Space micro-debris monitoring micro-nano satellite based on double-layer thin film sensor

Abstract

A kind of space micro debris monitoring micro-nano satellite based on double-layer film sensor.The satellite carries out bidirectional verification through non-vision in-situ measurement of double-layer film sensor and visual measurement of monitoring camera, carries out monitoring on space micro debris with size less than 1 cm, obtains data information such as velocity vector of debris, and provides real-time and accurate micro debris cloud data.The normal direction of satellite film is the same as the direction of satellite speed, which increases the probability of collision monitoring between satellite and space micro debris.The folding and unfolding mechanism adopted by the present application has small folding volume and is convenient to unfold, and can be used as a debris monitoring device and satellite de-orbit device commonly installed in micro-nano satellite module, and has double functions.The locking-releasing mechanism adopted by the present application can realize locking of the whole mechanism only by using small pre-tightening force, and the design of burning rope release can reduce the separation impact to the minimum, and improve the stability and safety of the system.

Description

TECHNICAL FIELD

[0001] The present application provides a kind of micro-nano satellite based on double-layer film sensor space micro debris monitoring, it relates to the double-layer film sensor of micro-nano satellite in-orbit deployment is carried out non-vision in situ measurement to the micro debris of size less than 1 centimeter, belongs to satellite design field. BACKGROUND

[0002] With the continuous development of space exploration and satellite applications, the number of space micro debris in Earth orbit is increasing, which brings serious safety and environmental problems to space exploration, communication and navigation activities. These space debris include abandoned satellites, rocket debris, collision debris, etc., which may cause serious damage to other satellites, spacecraft and even space stations in high-speed motion.

[0003] Monitoring space micro debris with a size less than 1 centimeter is a key challenge in the current space debris problem. Due to its small size, large quantity, speed up to 10 km / s relative to on-orbit spacecraft, and generally no clear orbit, traditional monitoring methods and equipment are difficult to accurately detect and track it, so it poses a great threat to satellites, space stations and other on-orbit infrastructure. Current space micro debris monitoring systems mainly rely on ground-based radar and optical telescopes, but these devices have limited detection range, cannot monitor in real time, and are difficult to deal with large-scale debris clouds. For sub-centimeter space micro debris, there is almost no relevant monitoring data internationally, and there is a lack of real-time on-orbit monitoring solutions. Currently, mainstream space agencies such as NASA and ESA usually use various models to estimate space debris smaller than 1 cm. However, these models need to determine the initial total amount of debris at a certain starting time point, but there is currently no reliable data source to obtain accurate total debris. In addition, in the prediction process, collisions between spacecraft can generate new debris, and there is currently a lack of reliable fragmentation models to deal with such collision situations, and simulating collisions on orbits is also not feasible. Model-based methods have low accuracy and are difficult to reliably estimate debris in complex space situations.

[0004] Using small satellites, especially micro-nano satellites for rapid scientific experiments and technology verification, and even forming a satellite constellation for military, civilian and commercial applications has become a major trend. Micro-nano satellites have the advantages of small mass, simple structure, low cost, short development cycle and high functional density, and batch launching of micro-nano satellites can be used to observe space micro debris. However, most small satellites have a long on-orbit working time of several years, and a short on-orbit working time of several days, and most of them are difficult to deorbit and reenter the atmosphere to burn out in a short time after the mission is completed, thus becoming long-term resident in orbit, threatening other spacecraft. Therefore, the present application proposes a micro-nano satellite with a deorbit mechanism and can be used for sub-centimeter space debris monitoring. SUMMARY

[0005] The present application provides a micro-nano satellite for monitoring space micro debris based on a double-layer thin film sensor, which aims to solve the problem of the limitation of traditional monitoring methods, provide real-time and high-accuracy space debris data, and enable the micro-nano satellite to automatically deorbit after completing the task. The present application performs bidirectional verification through non-visual in-situ measurement of the double-layer thin film sensor and visual measurement of the monitoring camera, monitors space micro debris with a size of less than 1 cm, and accurately obtains data information such as the velocity vector of the debris, so that space debris monitoring and resource protection can be performed more timely and accurately. The double-layer thin film sensor also functions as a deorbiting sail, serving as a deorbiting device after the expiration of the service life, thereby improving the safety and sustainability of space activities.

