A digital twin system for attitude and orbit control based on spacecraft cluster and its construction method

Abstract

The present invention provides a digital twin system for attitude and orbit control based on a spacecraft cluster and a construction method thereof. The digital twin system for attitude and orbit control based on a spacecraft cluster includes several digital simulation subsystems, and the digital simulation subsystems include a source code dynamic link library of the spacecraft cluster, an attitude and orbit dynamics module, a telemetry and remote control interface, and a fault setting interface. The source code dynamic link library of the spacecraft cluster is connected to the attitude and orbit dynamics module, the telemetry and remote control interface is used to implement the telemetry and remote control function, and the fault setting interface is used to implement fault setting. The technical solution of this application simplifies the testing process of attitude and orbit control software products, shortens the development cycle; saves development costs; provides a reliable environment; and can adapt to the continuous increase in the scale of spacecraft.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and in particular to an attitude and orbit control digital twin system based on a spacecraft cluster. Background Art

[0002] With the rapid development of science and technology in recent years, the aerospace industry is undergoing earth-shaking changes. Among them, giant constellations represented by low-orbit communication satellites are the hottest areas in the aerospace industry, attracting domestic and foreign capital markets and research institutions to compete for entry. However, the traditional model has shortcomings in design, development, and on-orbit control, such as: (1) Due to the difference between traditional simulation programs and actual spacecraft codes, it is necessary to maintain the simulation program and the actual spacecraft code at the same time during testing, resulting in cumbersome testing procedures and long development cycles for attitude and orbit control software products; (2) The system has single functions and poor reliability. Therefore, the industrial model of traditional spacecraft cannot adapt to the continuous expansion of the scale of spacecraft. Summary of the invention

[0003] In order to overcome the above technical defects, the first purpose of the present invention is to provide a digital twin system for attitude and orbit control based on a spacecraft cluster, including several digital simulation subsystems, the digital simulation subsystem includes a source code dynamic link library of the spacecraft cluster, an attitude and orbit dynamics module, a telemetry and remote control interface, and a fault setting interface. The source code dynamic link library of the spacecraft cluster is connected to the attitude and orbit dynamics module, the telemetry and remote control interface is used to implement the telemetry and remote control function, and the fault setting interface is used to implement fault setting. The remote control and telemetry interface is connected to the host computer of the operation decision and support subsystem through a network bus to realize the remote control instruction injection and telemetry data interaction of the digital simulation subsystem. The fault setting interface is connected to the host computer of the operation decision and support subsystem through a network bus. The decision and support subsystem performs fault diagnosis on the on-orbit spacecraft and interacts with the fault setting interface to implement the fault setting in the digital simulation subsystem.

[0004] Furthermore, the attitude and orbit control digital twin system based on a spacecraft cluster further includes a decision and support subsystem and a physical simulation subsystem. The decision and support subsystem includes a visualization interface and a fault diagnosis system. The fault diagnosis system is used to perform fault diagnosis on on-orbit spacecraft and transmit telemetry data to the digital simulation subsystem; the physical simulation subsystem includes a stand-alone interface simulator, at least one physical stand-alone machine and at least one ground test equipment. The at least one physical stand-alone machine and the at least one ground test equipment are respectively connected to the digital simulation subsystem through the stand-alone interface simulator.

[0005] Furthermore, the physical stand-alone machine and the ground test equipment respectively and independently transmit data to the stand-alone interface simulator.

[0006] Furthermore, the attitude and orbital dynamics module includes an orbital dynamics module, an attitude dynamics module, a space environment model, a space interference torque model, a sensor model and a control torque solution module; the orbital dynamics module is used to simulate the particle motion law of the on-orbit spacecraft under external force; the attitude dynamics module is used to simulate the attitude motion of the on-orbit spacecraft, including the motion of the spacecraft around its center of mass and the relative motion between the various parts of the spacecraft; the space environment model is used to simulate the space environment of the on-orbit spacecraft, including the solar model, the earth magnetic field model and the earth atmosphere model, etc., and the specific activation model is determined according to the actual operating environment of the spacecraft; the space interference torque model is used to generate the space interference torque that the on-orbit spacecraft is subjected to in the space environment, including the gravity gradient torque, the residual magnetic interference torque, the solar pressure torque and the atmospheric disturbance torque, etc.; the sensor model is used to convert the attitude and orbital dynamics module data into the sensor output signal or the excitation signal of the excitation device; the control torque solution module is used to convert the actuator signal collected by the measuring device into the control torque, which acts on the spacecraft attitude and orbital dynamics module.

