Thrust engine command distribution method, apparatus, and readable medium

Abstract

The application provides a simple and adaptive thruster command distribution method, device and readable medium under the condition of thruster failure. The method comprises the following steps: obtaining actual operation data of orbit control thrusters and attitude control thrusters; judging the working states of the orbit control thrusters and the attitude control thrusters according to the actual operation data and theoretical operation data of the orbit control thrusters and the attitude control thrusters, wherein the working states include available and unavailable; judging whether the condition "the orbit control thrusters are unavailable and any one of the attitude control thrusters is unavailable" is met based on the working states, if not, selecting a command distribution strategy according to the current orbit control direction and the working states, and distributing the thruster command based on the command distribution strategy.

Description

Technical Field

[0001] This invention mainly relates to the field of space rendezvous and docking, and in particular to a thruster command allocation method, apparatus and readable medium. Background Technology

[0002] In recent years, with the rise of modern space missions such as on-orbit servicing and space debris removal, space rendezvous and docking technology has attracted much attention both domestically and internationally. Compared with existing large rendezvous and docking spacecraft such as manned and cargo spacecraft, microsatellites are more suitable for demonstrating and verifying advanced space rendezvous and docking technologies due to their unique advantages of low development cost and short development cycle. The configuration and layout of the thruster, as the main actuator, are one of the key factors directly determining whether such microsatellites can successfully complete rendezvous and docking missions. Figure 1 The thruster layout design method shown, applicable to rendezvous and docking of micro and nano satellites, has been successfully verified in orbit. Based on this, thruster command allocation, as the final link in the control system, is a crucial element affecting the correct implementation of control actions, control accuracy, and the robustness of the control system in the event of thruster failure.

[0003] Current research on thruster command allocation methods mainly falls into two categories: dynamic allocation and static allocation. Dynamic allocation methods include rendezvous and docking thruster command allocation methods based on linear programming or nonlinear multi-objective programming. These methods require complex online optimization, involve large computational loads, and place high demands on the computing power of onboard computers, making them difficult to apply in engineering practices with high real-time requirements. Static allocation methods, exemplified by the command allocation lookup table method used by the European Space Agency's ATV, require assuming possible control command scenarios and performing extensive offline calculations beforehand to obtain all optimal thruster combinations and their sub-configuration inverse matrices, which are then stored in the onboard computer. Command allocation can be achieved through table lookups and simple matrix operations, resulting in fast computation speed. However, if unexpected control command scenarios or thruster failures occur in orbit, the pre-stored command allocation table becomes inapplicable.

[0004] In summary, there is an urgent need for a simple thruster command allocation method that can adapt to thruster failure scenarios. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a thruster command allocation method, device and readable medium, which solves the problems of large calculation volume of dynamic allocation method and the inapplicability of static allocation method when thruster failure occurs.

[0006] To address the aforementioned technical problems, this invention provides a thruster command allocation method suitable for rendezvous and docking of micro- and nano-satellites, comprising: acquiring actual operating data of the orbit control thruster and the attitude control thruster; determining the working status of the orbit control thruster and the attitude control thruster based on the actual operating data and the theoretical operating data of the orbit control thruster and the attitude control thruster, wherein the working status includes available and unavailable; determining whether the condition "the orbit control thruster is unavailable and any one of the attitude control thrusters is unavailable" is met based on the working status; if not, selecting a command allocation strategy based on the current orbit control direction and the working status, and allocating thruster commands based on the command allocation strategy.

[0007] Optionally, the orbit control thruster includes four thrusters, numbered F9 to F12, wherein the resultant force of each pair of orbit control thrusters passes through the center of mass; the attitude control thruster includes eight thrusters, numbered F1 to F8, wherein the attitude control thrusters are installed in the form of couples and the thrust of the attitude control thrusters does not pass through the center of mass.

[0008] Optionally, it also includes: calculating the theoretical operating data applied to the satellite by the orbit control thruster and attitude control thruster when they are working, based on the installation position and orientation of the orbit control thruster and attitude control thruster, wherein the theoretical operating data includes theoretical thrust and theoretical torque.

[0009] Optionally, selecting the command allocation strategy based on the current orbit control direction and the working state includes: determining whether the current orbit control direction is the +Y direction; if so, selecting the first command allocation strategy; wherein, the first command allocation strategy includes: turning off orbit control thrusters F9 to F12; for attitude control thrusters F1 to F8, if attitude control thrusters F2, F3, F6, and F7 are all available, then selecting attitude control thrusters F2, F3, F6, and F7 to start working, providing the required torque for satellite attitude control while providing the required resultant force in the +Y direction for satellite orbit control.

