Multi-axis momentum wheel system for microsatellites

Abstract

The present invention discloses a multi-axis momentum wheel system suitable for a microsatellite, comprising a shell, wherein the shell comprises an upper cover and a bottom shell, the bottom end of the upper cover is connected to the bottom shell by screws, four fixing bosses are installed on the inner top of the bottom shell, the top ends of the fixing bosses are connected to a fixing base plate by screws, four vertical side panels are installed on the top edges of the fixing base plate, and oblique side panels are installed on the top ends of adjacent vertical side panels, and mounting slots are provided in the middle portions of the vertical side panels, the oblique side panels and the fixing base plate. The present invention arranges fixing bosses, a fixing base plate, vertical side panels, oblique side panels, mounting slots, fixing holes, ribs, motors, mounting holes, connecting shafts and inertia, and simultaneously arranges multiple flywheel structures. Compared with a single flywheel, the present invention has higher integration, smaller size and lighter weight, ensures the accuracy of the angles of each axis, and facilitates subsequent attitude control.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite momentum wheels, and in particular to a multi-axis momentum wheel system suitable for microsatellites. Background Art

[0002] A momentum wheel is a motor-driven rotating body mounted on a spacecraft via a bracket or frame. It is an important actuator for satellite attitude control. If a single satellite needs to complete attitude adjustments such as pitch, yaw, and roll, it usually needs to deploy multiple sets of momentum wheels. Traditional satellites use a pyramid layout or a three-straight and one-slant layout. Existing momentum wheels, especially those with large rotational inertia, mostly adopt a single-axis design. A satellite often needs to be equipped with at least three momentum wheels.

[0003] However, the momentum wheels currently used in microsatellites have problems such as large installation envelope, heavy mass, and difficult to control installation accuracy. In addition, multiple momentum wheels need to be connected to the power supply / control end interface on the satellite using cables, which makes the wiring complicated. Summary of the Invention

[0004] The present invention provides a multi-axis momentum wheel system suitable for microsatellites, which can effectively solve the problems raised in the above background technology, such as the large installation envelope, heavy mass, and difficult to control installation accuracy of the momentum wheels currently used in microsatellites. In addition, multiple momentum wheels need to be connected to the power supply / control end interface on the satellite using cables, which makes the wiring complicated.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a multi-axis momentum wheel system suitable for a microsatellite, comprising a housing, wherein the housing comprises an upper cover and a bottom shell;

[0006] The bottom end of the upper cover is connected to the bottom shell by screws;

[0007] An inertia disk mechanism is installed on the inner side of the bottom shell, and the inertia disk mechanism includes a fixed boss, a fixed bottom plate, a vertical side plate, an inclined side plate, a mounting slot, a fixing hole, a rib plate, a motor, a mounting hole, a connecting shaft and an inertia disk;

[0008] Four fixing bosses are installed on the inner top of the bottom shell, and the top of the fixing boss is connected to the fixed base plate by screws, and four vertical side panels are installed on the top edge of the fixed base plate, and the tops of adjacent vertical side panels are installed with inclined side panels, and the middle parts of the vertical side panels, inclined side panels and fixed base plate are all provided with mounting slots, and the middle parts of the vertical side panels, inclined side panels and fixed base plate are provided with fixing holes at the positions of the mounting slots corresponding to the middle parts, and a rib plate is installed in the middle of the vertical side panels, and a motor is installed on the inside of the mounting slot, and mounting holes are opened at equal angles on the edge of one end of the motor, a connecting shaft is installed in the middle of one end of the motor, and an inertia disk is installed at one end of the connecting shaft.

[0009] According to the above technical solution, the four corners of the fixed base plate are each provided with a fixing circular hole, and the screws pass through the fixing circular hole and are tightened with the fixing boss;

[0010] The fixing hole at one end of the motor is aligned with the mounting hole.

[0011] According to the above technical solution, the sides of the four vertical side panels at the top of the fixed bottom plate are connected in sequence, and an inclined side panel is installed at one of the connection positions;

[0012] The middle of the inertia disk is hollowed out and the material of the inertia disk is brass.

[0013] According to the above technical solution, there are four mounting slots, one mounting slot is opened in the middle of the inclined side plate, one mounting slot is opened in the middle of the fixed bottom plate, and the remaining two mounting slots are opened in the middle of the vertical side plate away from the inclined side plate.

[0014] According to the above technical solution, a control mechanism is installed on the inner side of the bottom shell, and the control mechanism includes a fixing column, a pad, a thermal conductive silicone block, a PCB board and a power interface;

[0015] A fixing column is installed on the inner side of the bottom shell, a pad is installed in the middle of the top of the bottom shell, a thermal conductive silicone block is installed on the top of the bottom shell, the top of the fixing column is connected to the PCB board through screws, and a power interface is installed on the top of the PCB board.