[0006] The present application provides a micro-nano satellite for monitoring space micro debris based on a double-layer thin film sensor, which aims to solve the problem of the limitation of traditional monitoring methods, provide real-time and high-accuracy space debris data, and enable the micro-nano satellite to automatically deorbit after completing the task. The present application performs bidirectional verification through non-visual in-situ measurement of the double-layer thin film sensor and visual measurement of the monitoring camera, monitors space micro debris with a size of less than 1 cm, and accurately obtains data information such as the velocity vector of the debris, so that space debris monitoring and resource protection can be performed more timely and accurately. The double-layer thin film sensor also functions as a deorbiting sail, serving as a deorbiting device after the expiration of the service life, thereby improving the safety and sustainability of space activities.

[0007] The micro-nano satellite of the present application mainly consists of a double-layer thin film sensor system, a monitoring camera, a satellite-borne computer, a magnetic moment device, a power system, and a communication system, wherein the double-layer thin film sensor system and the monitoring camera are the effective payload for debris monitoring tasks. The double-layer thin film sensor is installed on the top of the satellite, and realizes non-visual in-situ measurement of micro debris by measuring the time, position, and area of the micro debris passing through the two layers of thin films. The monitoring camera is installed on the side panel of the satellite, and is used to observe the black holes produced by local ablation after the debris passes through the thin film to realize bidirectional verification. The remaining components are modular components, including a satellite-borne computer, a magnetic moment device, a power supply, and a communication system, which are used for central control, attitude control, power supply, and data transmission, respectively.

[0008] The double-layer thin film sensor system consists of a double-layer thin film sensor, a space stretching arm, and a locking-release device. The relationship between them is as follows: during the launch process, the satellite body and the storage device of the locking mechanism remain in a locked state, the double-layer thin film sensor is folded and fixed in the container, and the thin-walled tubular stretching arm winds the folded thin film onto the center hub; after entering the designated orbit, the release mechanism is unlocked, the bottom spring pops out the double-layer thin film sensor storage device, the double-layer thin film sensor automatically expands under the action of the elastic potential energy stored in the stretching arm, and the satellite always maintains a fully expanded state during the on-orbit process.

[0009] The shape of the double-layer thin film resistance sensor is square, and the thin film is divided into small grid areas. The principle of non-vision in-situ monitoring of the satellite is that when the space debris collides with the unfolded thin film sensor structure in sequence, the thin film is punctured and the circuit is broken, thereby generating two impulse excitation signals in sequence. The distance between the two layers of the thin film is known, and the size of the space debris relative to the satellite can be calculated by measuring the time interval of the space debris passing through the two layers of the thin film. The folding mode of the thin film is based on the Fushimi theorem, that is, for a folding mode in which a plurality of folds intersect at a point, the sum of the diagonals is equal, and a diagonal leaf folding mode is adopted.

[0010] The space stretching arm is made of thin-walled tubular carbon fiber composite material (CFRP) space stretching arm, and the cross section of the stretching arm is designed as a pod type. When the micro-nano satellite is in the launching state, the thin-walled tubular stretching arm is responsible for winding the folded thin film on the center hub. When the micro-nano satellite is in the running state, the thin-walled tubular stretching arm is responsible for supporting the unfolded thin film and the solar cell array.

[0011] The main components at the bottom of the locking-releasing mechanism include resistance wire, polyethylene fiber rope, tension spring, off-orbit sail storage device bottom clamping end, pressure rod, electrical connector, relay and hinge. When the micro-nano satellite is in the launching state, the mechanism is in the locking state, the double-layer thin film sensor is folded and fixed in the container, and is installed in the satellite. When the micro-nano satellite is in the running state, the electrical connector receives the release signal of the on-board computer, controls the relay to turn on the circuit, the resistance wire melts the polyethylene fiber rope, and the restoring force of the release spring makes the pressure rod quickly pop open, completing the release of the double-layer thin film sensor. The main part of the locking-releasing device is made of aluminum alloy.