[0007] The first object of the present invention is to provide a method for constructing the above-mentioned attitude and orbit control digital twin system based on a spacecraft cluster, comprising:

[0008] Step S1: Design and build a digital simulation subsystem of a single spacecraft;

[0009] Step S2: Expand the functions of the digital simulation subsystems of several single spacecraft, add decision-making and support subsystems and physical simulation subsystems, use a high-performance simulator to run all the digital simulation subsystems of single spacecraft, use a host computer to run the decision-making and support subsystem, and equip it with a dedicated database for data storage, and transmit data through a network bus, thereby completing the construction of a digital twin system for attitude and orbit control based on a spacecraft cluster.

[0010] Further, step S1 includes:

[0011] Step S1.1: Generate a spacecraft attitude and orbit control source code dynamic link library for porting MATLAB: Use C language to write the source code; then use Microsoft Visual Studio software to generate a dynamic link library for the source code: (1) Set up the compiler for Microsoft Visual Studio software, add dependencies and module definition files; (2) Write an interface function file for connecting to MATLAB and add it to the source code project; (3) Compile and generate a dynamic link library mexw file in Microsoft Visual Studio software.

[0012] Step S1.2: Use MATLAB Simulink simulation software to build a digital simulation subsystem: First, transplant the dynamic link library file into MATLAB Simulink and connect it with the attitude and orbital dynamics module; second, build an interface based on the real spacecraft telemetry and remote control transmission method to realize the telemetry and remote control function; finally, build a spacecraft fault interface to access the simulation model, change the relevant parameters in the attitude and orbital dynamics module to realize fault setting; use a high-performance simulation machine with Windows system to run MATLAB Simulink simulation software to simulate the on-orbit state of the spacecraft cluster, and the simulation machine transmits data with other parts of the system through the optical fiber network.

[0013] Further, step S2 includes:

[0014] Step S2.1: Use the Windows system host computer to build the decision-making and support subsystem: (1) Use MATLAB App Designer to design the visual interface of the digital twin system, realize signal transmission with the simulator, and execute the remote control and telemetry commands in full reference to the spacecraft design to build a reliable command rehearsal and mission planning environment; (2) Use MATLAB and AGI's STK software for joint simulation, and transfer the simulator data to STK to realize visual simulation; (3) Build a fault diagnosis program in the host computer, diagnose the fault of the on-orbit spacecraft and transfer the telemetry data to the simulator. After the host computer system successfully diagnoses the fault, it generates a diagnosis report, thereby providing a basis for fault handling for ground control personnel;

[0015] Step S2.2: Building a stand-alone interface simulator to connect the physical stand-alone machine and the ground test equipment to the digital simulation subsystem, thereby completing the construction of the physical simulation subsystem. The software part of the stand-alone interface simulator is written in NI LabVIEW program. The main functions of the software include network communication with the simulator, acquisition and processing of stand-alone signals, and acquisition and processing of ground test equipment signals. The hardware part of the stand-alone interface simulator adopts NI PXI system architecture to achieve physical layer connection with the physical stand-alone machine and the ground test equipment. All signal acquisition and output circuits of the stand-alone interface simulator adopt isolation design;

[0016] Step S2.3: Use a rack-mounted host server to build a professional database to store the operating data of the spacecraft cluster attitude and orbit control digital twin system. The spacecraft cluster attitude and orbit control digital twin system uses a linked list structure to manage the spacecraft cluster data, which facilitates the deployment and deorbit of single or multiple spacecraft.

[0017] Compared with the prior art, the above technical solution has the following beneficial effects:

[0018] The digital twin system for attitude and orbit control of spacecraft clusters designed in this patent adopts spacecraft code transplantation technology, eliminating the difference between traditional simulation programs and actual spacecraft codes, and greatly improving the efficiency of attitude and orbit control software product development. After testing with the digital twin system, the correction part can be directly merged into the code, without the need to maintain the simulation program and code at the same time as in the traditional method, which simplifies the testing process of attitude and orbit control software products and shortens the development cycle. In the subsystem development stage, the digital twin system can completely replace the spacecraft computer, saving development costs. The system is connected to a physical stand-alone machine, providing a reliable environment for control personnel to conduct operation drills, mission planning, visual simulation and troubleshooting. The system design is proposed for spacecraft clusters, and the digital twin technology is used to realize the digitization, networking and intelligence of subsystem development, which can adapt to the increasing scale of spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an information flow diagram of the attitude and orbit control digital twin system architecture based on a spacecraft cluster according to an embodiment of the present application;

[0020] Figure 2 This is an architecture diagram of an attitude and orbit control digital twin system based on a spacecraft cluster according to an embodiment of the present application;

[0021] Figure 3 Flowchart for generating source code dynamic link library;

[0022] Figure 4 This is the block diagram of the decision and support subsystem. DETAILED DESCRIPTION

[0023] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments. Those skilled in the art should understand that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0024] like Figure 1 As shown, the attitude and orbit control digital twin system based on a spacecraft cluster of this embodiment includes several digital simulation subsystems, a decision and support subsystem and a physical simulation subsystem.

