A space assembly spacecraft scene modeling and dynamics simulation system and method

Abstract

This invention relates to the field of spacecraft mission simulation and intelligent control technology, specifically disclosing a system and method for modeling and simulating spacecraft assembly scenarios. The invention constructs a coupled dynamics simulation module encompassing orbital dynamics, attitude dynamics, and robotic arm dynamics; builds a visual simulation module integrating multiple types of sensor models based on Unreal Engine; and employs the ROS2 communication framework to achieve real-time data interaction with external algorithm platforms. This solves the problems of lack of physical realism, real-time interaction capabilities, and open interfaces in existing space assembly simulation technologies. It achieves high-fidelity dynamic simulation of multi-spacecraft collaborative operations, deformation of large flexible structures, and precise control of robotic arms, enhancing the full-chain simulation support capabilities for space assembly missions from scenario construction and dynamics calculation to control algorithm verification.

Description

Technical Field

[0001] This invention relates to the field of spacecraft mission simulation and intelligent control technology, and in particular to a system and method for modeling and simulating the dynamics of spacecraft assembly scenarios. Background Technology

[0002] With the advancement of future space infrastructure construction, large spacecraft such as space stations, space telescopes, and space service facilities will overcome the size and weight limitations of launch vehicle fairings, and be constructed through multiple launches of modular units and on-orbit assembly. Due to the extreme characteristics of the space environment, including high vacuum, microgravity, and strong radiation, and the complex tasks involved in the assembly process, such as multi-spacecraft collaborative operation, large flexible structure deformation, and precise control of robotic arms, it is essential to construct a high-fidelity simulation and verification environment on the ground to support mission design, control algorithm development, and training verification, ensuring the reliable implementation of space assembly missions.

[0003] To address the simulation and verification requirements of the aforementioned space assembly missions, existing technologies have proposed several relevant solutions. Among these, patent CN120611484A discloses a space station maintenance simulation system and method. This system, based on digital twin technology, constructs a simulated environment for the space station using a space station environment simulation module based on sunlight, atmospheric radiation during dawn and dusk, and space debris orbital parameters. A model adaptive reconstruction module performs 3D rendering of the basic white model structure of each environmental element of the space station to obtain a space station model. A space station damage simulation module constructs damage images based on impact history data and overlays them onto the model. Finally, a space station maintenance plan selection module recommends robotic arm maintenance or astronaut extravehicular activity (EVA) maintenance plans based on the damage images, fault reports, and user strategies, thus achieving simulation training for extravehicular maintenance of the space station. Patent CN119830428A discloses a method and system for coupled simulation of on-orbit attitude control and structural dynamics of a spacecraft. The method uses Abaqus software to establish a simplified three-dimensional geometric model of a highly flexible spacecraft. Implicit dynamics is used as the analysis step and geometric nonlinearity is enabled. By setting triaxial moments and concentrated forces at the central star and truss, attitude control moments and vibration suppression of flexible structures are simulated. The attitude control equations and vibration suppression equations are compiled into UAMP subroutine scripts based on the Fortran language. Finally, the implicit dynamics analysis task is used to calculate and evaluate the attitude angle accuracy and vibration suppression effect of the spacecraft, realizing the coupled simulation analysis of on-orbit attitude control and structural dynamics of highly flexible spacecraft.

[0004] However, the aforementioned existing technologies all have significant limitations in terms of systematic simulation capabilities for assembling large spacecraft in space. The scheme with publication number CN120611484A focuses on maintenance operation drills and process management in a mixed reality environment. Its environment simulation construction module only models sunlight, dawn and dusk radiation, and space debris orbital parameters. It lacks a comprehensive expression of the multi-body relative motion dynamics, the mechanical characteristics of large flexible structures with variable configurations, and the physical phenomena of contact and collision during robotic arm operations in space construction missions. It cannot provide complete environmental support for high-fidelity space assembly simulation. Its model reconstruction focuses on visual presentation rather than accurate modeling of physical properties. It lacks the inherent coupling relationship between orbital dynamics, attitude dynamics, and structural dynamics, making it difficult to support cross-scale simulations from mission-level planning to joint-level control. Furthermore, it lacks real-time dynamic calculation-driven robotic arm manipulation simulation, and cannot reflect the dynamic response characteristics and contact force interaction process of the space robotic arm in a microgravity environment. At the same time, it does not involve the modeling and data generation of multi-source sensing sensors, and the system architecture is closed and does not provide an open interface with external algorithm development platforms. The scheme with publication number CN119830428A adopts an implicit dynamic analysis step and a subroutine interface compiled in Fortran. It is essentially an offline numerical simulation. The calculation process relies on batch submission and iterative solution, which cannot meet the rigid requirements of real-time and dynamic interaction for space assembly missions. Its modeling objects are limited to the platform structure and flexible attachments of a single spacecraft, ignoring key elements such as multi-spacecraft cooperative operation, multi-joint systems of robotic arms, and contact collisions during the assembly process. It cannot describe complex dynamic phenomena such as multi-body coupling, closed-chain constraints, and configuration changes. Moreover, the technical implementation relies on the specific interface of the commercial finite element software Abaqus. The simulation environment is closed and its scalability is limited. It lacks space environment modeling and sensor simulation capabilities and does not provide a cross-platform communication interface to achieve data interaction with the robot development framework.

