A breadth-priority autonomous selection method and system for a hexagonal pyramidal flywheel

Abstract

A breadth-first autonomous selection method for a hexagonal pyramid flywheel configuration includes: determining flywheel combinations that cannot be simultaneously connected to the control system; counting the number of faulty flywheels; counting the number of faulty flywheels initially connected to the control system; when the number of faulty flywheels is 2 or 3, directly selecting existing fault-free flywheels to connect to the control system; when the number of faulty flywheels is greater than 3, directly setting all flywheels not to be connected to the control system; when only 1 flywheel is faulty when initially connected to the control system, prioritizing traversing all available flywheels to obtain 4 flywheels containing the shortest path to all vertices, and using these as the initial value for connection to the control system, determining the 4 available flywheel connection methods through a breadth-first search algorithm; when flywheel combinations that cannot be simultaneously connected to the control system are found during the search process, continuing the breadth-first search algorithm to determine the final flywheel connection combination method, thus completing the breadth-first autonomous selection design of the hexagonal pyramid flywheel configuration.

Description

Technical Field

[0001] This invention relates to satellite fault diagnosis and system reconfiguration technology, which is a design method for autonomous on-board selection of multiple actuators using a breadth-first search technique, without relying on ground command control, and consisting of multiple hexagonal pyramidal reaction flywheels. Background Technology

[0002] The development of aerospace technology requires satellites to operate autonomously and reliably for a long lifespan. Fault diagnosis and system reconfiguration technologies for satellite control systems are key technologies. The reaction flywheel is a crucial actuator in the satellite control system for attitude stabilization. The function of the reaction flywheel is to generate a reaction torque by accelerating or decelerating the flywheel body through a drive motor, exchanging momentum with the satellite body to achieve precise control of the satellite's attitude angle and attitude angular velocity deviations, thereby achieving the purpose of controlling the satellite's attitude.

[0003] Based on design principles, flywheels can be divided into momentum flywheels, torque flywheels, etc. In order to ensure the reliability of satellite control systems, a configuration of 3 orthogonal flywheels and 1 oblique flywheel is often used for attitude control. Therefore, previous flywheel switching technologies mainly included two types.

[0004] One approach is to connect a skewed flywheel for combined control when any orthogonal flywheel fails. The other approach is to use multiple flywheels in the same direction for redundancy backup, switching to the backup flywheel in the same direction after the primary flywheel fails. Even if the number and method of flywheel configurations vary or increase (5 or 6 units) depending on the satellite's inertia, platform control requirements, mission planning needs, etc., the autonomous switching technology still does not deviate from the original two fixed switching methods.

[0005] However, when the number of flywheels reaches 6 and forms a hexagonal pyramid configuration, each flywheel can provide control torque in 3 directions for the satellite control system. Therefore, there are as many as 22 autonomous switching options. If the previous fixed switching method is still used, not only will the software implementation logic be complex and redundant, but the flywheel switching efficiency will also be low, and higher requirements will be placed on the test coverage. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a breadth-first autonomous selection method for a hexagonal pyramidal flywheel. This method can improve the autonomous reconfiguration capability of the satellite control system's actuators, expand the application scope of the breadth-first search algorithm, and enable the satellite to improve reliability and safety under more complex orbits and more flexible onboard unit configurations.

[0007] The solution of the present invention is:

[0008] A breadth-first autonomous selection method for a hexagonal pyramidal flywheel configuration includes:

[0009] Step 1: Among the hexagonal pyramidal flywheels, determine the flywheel combination that cannot be simultaneously connected to the control system, count the number of flywheel failures, and count the number of flywheel failures currently connected to the control system before using the breadth-first autonomous selection method.

[0010] Step 2: When the number of flywheel failures is 2 or 3, directly select an existing fault-free flywheel to connect to the control system.

[0011] Step 3: When the number of flywheel failures exceeds 3, directly set all flywheels to be disconnected from the control system.

[0012] Step 4: When only one flywheel fails during the initial connection of the control system, all available flywheels are traversed first to obtain the four flywheels containing the shortest path to all vertices. Then, using these four flywheels as the initial values ​​for connection to the control system, a breadth-first search algorithm is used to determine all available four flywheel connection methods.

