Ground-based educational satellite capable of realizing cubic satellite functions and its self-power-on simulation method

Abstract

The present invention discloses a ground-based educational satellite capable of realizing cubic satellite functions and a self-power-on simulation method thereof. The satellite comprises two satellite cubic frames, three solar cell array panels, a siding made of organic glass, an attitude control board located inside the two satellite cubic frames, a satellite service computer board and a power board, wherein the attitude control board and the power board are respectively connected to the satellite service computer board in communication; the self-power-on simulation method of the present invention collects the read air pressure value of the space where the educational satellite is located three times through the barometer of the integrated module 15 of the six-axis sensor, the barometer and the magnetometer, and determines whether the two air pressure differences are within the preset air pressure change threshold value to determine whether the self-power-on separation condition is met. The present invention can be used not only for the educational demonstration of primary scholars of cubic satellites, but also for professionals to debug, design, manufacture, operate and verify cubic satellites, and has powerful functions and can simulate the real flight state of the satellite in orbit.

Description

Technical Field

[0001] The present invention relates to the technical field of cubic satellites, and in particular to a ground-based educational satellite capable of realizing cubic satellite functions and a self-power-on simulation method thereof. Background Art

[0002] In recent years, with the rapid development of computers, new materials, microelectronic machinery, high-density energy and space propulsion technology, people are in urgent need of accelerating the satellite development cycle while demanding to reduce satellite costs and risks, especially for dedicated satellites for single tasks and satellite networking, which require satellite technology with low investment and quick results. CubeSats have become the most active research direction in the aerospace field with a new concept and brand-new design ideas. The standard size of the cubesat is 10×10×10cm, which can be expanded to 2-unit, 3-unit, 6-unit structures as needed to carry more scientific payloads. It has the advantages of good functional scalability, fast networking, convenient and flexible use, short mission completion time, great results, strong adaptability, and is very suitable for distributed space systems, including constellations, space networks and formation flying. CubeSats have been successfully applied to earth observation, communications, space science exploration and new technology experiments, and have gradually become an important part of the space system.

[0003] The widespread use of cubic satellites has promoted the desire of industry insiders or learners to learn more about cubic satellites. However, in actual satellite education, due to the high cost of cubic satellites, much knowledge can only remain at the theoretical level and cannot be deeply practiced. In recent years, the satellite education products that have appeared are limited to simple teaching demonstrations and theoretical framework models. There is no educational kit that can fully simulate the actual flight status of satellites in orbit and can be designed, manufactured, verified and operated by professional learners. Summary of the invention

[0004] The purpose of the present invention is to provide a practically operable ground-based educational satellite that can realize the functions of a cubic satellite and a self-power-on simulation method thereof, which is suitable for training personnel at various levels and for learning and debugging of learners.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A ground-based educational satellite capable of realizing cubic satellite functions, comprising two satellite cubic frames, three solar cell array panels, a plexiglass wall panel, an attitude control panel located inside the two satellite cubic frames, a satellite service computer panel and a power supply panel, wherein the two satellite cubic frames are fixedly butted to form four mounting surfaces in the circumferential direction, the three solar cell array panels and the plexiglass wall panel are respectively fixedly mounted on the four mounting surfaces, and the attitude control panel and the power supply panel are respectively connected to the satellite service computer panel for communication;

[0007] The attitude control board includes an attitude control substrate and a six-axis sensor installed on the attitude control substrate, an integrated module of a barometer and a magnetometer, a momentum wheel module, and two magnetic moment rods; the satellite service computer board includes a satellite service computer substrate and a satellite service computer main control module, a Lora wireless communication module and antenna, a GPS positioning module, a camera, and a Micro SD card memory storage module installed on the satellite service computer substrate; the power supply board includes a power supply substrate and a battery and a voltage conversion module installed on the power supply substrate.

[0008] Furthermore, it also includes four threaded rods and multiple columns. The top and bottom of the two satellite cube frames are respectively provided with four threaded holes. The four threaded rods pass through the threaded holes on the top, the attitude control board, the satellite computer board, the power board and the threaded holes on the bottom. The outsides of the threaded rods between the attitude control board, the satellite computer board and the power board are all sleeved with columns.