[0005] In summary, existing technologies either focus on digital simulations of maintenance processes while lacking physical realism and real-time interactive capabilities, or are limited to offline structural dynamics analysis of a single spacecraft, failing to meet the needs of multi-body collaboration, real-time control, and system-level integration. Neither can fully cover the entire simulation chain of space assembly missions, from scenario construction and dynamics calculation to algorithm verification. Therefore, there is an urgent need to provide a technical solution to address these issues. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a system and method for modeling and simulating the dynamics of spacecraft assembly scenarios.

[0007] Firstly, the present invention provides a spacecraft assembly scene modeling and dynamics simulation system, the technical solution of which is as follows: Includes: a visual simulation module, a dynamics simulation module, and a cross-platform communication control module; The dynamics simulation module includes an orbital dynamics subsystem, an attitude dynamics subsystem, and a robotic arm dynamics subsystem. The orbital dynamics subsystem calculates the orbital motion of the spacecraft under perturbation and outputs orbital data. The attitude dynamics subsystem calculates the attitude motion of the rigid body coupled with the flexible structure and outputs attitude data. The robotic arm dynamics subsystem calculates the forward and inverse kinematics and dynamics of the robotic arm and outputs joint state data and end-effector contact force data. The dynamics simulation module couples and solves the orbital data, attitude data, and joint state data to obtain the spacecraft body pose and robotic arm end-effector pose data, and outputs the spacecraft body pose to the visual simulation module. The visual simulation module constructs a 3D scene of the space assembly mission based on Unreal Engine. The 3D scene includes a satellite platform model, a truss structure model, a space robotic arm model, a visible light camera model, a time-of-flight camera model, a lidar model, an inertial measurement unit model, a global navigation satellite system receiver model, and a sun sensor model. The visual simulation module drives the movement of the satellite platform model, the truss structure model, and the space robotic arm model according to the spacecraft's pose, and generates perception data for the visible light camera model, the time-of-flight camera model, the lidar model, the inertial measurement unit model, the global navigation satellite system receiver model, and the sun sensor model. The cross-platform communication control module is built on the ROS2 communication framework and includes a ROS2 bridging unit and a simulation control unit. The ROS2 bridging unit receives control command topics published by an external algorithm platform, converts the control command topics into drive commands executed by the dynamics simulation module, and encapsulates the sensing data, trajectory data, attitude data, joint state data, and end-effector contact force data into ROS2 standard messages before publishing them to the external algorithm platform. The simulation control unit controls the operation mode of the simulation process, which includes manual control mode, program control mode, and batch processing mode.

[0008] The beneficial effects of the space assembly spacecraft scene modeling and dynamics simulation system of the present invention are as follows: The system of this invention constructs a coupled dynamics simulation module that includes orbital dynamics, attitude dynamics, and robotic arm dynamics; builds a visual simulation module that integrates multiple types of sensor models based on Unreal Engine; and uses the ROS2 communication framework to achieve real-time data interaction with external algorithm platforms. This solves the problems of lack of physical realism, real-time interaction capability, and open interface in existing space assembly simulations. It achieves high-fidelity dynamic simulation of multi-spacecraft collaborative operation, deformation of large flexible structures, and precision control of robotic arms, and improves the full-chain simulation support capability of space assembly missions from scene construction and dynamics calculation to control algorithm verification.

[0009] Based on the above scheme, the space assembly spacecraft scene modeling and dynamics simulation system of the present invention can be further improved as follows.

[0010] In one alternative approach, the three-dimensional scene further includes a starry background model, a sunlight model, an Earth model, a Moon model, and a Mars model; The star background model is generated using star distribution and brightness levels based on real star catalog data; The solar illumination model automatically calculates the sun's position based on the mission time. The light intensity in the solar illumination model decreases with distance. The solar illumination model includes the alternation of the Earth's shadow area and the illuminated area. The Earth model uses high-precision terrain and texture data, and includes atmospheric scattering, cloud dynamics, and surface illumination reflection. The lunar model and the Mars model are constructed based on digital elevation model data and image textures from the exploration mission.

[0011] The beneficial effects of adopting the above optional methods are as follows: further construct a space environment model that includes star background, sunlight, Earth, Moon and Mars, generate star distribution and brightness levels through real star surface data, realize the attenuation of light intensity and color temperature with distance and the alternation of ground shadow, and adopt high-precision terrain texture and atmospheric scattering effect to provide a highly realistic space environment simulation basis for space assembly missions.

[0012] In one alternative approach, the satellite platform model has the ability to customize body dimensions, mass characteristics, and surface materials. The truss structure model is used to simulate the construction process of the space station. The truss structure model has the functions of switching between truss splicing state, truss deployment state, and truss locking state. The space robotic arm model has a basic configuration of seven degrees of freedom. The space robotic arm model has parameterized configuration functions for the length of each link, parameterized configuration functions for each joint type, and parameterized configuration functions for the light intensity attenuation with distance in the solar illumination model for each range of motion.

[0013] The advantages of adopting the above optional methods are: further realizing the custom configuration of satellite platform body size, mass characteristics and surface material, supporting the switching function of three states of truss structure splicing, deployment and locking, and parametric adjustment of the basic configuration of the seven degrees of freedom of the space robotic arm, including flexible configuration of link length, joint type and range of motion, and improving the system's adaptability to diverse spacecraft configurations and assembly stages.

[0014] In one alternative approach, the visible light camera model has multiple focal length configurations and multiple field-of-view configurations, and the visible light camera model includes the distortion characteristics, depth-of-field characteristics, and exposure characteristics of a real camera. The time-of-flight camera model generates point cloud data containing distance information based on the depth measurement principle; The lidar model has configuration functions for different scanning modes and different angular resolutions, and outputs three-dimensional environment scanning results. The inertial measurement unit model simulates the measurement characteristics of an accelerometer and a gyroscope, and includes a drift error model and a noise error model. The global navigation satellite system receiver model simulates the navigation signal reception process and the positioning calculation process. The solar sensor model outputs solar azimuth measurement data.