[0013] Step 5: If a flywheel combination that cannot be simultaneously connected to the control system is found during the search process, the breadth-first search algorithm is used to continue the search to determine the final flywheel connection combination and complete the breadth-first autonomous selection of the hexagonal pyramid flywheel.

[0014] Furthermore, the hexagonal pyramid configuration refers to the installation of six reaction flywheels in a spatial configuration of a hexagonal pyramid.

[0015] Furthermore, the coordinate system of the reaction flywheel is defined as follows: the origin Ow is at the center of mass of the flywheel, the Zw axis is perpendicular to the mounting reference surface and points to the housing, the Xw and Yw axes are in a plane passing through the center of mass and parallel to the reference surface, the Xw axis points to the air extraction device, and the Yw axis is perpendicular to the Xw and Zw axes. Xw, Yw, and Zw form a right-handed system.

[0016] Furthermore, the six reaction flywheels are respectively installed at an equal inclination angle of 45° to the XbObYb plane of the satellite body, and the OwZw axis of each reaction flywheel is installed at 45° to the ObZb axis of the satellite body, with a deviation of less than 3'.

[0017] Furthermore, in step one, under the condition that the flywheels are allowed to switch autonomously, the six reaction flywheels are numbered RCW1, RCW2, RCW3, RCW4, RCW5, and RCW6. First, based on the fault flags of the six flywheels, the number of usable flywheels is determined, and the combination of flywheels that cannot be simultaneously connected to the control system is determined. There are six types of consecutive flywheel numbers, namely RCW... 1..4 Access, RCW 2..5 Access, RCW 3..6 Access, RCW 4..6RCW1 access, RCW 5..6 and RCW 1..2 Access, RCW6 and RCW 1..3 Access and count the number of flywheel failures. Before the control system uses the breadth-first autonomous selection method, the number of flywheel failures currently accessing and used is counted.

[0018] Furthermore, in step two, when the number of flywheel failures is 2 or 3,

[0019] (1) If there are 4 flywheels available, then select these 4 flywheels to connect to the control system.

[0020] (2) If there are 3 flywheels available, then select these 3 flywheels to connect to the control system.

[0021] Furthermore, in step three, when the number of flywheel failures is greater than three, the flywheels are directly set to not be connected to the control system. That is, when the number of available flywheels is less than three, the flywheel control is stopped.

[0022] Furthermore, in step four, when only one flywheel fails during the initial connection of the control system, all available flywheels are traversed first to obtain four flywheels containing the shortest path to all vertices. Then, using these four flywheels as the initial value for connection to the control system, a breadth-first search algorithm is used to determine all available four flywheel connection methods.

[0023] The breadth-first search algorithm was used to determine all four possible flywheel connection methods, specifically:

[0024] Access vertex RCWi;

[0025] Visit all unvisited adjacent points RCW1, RCW2, ..., RCWk of RCWi;

[0026] Starting from these adjacent vertices in turn, visit all their unvisited adjacent vertices; and so on, until all the adjacent vertices of all visited vertices in the graph have been visited.

[0027] Furthermore, this invention also proposes a breadth-priority autonomous selection system for a hexagonal pyramidal flywheel, comprising:

[0028] Module 1: Among the hexagonal pyramidal flywheels, determine the flywheel combination that cannot be simultaneously connected to the control system, count the number of flywheel failures, and count the number of currently connected and used flywheel failures before the control system uses the breadth-first autonomous selection method.

[0029] Module 2: When the number of flywheel failures is 2 or 3, directly select existing fault-free flywheels to connect to the control system; when the number of flywheel failures is greater than 3, directly set all flywheels to not connect to the control system.

[0030] Module 3: When the control system initially connects to the system and only one flywheel fails, it first traverses all available flywheels to obtain four flywheels containing the shortest path to all vertices. Then, using these four flywheels as the initial values ​​for connecting to the control system, it uses a breadth-first search algorithm to determine all available four flywheel connection methods.

[0031] Module 4: If a flywheel combination that cannot be simultaneously accessed by the control system is found during the search process, the breadth-first search algorithm is used to continue the search to determine the final flywheel access combination and complete the breadth-first autonomous selection of the hexagonal pyramid flywheel configuration.