[0009] Furthermore, it also includes an organic glass top plate, which is located on the top of the two satellite cube frames.

[0010] Furthermore, the attitude control board, satellite service computer board and power board are arranged in sequence from top to bottom, the four threaded rods are arranged through the organic glass top plate, and columns are sleeved on the outside of the threaded rods between the attitude control board and the organic glass top plate.

[0011] Furthermore, the wall panel made of organic glass is arranged facing the camera.

[0012] Furthermore, the attitude control board also includes a first PC104 row seat, a first LED light and a Molex interface installed on the attitude control base plate.

[0013] Furthermore, the satellite service computer board also includes a second PC104 socket installed on the satellite service computer baseboard, an I2C bus interface, a first USART serial port, a Micro SD card memory storage module, an SPI interface, a second LED light and a DEBUG test interface.

[0014] Furthermore, the power board (7) also includes a third PC104 row seat, a battery charging interface, a second USART serial port, and an AD conversion module installed on the power substrate.

[0015] According to the above-mentioned self-power-on simulation method of the ground-based educational satellite, the ground-based educational satellite is located in a space with adjustable air pressure, and the method comprises the following steps:

[0016] Step 1: The barometer of the integrated module of the six-axis sensor, barometer and magnetometer collects the read air pressure value P1 of the space where the educational satellite is located;

[0017] Step 2: After a delay of t1, the barometer collects the air pressure value P2 of the space where the educational satellite is located;

[0018] Step 3: After a delay of t2, the barometer collects the air pressure value P3 of the space where the educational satellite is located;

[0019] Step 4, the satellite computer main control module calculates the absolute value ξ1 of the difference between P1 and P2 and the absolute value ξ2 of the difference between P2 and P3, and determines the magnitude relationship between ξ1 and the preset first air pressure change threshold e1, as well as the magnitude relationship between ξ2 and the preset second air pressure change threshold e2. If the power-on condition is met, the battery powers on the satellite through the voltage conversion module, and the satellite starts working. The power-on condition is ξ1<e1 and ξ2<e2. If the power-on condition is not met, return to step 1.

[0020] Furthermore, said t1=t2.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) Compared with real satellites, the present invention can enable learners to design, manufacture, verify and operate satellites at a lower cost. The present invention provides two methods of use, which are suitable for learning by people at different levels. It can be used not only for elementary learning but also for research and development work of professionals, and can be learned from the shallow to the deep.

[0023] (2) Compared with existing educational satellites, the present invention can not only perform simple teaching demonstrations and theoretical framework models, but also has authenticity. The present invention has the same system composition and functions as real cubic satellites and can fully simulate the real flight state of satellites in orbit;

[0024] (3) The present invention reserves a wealth of interfaces, and learners can independently design partial or overall functions of the satellite through programming, and test and debug the functions of the cubic satellite through these interfaces, thus realizing the combination of embedded software and aerospace technology;

[0025] (4) The invention provides a new satellite separation and self-powering method, which can judge the satellite's on-orbit status through sensitive air pressure changes and realize satellite separation and self-powering. It can fully simulate the actual separation and self-powering process of the satellite in space and has high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The system working block diagram of the ground-based educational satellite of the present invention which can realize the function of a cubic satellite.

[0027] Figure 2 It is the overall structural diagram of the ground-based educational satellite capable of realizing the cubic satellite function of the present invention.

[0028] Figure 3 It is a structural exploded diagram of the ground-based educational satellite capable of realizing the function of a cubic satellite according to the present invention.

[0029] Figure 4 This is the structure diagram of the cubic satellite attitude control board.

[0030] Figure 5 This is the structural diagram of the CubeSat service computer board.

[0031] Figure 6 This is the structural diagram of the cubic satellite power board.