[0025] The digital simulation subsystem includes a source code dynamic link library of a spacecraft cluster, an attitude and orbital dynamics module, a telemetry and remote control interface, and a fault setting interface. The source code dynamic link library of the spacecraft cluster is connected to the attitude and orbital dynamics module. The telemetry and remote control interface is used to realize the telemetry and remote control function, and the fault setting interface is used to realize the fault setting. The attitude and orbital dynamics module includes an orbital dynamics module, an attitude dynamics module, a space environment model, a space interference torque model, a sensor model, and a control torque solution module. The orbital dynamics module is used to simulate the particle motion law of the on-orbit spacecraft under external force. The attitude dynamics module is used to simulate the attitude motion of the on-orbit spacecraft, including the motion of the spacecraft around its center of mass and the relative motion between the various parts of the spacecraft. The space environment model is used to simulate the space environment of the on-orbit spacecraft, including the solar model, the earth magnetic field model, and the earth atmosphere model, etc. The specific activation model is determined according to the actual operating environment of the spacecraft. The space interference torque model is used to generate the space interference torque that the on-orbit spacecraft is subjected to in the space environment, including the gravity gradient torque, the residual magnetic interference torque, the sunlight pressure torque, and the atmospheric disturbance torque, etc. The sensor model is used to convert the data of the attitude and orbital dynamics module into the sensor output signal or the excitation signal of the excitation device. The control torque solution module is used to convert the actuator signal collected by the measurement device into the control torque, which acts on the spacecraft attitude and orbital dynamics module.

[0026] The decision and support subsystem includes a visualization interface and a fault diagnosis system, wherein the fault diagnosis system is used to perform fault diagnosis on the on-orbit spacecraft and transmit telemetry data to the digital simulation subsystem.

[0027] The physical simulation subsystem includes a stand-alone interface simulator, at least one physical stand-alone machine and at least one ground test equipment, wherein the at least one physical stand-alone machine and the at least one ground test equipment are respectively connected to the digital simulation subsystem through the stand-alone interface simulator. The physical stand-alone machine and the ground test equipment are respectively and independently transmitted with the stand-alone interface simulator.

[0028] like Figure 1 As shown, the information flow of the attitude and orbit control digital twin system based on the spacecraft cluster in this embodiment is as follows:

[0029] The information flow between the digital simulation subsystem and the physical simulation subsystem includes sensor excitation signals, sensor signals, actuator control instructions, and actuator signals. First, the digital simulation subsystem outputs the sensor excitation signal to the excitation device, the device excites the physical sensor, and the sensor outputs the sensor signal back to the digital simulation subsystem. Second, the digital simulation subsystem outputs the actuator control instruction to drive the physical actuator to work, and the measurement device collects the actuator working status and returns the signal to the digital simulation subsystem.

[0030] The information flow between the digital simulation subsystem and the decision and support subsystem includes the simulation system telemetry data, the downlink telemetry data of the on-orbit spacecraft, and the on-orbit spacecraft fault data. The simulation system telemetry data is transmitted to the visualization window of the decision and support subsystem for display. The downlink telemetry data of the on-orbit spacecraft is transmitted to the digital simulation subsystem for real-time simulation data correction. The decision and support subsystem performs fault diagnosis on the on-orbit spacecraft and transmits the fault data to the digital simulation subsystem to interact with the fault setting interface and implement the fault setting in the digital simulation subsystem.

[0031] like Figure 2 As shown, the method for constructing the attitude and orbit control digital twin system based on the spacecraft cluster includes the following steps S1-S2:

[0032] Step S1: Design and construct a digital simulation subsystem of a single spacecraft. Specifically, step S1 includes steps S1.1 to S1.2:

[0033] Step S1.1: Generate a spacecraft attitude and orbit control source code dynamic link library for porting MATLAB: Use C language to write the source code; then, Figure 3 As shown in the figure, use Microsoft Visual Studio software to generate a dynamic link library for the source code: (1) Set up the compiler for Microsoft Visual Studio software and add dependencies and module definition files; (2) Write an interface function file for connecting to MATLAB and add it to the source code project; (3) Compile and generate a dynamic link library mexw file in Microsoft Visual Studio software.