[0015] The advantages of adopting the above optional approach are as follows: it further integrates models of various sensing devices such as visible light cameras, time-of-flight cameras, lidar, inertial measurement units, global navigation satellite system receivers, and sun sensors; the visible light camera simulates real distortion, depth of field, and exposure characteristics; the time-of-flight camera generates point cloud data containing distance information; the lidar supports multiple scanning methods and angular resolution configurations; and the inertial measurement unit includes drift and noise error models, providing a high-fidelity sensing data source for external algorithm platforms.

[0016] In one alternative approach, the orbital dynamics subsystem is specifically used for: Using a high-precision orbital propagator and incorporating perturbations from Earth's non-spherical gravitational force, atmospheric drag, solar radiation pressure, and third-body gravity as perturbation factors, the system calculates the satellite's position and velocity in the J2000 inertial frame; it also calculates orbital maneuvers under pulsed thrust or continuous thrust, including orbital lifting, plane correction, phase adjustment, and rendezvous and docking trajectory planning; and performs relative motion modeling for multiple spacecraft, calculating relative orbital dynamics during formation flying, close-range operations, and docking.

[0017] The beneficial effects of adopting the above-mentioned optional methods are as follows: further introducing perturbation factors such as Earth's non-spherical gravity, atmospheric drag, solar radiation pressure and third-body gravity, supporting orbit lifting, plane correction, phase adjustment and rendezvous and docking trajectory planning under pulse thrust and continuous thrust, and realizing relative orbital dynamics simulation in the process of multi-spacecraft formation flight, close operation and docking.

[0018] In one alternative approach, the attitude dynamics subsystem is specifically used for: It employs a reaction flywheel, thruster, and magnetic torque generator as actuators, and adopts three-axis stabilization control mode, ground orientation control mode, sun orientation control mode, and inertial orientation control mode; Calculate the bending and torsional vibration modes of a large flexible solar panel structure, and calculate the dynamic response and thermoelastic deformation caused by temperature gradient during the deployment process; The finite element method and modal superposition technology were used to calculate the deformation and vibration characteristics of the space truss structure under the action of gravity gradient torque, thermal stress, and contact force.

[0019] The advantages of adopting the above-mentioned optional methods are as follows: further using reaction flywheels, thrusters and magnetic torquers as attitude actuators, supporting multiple control modes such as three-axis stabilization, ground orientation, sun orientation and inertial orientation, calculating the bending and torsional vibration modes of large flexible panels and the dynamic response and thermal deformation effects during the deployment process, and realizing the simulation of the deformation and vibration characteristics of space trusses under the action of gravity gradient torque, thermal stress and contact force.

[0020] In one alternative approach, the robotic arm dynamics subsystem is specifically used for: Using the Lagrange method or the Newton-Euler method, dynamic equations for the joint space and the operating space are established based on the mass distribution of the connecting rod, joint friction, and flexibility effects. The free space motion process, the constrained surface contact process, and the load handling process are calculated by employing position control strategy, impedance control strategy, and force-position hybrid control strategy. Perform multi-arm cooperative motion planning, load distribution algorithm and collision detection.

[0021] The advantages of adopting the above-mentioned optional methods are: further establishing the dynamic equations of the joint space and operation space of the robotic arm based on the Lagrange method or the Newton-Euler method, supporting position control, impedance control and force-position hybrid control strategies, and realizing multi-arm cooperative motion planning, load distribution algorithm and collision detection function for free space motion, constrained surface contact and load handling operations.

[0022] In one alternative approach, the ROS2 bridging unit employs a hierarchical communication architecture, including: The underlying layer uses ROS2's DDS data distribution service to achieve real-time communication between simulation nodes; the upper layer uses the rosbridge_suite bridging component and WebSocket full-duplex asynchronous communication mechanism to achieve cross-platform remote connection with external algorithm platforms. The ROS2 bridging unit uses a TCP / IP protocol stack for network transmission; The ROS2 bridging unit publishes the encapsulated ROS2 standard messages according to the quality of service (QoS) policy configuration, which includes a reliable transmission mode and a best-effort transmission mode. The ROS2 bridging unit has a co-simulation interface with MATLAB and a co-simulation interface with Simulink.

[0023] The advantages of adopting the above optional methods are: further realizing data transmission based on the WebSocket full-duplex asynchronous communication mechanism and TCP / IP protocol, configuring quality of service strategies according to reliable transmission mode and best-effort transmission mode, and providing joint simulation interfaces with MATLAB and Simulink to ensure real-time data interaction capabilities with external algorithm platforms.

[0024] Secondly, this invention provides a method for modeling and simulating the dynamics of a spacecraft assembly scene, the technical solution of which is as follows: The system calculates the orbital motion of the spacecraft under perturbation and outputs orbital data; calculates the attitude motion of the rigid body coupled with the flexible structure and outputs attitude data; calculates the forward and inverse kinematics and dynamics of the robotic arm and outputs joint state data and end contact force data; and couples the orbital data, attitude data, and joint state data to obtain the spacecraft body pose and robotic arm end pose data. The satellite platform model, the truss structure model, and the space robotic arm model are driven to move according to the attitude of the spacecraft body, and the sensing data of the visible light camera model, the time-of-flight camera model, the lidar model, the inertial measurement unit model, the global navigation satellite system receiver model, and the sun sensor model are generated. The system receives control command topics published by an external algorithm platform, converts the control command topics into drive commands, and encapsulates the sensing data, the orbit data, the attitude data, the joint state data, and the end contact force data into ROS2 standard messages before publishing them to the external algorithm platform; it controls the operation mode of the simulation process, which includes manual control mode, program control mode, and batch processing mode.