[0032] The advantages of this invention compared to the prior art are:

[0033] This invention eliminates the need to traverse all 22 available combination options for the hexagonal pyramid flywheel configuration and then switch them in a fixed switching order, thus reconstructing the actuators of the satellite control system. By introducing breadth-first search technology, the efficiency of flywheel autonomous selection can be effectively improved. The optimal flywheel combination control method can be quickly determined based on a pre-determined table of flywheel combination methods that cannot be accessed by the system. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the reaction flywheel mounting configuration selected in this invention;

[0035] Figure 2 This is a schematic diagram of the breadth-first search technique used in this invention;

[0036] Figure 3 This is a schematic diagram of the breadth-priority autonomous selection process of the hexagonal pyramidal flywheel configuration used in this invention. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings.

[0038] This invention provides a broad-based, autonomous selection method for hexagonal pyramidal flywheels. The coordinate system for the reaction flywheel is defined as follows: the origin Ow is at the flywheel's center of mass; the Zw axis is perpendicular to the mounting reference plane and points towards the housing; the Xw and Yw axes lie in a plane passing through the center of mass and parallel to the reference plane; the Xw axis points towards the extraction device, and the Yw axis is perpendicular to the Xw and Zw axes. Xw, Yw, and Zw form a right-handed system. Six reaction flywheels are installed in a hexagonal pyramidal configuration. For example... Figure 1 As shown.

[0039] The six reaction flywheels are respectively installed at an equal inclination angle of 45° to the XbObYb plane of the satellite body, and the OwZw axis of each reaction flywheel is installed at 45° to the ObZb axis of the satellite body, with a deviation of less than 3'.

[0040] This invention proposes a breadth-priority autonomous selection method for a hexagonal pyramidal flywheel, such as... Figure 3 As shown, it includes the following steps:

[0041] Step 1: Among the hexagonal pyramidal flywheels, determine the flywheel combination that cannot be simultaneously connected to the control system, count the number of flywheel failures, and count the number of flywheel failures currently connected to the control system before using the breadth-first autonomous selection method.

[0042] The hexagonal pyramid configuration refers to the installation of six reaction flywheels in a hexagonal pyramid spatial configuration.

[0043] Under the condition that the flywheels can switch autonomously, the six reaction flywheels are numbered RCW1, RCW2, RCW3, RCW4, RCW5, and RCW6. First, based on the fault flags of the six flywheels, the number of usable flywheels is determined, and then the flywheel combinations that cannot be simultaneously connected to the control system are identified. There are six types of flywheels with consecutive serial numbers, namely RCW... 1..4 Access, RCW 2..5 Access, RCW 3..6 Access, RCW 4..6 RCW1 access, RCW 5..6 and RCW 1..2 Access, RCW6 and RCW 1..3 Access and count the number of flywheel failures. Before the control system uses the breadth-first autonomous selection method, the number of flywheel failures currently accessing and used is counted.

[0044] Step 2: When the number of flywheel failures is 2 or 3, directly select an existing fault-free flywheel to connect to the control system.

[0045] (2.1) If there are 4 flywheels available, then select these 4 flywheels to connect to the control system.

[0046] (2.2) If there are 3 flywheels available, then select these 3 flywheels to be connected to the control system.

[0047] Step 3: When the number of flywheel failures is greater than 3, directly set all flywheels to be disconnected from the control system; that is, if the number of available flywheels is less than 3, then the flywheel control will be stopped.

[0048] Step 4: When only one flywheel fails during the initial connection of the control system, prioritize traversing all available flywheels to obtain the four flywheels containing the shortest path to all vertices. Then, using these four flywheels as the initial connection to the control system, determine all possible four-flywheel connection methods through a breadth-first search algorithm; for example... Figure 2As shown, the breadth-first search algorithm is a graph search algorithm. It starts from the root node and traverses the nodes of the tree along its width. If the target is found, the algorithm terminates.

[0049] 1. Access vertex RCWi;

[0050] 2. Access all unvisited adjacent points RCW1, RCW2, ..., RCWk of RCWi;

[0051] 3. Starting from these adjacent vertices (the vertices visited in step ②), visit all their unvisited adjacent vertices in turn; and so on, until all the adjacent vertices of all visited vertices in the graph have been visited.