[0010] Optionally, it also includes: determining whether the current orbit control direction is the -Y direction; if so, selecting a second command allocation strategy; wherein the second command allocation strategy includes: turning off orbit control thrusters F9 to F12; for attitude control thrusters F1 to F8, if attitude control thrusters F1, F4, F5, and F8 are all available, then selecting attitude control thrusters F1, F4, F5, and F8 to start working, providing the required torque for satellite attitude control while providing the required resultant force in the -Y direction for satellite orbit control.

[0011] Optionally, it further includes: determining whether the current track control direction is ±X or ±Z or there is currently no track control; if so, determining whether track control thrusters F9 to F12 are all available and attitude control thrusters F1 to F8 are all available; if so, selecting a third command allocation strategy; wherein, the third command allocation strategy includes: when the current track control direction is +X, selecting track control thrusters F11 and F12 to start working; when the current track control direction is -X, selecting track control thrusters F9 and F1... 0. Start-up operation; when the current track control direction is +Z, select track control thrusters F10 and F11 to start up operation; when the current track control direction is -Z, select track control thrusters F9 and F12 to start up operation; when there is no track control, all track control thrusters F9 to F12 are turned off; attitude control thrusters F1 to F4 are selected according to attitude control torque requirements, and the start-up operation status of attitude control thrusters F5, F6, F7, and F8 is consistent with the start-up operation status of F3, F4, F1, and F2, respectively.

[0012] Optionally, it also includes: determining whether the orbital control thrusters F9 to F12 are unavailable and the attitude control thrusters F1 to F8 are available; if so, selecting the fourth instruction allocation strategy.

[0013] The fourth instruction allocation strategy includes: shutting down the track control thrusters F9 to F12; when the current track control direction is +X, selecting attitude control thrusters F7, F8, F5, and F6 to start working; when the current track control direction is -X, selecting attitude control thrusters F1, F2, F3, and F4 to start working; when the current track control direction is +Z, selecting attitude control thrusters F7, F8, F3, and F4 to start working; and when the current track control direction is -Z, selecting attitude control thrusters F1, F2, F5, and F6 to start working.

[0014] Optionally, the fourth instruction allocation strategy further includes: if there is no track control at present, then the track control thrusters F9 to F12 are turned off, the attitude control thrusters F1 to F4 are selected according to the attitude control torque requirements, and the power-on working status of the attitude control thrusters F5, F6, F7, and F8 is consistent with the power-on working status of F3, F4, F1, and F2, respectively.

[0015] Optionally, it also includes: determining whether all orbital control thrusters F9 to F12 are available and any one of the attitude control thrusters F1 to F8 is unavailable; if so, selecting the fifth instruction allocation strategy.

[0016] The fifth instruction allocation strategy includes: selecting two orbit control thrusters to start operation according to the third instruction allocation strategy, and selecting an attitude control thruster to start operation according to Table 3. Table 3 describes how, when any one of the attitude control thrusters F1 to F8 is unavailable, an attitude control thruster is selected to start operation according to the current orbit control direction.

[0017] To address the aforementioned technical problems, the present invention provides a thruster command allocation device, comprising: a memory for storing instructions executable by a processor; and a processor for executing the instructions to implement the method described above.

[0018] To address the aforementioned technical problems, the present invention provides a computer-readable medium storing computer program code, which, when executed by a processor, implements the method described above.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The present invention relates to a thruster command allocation method, apparatus, and readable medium applicable to rendezvous and docking of micro and nano satellites. It determines whether the orbit control thruster and attitude control thruster are malfunctioning based on actual and theoretical operating data. The command allocation strategy is selected according to the malfunction and the current orbit control direction. Essentially, it is a command allocation lookup table method, with simple and clear steps, low computational load, minimal onboard computing resource consumption, and easy implementation. Furthermore, it is adaptable to thruster malfunctions and has significant engineering value for completing rendezvous and docking missions for micro and nano satellites with high functional density and limited computing resources. Attached Figure Description

[0021] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of the invention. In the drawings:

[0022] Figure 1 This is a schematic diagram of a thruster layout suitable for rendezvous and docking of micro and nano satellites according to one embodiment;

[0023] Figures 2A-2C yes Figure 1 A schematic diagram showing the position and thrust direction of each thruster in the middle;

[0024] Figure 3 This is a flowchart of a thruster command allocation method for rendezvous and docking of micro and nano satellites according to an embodiment of the present invention;

[0025] Figure 4 yes Figure 3 A flowchart of an embodiment of step S35;

