, and is used to find the characteristic points of the assigned area, dock with the non-cooperative spacecraft at the optimal characteristic point, and complete the takeover of the non-cooperative spacecraft according to the control instructions issued by the main spacecraft; In step S2, the satellite searches for multiple feature points in the area where the non-cooperative spacecraft is located, and feeds the result back to the main spacecraft. The specific process is as follows: After being released by the main spacecraft, the captured satellite arrives at the assigned working area, searches for all feature points in the area that can be electromagnetically docked with it through the camera, and sends the specific location information of each feature point on the non-cooperative spacecraft to the main spacecraft based on the intersatellite communication module; In step S3, the main spacecraft calculates the optimal feature points of each region, and generates control instructions based on the results and sends them to the capture satellites of each region; the specific process is as follows: The main spacecraft sorts out the received multiple feature points, calculates the optimal feature point distribution suitable for subsequent takeover of the non-cooperative spacecraft, and then plans the trajectory of each capture satellite based on the distribution, and generates control instructions based on the results and sends them to the capture satellites in each region; In step S4, the capture satellite flies to each optimal feature point after receiving the command, and completes the capture one by one at the optimal feature point by electromagnetic docking to form a takeover assembly; the specific process is: After receiving the control command from the main spacecraft, the capture satellite with docking requirements will track the trajectory to the corresponding optimal feature point, and the capture satellite without docking requirements will return to the main spacecraft, or the main spacecraft will send an additional capture satellite to track the trajectory to the corresponding optimal feature point, and conduct electromagnetic docking with the non-cooperative spacecraft at the optimal feature point through an electromagnetic device to form a takeover combination with it; In step S5, the inertial parameters of the take-over assembly are identified, and the uncertainty of the attitude dynamics system caused by the identification error is attributed to the comprehensive disturbance to form a parameter identification enhancement effect; the specific process is: The main spacecraft performs parameter identification on the rotational inertia of the takeover assembly consisting of multiple captured satellites and non-cooperative spacecraft, and attributes the uncertainty of the attitude dynamics system caused by the identification error, that is, the difference between the parameter identification result and the actual rotational inertia, to the comprehensive disturbance, thereby forming an enhanced effect of parameter identification on the rotational inertia of the takeover assembly; In step S6, a controller based on an interference observer is designed to send instructions to each capture satellite actuator through the torque distribution principle, so as to achieve electromagnetic capture and takeover of the non-cooperative spacecraft; the specific process is: A disturbance observer is designed to reduce the impact of the comprehensive disturbance, observe the equivalent disturbance and introduce equivalent compensation when designing the controller. Then, the torque of the takeover assembly is distributed according to the torque distribution principle, and control instructions are generated and sent to the actuators of each capture satellite, so as to realize the electromagnetic capture takeover of non-cooperative spacecraft.

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