[0032] In the figure: 1. Organic glass top plate, 2. Threaded holes, 3. Solar cell array mounting plate, 4. Cube frame, 5. Attitude control board, 6. Satellite computer board, 7. Power board, 8. Attitude control base plate, 9. Organic glass wall plate, 10. Threaded rod, 11. Column, 12. Magnetic moment rod, 13. First LED light, 14. Molex interface, 15. Integrated module of six-axis sensor, barometer and magnetometer, 16. First PC104 seat, 17. Momentum wheel module, 18. I2C bus interface, 19. Satellite computer main control module, 20. GPS positioning module, 21. First USART serial port, 22. Micro SD card memory storage module, 23. Lora wireless communication module and antenna, 24. SPI interface, 25. Second LED light, 26. Camera, 27. DEBUG test interface, 28. Battery charging interface, 29. Second USART serial port, 30. Battery, 31. Jumper cap, 32. AD conversion module, 33. Voltage conversion module, 34. Star service computer baseboard, 35. Power baseboard, 36. Second PC104 seat, 37. Third PC104 seat. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings.

[0034] Combination Figure 1-6 In this embodiment, a satellite ground education kit that can realize the function of a cubic satellite has a structure of a cubic frame. The satellite cubic frame 4 is composed of a pair of symmetrical frames, and a separation switch 8 is installed inside the frame. After the entire satellite circuit is connected, the first LED light 13 and the second LED light 25 light up to indicate that the system power supply is normal. One side of the cube frame top plate 1 and the cube camera 26 lens is a plexiglass wall panel 9, and the other three side walls are solar cell array mounting panels 3. The frame has reserved threaded holes 2. The solar cell array mounting panel 3 leads out the power line and is connected to the power supply module of the power board 7, which can not only store electrical energy and supply power for the entire satellite, but also use a voltmeter to measure pressure and current, so that learners can clearly understand the working principle of the solar cell array.

[0035] The interior of the CubeSat is composed of an attitude control board 5, a satellite computer board 6 and a power board 7. The boards are connected in series by frame threaded rods 10 and supported by columns 11 to ensure the spacing between the boards. The attitude control board and the power board are respectively connected to the satellite computer board through PC104 sockets.

[0036] The top layer is the attitude control board 5. The attitude control board 5 includes an attitude control substrate 8 and an integrated module 15 of a six-axis sensor, a barometer and a magnetometer installed on the attitude control substrate, a momentum wheel module 17, and two magnetic moment bars 12. The first LED lamp 13 is integrated on the attitude control substrate 8. The six-axis sensor measures the satellite attitude, and the measurement data is transmitted back to the satellite service computer main control module 19 for processing. The barometer measures the ambient air pressure of the cubic satellite, monitors and transmits the data back to the satellite service computer main control module 19 for processing. The magnetometer sensor measures the magnetic field strength and direction in the satellite body coordinate system. The satellite service computer main control module 19 transmits the satellite attitude transmitted back by the six-axis sensor 15 to the ground demonstration terminal through the Lora wireless communication module 23. The ground demonstration terminal transmits instructions to the satellite service computer main control module 19 through the Lora wireless communication module 23 according to the current attitude data of the satellite. The satellite service computer main control module 19 controls the momentum wheel module 17 and the two magnetic moment bars 12 to implement specific instructions to simulate the process of satellite attitude adjustment. The top plate 1 of the CubeSat is made of transparent organic glass, which allows clear viewing of the attitude control module structure and the rotation of the momentum wheel 17. After the satellite is powered, the LED light 13 lights up to indicate that the satellite attitude control board is powered normally.