[0026] Figure 5 yes Figure 4 A flowchart of an embodiment of step S353;

[0027] Figure 6 This is a system block diagram of a thruster command distribution device according to an embodiment of this application. Detailed Implementation

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0029] Figure 1 This is a schematic diagram of a thruster layout suitable for rendezvous and docking of micro and nano satellites, according to one embodiment. Figure 1 As shown, this layout method reduces the number of thrusters required for microsatellites and nanosatellites to complete rendezvous and docking missions to 12. Among them, thrusters F1 to F8 are called attitude control thrusters, and thrusters F9 to F12 are called orbit control thrusters. Using the satellite body coordinate system X... b Y b Z b Using [reference frame], the origin of the satellite's body coordinate system is located at the satellite's center of mass. When orienting the satellite towards Earth, the three axes of the satellite's body coordinate system are parallel and in the same direction as the axes of the orbital coordinate system. The positions and thrust directions of each thruster are arranged within the satellite's body coordinate system. Figure 1 It can be seen that the resultant force of each pair of orbit control thrusters F9 to F12 passes through the center of mass, while the thrust of attitude control thrusters F1 to F8 does not pass through the center of mass. In this embodiment, the thrust of orbit control thrusters F9 to F12 is within X... b Z b In the plane, at ±Y b Orbital control requires the use of attitude control thrusters F1 to F8. These thrusters are divided into two groups: the first group includes thrusters F1 to F4, and the second group includes thrusters F5 to F8. The first group of attitude control thrusters F1 to F4 is installed on the +X orbital surface. b On the other hand, the second set of attitude control thrusters, F5 to F8, are installed on the X-planet. b The two sets of attitude control thrusters are symmetrically installed in the form of force couples, which can achieve ideal zero-force interference for satellite orbit control.

[0030] Figures 2A-2C yes Figure 1 A schematic diagram showing the position and thrust direction of each thruster. (See diagram below.) Figure 2C As shown, the triangle next to the number represents the orbital control thruster. The axis in the middle of the triangle represents the thrust f generated by the orbital control thruster. m The thrust directions (m=9,10,11,12) are as follows. Among them, the orbital control thrusters F9 and F12 are located at +Z. b The axial direction is called +Z. b End-rail control thrusters. Among them, rail control thrusters F10 and F11 are located at -Z. bThe axial direction is called -Z. b End-rail controlled thruster. For +Z b Regarding the end-rail control thruster, the thrust direction of the F9 end-rail control thruster is parallel to +Z. b The included angle between the axes is α. For example... Figure 2A and Figure 2B As shown, the triangle next to the number represents the attitude control thruster. The axis in the middle of the triangle indicates the direction of thrust generated by the attitude control thruster in the X direction. b Y b Planar projection. β is the axis of the attitude control thruster in the X-ray plane. b Y b Plane projection and +X b Angle, γ is +Z b Attitude control thruster vector and +Z b The included angle. Based on the installation position and orientation of each thruster in Figure 2, the theoretical operating data applied to the satellite by each thruster can be calculated. The theoretical operating data includes theoretical thrust and theoretical torque. Wherein, the theoretical thrust f of the i-th thruster... i and theoretical torque T i The calculation formula is as follows, where i = 1 to 12:

[0031]

[0032]

[0033] Among them, f g f represents the thrust of a single orbital control thruster. z C represents the thrust of a single attitude control thruster. i For thruster F i The installation location.

[0034] As the background technology states, Figure 1 A thruster layout design method suitable for micro- and nano-satellite rendezvous and docking, as shown, has been successfully verified in orbit. Based on this, thruster command allocation, as the final link in the control process, is a crucial step affecting the correct implementation of control actions, control accuracy, and the robustness of the control system in the event of thruster failure. This invention is applicable to layouts such as... Figure 1 The thruster group shown takes into account the attitude control torque requirements, the orbit control resultant force requirements, and the availability of each thruster. A set of thrusters that meet the conditions is selected by referring to a table to work, so as to achieve correct control of the attitude and orbit of the micro-nano satellite and complete the rendezvous and docking mission.

[0035] Figure 3 This is a flowchart of a thruster command allocation method applicable to micro- and nano-satellite rendezvous and docking according to an embodiment of the present invention. Figure 3As shown, the thruster command allocation method 300 applicable to micro- and nano-satellite rendezvous and docking includes:

[0036] Step S31: Obtain the actual operating data of the orbital control thruster and the attitude control thruster.

[0037] The actual operating data includes actual thrust and actual torque. For Figure 1 The thruster assembly shown obtains the actual thrust and actual torque of each thruster.