[0025] The beneficial effects of the space assembly spacecraft scene modeling and dynamic simulation method of the present invention are as follows: The method of this invention solves the problems of lack of physical realism, real-time interactive capability and open interface in the existing technology of space assembly simulation. It realizes high-fidelity dynamic simulation of multi-spacecraft collaborative operation, deformation of large flexible structures and precision control of robotic arms, and improves the simulation support capability of the whole chain of space assembly mission from scene construction, dynamic calculation to control algorithm verification.

[0026] Thirdly, the technical solution of an electronic device according to the present invention is as follows: It includes a memory, a processor, and a program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps of the space assembly spacecraft scene modeling and dynamic simulation method of the present invention.

[0027] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0028] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of an embodiment of a spacecraft assembly scene modeling and dynamics simulation system according to the present invention; Figure 2 This is a schematic diagram of the visual simulation module architecture; Figure 3 This is a schematic diagram of the coupling relationship in multibody dynamics. Figure 4 Screenshot of the space robotic arm dynamics simulation interface; Figure 5 This is a diagram of a cross-platform communication architecture. Figure 6 Screenshot of the simulation system's interactive interface; Figure 7 A screenshot of a real-time image from a visible light camera; Figure 8 Screenshots showing real-time linear velocity and angular velocity monitoring during the movement of the robotic arm; Figure 9 Screenshots of user-end node subscription and remote control of the robotic arm's motion status during the simulation process; Figure 10 This is a flowchart illustrating an embodiment of a spacecraft assembly scene modeling and dynamics simulation method according to the present invention; Figure 11 This is a schematic diagram of an embodiment of an electronic device according to the present invention. Detailed Implementation

[0029] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0030] Figure 1 This diagram illustrates a structural schematic of an embodiment of a spacecraft assembly scene modeling and dynamics simulation system 100 provided by the present invention. Figure 1 As shown, the space assembly spacecraft scene modeling and dynamics simulation system 100 includes: a visual simulation module 101, a dynamics simulation module 102, and a cross-platform communication and control module 103.

[0031] The dynamics simulation module 102 includes an orbital dynamics subsystem, an attitude dynamics subsystem, and a robotic arm dynamics subsystem. The orbital dynamics subsystem calculates the orbital motion of the spacecraft under perturbation and outputs orbital data. The attitude dynamics subsystem calculates the attitude motion of the rigid body coupled with the flexible structure and outputs attitude data. The robotic arm dynamics subsystem calculates the forward and inverse kinematics and dynamics of the robotic arm and outputs joint state data and end-effector contact force data. The dynamics simulation module 102 couples and solves the orbital data, the attitude data, and the joint state data to obtain the spacecraft body pose and the robotic arm end-effector pose data, and outputs the spacecraft body pose to the visual simulation module 101.

[0032] Spacecraft refer to man-made flying objects that perform specific missions in the space environment; for example, a service spacecraft assembling a space telescope in low Earth orbit. Perturbation refers to the effects of additional forces on a spacecraft during its orbital motion, such as the Earth's non-spherical gravity, atmospheric drag, solar radiation pressure, and third-body gravity; for example, a service spacecraft experiencing orbital perturbation due to the Earth's non-spherical gravitational force causes periodic changes in its orbital elements. Orbital motion refers to the periodic motion of a spacecraft around a central celestial body under the influence of a gravitational field; for example, a service spacecraft orbiting the Earth in a near-circular orbit at an altitude of 400 km has an orbital period of approximately 92 minutes.

[0033] Orbital data refers to the set of parameters describing the orbital state of a spacecraft, including position vector, velocity vector, orbital elements, and nadir trajectory. For example, the position of the servicing spacecraft in the J2000 inertial frame is [6871km, 0km, 0km], and its velocity is [0km / s, 7.5km / s, 0km / s]. Attitude motion refers to the rotational motion of a spacecraft around its own center of mass, including pitch, yaw, and roll. For example, before docking, the servicing spacecraft performs attitude maneuvers to orient the robotic arm's operating surfaces toward the target spacecraft. Attitude data refers to the set of parameters describing the attitude state of a spacecraft, including attitude quaternions, angular velocity vector, and Euler angles. For example, the attitude quaternion of the servicing spacecraft is [0.707, 0, 0.707, 0], indicating a 90° rotation around the Y-axis. Joint state data refers to parameters that describe the motion state of each joint of a space robotic arm, including joint angle, angular velocity, and angular acceleration. For example, the angle of joint 1 of the robotic arm is 30° and the angular velocity is 2° / s, while the angle of joint 2 is -15° and the angular velocity is 1° / s.

[0034] Among them, end contact force data refers to the measured values ​​of force and torque generated when the end effector of the robotic arm comes into contact with an object in the environment; for example, when the end gripper of the robotic arm grasps a truss, the measured contact force is 5N and the contact torque is 0.1N·m.