[0012] The monitoring camera is located at the bottom of the micro-nano satellite. When the micro-nano satellite is in the launching state, the monitoring camera is stored in the satellite body; when the micro-nano satellite is in the running state, the monitoring camera is stretched out from the side plate and used for high-resolution shooting of the impact holes on the thin film. Through analyzing the position and shape of the impact holes, reliable two-way verification is provided for the debris data information obtained by the double-layer thin film sensor through non-vision in-situ monitoring.

[0013] (Three) advantages

[0014] The advantage of the space micro-debris monitoring micro-nano satellite based on the double-layer thin film sensor is that:

[0015] ① A new micro-nano satellite for monitoring space micro-debris with a size less than 1 cm is proposed in the present application.

[0016] The micro-nano satellite based on the double-layer film sensor for monitoring space micro debris has the ability to provide real-time and accurate micro debris cloud data.

[0017] The normal direction of the satellite film is the same as the speed direction of the satellite, which greatly increases the probability of collision between the satellite and the micro space debris, and makes the monitoring system have higher collision event detection sensitivity and accuracy.

[0018] The innovative folding and unfolding mechanism is adopted, and during the satellite launching stage, the double-layer film sensor is stored in the locking device according to the Fubuki theorem by adopting the inclined leaf folding mode, so as to save space and realize stable and controllable unfolding of the film, which brings greater flexibility and adaptability to the satellite configuration and deployment mode. The folding and unfolding mechanism of the double-layer film sensor has small folding volume, convenient unfolding and low cost, and can be used as a space micro debris monitoring device and satellite de-orbiting device commonly installed in micro-nano satellites, which has dual functions.

[0019] The innovative locking-releasing mechanism is adopted, which can realize locking of the whole mechanism only by small pre-tightening force, and the non-explosive separation design of burning rope release can reduce the separation impact to the minimum, so that the whole system has high stability and safety. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the internal installation and overall structure diagram of the micro-nano satellite.

[0021] Figures 2a to 2e is the folding and unfolding mechanism diagram of the micro-nano satellite.

[0022] Figure 3 is the non-visual in-situ measurement algorithm flowchart of the micro-nano satellite.

[0023] The product code in the figure is as follows:

[0024] 1. Double-layer film sensor system 1 a. Double-layer film sensor 1 b. Space stretching arm

[0025] 1 c. Locking-releasing device 2. Monitoring camera 3. Onboard computer

[0026] 4. Magnetic torque device 5. Power system 6. Communication system DETAILED DESCRIPTION

[0027] The application will be further described in detail below with reference to the drawings.

[0028] Referring to Figure 1 The application is a micro-nano satellite for monitoring space micro debris based on a double-layer film sensor, which mainly comprises a double-layer film sensor system 1, a monitoring camera 2, a satellite-borne computer 3, a magnetic moment device 4, a power supply system 5 and a communication system 6. Their mutual relationship is as follows: the double-layer film sensor system 1 is installed on the top of the satellite, and the non-vision in-situ measurement of the micro debris is realized by measuring the time, position and area of the micro debris crossing the double-layer film resistance sensor net; the monitoring camera 2 is installed on the side plate of the satellite, and is used for observing the black hole produced by the local ablation after the debris crosses the film to realize the bidirectional verification; the satellite-borne computer 3 is installed in the interior of the satellite main body, and is used for sending instructions to the satellite subsystems and storing part of the data needed to be transmitted to the ground; the magnetic moment device 4 is used for attitude control, and is jointly constructed with the accelerometer chip to form the attitude and orbit control subsystem of the task; the power supply system 5 is composed of a storage battery and a solar cell array, and is installed in the interior of the satellite main body, and is responsible for power supply for other components on the satellite; the communication system 6 is installed in the interior of the satellite main body, and is mainly responsible for receiving the ground instructions and transmitting the data to the ground.