[0038] Step S32: Determine the working status of the orbit control thruster and attitude control thruster based on the actual operating data and the theoretical operating data of the orbit control thruster and attitude control thruster. The working status includes available and unavailable.

[0039] Theoretical operating data can be pre-calculated and stored in the storage unit. The operating status of the orbit control thruster and attitude control thruster can be determined based on the deviation between the actual operating data and the theoretical operating data. The operating status includes available and unavailable. For example, when the deviation between the actual operating data and the theoretical operating data of one of the orbit control thrusters is greater than a preset threshold, the operating status of that orbit control thruster is set to unavailable. Similarly, when the deviation between the actual operating data and the theoretical operating data of one of the attitude control thrusters is greater than a preset threshold, the operating status of that attitude control thruster is set to unavailable.

[0040] Step S33: Determine whether the condition "the orbital control thruster is unavailable and any attitude control thruster is unavailable" is met based on the working status. If yes, proceed to step S34; otherwise, proceed to step S35.

[0041] For track control thrusters F9-F12 and attitude control thrusters F1-F8, the condition "track control thrusters are unavailable and any one of the attitude control thrusters is unavailable" is met when track control thrusters F9, F10, F11, and F12 are all unavailable, and any one of the attitude control thrusters F1-F8 is also unavailable. This can be understood as all track control thrusters malfunctioning, and some attitude control thrusters also malfunctioning. The attitude control thrusters cannot serve as backup thrusters in case of track control thruster failure, and the thruster group cannot complete the rendezvous and docking task; it can only proceed to step S34.

[0042] Step S34: Turn off attitude control thrusters F1 to F8 and orbit control thrusters F9 to F12.

[0043] Step S35: Select the command allocation strategy based on the current orbit control direction and working status, and allocate thruster commands based on the command allocation strategy.

[0044] If the attitude control thrusters F1-F8 and the orbit control thrusters F9-F12 are not faulty, or if some are faulty but the thruster assembly can still complete the rendezvous and docking mission, a command allocation strategy is selected based on the current orbit control direction and operating status, and thruster commands are allocated based on this strategy. The current orbit control direction includes +Y. b Direction, -Y b Direction, ±X b Direction or ±Z b Direction, or currently no track control. For ease of description, the current track control direction will be directly described as +Y direction, -Y direction, ±X direction, or ±Z direction, or currently no track control.

[0045] Figure 4 yes Figure 3 A flowchart of an embodiment of step S35. (See attached flowchart.) Figure 4 As shown, step S35 includes:

[0046] Step S351: Determine if the current track control direction is +Y. If so, select the first command allocation strategy; wherein, the first command allocation strategy includes:

[0047] For reference Figure 1 As shown, turn off the orbit control thrusters F9 to F12. For the attitude control thrusters F1 to F8, if attitude control thrusters F2, F3, F6, and F7 are all available, then select attitude control thrusters F2, F3, F6, and F7 to start working, providing the required torque for satellite attitude control and the required resultant force in the +Y direction for satellite orbit control. If not all attitude control thrusters F2, F3, F6, and F7 are available, then turn off attitude control thrusters F1 to F8.

[0048] Step S352: Determine if the current track control direction is -Y. If so, select the second command allocation strategy; wherein, the second command allocation strategy includes:

[0049] If the orbit control thrusters F9 to F12 are turned off, and the attitude control thrusters F1 to F8 are all available, then select the attitude control thrusters F1, F4, F5 and F8 to turn on and work, providing the required torque for satellite attitude control and the required resultant force in the Y direction for satellite orbit control.

[0050] Step S353: Determine whether the current track control direction is ±X or ±Z or there is no track control. If so, select the command allocation strategy based on the availability of the track control thruster and attitude control thruster.

[0051] Figure 5 yes Figure 4 A flowchart of an embodiment of step S353. (See attached flowchart.) Figure 5 As shown, step S353 includes:

[0052] Step S3531: Determine whether the orbital control thrusters F9 to F12 are all available and the attitude control thrusters F1 to F8 are all available. If so, select the third instruction allocation strategy.

[0053] The third instruction allocation strategy includes: selecting two orbital control thrusters according to Table 1 for startup, selecting attitude control thrusters F1 to F4 according to attitude control torque requirements, and the startup working status of attitude control thrusters F5, F6, F7, and F8 being consistent with the startup working status of F3, F4, F1, and F2, respectively.