[0034] Step S1.2: Use MATLAB Simulink simulation software to build a digital simulation subsystem: First, transplant the dynamic link library file generated in step S1.1 into MATLAB Simulink and connect it to the attitude and orbital dynamics module; second, build an interface based on the actual spacecraft telemetry and remote control transmission method to realize the telemetry and remote control function; finally, build a spacecraft fault interface to access the simulation model, change the relevant parameters in the attitude and orbital dynamics module to realize fault setting; use a high-performance simulation machine with Windows system to run MATLAB Simulink simulation software to simulate the on-orbit state of the spacecraft cluster, and the simulation machine transmits data with other parts of the system through the optical fiber network.

[0035] Step S2: Expand the functions of the digital simulation subsystems of several single spacecraft, add decision-making and support subsystems and physical simulation subsystems, use a high-performance simulator to run all the digital simulation subsystems of single spacecraft, use a host computer to run the decision-making and support subsystem, and equip it with a dedicated database for data storage, and transmit data through a network bus, thereby completing the construction of a digital twin system for attitude and orbit control based on a spacecraft cluster.

[0036] Specifically, step S2 includes steps S2.1 to S2.3:

[0037] Step S2.1: Figure 4 As shown in the figure, the decision-making and support subsystem is constructed using a Windows-based host computer: (1) MATLAB App Designer is used to design the visual interface of the digital twin system to achieve signal transmission with the simulator. The remote control and telemetry commands are completely executed in accordance with the spacecraft design to build a reliable command rehearsal and mission planning environment; (2) MATLAB and AGI's STK software are used for joint simulation, and the simulator data is transferred to STK to achieve visual simulation; (3) A fault diagnosis program is constructed in the host computer to diagnose the fault of the on-orbit spacecraft and transmit the telemetry data to the simulator. After the host computer system successfully diagnoses the fault, a diagnostic report is generated, thereby providing a basis for fault handling for ground control personnel. In summary, the decision-making and support subsystem includes a visual interface and a fault diagnosis system, and supports the introduction of telemetry signals from actual on-orbit spacecraft.

[0038] Step S2.2: Build a stand-alone interface simulator to connect the physical stand-alone and ground test equipment to the digital simulation subsystem, thereby completing the construction of the physical simulation subsystem. The construction of the physical simulation subsystem makes the attitude and orbit control digital twin system based on the spacecraft cluster closer to the actual on-orbit situation, and further enhances the credibility of the system operation results. The software part of the stand-alone interface simulator is written in NI LabVIEW program. The main functions of the software include network communication with the simulator, acquisition and processing of stand-alone signals, and acquisition and processing of ground test equipment signals. The hardware part of the stand-alone interface simulator uses the NI PXI system architecture to realize the physical layer connection with the physical stand-alone and ground test equipment. All signal acquisition and output circuits of the stand-alone interface simulator are isolated to avoid damage to the physical stand-alone.

[0039] Step S2.3: Use Lenovo rack-mounted host servers to build a professional database to store the operating data of the spacecraft cluster attitude and orbit control digital twin system. The spacecraft cluster attitude and orbit control digital twin system uses a linked list structure to manage the spacecraft cluster data, which facilitates the deployment and deorbit of single or multiple spacecraft.

[0040] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A digital twin system for attitude and orbit control based on spacecraft clusters, characterized in that: It includes several digital simulation subsystems, which include a source code dynamic link library of a spacecraft cluster, an attitude and orbital dynamics module, a telemetry and remote control interface, and a fault setting interface. The source code dynamic link library of the spacecraft cluster is connected to the attitude and orbital dynamics module, the telemetry and remote control interface is used to implement the telemetry and remote control function, and the fault setting interface is used to implement the fault setting; The attitude and orbit control digital twin system based on the spacecraft cluster further includes a decision-making and support subsystem and a physical simulation subsystem. The decision-making and support subsystem includes a visualization interface and a fault diagnosis system. The fault diagnosis system is used to perform fault diagnosis on the on-orbit spacecraft and transmit telemetry data to the digital simulation subsystem; the physical simulation subsystem includes a stand-alone interface simulator, at least one physical stand-alone machine and at least one ground test equipment. The at least one physical stand-alone machine and the at least one ground test equipment are respectively connected to the digital simulation subsystem through the stand-alone interface simulator; The attitude and orbital dynamics module includes an orbital dynamics module, an attitude dynamics module, a space environment model, a space interference torque model, a sensor model and a control torque solution module; The orbital dynamics module is used to simulate the motion law of particles of an on-orbit spacecraft under external forces; the attitude dynamics module is used to simulate the attitude motion of an on-orbit spacecraft, including the motion of the spacecraft around its center of mass and the relative motion between the various parts of the spacecraft; the space environment model is used to simulate the space environment of the on-orbit spacecraft, including the solar model, the earth's magnetic field model and the earth's atmosphere model. The specific activation model depends on the actual operating environment of the spacecraft; the space interference torque model is used to generate the space interference torque that the on-orbit spacecraft is subjected to in the space environment, including the gravity gradient torque, the residual magnetic interference torque, the solar pressure torque and the atmospheric disturbance torque; the sensor model is used to convert the attitude and orbital dynamics module data into the sensor output signal or the excitation signal of the excitation device; the control torque solution module is used to convert the actuator signal collected by the measurement equipment into the control torque, which acts on the spacecraft attitude and orbital dynamics module.