[0037] The second PCB board is the satellite computer board 6, including a satellite computer substrate 34 and a satellite computer main control module 19 installed on the satellite computer substrate, a Lora wireless communication module and antenna 23, a GPS positioning module 20, a camera 26, a Micro SD card memory storage module 22, a second LED light 25, and a reserved JTAG / SWD and I2C interface 18. The satellite computer main control module 19, the GPS positioning module 20, and the camera 26 are connected to the satellite computer substrate 34 through a row seat, and the Micro SD card slot is fixed on the back of the satellite computer substrate 34, wherein a spring is installed to realize the insertion and removal of the Micro SD card. The side panel facing the camera head in the cubic satellite is made of transparent organic glass material 9, through which the internal structure of the cubic satellite can be clearly seen, a hole is dug on the surface of the glass plate, and the antenna extends out of the cube. The satellite computer main control module 19 is not only responsible for processing satellite data, but also needs to complete the tasks of on-board equipment status detection, satellite attitude control, sensor data collection and execution of various onboard experiments. The attitude control board and the power board are respectively connected to the satellite computer board through the PC104 seat communication. The satellite subsystem of the present invention ensures the normal operation of the entire system. The Lora wireless communication module and antenna 23 cooperate with the ground station to issue uplink and downlink instructions for data, realizing the interconnection of ground station and satellite information. The GPS positioning module 20 monitors the satellite position. The satellite computer substrate 34 is equipped with a payload, specifically a camera 26, which can realize the photo function. After taking a photo, the camera automatically sends and stores the picture in the Micro SD card memory storage module 22. The LED light 25 can display the power-on and working status of the satellite computer board 6. The I2C interface 18 is reserved on the satellite computer board 6 for ground testing.

[0038] The third layer is the power board 7, including a power substrate 35 and a battery 30 installed on the power substrate, a voltage conversion module 33, a third PC104 row seat 37, a battery charging interface 28, a second USART serial port 29, and an AD conversion module 32. The solar cell array 3 and the battery pack 30 can both provide power for the entire satellite. The battery 30 is fixed on the back of the solar panel. A power adjustment unit is connected in series between the solar cell array and the battery pack to track the maximum power point of the solar energy; a shunt module is connected in parallel to realize overcharge protection of the battery and bus overvoltage protection. The satellite uses a single unregulated bus, and the bus voltage is the battery pack voltage, ranging from 6.5 to 8.4V. When the bus voltage is less than the lower limit of 6.5V, the undervoltage lockout module cuts off the bus and the entire satellite is powered off until the battery voltage is charged to 6.7V, and the bus automatically restarts. The bus also has an interface for ground testing. The AD conversion module 32 is used to transmit the current, voltage and temperature information to the satellite computer main control module 19 through the SPI bus to complete the collection of subsystem telemetry. The voltage conversion module 33 uses a DC / DC converter with a bus voltage of 6.5V to 8.4V. A buck converter is used to supply 5V or 3.3V to the load, while preventing short circuit.

[0039] The satellite computer main control module 19 of the present invention is based on a 32-bit microprocessor of the ARM Cortex-M4 architecture, with a maximum operating frequency of 168MHz, 1MB of Flash storage and 192+4KB of SRAM storage, an operating voltage of 3.3V, a power consumption of 600mW, and a Cortex-M4F core that supports all ARM single-precision data processing instructions and single-precision floating-point unit data types. At the same time, a complete set of DSP instruction access and memory protection unit mechanisms are implemented, which can enhance the stability and security of the application.

[0040] The satellite body of a unit reserves a wide range of I / O device interfaces. Through multiple pre-dividers, two AHB buses can be configured separately, the high-speed bus APB (APB2) and the low-speed bus APB (APB1). Micro SD Card, or TF card, is selected as the system memory. The TF card contains 4 data lines (DATA0-3), 1 clock line (CLK) and 1 control command line (CMD), which are respectively connected to the corresponding pins of the main control module. The data transmission of the TF card follows the SD 2.0 protocol. CubeSat uses the I2C bus to transmit data between multiple system modules. In order to ensure that the minimum system and system functions are more complete, the crystal oscillator circuit, reset circuit, overcurrent protection circuit, temperature monitoring circuit, current and voltage monitoring circuit are also designed. In addition, in order to facilitate desktop debugging, the JTAG / SWD interface circuit is designed.