[0054] Table 1. Selection Method for Rail Control Thrusters

[0055] Serial Number Current track control direction Rail control thruster assembly in operation 1 +X F11, F12 2 -X F9, F10 3 +Z F10, F11 4 -Z F9, F12 5 trackless control F9-F12 are all off.

[0056] As shown in Table 1, when the current track control direction is +X, track control thrusters F11 and F12 are activated; when the current track control direction is -X, track control thrusters F9 and F10 are activated; when the current track control direction is +Z, track control thrusters F10 and F11 are activated; when the current track control direction is -Z, track control thrusters F9 and F12 are activated; when there is no track control, track control thrusters F9 to F12 are all deactivated.

[0057] Step S3532: Determine whether the orbital control thrusters F9 to F12 are unavailable and the attitude control thrusters F1 to F8 are available. If so, select the fourth instruction allocation strategy.

[0058] The fourth instruction allocation strategy includes: if the current track control direction is ±X or ±Z, then turn off the track control thrusters F9 to F12 and select the attitude control thrusters to start working according to Table 2.

[0059] Table 2. Attitude control thruster selection method when orbital control thrusters are unavailable and orbital control is required in the ±X or ±Z directions.

[0060] Serial Number Current track control direction Attitude control thruster assembly in operation 1 +X F7, F8, F5, F6 2 -X F1, F2, F3, F4 3 +Z F7, F8, F3, F4 4 -Z F1, F2, F5, F6

[0061] As shown in Table 2, under the condition that the orbital control thruster is unavailable:

[0062] When the current track control direction is +X, select attitude control thrusters F7, F8, F5, and F6 to start working; when the current track control direction is -X, select attitude control thrusters F1, F2, F3, and F4 to start working; when the current track control direction is +Z, select attitude control thrusters F7, F8, F3, and F4 to start working; when the current track control direction is -Z, select attitude control thrusters F1, F2, F5, and F6 to start working.

[0063] The fourth instruction allocation strategy also includes: if the rail control thrusters are unavailable and there is currently no rail control, then the rail control thrusters F9 to F12 are turned off, and the attitude control thrusters F1 to F4 are selected according to the attitude control torque requirements. The power-on working status of the attitude control thrusters F5, F6, F7, and F8 is consistent with the power-on working status of F3, F4, F1, and F2, respectively.

[0064] Step S3533: Determine whether all orbital control thrusters F9 to F12 are available and any one of the attitude control thrusters F1 to F8 is unavailable. If so, select the fifth instruction allocation strategy.

[0065] The fifth instruction allocation strategy includes: selecting two track control thrusters to start operation according to Table 1, and selecting an attitude control thruster to start operation according to Table 3. Table 3 describes how, when any one of the attitude control thrusters F1 to F8 is unavailable, an attitude control thruster is selected to start operation based on the current track control direction.

[0066] Table 3. Attitude control thruster selection method when orbital control thruster is available and any one of the attitude control systems is unavailable.

[0067]

[0068] The usage rules for Table 3 are as follows:

[0069] a) First, determine whether the thruster is usable in the order of F1 to F8. If Fi (i = 1 to 8) is not usable, then obtain the table row number j (j = 1 to 8) according to the table above.

[0070] b) Continue to determine whether there are any unavailable thrusters in the Z-direction combination, X-direction, and Y-direction according to the rules in row j;

[0071] c) If all Z-direction combinations are available, then select the Z-direction attitude control thruster combination to start operation;

[0072] d) Otherwise, if all X-direction combinations are available, select the X-direction attitude control thruster combination to start operation;

[0073] e) Otherwise, if all Y-direction combinations are available, select the Y-direction attitude control thruster combination to start working.

[0074] f) Otherwise, shut down all thrusters.

[0075] In some embodiments, when the layout of the orbital control thrusters F9 to F12 is not... Figure 1 The indicated position and thrust direction, for example, changing the thrust of the orbital control thrusters F9 to F12 to be in the X direction. b Y b In the plane, then at ±Z bOrientation control requires the use of attitude control thrusters F1 to F8. Correspondingly, the command allocation strategy needs to be adaptively modified based on the current orbit control direction and operating status. In this case, the command allocation strategy based on the current orbit control direction and operating status includes:

[0076] The current orbit control direction is +Z. Select the first command allocation strategy, which is then adaptively modified as follows: Deactivate orbit control thrusters F9-F12. For attitude control thrusters F1-F8, if attitude control thrusters F3, F4, F7, and F8 are all available, then activate them to provide the required torque for satellite attitude control and the required resultant force in the +Z direction for satellite orbit control. If not all attitude control thrusters F3, F4, F7, and F8 are available, then deactivate attitude control thrusters F1-F8.