[0016] According to the above technical solution, a placement hole is opened at the side end of the bottom shell corresponding to the position of the power interface, and the power interface is snapped into the placement hole;

[0017] The thermally conductive silica gel block contacts the bottom end of the PCB board.

[0018] According to the above technical solution, the control core of the PCB board is a Flash FPGA chip, and the Flash FPGA chip has an ARM core;

[0019] The inertia disk control algorithm including field-oriented control, speed control, current control, speed calculation, and position calculation is implemented through Flash FPGA chips.

[0020] The ARM core is used to implement load characteristic analysis, speed curve analysis, process control and protection, read configuration data stored in non-volatile memory, and save key variables.

[0021] According to the above technical solution, the input end of the Flash FPGA chip is provided with a memory, an air pressure sensor, a temperature sensor, an ADC sampling for current and voltage monitoring, and a thermistor sampling resistor installed on the motor 208;

[0022] The external interfaces of the momentum wheel system include CANA, CANB, RS422A and RS422B, which are mutually backed up. They can carry out two-way data communication with the satellite service. There is also a JTAG interface inside to realize program download and debugging of FPGA and ARM core.

[0023] According to the above technical solution, the motor, connecting shaft and inertia disk form a flywheel structure, the output end of the flywheel is connected to the current sampling ADC and the Hall sampling ADC, and the input end of the flywheel is connected to the integrated drive;

[0024] The Flash FPGA chip controls the rotation of the flywheel through an integrated driver, and receives data such as flywheel current, speed, and angle through current sampling ADC and Hall sampling ADC.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. By setting a fixed boss, a fixed base plate, a vertical side plate, an inclined side plate, a mounting slot, a fixing hole, a rib plate, a motor, a mounting hole, a connecting shaft and an inertia, multiple flywheel structures are set up at the same time. Compared with a single flywheel, the integration is higher, the volume is smaller, the weight is lighter, the angle accuracy of each axis is guaranteed, and the subsequent attitude control is convenient.

[0027] 2. By using a Flash FPGA chip with an ARM core as the control core, it is easy to deploy efficient motor control algorithms. Flash FPGAs have high security and high reliability, which can effectively solve the problem of controller failure caused by high-energy particles in the space environment, greatly improving the reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the oblique side plate of the present invention;

[0031] Figure 3 It is a structural schematic diagram of the inertia disk of the present invention;

[0032] Figure 4 It is a structural schematic diagram of the motor of the present invention;

[0033] Figure 5 It is a structural schematic diagram of the PCB board of the present invention;

[0034] Figure 6 It is a structural schematic diagram of the power interface of the present invention;

[0035] Figure 7 This is a schematic structural diagram of the thermally conductive silica gel block of the present invention;

[0036] Figure 8 It is a schematic diagram of the control structure of the present invention;

[0037] Reference numerals in the figure: 1, housing; 101, upper cover; 102, bottom shell;

[0038] 2. Inertia disk mechanism; 201. Fixed boss; 202. Fixed base plate; 203. Vertical side plate; 204. Oblique side plate; 205. Mounting slot; 206. Fixing hole; 207. Rib plate; 208. Motor; 209. Mounting hole; 210. Connecting shaft; 211. Inertia disk;

[0039] 3. Control mechanism; 301. Fixing column; 302. Pad; 303. Thermal conductive silicone block; 304. PCB board; 305. Power interface. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0041] Example: Figure 1-7 As shown, the present invention provides a technical solution suitable for a multi-axis momentum wheel system of a micro satellite, comprising a housing 1, wherein the housing 1 comprises an upper cover 101 and a bottom shell 102;

[0042] The bottom end of the upper cover 101 is connected to the bottom shell 102 by screws;

[0043] The inertia disk mechanism 2 is installed on the inner side of the bottom shell 102. The inertia disk mechanism 2 includes a fixed boss 201, a fixed bottom plate 202, a vertical side plate 203, an inclined side plate 204, a mounting slot 205, a fixing hole 206, a rib 207, a motor 208, a mounting hole 209, a connecting shaft 210 and an inertia disk 211.