[0041] The present invention also provides a self-power-on simulation method for a ground-based educational satellite according to the above-mentioned method, wherein the ground-based educational satellite is located in a space with adjustable air pressure, and the method comprises the following steps:

[0042] Step 1: The barometer of the integrated module 15 of the six-axis sensor, barometer and magnetometer collects the read air pressure value P1 of the space where the educational satellite is located;

[0043] Step 2: After a delay of t1 (e.g., 20 seconds), the barometer collects the air pressure value P2 of the space where the educational satellite is located;

[0044] Step 3: After a delay of t2 (e.g., 20 seconds), the barometer collects the air pressure value P3 of the space where the educational satellite is located;

[0045] Step 4, the satellite computer main control module 19 calculates the absolute value ξ1 of the difference between P1 and P2 and the absolute value ξ2 of the difference between P2 and P3, and determines the magnitude relationship between ξ1 and the preset first pressure change threshold value e1 and the magnitude relationship between ξ2 and the preset second pressure change threshold value e2. If the power-on condition is met, the battery 30 powers on the satellite through the voltage conversion module 33, and the satellite starts working. The power-on condition is ξ1<e1 and ξ2<e2. If the power-on condition is not met, return to step 1. When the actual satellite is launched into space, it is in a vacuum environment. Therefore, as the satellite continues to fly, the pressure of the environment around it remains basically unchanged. At this time, the satellite meets the power-on separation condition. Therefore, one of the functions of the present invention is to simulate such a situation to realize the self-separation power-on of the satellite. When the pressure values ​​are collected three times and the pressure difference between the two times is within the preset pressure change threshold value, it means that the satellite is in space and meets the power-on separation condition. The self-power-on method is novel, simple, and easy to operate.

[0046] The educational satellite capable of realizing the cubic satellite function described in the present invention is used in conjunction with a corresponding ground demonstration terminal, and the ground demonstration terminal sends uplink instructions to the satellite and receives downlink data sent by the satellite.

[0047] The educational satellite capable of realizing the function of a cubic satellite described in the present invention is equipped with a ground demonstration terminal, which can receive satellite data transmitted back by the Lora wireless communication module, including information such as the atmospheric pressure, position, and attitude of the cubic satellite environment, as well as photos transmitted back by the camera. The ground demonstration terminal can also send uplink instructions to the satellite through the Lora wireless communication module, including sending instructions to the magnetometer, changing the attitude and angle, sending photo instructions, etc. The educational satellite capable of realizing the function of a cubic satellite described in the present invention is equipped with a tested program and can be directly used by learners. The learners only need to click the corresponding button on the interface to complete the sending of cubic satellite instructions.

[0048] The cubic satellite in the kit of the present invention has a rich set of interfaces, including I2C bus interface 18, USART1 serial port 121, USART3 serial port 329, SPI2 interface 24, DEBUG test interface 27, etc. The learner can independently design the partial or overall functions of the satellite through programming, and test and debug the functions of the cubic satellite through these interfaces, thus realizing the combination of embedded software and aerospace technology.

[0049] The present invention can be used not only for educational demonstration of beginners of cubic satellites, but also for professionals to debug, design, manufacture, operate and verify cubic satellites. The kit of the present invention can simulate and realize the functions of standard cubic satellites, including on-board power supply detection, air pressure measurement, ground communication, satellite positioning, attitude measurement and adjustment, etc. The present invention can also be used for satellite design, manufacture, verification and integration operations.

[0050] The present invention has a wide audience and can be used in the following two ways for different groups of people.

[0051] For beginners, the present invention can use the existing ground demonstration terminal to collect information such as the ambient air pressure, position, and attitude of the cubic satellite, and can also demonstrate functions such as taking pictures, storing and sending data, and changing the satellite's attitude. The learner only needs to click the corresponding button on the ground demonstration terminal to complete the operation of the cubic satellite.

[0052] For learners who already have a good foundation, they can independently design the functions of part or all of the satellite through programming. The cubic satellite in the kit of the present invention has abundant interfaces reserved, and learners can debug the functions of the cubic satellite through these interfaces, thus realizing the combination of embedded and aerospace technologies.