[0077] The current orbit control direction is -Z. Select the second command allocation strategy. The adaptive modification of the second command allocation strategy is as follows: Turn off orbit control thrusters F9-F12. For attitude control thrusters F1-F8, if attitude control thrusters F1, F2, F5, and F6 are all available, then select attitude control thrusters F1, F2, F5, and F6 to operate, providing the required torque for satellite attitude control and the required resultant force in the -Z direction for satellite orbit control. If attitude control thrusters F1, F2, F5, and F6 are not all available, then turn off attitude control thrusters F1-F8.

[0078] If the current orbit control direction is ±X or ±Y, or there is currently no orbit control, then the command allocation strategy is selected based on the availability of the orbit control thruster and attitude control thruster. Similarly, the third, fourth, and fifth command allocation strategies also need to be adapted, which will not be elaborated here.

[0079] The thruster command allocation method of the present invention, applicable to rendezvous and docking of micro and nano satellites, determines whether the orbit control thruster and attitude control thruster are malfunctioning based on the actual and theoretical operating data of the orbit control thruster and attitude control thruster, and selects a command allocation strategy according to the malfunction and the current orbit control direction. Essentially, it is a command allocation lookup table method, with simple and clear steps, low computational load, low on-board computing resource consumption, and easy implementation. Moreover, it is adaptable to thruster malfunctions and has great engineering value for completing rendezvous and docking missions for micro and nano satellites with high functional density and limited computing resources.

[0080] This application also includes a thruster command allocation apparatus, comprising a memory and a processor. The memory stores instructions executable by the processor; the processor executes the instructions to implement the thruster command allocation method described above.

[0081] Figure 6This is a system block diagram of a thruster command distribution device according to an embodiment of this application. (See reference...) Figure 6 As shown, the thruster command distribution device 600 may include an internal communication bus 601, a processor 602, a read-only memory (ROM) 603, a random access memory (RAM) 604, and a communication port 605. When applied to a personal computer, the thruster command distribution device 600 may also include a hard disk 606. The internal communication bus 601 enables data communication between the components of the thruster command distribution device 600. The processor 602 can perform judgments and issue prompts. In some embodiments, the processor 602 may consist of one or more processors. The communication port 605 enables data communication between the thruster command distribution device 600 and external devices. In some embodiments, the thruster command distribution device 600 can send and receive information and data from a network through the communication port 605. The thruster command distribution device 600 may also include different types of program storage units and data storage units, such as a hard disk 606, a read-only memory (ROM) 603, and a random access memory (RAM) 604, capable of storing various data files used for computer processing and / or communication, as well as possible program instructions executed by the processor 602. The processor executes these instructions to implement the main part of the method. The results of the processor processing are transmitted to the user equipment via a communication port and displayed on the user interface.

[0082] The above-described operation method can be implemented as a computer program, stored in the hard disk 606, and loaded into the processor 602 for execution to implement the thruster instruction allocation method of this application.

[0083] This application also includes a computer-readable medium storing computer program code that, when executed by a processor, implements the thruster instruction assignment method described above.

[0084] When the thruster command assignment method is implemented as a computer program, it can also be stored as an article of manufacture in a computer-readable storage medium. For example, a computer-readable storage medium may include, but is not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic stripes), optical discs (e.g., compact discs (CDs), digital multifunction discs (DVDs)), smart cards, and flash memory devices (e.g., electrically erasable programmable read-only memory (EPROM), cards, sticks, key drives). Furthermore, the various storage media described herein can represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media (and / or storage media) capable of storing, containing, and / or carrying code and / or instructions and / or data.

[0085] It should be understood that the embodiments described above are merely illustrative. The embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For hardware implementation, the processor may be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and / or other electronic units designed to perform the functions described herein, or combinations thereof.

[0086] Some aspects of this application can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The aforementioned hardware or software may be referred to as a "data block," "module," "engine," "unit," "component," or "system." The processor may be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. Furthermore, aspects of this application may manifest as computer products residing in one or more computer-readable media, including computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes, etc.), optical discs (e.g., compressed CDs, digital multifunction DVDs, etc.), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0087] A computer-readable medium may contain a propagated data signal containing computer program code, for example, on baseband or as part of a carrier wave. This propagated signal may take various forms, including electromagnetic, optical, and so on, or suitable combinations thereof. A computer-readable medium can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, apparatus, or device to enable communication, propagation, or transmission of a program for use. The program code located on the computer-readable medium can be propagated through any suitable medium, including radio, cable, fiber optic cable, radio frequency signals, or similar media, or any combination of the above media.