[0029] The double-layer film sensor system 1 comprises a double-layer film sensor 1a, a space stretching arm 1b and a locking-releasing device 1c, and their mutual relationship is as follows: the satellite main body and the storage device 1c of the locking mechanism are always combined together during the launching process of the micro-nano satellite, the double-layer film sensor 1a is folded and fixed in the container, and the thin-walled tubular stretching arm 1b winds the folded film on the center hub; the locking is released by the releasing mechanism after entering the given orbit, the double-layer film sensor storage device 1c is ejected by the bottom spring, the double-layer film sensor 1a is automatically unfolded under the action of the elastic potential energy stored in the stretching arm 1b, and the double-layer film sensor 1a always maintains the fully unfolded state during the in-orbit process of the satellite.

[0030] The double-layer film sensor is a square film, and small grid areas are divided on the film to form a film resistance sensor net. During the launching stage of the satellite, the double-layer film sensor is folded in the locking device according to the sawa theory by adopting the oblique leaf folding mode.

[0031] The space stretching arm is designed as a thin-walled tubular structure with a pod type cross section, and is used as the unfolding device of the double-layer film sensor.

[0032] The main part of the locking-releasing device is a cuboid structure, and has four mounting hole positions for being fixed on the micro-nano satellite main frame.

[0033] Referring to FIG. 2a, the folding mode of the double-layer thin film sensor is selected as the oblique-leaf outer folding mode. The specific folding method is as follows: first, a square film-rod coupling configuration is constructed, that is, a smaller square hole is cut in the center, four support rods are installed on the four diagonal lines of the square hole, a 500mm*500mm square and a small square hole geometric model are established, the crease interval s=10mm, and according to the principle of alternate arrangement of ridge lines and valley lines, the thin film geometric model based on the oblique-leaf outer folding mode shown in FIG. 2a can be obtained. Among them, OA, OC, OD are ridge lines, and OB is a valley line. The ridge lines and valley lines appear alternately between the parallel line segments. In FIG. 2a, the dark lines are ridge lines, and the light lines are valley lines. The sum of the diagonals intersected by the four creases is: , , which meets the Fushimi theorem, that is, for a folding mode in which a plurality of creases intersect at a point, the sum of the diagonals is equal.

[0034] Referring to FIG. 2b, it is the unfolding process of the folding model based on the oblique-leaf outer folding mode.

[0035] Referring to FIG. 2c, the cross section of the spatial stretching arm is a thin-walled structure of a pod shape. The specific implementation mode of the spatial stretching arm to realize the folding and unfolding of the film-rod coupling structure is as follows: the stretching arm is fixedly connected with the sail surface, before unfolding, the stretching arm and the sail surface are co-wound according to the creases, and when unfolded, the limiting device outside the sail surface is removed, and the elastic potential energy stored when the stretching arm bends is utilized, without the need for any external force, the automatic unfolding can be realized. The material of the spatial stretching arm is carbon fiber reinforced polymer (CFRP).

[0036] Referring to FIGS. 2d and 2e, the main components at the bottom of the locking-releasing mechanism include: resistance wire, polyethylene fiber rope, tension spring, off-orbit sail storage device bottom clamping end, pressing rod, electrical connector, relay, hinge. In the locked state, the double-layer thin film sensor is folded and fixed in the container and installed inside the satellite. The double-layer thin film sensor is connected with the container through a conical spring, one end (the largest diameter end) of the spring is fixed at the bottom of the container, and the other end is fixed to the sensor body; when the spring is compressed, the double-layer thin film sensor reel clamping end extends from the bottom of the container and is fixed by the locking-releasing mechanism, that is, the ground locking state of the double-layer thin film sensor module is formed. The polyethylene fiber rope is fixed around the pressing rod, so that the pressing rod remains in the compressed state, and is wound around the resistance wire and fixed by the leaf spring. The design and installation of the spring can provide appropriate force to keep the polyethylene fiber rope in a tense state during the launch overload stage. At a predetermined time, the electrical connector receives a release signal from the on-board computer, controls the relay to turn on the circuit, and the resistance wire melts the polyethylene fiber rope, and the return force of the spring releases the pressing rod to quickly pop open, completing the release of the double-layer thin film sensor.