[0052] like Figure 2 As shown, taking RCW1, RCW3, RCW4, and RCW5 as the initial access and usage state as an example, if we were to perform a breadth-first traversal, our result would be RCW2, RCW3, RCW4, RCW5, RCW6, and RCW1, and then we would traverse downwards layer by layer.

[0053] Step 5: If a flywheel combination that cannot be simultaneously connected to the control system is found during the search process, the breadth-first search algorithm is used to continue the search to determine the final flywheel connection combination and complete the breadth-first autonomous selection of the hexagonal pyramid flywheel.

[0054] This invention eliminates the need to traverse all 22 available combination options for the hexagonal pyramid flywheel configuration and then switch them in a fixed switching order, thus reconstructing the actuators of the satellite control system. By introducing breadth-first search technology, the efficiency of flywheel autonomous selection can be effectively improved. The optimal flywheel combination control method can be quickly determined based on a pre-determined table of flywheel combination methods that cannot be accessed by the system.

[0055] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. A hexagonal pyramid configuration flywheel breadth-first autonomous selection method, characterized by Comprise: Step one: in the flywheel of six pyramid configuration, determine the flywheel combination mode that cannot be accessed to the control system at the same time, count the number of flywheel failure, count the number of flywheel failure currently accessed to the control system before the control system uses the breadth first autonomous selection method; Step two: when the number of flywheel failure is 2 or 3, directly select the existing fault-free flywheel to access the control system; Step three: when the number of flywheel failure is greater than 3, directly set the flywheel not to access the control system; Step four: when the initial flywheel failure accessed to the control system is only 1, preferentially traverse all available flywheels, obtain the 4 flywheels containing the shortest path of all vertices, then take the 4 flywheels accessed to the control system as the initial value, and determine all selectable 4 flywheel access modes through the breadth first search algorithm; Step five: if it is found in the search process that there is a flywheel combination mode that cannot be accessed to the control system at the same time, continue to search using the breadth first search algorithm to determine the final flywheel access combination mode, and complete the flywheel breadth first autonomous selection of six pyramid configuration.

2. The hexagonal pyramid configuration flywheel breadth-first autonomous selection method according to claim 1, characterized in that: The six pyramid configuration refers to that 6 reaction flywheels are installed according to the space configuration of six pyramid.

3. The hexagonal pyramid configuration flywheel breadth-first autonomous selection method according to claim 2, characterized in that: Definition of reaction flywheel coordinate system: the coordinate origin Ow is at the flywheel centroid, the Zw axis is perpendicular to the installation reference surface and points to the shell, the Xw and Yw axes are in the plane passing through the centroid and parallel to the reference surface, the Xw axis points to the air extraction device, the Yw axis is perpendicular to the Xw and Zw axes, and the Xw, Yw and Zw form a right-handed system.

4. The hexagonal pyramid configuration flywheel breadth-first autonomous selection method according to claim 2, characterized in that: Six reaction flywheels are obliquely installed at an equal inclination angle of 45° with the XbObYb plane of the satellite body, and the OwZw axis of each reaction flywheel is installed at an angle of 45° with the ObZb axis of the satellite body, with a deviation less than 3'.

5. The hexagonal pyramid configuration flywheel breadth-first autonomous selection method according to claim 4, characterized in that: The step one, the condition of allowing flywheel autonomous switching, 6 reaction flywheel is numbered as RCW1, RCW2, RCW3, RCW4, RCW5, RCW6, first according to the fault flag of 6 flywheel, determine the available number of flywheel, determine the flywheel combination mode that cannot access control system simultaneously, 4 flywheel serial number continuous kind has 6, that is, RCW 1..4 Access, RCW 2..5 Access, RCW 3..6 Access, RCW 4..6 And RCW1 access, RCW 5..6 And RCW 1..2 Access, RCW6 and RCW 1..3 Access, statistics flywheel fault number, statistics control system in use before the scope of autonomous selection method, the flywheel fault number of current access use.

6. The hexagonal pyramid configuration flywheel breadth-first autonomous selection method according to claim 5, characterized in that: In step two, when the number of flywheel failure is 2 or 3, (1) if the number of available flywheels is equal to 4, select the 4 flywheels to access the control system; (2) if the number of available flywheels is equal to 3, select the 3 flywheels to access the control system.