[0035] Coupled solution refers to the process of jointly calculating the mutual influence between orbital motion, attitude motion, and robotic arm joint motion. For example, servicing a spacecraft simultaneously calculates the center-of-mass shift caused by orbital perturbations, attitude maneuvers, and robotic arm motion to obtain a comprehensive attitude change. Specifically, coupled solution employs the following method: the reaction forces and torques generated by the motions of each joint of the robotic arm are used to calculate the resultant force and resultant torque acting on the spacecraft body in real time using the Newton-Euler recursive algorithm. This resultant torque is then superimposed on the external torque term in the attitude dynamics equation, and the resultant force is superimposed on the perturbation term in the orbital dynamics equation. Simultaneously, the angular acceleration and angular velocity generated by the attitude motion of the spacecraft body are used as additional motions of the robotic arm base and introduced into the inertial term and Coriolis force term in the robotic arm dynamics equation. Quaternion multiplication is used to transform the position vector in the orbital system to the body coordinate system, achieving a unified description of the robotic arm end-effector attitude and the spacecraft attitude.

[0036] Among them, the spacecraft body pose refers to the general term for the position and attitude of the spacecraft, including the position vector, velocity vector, attitude quaternion and angular velocity vector; for example, the pose data of the servicing spacecraft at simulation time t=100s is: position [6850km,100km,50km], attitude quaternion [0.5,0.5,0.5,0.5]. The end effector pose data of a robotic arm refers to the collective position and attitude of the end effector in space, including position vector, velocity vector, attitude quaternion, and angular velocity vector. For example, when a seven-DOF robotic arm servicing a spacecraft grasps a truss, its end effector pose data is: position [1.2m, 0.5m, 0.3m], velocity [0.01m / s, 0.02m / s, 0.01m / s], attitude quaternion [0.707, 0, 0.707, 0], and angular velocity [0.1rad / s, 0.05rad / s, 0.02rad / s].

[0037] The visual simulation module 101 constructs a three-dimensional scene of the space assembly mission based on Unreal Engine. The three-dimensional scene includes a satellite platform model, a truss structure model, a space robotic arm model, a visible light camera model, a time-of-flight camera model, a lidar model, an inertial measurement unit model, a global navigation satellite system receiver model, and a sun sensor model. The visual simulation module 101 drives the satellite platform model, the truss structure model, and the space robotic arm model to move according to the pose of the spacecraft body, and generates perception data of the visible light camera model, the time-of-flight camera model, the lidar model, the inertial measurement unit model, the global navigation satellite system receiver model, and the sun sensor model.

[0038] Unreal Engine refers to a development platform used to create real-time interactive 3D content, featuring high-fidelity rendering and physical simulation capabilities. For example, Unreal Engine can be used to build 3D scenes for space assembly missions, including models of the starry sky, Earth, and spacecraft. A space assembly mission refers to a task that involves constructing a large spacecraft in orbit through multiple launches of units and on-orbit assembly, deployment, or locking operations. For instance, a space assembly mission might require five launch vehicles to send the primary mirror, secondary mirror, sunshade, service module, and truss structure of a space telescope into orbit, where the service spacecraft uses a robotic arm to assemble them sequentially.

[0039] Among them, the satellite platform model refers to a digital 3D model of the spacecraft's main structure, including its dimensions, mass characteristics, and surface material properties; for example, a cube-shaped satellite platform model with a side length of 2m, a mass of 500kg, and a surface covered with multiple layers of thermal insulation material. The truss structure model refers to a digital 3D model of the modular connection structure used to construct the skeleton of large spacecraft; for example, a 5m long carbon fiber truss model that supports switching between splicing, unfolding, and locking states. The space robotic arm model refers to a digital 3D model simulating the manipulator arm of a space robot, possessing multiple degrees of freedom and joint parameters; for example, a seven-DOF robotic arm model with link lengths of 0.8m, 0.6m, 0.5m, 0.4m, 0.3m, 0.2m, and 0.1m, and joint types of rotary joints.

[0040] The visible light camera model refers to a sensor model that simulates the imaging characteristics of a real visible light camera, including focal length, field of view, distortion, depth of field, and exposure parameters. For example, a visible light camera model with a focal length of 50mm and a field of view of 40° outputs a color image with a resolution of 1920×1080 pixels, containing radial distortion and motion blur. The time-of-flight camera model refers to a sensor model that measures distance based on the principle of light time-of-flight, outputting depth information for each pixel. For example, a time-of-flight camera model generates point cloud data with a resolution of 640×480 within a 10m range, with each point containing X, Y, and Z coordinates. The lidar model refers to a sensor model that measures the 3D point cloud of the environment by emitting a laser beam and receiving the echo, supporting scanning methods and angular resolution configurations. For example, a lidar model using a helical scanning method with an angular resolution of 0.1° outputs a 3D point cloud of 300,000 points per second. An inertial measurement unit (IMU) model refers to a sensor model that simulates the measurement characteristics of accelerometers and gyroscopes, including drift and noise errors. For example, an IMU model outputs triaxial acceleration and triaxial angular velocity, with an acceleration drift of 0.01 m / s² and a gyroscope drift of 0.001 rad / s. A global navigation satellite system (GNSS) receiver model refers to a sensor model that simulates receiving navigation satellite signals and performing positioning calculations. For example, a GNSS receiver model simultaneously receives satellite signals from systems A and B, outputting a positioning result with a position error of 5 m (1σ). A sun sensor model refers to a sensor model that measures the sun's direction vector, outputting the azimuth and elevation angles of the sun relative to the spacecraft. For example, a sun sensor model outputs a sun azimuth of 120° and an elevation angle of 45°.