[0053] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A self-power-on simulation method for a ground-based educational satellite, the ground-based educational satellite comprising two satellite cube frames (4), three solar cell array panels (3), a plexiglass wall panel (9), an attitude control panel (5) located inside the two satellite cube frames (4), a satellite service computer panel (6) and a power panel (7), the two satellite cube frames (4) are fixedly connected to form four mounting surfaces in the circumferential direction, the three solar cell array panels (3) and the plexiglass wall panel (9) are respectively fixedly installed on the four mounting surfaces, and the attitude control panel (5) and the power panel (7) are respectively connected to the satellite service computer panel (6) for communication; The attitude control board (5) comprises an attitude control substrate (8) and a six-axis sensor, an integrated module of a barometer and a magnetometer (15) mounted on the attitude control substrate, a momentum wheel module (17), and two magnetic moment rods (12); the satellite service computer board (6) comprises a satellite service computer substrate (34) and a satellite service computer main control module (19) mounted on the satellite service computer substrate, a Lora wireless communication module and antenna (23), a GPS positioning module (20), a camera (26), and a Micro SD card memory storage module (22); the power supply board (7) comprises a power supply substrate (35) and a storage battery (30) and a voltage conversion module (33) mounted on the power supply substrate; It is characterized in that The ground-based educational satellite is located in a space with adjustable air pressure, and the method comprises the following steps: Step 1, the barometer of the integrated module (15) of the six-axis sensor, barometer and magnetometer collects the read air pressure value P1 of the space where the educational satellite is located; Step 2: After a delay of t1, the barometer collects the air pressure value P2 of the space where the educational satellite is located; Step 3: After a delay of t2, the barometer collects the air pressure value P3 of the space where the educational satellite is located; Step 4, the satellite service computer main control module (19) calculates the absolute value ξ1 of the difference between P1 and P2 and the absolute value ξ2 of the difference between P2 and P3, and determines the magnitude relationship between ξ1 and a preset first air pressure change threshold value e1, and the magnitude relationship between ξ2 and a preset second air pressure change threshold value e2. If the power-on condition is met, the battery (30) powers on the satellite through the voltage conversion module (33), and the satellite starts to work. The power-on condition is ξ1<e1 and ξ2<e2. If the power-on condition is not met, return to step 1.

2. The method according to claim 1, characterized in that The t1=t2.

3. The method according to claim 1, characterized in that The ground education satellite also includes four threaded rods (10) and a plurality of columns (11). The top and bottom of the two satellite cube frames (4) are respectively provided with four threaded holes (2). The four threaded rods (10) are arranged through the threaded holes (2) at the top, the attitude control board (5), the satellite computer board (6), the power board (7) and the threaded holes (2) at the bottom. The outsides of the threaded rods (10) between the attitude control board (5), the satellite computer board (6) and the power board (7) are all sleeved with columns (11).

4. The method according to claim 3, characterized in that: The ground-based educational satellite further comprises an organic glass top plate (1), and the organic glass top plate (1) is located on the top of the two satellite cube frames (4).

5. The method according to claim 4, characterized in that The attitude control board (5), the satellite service computer board (6) and the power supply board (7) are arranged in sequence from top to bottom, the four threaded rods (10) are arranged through the organic glass top plate (1), and the outsides of the threaded rods (10) between the attitude control board (5) and the organic glass top plate (1) are all sleeved with columns (11).

6. The method according to any one of claims 1 to 5, characterized in that: The wall panel (9) made of organic glass is arranged facing the camera (26).

7. The ground-based educational satellite capable of realizing the function of a cubic satellite according to claim 6, characterized in that: The posture control board (5) also includes a first PC104 row seat (16), a first LED lamp (13) and a Molex interface (14) installed on the posture control base board.

8. The ground-based educational satellite capable of realizing the function of a cubic satellite according to claim 6, characterized in that: The satellite service computer board (6) also includes a second PC104 row seat (36) installed on the satellite service computer baseboard, an I2C bus interface (18), a first USART serial port (21), a Micro SD card memory storage module (22), an SPI interface (24), a second LED lamp (25) and a DEBUG test interface (27).

9. The ground-based educational satellite capable of realizing the function of a cubic satellite according to claim 6, characterized in that: The power board (7) also includes a third PC104 row seat (37) installed on the power substrate, a battery charging interface (28), a second USART serial port (29), and an AD conversion module (32).

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