[0044] The top of the bottom shell 102 is provided with four fixing bosses 201, and the top of the fixing boss 201 is connected to the fixing base plate 202 by screws. The four corner positions of the fixing base plate 202 are provided with fixing round holes, and the screws pass through the fixing round holes and are tightened with the fixing bosses 201 to facilitate the installation of the fixing base plate 202. The top edge of the fixing base plate 202 is provided with four vertical side panels 203, and the tops of the adjacent vertical side panels 203 are provided with inclined side panels 204. The four vertical side panels 203 at the top of the fixing base plate 202 are connected in sequence, and the inclined side panels 204 are installed at one of the connection positions to facilitate the setting of the inclined side panels 204. The vertical side panels 203, the inclined side panels 204 and the middle of the fixing base plate 202 are all provided with mounting slots 205, and the vertical side panels 203, the inclined side panels 204 and the middle of the fixing base plate 202 correspond to the mounting slots 205. A fixed hole 206 and a rib plate 207 are installed in the middle of the vertical side plate 203. A motor 208 is installed on the inner side of the mounting slot 205. A mounting hole 209 is opened at equal angles on the edge of one end of the motor 208. The fixing hole 206 at one end of the motor 208 is aligned with the mounting hole 209 to facilitate the positioning and installation of the motor 208. A connecting shaft 210 is installed in the middle of one end of the motor 208, and an inertia disk 211 is installed at one end of the connecting shaft 210. There are four mounting slots 205, one mounting slot 205 is opened in the middle of the inclined side plate 204, one mounting slot 205 is opened in the middle of the fixed base plate 202, and the remaining two mounting slots 205 are opened in the middle of the vertical side plate 203 away from the inclined side plate 204. Three inertia disks 211 can be installed in a concentrated manner to obtain a momentum wheelset with small size and light weight. The middle part of the inertia disk 211 is hollowed out, and the material of the inertia disk 211 is brass.

[0045] By placing the four motors 208 respectively in the mounting slots 205 in the middle of the two vertical side plates 203, the oblique side plates 204 and the fixed base plate 202, the motors 208 are installed with screws passing through the fixing holes 206 and the mounting holes 209. One end of the connecting shaft 210 at one end of the motor 208 is connected to the inertia disk 211, and the inertia disk 211 is placed on the outside of the fixed base plate 202, the vertical side plates 203 and the oblique side plates 204, forming a multi-axis momentum wheel structure. Compared with four separate momentum wheels, the overall structure has a smaller volume and mass and does not occupy a large space.

[0046] The control mechanism 3 is installed on the inner side of the bottom shell 102. The control mechanism 3 includes a fixing column 301, a pad 302, a thermal conductive silicone block 303, a PCB board 304 and an external interface 305;

[0047] A fixing column 301 is installed on the inner side of the bottom shell 102, a pad 302 is installed in the middle of the top of the bottom shell 102, and a thermally conductive silicone block 303 is installed on the top of the bottom shell 102. The top of the fixing column 301 is connected to the PCB board 304 by screws. The thermally conductive silicone block 303 contacts the bottom end of the PCB board 304, which is convenient for conducting heat dissipated from the bottom structure of the PCB board 304, increasing the heat dissipation effect and avoiding damage to the PCB board 304. A power interface 305 is installed on the top of the PCB board 304, and a placement hole is opened at the side end of the bottom shell 102 corresponding to the position of the power interface 305. The power interface 305 is snapped into the inside of the placement hole, which is convenient for the installation of the power interface 305 and the power connection.

[0048] like Figure 8 As shown, the control core of the PCB board 304 is a Flash FPGA chip, and the Flash FPGA chip has an ARM core;

[0049] The control algorithms including magnetic field oriented control, speed control, current control, speed calculation and position calculation are realized through Flash FPGA chip;

[0050] The ARM core is used to implement load characteristic analysis, speed curve analysis, process control and protection, read configuration data stored in non-volatile memory, and save key variables;

[0051] The input end of the Flash FPGA chip is provided with a memory, an air pressure sensor, a temperature sensor, an ADC sampling for current and voltage monitoring, and a thermistor sampler installed on the motor 208;

[0052] The external interfaces of the momentum wheel system include CANA, CANB, RS422A and RS422B, which are mutually backed up. They can carry out two-way data communication with the satellite service. There is also a JTAG interface inside to realize program download and debugging of FPGA and ARM core.

[0053] The motor 208, the connecting shaft 210 and the inertia disk 211 form a flywheel structure. The output end of the flywheel is connected to the current sampling ADC and the Hall sampling ADC. The input end of the flywheel is connected to the integrated driver. There are four flywheels, namely flywheel X, flywheel Y, flywheel Z and flywheel R.

[0054] The Flash FPGA chip controls the rotation of the flywheel through an integrated driver and receives flywheel data through a current sampling ADC and a Hall sampling ADC.

[0055] The calculation formula of the moment of inertia of a rigid body with continuous mass distribution It can be seen that the inertia disk 211 is made of brass with a higher density and has a hollow structure in the middle, so that the larger mass of the inertia disk 211 is concentrated at the edge, achieving a larger inertia, and further realizing a maximum angular momentum greater than 0.2Nms@6000rpm.