[0088] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0089] The basic concepts have been described above. Obviously, for those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0090] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0091] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0092] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0093] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0094] Although this application has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, any changes or modifications to the above embodiments within the essential spirit of this application will fall within the scope of the claims of this application.

Claims

1. A thruster command allocation method suitable for rendezvous and docking of micro and nano satellites, characterized in that, include: Obtain actual operating data of the orbital control thruster and attitude control thruster; The working status of the orbit control thruster and attitude control thruster is determined based on the actual operating data and the theoretical operating data of the orbit control thruster and attitude control thruster. The working status includes available and unavailable. Based on the working status, determine whether the condition "the orbit control thruster is unavailable and any attitude control thruster is unavailable" is met. If not, select the command allocation strategy according to the current orbit control direction and the working status, and allocate thruster commands based on the command allocation strategy.

2. The thruster command allocation method as described in claim 1, characterized in that, The orbit control thruster includes four thrusters, numbered F9 to F12, wherein the resultant force of each pair of orbit control thrusters passes through the center of mass; the attitude control thruster includes eight thrusters, numbered F1 to F8, wherein the attitude control thrusters are installed in the form of couples and the thrust of the attitude control thrusters does not pass through the center of mass.

3. The thruster command allocation method as described in claim 2, characterized in that, Also includes: Using the satellite's body coordinate system XYZ as the reference frame, with its origin located at the satellite's center of mass, and its three axes parallel and aligned with the axes of the orbital coordinate system during Earth orientation, the theoretical operational data applied to the satellite by the orbital control thrusters F9~F12 and attitude control thrusters F1~F8 are calculated based on their installation positions and orientations. This theoretical operational data includes theoretical thrust and theoretical torque. The formulas for calculating these theoretical operational data are as follows: Among them, f i Let T be the theoretical thrust of the i-th thruster. i f is the theoretical torque of the i-th thruster. g f represents the thrust of a single orbital control thruster. z C represents the thrust of a single attitude control thruster. i For thruster F i In the satellite's coordinate system, the first set of attitude control thrusters, F1~F4, is installed in the satellite's +X plane, and the second set of attitude control thrusters, F5~F8, is installed in the satellite's -X plane. The two sets of attitude control thrusters are symmetrically installed in the form of a couple. Here are the coordinates of attitude control thruster F1 in the satellite's body coordinate system; orbit control thrusters F9 and F12 are located in the +Z axis direction and are referred to as the +Z-end orbit control thrusters, while orbit control thrusters F10 and F11 are located in the -Z axis direction and are referred to as the -Z-end orbit control thrusters. The coordinates of the orbital control thruster F9 in the satellite body coordinate system; The angle between the thrust direction of the +Z end rail control thruster and the +Z axis. Let γ be the angle between the projection of the attitude control thruster axis onto the XY plane and +X, and let γ be the angle between the +Z end attitude control thruster vector and +Z.

4. The thruster command allocation method as described in claim 3, characterized in that, The command allocation strategy selected based on the current track control direction and the aforementioned working status includes: Determine if the current track control direction is +Y. If so, select the first command allocation strategy; wherein, the first command allocation strategy includes: If the orbit control thrusters F9~F12 are turned off, and the attitude control thrusters F1~F8 are all available, then select the attitude control thrusters F2, F3, F6 and F7 to turn on and operate, providing the required torque for satellite attitude control and the required resultant force in the +Y direction for satellite orbit control.

5. The thruster command allocation method as described in claim 4, characterized in that, Also includes: Determine if the current track control direction is -Y. If so, select the second command allocation strategy; wherein the second command allocation strategy includes: If the orbit control thrusters F9~F12 are turned off, and the attitude control thrusters F1~F8 are all available, then select the attitude control thrusters F1, F4, F5 and F8 to turn on and work, providing the required torque for satellite attitude control and the required resultant force in the Y direction for satellite orbit control.

6. The thruster command allocation method as described in claim 4, characterized in that, Also includes: Determine whether the current track control direction is ±X or ±Z or there is no track control. If so, determine whether track control thrusters F9~F12 are available and attitude control thrusters F1~F8 are available. If so, select the third instruction allocation strategy. The third instruction allocation strategy includes: When the current track control direction is +X, select track control thrusters F11 and F12 to start working; when the current track control direction is -X, select track control thrusters F9 and F10 to start working; when the current track control direction is +Z, select track control thrusters F10 and F11 to start working; when the current track control direction is -Z, select track control thrusters F9 and F12 to start working; when there is no track control, all track control thrusters F9 to F12 are turned off. The attitude control thrusters F1 to F4 are selected according to the attitude control torque requirements. The start-up working states of attitude control thrusters F5, F6, F7, and F8 are the same as those of F3, F4, F1, and F2, respectively.