2. The attitude and orbit control digital twin system based on spacecraft clusters as claimed in claim 1, characterized in that: The physical stand-alone machine and the ground test equipment respectively and independently transmit data to the stand-alone interface simulator.

3. A method for constructing a digital twin system for attitude and orbit control based on a spacecraft cluster as claimed in claim 1 or 2, characterized in that: include: Step S1: Design and build a digital simulation subsystem of a single spacecraft; Step S1 includes: Step S1.1: Generate a spacecraft attitude and orbit control source code dynamic link library for porting MATLAB: Use C language to write the source code; then use Microsoft Visual Studio software to generate a dynamic link library for the source code: (1) Set up the compiler for Microsoft Visual Studio software, add dependencies and module definition files; (2) Write an interface function file for connecting to MATLAB and add it to the source code project; (3) Compile and generate a dynamic link library mexw file in Microsoft Visual Studio software; Step S1.2: Use MATLAB Simulink simulation software to build a digital simulation subsystem: First, transplant the dynamic link library file into MATLAB Simulink and connect it with the attitude and orbital dynamics module; second, build an interface based on the real spacecraft telemetry and remote control transmission method to realize the telemetry and remote control function; finally, build a spacecraft fault interface to access the simulation model, change the relevant parameters in the attitude and orbital dynamics module to realize the fault setting; use a Windows system simulation machine to run MATLAB Simulink simulation software to simulate the on-orbit state of the spacecraft cluster, and the simulation machine transmits data with other parts of the system through the optical fiber network; Step S2: Expand the functions of the digital simulation subsystems of several single spacecraft, add a decision-making and support subsystem and a physical simulation subsystem, use one simulation machine to run all the digital simulation subsystems of the single spacecraft, use one host computer to run the decision-making and support subsystem, and equip a dedicated database for data storage, and transmit data through a network bus, so as to complete the construction of the attitude and orbit control digital twin system based on the spacecraft cluster; Step S2 includes: Step S2.1: Use the Windows system host computer to build the decision-making and support subsystem: (1) Use MATLAB AppDesigner to design the visual interface of the digital twin system, realize signal transmission with the simulator, and execute the remote control and telemetry commands in full reference to the spacecraft design to build a reliable command rehearsal and mission planning environment; (2) Use MATLAB and AGI's STK software for joint simulation, and transfer the simulator data to STK to realize visual simulation; (3) Build a fault diagnosis program in the host computer, diagnose the fault of the on-orbit spacecraft and transmit the telemetry data to the simulator. After the host computer system successfully diagnoses the fault, it generates a diagnosis report, thereby providing a basis for fault handling for ground control personnel; Step S2.2: Build a stand-alone interface simulator to connect the physical stand-alone and ground test equipment to the digital simulation subsystem, thereby completing the construction of the physical simulation subsystem. The software part of the stand-alone interface simulator is written in NI LabVIEW program. The main functions of the software include network communication with the simulator, acquisition and processing of stand-alone signals, and acquisition and processing of ground test equipment signals. The hardware part of the stand-alone interface simulator adopts NIPXI system architecture to achieve physical layer connection with the physical stand-alone and ground test equipment. All signal acquisition and output circuits of the stand-alone interface simulator adopt isolation design; Step S2.3: Use a rack-mounted host server to build a professional database to store the operating data of the spacecraft cluster attitude and orbit control digital twin system. The spacecraft cluster attitude and orbit control digital twin system uses a linked list structure to manage the spacecraft cluster data, which facilitates the deployment and deorbit of single or multiple spacecraft.

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