[0056] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A multi-axis momentum wheel system suitable for a microsatellite, comprising a housing (1), characterized in that: The housing (1) comprises an upper cover (101) and a bottom shell (102); The bottom end of the upper cover (101) is connected to the bottom shell (102) via screws; An inertia disk mechanism (2) is installed on the inner side of the bottom shell (102), and the inertia disk mechanism (2) comprises a fixed boss (201), a fixed bottom plate (202), a vertical side plate (203), an inclined side plate (204), a mounting slot (205), a fixing hole (206), a rib plate (207), a motor (208), a mounting hole (209), a connecting shaft (210), and an inertia disk (211); Four fixing bosses (201) are installed on the inner top of the bottom shell (102), and the top of the fixing boss (201) is connected to the fixing base plate (202) by screws. Four vertical side panels (203) are installed on the top edge of the fixing base plate (202), and the tops of the adjacent vertical side panels (203) are installed with oblique side panels (204). The middle parts of the vertical side panels (203), the oblique side panels (204) and the fixing base plate (202) are all provided with mounting slots (205). The vertical side panels (203) A fixing hole (206) is provided in the middle of the oblique side plate (204) and the fixed bottom plate (202) at a position corresponding to the mounting slot (205), a rib plate (207) is installed in the middle of the vertical side plate (203), a motor (208) is installed inside the mounting slot (205), a mounting hole (209) is provided at an equal angle on one end edge of the motor (208), a connecting shaft (210) is installed in the middle of one end of the motor (208), and an inertia disk (211) is installed at one end of the connecting shaft (210); The four vertical side panels (203) at the top of the fixed bottom panel (202) are connected in sequence, and an inclined side panel (204) is installed at one of the connection positions; The middle portion of the inertia disk (211) is hollowed out, and the material of the inertia disk (211) is brass; Four mounting slots (205) are provided, one mounting slot (205) is provided in the middle of the oblique side plate (204), one mounting slot (205) is provided in the middle of the fixed bottom plate (202), and the remaining two mounting slots (205) are provided in the middle of the vertical side plate (203) away from the oblique side plate (204).

2. The multi-axis momentum wheel system suitable for microsatellites according to claim 1, characterized in that: The four corners of the fixed base plate (202) are each provided with a fixing circular hole, through which screws are passed and tightened with the fixing boss (201); The fixing hole (206) at one end of the motor (208) is aligned with the mounting hole (209).

3. The multi-axis momentum wheel system suitable for microsatellites according to claim 1, characterized in that: A control mechanism (3) is installed on the inner side of the bottom shell (102), and the control mechanism (3) comprises a fixing column (301), a cushion block (302), a heat-conducting silica gel block (303), a PCB board (304) and a power interface (305); A fixing column (301) is installed on the inner side of the bottom shell (102), a cushion block (302) is installed at the middle of the top of the bottom shell (102), a heat-conducting silica gel block (303) is installed at the top of the bottom shell (102), the top of the fixing column (301) is connected to a PCB board (304) via screws, and a power interface (305) is installed on the top of the PCB board (304).

4. The multi-axis momentum wheel system suitable for microsatellites according to claim 3, characterized in that: A placement hole is provided at the side end of the bottom shell (102) at a position corresponding to the power interface (305), and the power interface (305) is snap-fitted into the placement hole; The heat-conducting silica gel block (303) contacts the bottom end of the PCB board (304); The power input terminal of the motor (208) is connected to the power output terminal of the PCB board (304).

5. The multi-axis momentum wheel system suitable for microsatellites according to claim 3, characterized in that: The control core of the PCB board (304) is a Flash FPGA chip, and the Flash FPGA chip has an ARM core; The inertia disk control algorithm including field-oriented control, speed control, current control, speed calculation, and position calculation is implemented through Flash FPGA chips. The ARM core is used to implement load characteristic analysis, speed curve analysis, process control and protection, read configuration data stored in non-volatile memory, and save key variables.

6. The multi-axis momentum wheel system suitable for microsatellites according to claim 5, characterized in that: The input end of the FlashFPGA chip is provided with a memory, an air pressure sensor, a temperature sensor, a current and voltage monitoring ADC sampling, and a thermistor sampling resistor installed on the motor (208); The momentum wheel system's external interfaces include CANA, CANB, RS422A and RS422B, which back up each other and enable two-way data communication with satellite services. A JTAG interface is also provided internally to enable program downloading and debugging of FPGA and ARM cores.

7. The multi-axis momentum wheel system suitable for microsatellites according to claim 5, characterized in that: The motor (208), the connecting shaft (210) and the inertia disk (211) form a flywheel structure, the output end of the flywheel is connected to a current sampling ADC and a Hall sampling ADC, and the input end of the flywheel is connected to an integrated driver; The Flash FPGA chip controls the rotation of the flywheel through an integrated driver, and receives data such as flywheel current, speed, and angle through current sampling ADC and Hall sampling ADC.

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