[0037] Referring to Figure 3Flow chart of non-visual in-situ measurement algorithm, the implementation steps are as follows:

[0038] The space debris collides with the two-layer film sensor in turn, and the two-layer film sensor generates 2 pulse excitation signals in turn.

[0039] The on-board computer calculates the speed of the space debris relative to the satellite according to the known distance between the two layers of film and the time interval of the two excitation signals measured.

[0040] The on-board computer calculates the vector direction of the debris velocity and the approximate size of the debris according to the position and area of the debris passing through the film grid area measured.

[0041] The small monitoring camera carried by the satellite takes pictures of the impact holes on the film, thereby obtaining high-resolution impact position images. The debris data information obtained by the double-layer film sensor through non-visual in-situ monitoring provides reliable two-way verification.

Claims

1. A micro / nano satellite for monitoring space micro-debris based on a dual-layer thin-film sensor, characterized in that: Composed of a dual-layer thin-film sensor system, a monitoring camera, an onboard computer, a magnetic torquer, a power supply system, and a communication system, the dual-layer thin-film sensor system is installed on the top of the satellite. It achieves non-visual in-situ measurement of tiny debris by measuring the time, position, and area of ​​the debris passing through the two-layer thin-film resistive sensor network. The aforementioned dual-layer thin-film sensor system comprises a dual-layer thin-film sensor, a spatial extension arm, and a locking-release device. The locking-release device includes a locking mechanism and a release mechanism, which are related as follows: During launch, the satellite body remains locked to the storage device of the locking mechanism, the dual-layer thin-film sensor is folded and fixed inside the container, and the thin-walled tubular spatial extension arm winds the folded film onto the central hub; after entering the predetermined orbit, the release mechanism releases the lock, the bottom spring pops out the dual-layer thin-film sensor storage device, and the dual-layer thin-film sensor automatically unfolds under the action of the elastic potential energy stored in the extension arm. During the satellite's orbit, the dual-layer thin-film sensor remains fully unfolded. The shape and structure of the dual-layer thin-film sensor are as follows: the dual-layer thin-film sensor is a square thin film, and the thin film is divided into small grid areas to form a thin-film resistance sensor network; The shape and structure of the space extension arm are as follows: the cross-section of the extension arm is designed as a pod-shaped thin-walled tubular structure, serving as an deployment device for the double-layer thin-film sensor. The locking-release device is constructed as follows: the main body of the locking-release device is a cuboid structure with four mounting holes for fixing it to the main frame of the micro-nano satellite.

2. A space micro-nano satellite for monitoring tiny debris based on a dual-layer thin-film sensor according to claim 1, characterized in that: During the satellite launch phase, the dual-layer thin-film sensor is housed within the locking mechanism using an outward folding method.

3. A space micro-nano satellite for monitoring tiny debris based on a dual-layer thin-film sensor according to claim 1, characterized in that: Based on the non-visual in-situ monitoring principle of satellites, the dual-layer thin-film sensor system has the ability to provide real-time, accurate cloud data of tiny debris smaller than 1 cm in size; the normal of the thin film is the same as the velocity direction of the satellite; the satellite carries a small monitoring camera to perform bidirectional verification to ensure the accuracy and reliability of the monitoring results; The specific implementation steps for satellite-based non-visual in-situ monitoring are as follows: Space debris collided with the two thin-film sensors in sequence, and the two thin-film sensors generated two pulse excitation signals in sequence. The onboard computer calculates the velocity of the space debris relative to the satellite based on the known gap between the two thin films and the time interval between the two measured excitation signals. The onboard computer calculates and determines the vector direction of the debris's velocity and the approximate size of the debris based on the measured position and area of ​​the region through which the debris crosses the thin film grid. The satellite carries a small surveillance camera that captures images of the impact holes on the thin film, thereby obtaining high-resolution images of the impact location; this provides two-way verification for the debris data obtained by the dual-layer thin-film sensor through non-visual in-situ monitoring.

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