[0041] Among them, perception data refers to the raw or processed data output by various sensor models, including images, point clouds, inertial measurement values, positioning results, and solar direction; for example, perception data includes a visible light image, a depth point cloud, a set of accelerometer readings, a positioning coordinate, and a solar direction vector.

[0042] The cross-platform communication control module 103 is built based on the ROS2 communication framework and includes a ROS2 bridging unit and a simulation control unit. The ROS2 bridging unit receives control command topics published by an external algorithm platform, converts the control command topics into drive commands executed by the dynamics simulation module 102, and encapsulates the sensing data, the trajectory data, the attitude data, the joint state data, and the end contact force data into ROS2 standard messages before publishing them to the external algorithm platform. The simulation control unit controls the operation mode of the simulation process, including manual control mode, program control mode, and batch processing mode.

[0043] Among them, the ROS2 communication framework refers to: Robot Operating System Version 2, a distributed real-time communication middleware based on the publish-subscribe model; for example, the simulation platform acts as a ROS2 node, publishes the topic of spacecraft pose, and external algorithm nodes subscribe to the topic to obtain data.

[0044] The external algorithm platform refers to a computing environment that runs control algorithms, planning algorithms, or intelligent decision-making algorithms independently of the simulation platform. For example, an industrial control computer running operating system A deploys a reinforcement learning-based robotic arm grasping control algorithm and communicates with the simulation platform via ROS2. The control command topic refers to a named channel used in ROS2 communication for transmitting control commands. Publishers and subscribers exchange data by matching topic names. For example, a topic named "space_robot / joint_position_control" is used to transmit robotic arm joint position commands. The drive command refers to a low-level command that, after being converted from the control command topic, can be directly executed by the dynamics simulation part. For example, converting the joint position target [30°, -15°, 45°] published by the external platform into torque commands [2N·m, 1.5N·m, 3N·m] recognizable by the dynamics part.

[0045] ROS2 standard messages refer to message data structures conforming to the ROS2 communication protocol definition, used for data transmission between nodes; for example, the "sensor_msgs / Image" message encapsulates visible light images, and the "geometry_msgs / Pose" message encapsulates spacecraft pose. Manual control mode refers to the mode where the operator directly intervenes in the simulation process through a graphical interface; for example, the operator uses a mouse to drag and drop to adjust the attitude of the service spacecraft, or controls the movement of the robotic arm joints via keyboard keys. Program control mode refers to the mode where the simulation platform receives a sequence of control commands autonomously generated by an external algorithm platform and executes them frame by frame according to the simulation step size; for example, the simulation platform executes 1000 robotic arm trajectory commands sent by the external platform in 10ms steps, and provides real-time feedback on joint status. Batch processing mode refers to the mode where the simulation platform loads predefined task scripts and automatically executes simulation experiments with multiple sets of parameter combinations; for example, batch processing mode automatically runs 20 simulations with different robotic arm grasping speeds, recording the peak value of the end-effector contact force after each experiment.

[0046] The technical solution of this embodiment constructs a coupled dynamics simulation module 102 that includes orbital dynamics, attitude dynamics, and robotic arm dynamics, builds a visual simulation module 101 that integrates multiple types of sensor models based on Unreal Engine, and uses the ROS2 communication framework to achieve real-time data interaction with external algorithm platforms. This solves the problems of lack of physical realism, real-time interaction capability, and open interface in existing space assembly simulations. It realizes high-fidelity dynamic simulation of multi-spacecraft collaborative operation, large flexible structure deformation, and precise control of robotic arms, and improves the full-chain simulation support capability of space assembly missions from scene construction and dynamics calculation to control algorithm verification.

[0047] In one alternative approach, the three-dimensional scene also includes a starry background model, a sunlight model, an Earth model, a Moon model, and a Mars model.

[0048] The following models are used to simulate different aspects of space: **Starry Sky Background Model:** A 3D scene model simulating the distribution and brightness of stars in deep space. For example, a starry sky background model might generate 5000 stars based on star catalog A, with brightness levels ranging from -1.46 to magnitude 6. **Sunlight Model:** A lighting model simulating sunlight intensity, color temperature decay with distance, and the Earth's shadow effect. For example, a sunlight model automatically calculates the sun's position based on the mission time of January 1, 2026, at 12:00:00, with a light intensity of 0 when the spacecraft is in Earth's shadow. **Earth Model:** A 3D model simulating the Earth's shape, terrain, texture, atmosphere, and clouds. For example, an Earth model using a 30m resolution digital elevation model and satellite image textures, including atmospheric scattering and dynamic clouds. **Lunar Model:** A 3D model simulating the lunar surface terrain and texture. For example, a lunar model built based on digital elevation model data acquired by probe A, featuring craters and lunar maria textures. **Mars Model:** A 3D model simulating the Martian surface terrain and texture. For example, a Mars model built based on digital elevation model data acquired by probe B, including textures of volcanoes and canyons.

[0049] The star background model is generated using star distribution and brightness levels from real star catalog data.

[0050] The term "real star catalog data" refers to a database of precise parameters such as stellar positions, brightness, and spectra obtained through astronomical observations. For example, catalog A contains data on approximately 118,000 stars and is used to generate the star background. "Stellar distribution" refers to the geometric arrangement of stars in the sky; for example, in the star background model, the star distribution in constellation A presents a cross shape. "Brightness rating" refers to the apparent magnitude of a star, used to represent its relative brightness; for example, star A has a brightness rating of -1.46 magnitude, and star B has a brightness rating of 2.0 magnitude.