7. The hexagonal pyramid configuration flywheel breadth-first autonomous selection method according to claim 6, characterized in that: In step three, when the number of flywheel failure is greater than 3, directly set the flywheels not to access the control system, that is, the number of available flywheels is less than 3, and the flywheels are stopped.

8. The hexagonal pyramid configuration flywheel breadth-first autonomous selection method according to claim 7, characterized in that: In step four, when the initial flywheel failure accessed to the control system is only 1, preferentially traverse all available flywheels, obtain the 4 flywheels containing the shortest path of all vertices, then take the 4 flywheels accessed to the control system as the initial value, and determine all selectable 4 flywheel access modes through the breadth first search algorithm; Determine all selectable 4 flywheel access modes through the breadth first search algorithm, specifically as follows: Visit the vertex RCWi; Visit all unvisited adjacent points RCW1, RCW2, …, RCWk of RCWi; In turn, visit all unvisited adjacent points of these adjacent points; in this way, visit all adjacent points of all visited vertices in the graph.

9. A hexagonal pyramid configuration flywheel breadth-first autonomous selection system characterized by Comprise: Module one: in the flywheel of six pyramid configuration, determine the flywheel combination mode that cannot be accessed to the control system at the same time, count the number of flywheel fault, count the number of flywheel fault currently accessed to the control system before the control system uses the breadth first autonomous selection method; Module two: when the number of flywheel fault is 2 or 3, directly select the existing fault-free flywheel to access the control system; when the number of flywheel fault is greater than 3, directly set the flywheel not to access the control system; Module three: when the initial flywheel fault accessed to the control system is only one, preferentially traverse all available flywheels, obtain the four flywheels containing the shortest path of all vertices, and then take the four flywheels accessed to the control system as the initial value, determine the access mode of all available four flywheels through the breadth first search algorithm. Module four: if it is found that there is a flywheel combination mode that cannot be accessed to the control system at the same time in the search process, continue to search using the breadth first search algorithm to determine the final flywheel access combination mode, and complete the breadth first autonomous selection of six pyramid configuration flywheel.

10. A hexagonal pyramid configuration flywheel breadth-first autonomous selection system according to claim 9, characterized in that: The six pyramid configuration refers to the installation of six reaction flywheels according to the spatial configuration of six pyramid; The definition of reaction flywheel coordinate system: the coordinate origin Ow is at the flywheel centroid, the Zw axis is perpendicular to the installation reference surface and points to the shell, the Xw and Yw axes are in the plane passing through the centroid and parallel to the reference surface, the Xw axis points to the air extraction device, the Yw axis is perpendicular to the Xw and Zw axes, the Xw, Yw and Zw form a right-handed system; six reaction flywheels are installed at an equal inclination angle of 45° with the XbObYb plane of the satellite body, and the OwZw axis of each reaction flywheel is installed at an angle of 45° with the ObZb axis of the satellite body, with a deviation less than 3'; Under the condition of allowing flywheel autonomous switching, six reaction flywheels are numbered as RCW1, RCW2, RCW3, RCW4, RCW5 and RCW6. First, according to the fault flag of the six flywheels, the number of available flywheels is determined, and the flywheel combination mode that cannot be simultaneously accessed to the control system is determined. There are six kinds of 4-flywheel serial numbers, i.e. RCW 1..4 access, RCW 2..5 access, RCW 3..6 access, RCW 4..6 and RCW1 access, RCW 5..6 and RCW 1..2 access, RCW6 and RCW 1..3 access, and the number of flywheel fault stations is counted. Before the control system uses the breadth-first autonomous selection method, the number of flywheel fault stations currently used in access is counted. When the number of flywheel fault is 2 or 3, (1) if the number of available flywheels is equal to 4, select the four flywheels to access the control system; (2) if the number of available flywheels is equal to 3, select the three flywheels to access the control system; When the number of flywheel fault is greater than 3, directly set the flywheels not to access the control system, that is, the number of available flywheels is less than 3, and the flywheels are stopped; When the initial flywheel fault accessed to the control system is only one, preferentially traverse all available flywheels, obtain the four flywheels containing the shortest path of all vertices, and then take the four flywheels accessed to the control system as the initial value, determine the access mode of all available four flywheels through the breadth first search algorithm.

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