7. The thruster command allocation method as described in claim 6, characterized in that, Also includes: Determine whether the orbital control thrusters F9~F12 are unavailable and the attitude control thrusters F1~F8 are available. If so, select the fourth instruction allocation strategy. The fourth instruction allocation strategy includes: With track control thrusters F9~F12 off, when the current track control direction is +X, select attitude control thrusters F7, F8, F5, and F6 to start working; when the current track control direction is -X, select attitude control thrusters F1, F2, F3, and F4 to start working; when the current track control direction is +Z, select attitude control thrusters F7, F8, F3, and F4 to start working; when the current track control direction is -Z, select attitude control thrusters F1, F2, F5, and F6 to start working.

8. The thruster command allocation method as described in claim 7, characterized in that, The fourth instruction allocation strategy also includes: If there is no track control at present, turn off track control thrusters F9~F12, and select attitude control thrusters F1~F4 according to attitude control torque requirements. The working status of attitude control thrusters F5, F6, F7, and F8 is the same as the working status of F3, F4, F1, and F2 respectively.

9. The thruster command allocation method as described in claim 6, characterized in that, Also includes: Determine whether all orbital control thrusters F9~F12 are available and any one of the attitude control thrusters F1~F8 is unavailable. If so, select the fifth instruction allocation strategy. The fifth instruction allocation strategy includes: selecting two orbital control thrusters for startup according to the third instruction allocation strategy, and selecting the attitude control thruster for startup according to the following rules: When attitude control thruster F1 is unavailable: If the current orbit control direction is ±Z, then select attitude control thrusters F3, F4, F7, and F8. If the current orbit control direction is ±X, then select attitude control thrusters F5, F6, F7, and F8. If the current orbit control direction is ±Y, then select attitude control thrusters F2, F3, F6, and F7; When attitude control thruster F2 is unavailable: If the current orbit control direction is ±Z, then select attitude control thrusters F3, F4, F7, and F8. If the current orbit control direction is ±X, then select attitude control thrusters F5, F6, F7, and F8. If the current track control direction is ±Y, then select attitude control thrusters F1, F4, F5, and F8; When attitude control thruster F3 is unavailable: If the current orbit control direction is ±Z, then select attitude control thrusters F1, F2, F5, and F6. If the current orbit control direction is ±X, then select attitude control thrusters F5, F6, F7, and F8. If the current track control direction is ±Y, then select attitude control thrusters F1, F4, F5, and F8; When attitude control thruster F4 is unavailable: If the current orbit control direction is ±Z, then select attitude control thrusters F1, F2, F5, and F6. If the current orbit control direction is ±X, then select attitude control thrusters F5, F6, F7, and F8. If the current orbit control direction is ±Y, then select attitude control thrusters F2, F3, F6, and F7; When attitude control thruster F5 is unavailable: If the current orbit control direction is ±Z, then select attitude control thrusters F3, F4, F7, and F8. If the current orbit control direction is ±X, then select attitude control thrusters F1, F2, F3, and F4. If the current orbit control direction is ±Y, then select attitude control thrusters F2, F3, F6, and F7; When attitude control thruster F6 is unavailable: If the current orbit control direction is ±Z, then select attitude control thrusters F3, F4, F7, and F8. If the current orbit control direction is ±X, then select attitude control thrusters F1, F2, F3, and F4. If the current track control direction is ±Y, then select attitude control thrusters F1, F4, F5, and F8; When attitude control thruster F7 is unavailable: If the current orbit control direction is ±Z, then select attitude control thrusters F1, F2, F5, and F6. If the current orbit control direction is ±X, then select attitude control thrusters F1, F2, F3, and F4. If the current track control direction is ±Y, then select attitude control thrusters F1, F4, F5, and F8; When attitude control thruster F8 is unavailable: If the current orbit control direction is ±Z, then select attitude control thrusters F1, F2, F5, and F6. If the current orbit control direction is ±X, then select attitude control thrusters F1, F2, F3, and F4. If the current track control direction is ±Y, then select attitude control thrusters F2, F3, F6, and F7.

10. A thruster command distribution device, characterized in that, include: Memory is used to store instructions that can be executed by the processor; A processor for executing the instructions to implement the method as described in any one of claims 1-9.

11. A computer-readable medium storing computer program code that, when executed by a processor, implements the method as claimed in any one of claims 1-9.

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