[0051] The solar illumination model automatically calculates the sun's position based on the mission time. The light intensity in the solar illumination model decreases with distance, and the solar illumination model includes the alternation of the Earth's shadow area and the illuminated area.

[0052] The Earth model uses high-precision terrain and texture data, and includes atmospheric scattering, cloud dynamics, and surface illumination reflection.

[0053] High-precision terrain refers to a digital model of the Earth's or celestial surface with high resolution and elevation accuracy; for example, an Earth model using a 30m resolution digital elevation model can clearly show the undulations of mountain range A. Texture data refers to two-dimensional images used to cover the surface of a three-dimensional model, used to represent color and detail; for example, the texture data of an Earth model includes satellite imagery with a resolution of 4096×2048 pixels, showing the colors of continents and oceans.

[0054] Atmospheric scattering refers to the physical phenomenon of sunlight scattering in the Earth's atmosphere, resulting in the blue sky and the transition between day and night (the terminator). For example, the Earth model simulates A-scattering near the terminator, showing a gradient from orange-red to dark blue. Cloud dynamics refers to the movement and changes of clouds in the Earth's atmosphere. For example, the Earth model's clouds rotate from west to east at an angular velocity of 5° per hour, simulating changes in real cloud formations. Surface reflection refers to the optical properties of sunlight reflected off the Earth's surface. For example, desert areas in the Earth model exhibit high reflectivity, while ocean areas show a specular reflection effect.

[0055] The lunar model and the Mars model are constructed based on digital elevation model data and image textures from the exploration mission.

[0056] Digital elevation model (DEM) data refers to digital files that store surface elevation values ​​in raster format; for example, the DEM data for the Mars model has a resolution of 200m per pixel and covers the entire Martian surface. Image texture refers to surface maps of a 3D model generated based on remote sensing images; for example, the image texture for the Lunar model comes from images of the lunar surface taken by the A probe.

[0057] Among the above-mentioned optional methods, a space environment model including star background, sunlight, Earth, Moon and Mars is further constructed. Star distribution and brightness levels are generated through real star surface data, realizing the attenuation of light intensity and color temperature with distance and the alternation of ground shadow. High-precision terrain texture and atmospheric scattering effects are adopted to provide a highly realistic space environment simulation basis for space assembly missions.

[0058] In one alternative approach, the satellite platform model has the ability to customize body dimensions, mass characteristics, and surface materials.

[0059] Here, "body dimensions" refers to the geometric dimensions of the spacecraft platform itself; for example, the body dimensions of a satellite platform model are 2m long, 2m wide, and 3m high. "Mass characteristics" refers to the spacecraft's mass, center of mass location, and moment of inertia; for example, the satellite platform model has a mass of 500kg, a center of mass located at the geometric center, and moments of inertia along the three axes of [200, 200, 250] kg·m². "Surface material" refers to the material properties of the spacecraft's outer shell, including color, reflectivity, and roughness; for example, the satellite platform model's surface material is a multi-layered heat-insulating material with a visible light reflectivity of 0.7 and an infrared emissivity of 0.8.

[0060] The truss structure model is used to simulate the construction process of the space station. The truss structure model has the functions of switching between truss splicing state, truss deployment state, and truss locking state.

[0061] The truss splicing state switching function refers to the function of changing the truss model from a separated state to a connected state; for example, when the robotic arm servicing a spacecraft docks two truss modules with a length of 5m, the simulation platform switches the truss state from "separated" to "spliced". The truss unfolding state switching function refers to the function of changing the truss model from a retracted state to an unfolded state; for example, when a folding truss unfolds into a 10m long support structure after being unlocked, the simulation platform switches the truss state from "retracted" to "unfolded". The truss locking state switching function refers to the function of changing the truss model from a movable state to a rigidly locked state; for example, after the truss is unfolded into place, the locking mechanism engages, and the simulation platform switches the truss state from "unlocked" to "locked".

[0062] The space robotic arm model has a basic configuration with seven degrees of freedom. The space robotic arm model has parameterized configuration functions for the length of each link, the type of each joint, and the range of motion.

[0063] The basic configuration of seven degrees of freedom refers to the kinematic configuration of a space robot arm with seven rotational joints, which can realize redundant degrees of freedom operation. For example, the joint sequence of a seven-degree-of-freedom robot arm is: shoulder yaw, shoulder pitch, elbow pitch, wrist pitch, wrist yaw, wrist roll, and end effector.

[0064] It should be noted that the space robotic arm model in this embodiment supports multi-degree-of-freedom configurations, including but not limited to the basic seven-degree-of-freedom configuration. The specific configuration can be adjusted according to the actual situation, and no restrictions are set here.

[0065] Among the above-mentioned optional methods, the satellite platform body size, mass characteristics and surface material can be further customized, supporting the switching function of three states: truss structure splicing, deployment and locking, as well as the parametric adjustment of the basic configuration of the seven degrees of freedom of the space robotic arm, including the flexible configuration of link length, joint type and range of motion, thereby improving the system's adaptability to diverse spacecraft configurations and assembly stages.

[0066] In one alternative approach, the visible light camera model has multiple focal length configurations and multiple field-of-view configurations, and the visible light camera model includes the distortion characteristics, depth-of-field characteristics, and exposure characteristics of a real camera.

[0067] Distortion characteristics refer to the geometric deformation produced when a camera lens images, including radial and tangential distortion. For example, a visible light camera model produces 2% barrel distortion at the image edges, causing straight lines to become convex curves. Depth of field characteristics refer to the range of distances from which objects near the camera's focal plane can be clearly imaged. For example, a visible light camera model has a depth of field range of 5m to 15m, with objects outside this range appearing blurred. Exposure characteristics refer to the duration and sensitivity of light received by the camera's image sensor, affecting image brightness. For example, a visible light camera model simulating automatic exposure automatically increases the exposure time to 1 / 30s in low light conditions.

[0068] The time-of-flight camera model generates point cloud data containing distance information based on the principle of depth measurement.

[0069] Point cloud data refers to a data structure composed of a set of points in three-dimensional space, where each point contains X, Y, and Z coordinates and possible intensity information. For example, a time-of-flight camera model outputs a point cloud containing 300,000 points, with each point's coordinates accurate to the centimeter level.

[0070] The lidar model has configuration functions for different scanning modes and different angular resolutions, and outputs three-dimensional environment scanning results.

[0071] Among them, the three-dimensional environment scanning result refers to the three-dimensional point cloud data of the environment obtained by the lidar through scanning; for example, the lidar model scan obtains the target point cloud within a 100m range around the service spacecraft, including the outer surface of the target spacecraft and space debris.

[0072] The inertial measurement unit model simulates the measurement characteristics of an accelerometer and a gyroscope, and includes a drift error model and a noise error model.

[0073] The drift error model refers to a mathematical model that simulates the slow-changing zero-bias error of the inertial measurement unit output over time; for example, the drift error model sets the accelerometer zero bias to wander randomly at a speed of 0.01 m / s² / h. The noise error model refers to a mathematical model that simulates random noise in sensor measurements; for example, the noise error model sets the gyroscope output to have an additional Gaussian noise with a root mean square of 0.001 rad / s.

[0074] The global navigation satellite system receiver model simulates the navigation signal reception process and the positioning calculation process.

[0075] The navigation signal reception process refers to the process by which a Global Navigation Satellite System (GNSS) receiver acquires, tracks, and demodulates satellite signals. For example, the receiver simultaneously tracks signals from 8 System A satellites and 6 System B satellites, calculating pseudorange and carrier phase. The positioning calculation process refers to the process of calculating the receiver's three-dimensional position, velocity, and time using ranging information from multiple navigation satellites. For example, the receiver solves the pseudorange equation using the least squares method to obtain a positioning result with a three-dimensional position error of less than 5 meters.

[0076] The solar sensor model outputs solar azimuth measurement data.

[0077] Among them, solar azimuth measurement data refers to the angle value of the solar direction vector output by the solar sensor in the spacecraft's coordinate system; for example, the solar sensor outputs a solar azimuth angle of 135° and a solar elevation angle of 30°.

[0078] Among the above optional approaches, models of various sensing devices such as visible light cameras, time-of-flight cameras, lidar, inertial measurement units, global navigation satellite system receivers, and sun sensors are further integrated. The visible light camera simulates real distortion, depth of field, and exposure characteristics; the time-of-flight camera generates point cloud data containing distance information; the lidar supports multiple scanning methods and angular resolution configurations; and the inertial measurement unit includes drift and noise error models, providing a high-fidelity sensing data source for external algorithm platforms.

[0079] In one alternative approach, the orbital dynamics subsystem is specifically used for: Using a high-precision orbital propagator and incorporating the perturbations of Earth's non-spherical gravitational force, atmospheric drag, solar radiation pressure, and third-body gravity as perturbation factors, the position and velocity of the satellite in the J2000 inertial frame were calculated.

[0080] The high-precision orbit propagator refers to an algorithmic unit used for numerical integration or analytical prediction of spacecraft orbits, considering various perturbation factors. For example, the high-precision orbit propagator uses an 8th-order Runge-Kutta integrator with an integration step size of 1 second to calculate the orbit for the next 24 hours. Perturbation factors refer to various additional force sources that cause the spacecraft orbit to deviate from ideal two-body motion; for example, perturbation factors include Earth's J2 non-spherical gravity, atmospheric damping, solar radiation pressure, and lunar gravity.

[0081] The calculation of orbital maneuvering processes under pulsed thrust or continuous thrust includes orbital lifting, plane correction, phase adjustment, and rendezvous and docking trajectory planning; and the modeling of relative motion of multiple spacecraft to calculate relative orbital dynamics during formation flight, close maneuvering, and docking.

[0082] Among the above-mentioned optional methods, perturbation factors such as Earth's non-spherical gravity, atmospheric drag, solar radiation pressure, and third-body gravity are further introduced to support orbital lifting, plane correction, phase adjustment, and rendezvous and docking trajectory planning under pulsed thrust and continuous thrust, thereby realizing relative orbital dynamics simulation during multi-spacecraft formation flight, close-range operation, and docking.

[0083] In one alternative approach, the attitude dynamics subsystem is specifically used for: It employs a reaction flywheel, thruster, and magnetic torque generator as actuators, and adopts three-axis stabilization control mode, ground orientation control mode, sun orientation control mode, and inertial orientation control mode.

[0084] The actuator refers to the physical device used to generate attitude control torque; for example, the actuator includes three orthogonally mounted reaction flywheels, four 10N thrusters and three magnetic torque generators.

[0085] Among these, the three-axis stabilization control mode refers to a control mode that maintains a stable pointing direction for the spacecraft along all three rotational axes; for example, a servicing spacecraft uses a three-axis stabilization control mode during robotic arm operations to keep its body fixed relative to the inertial frame. The Earth-oriented control mode refers to a control mode that ensures a specific facet of the spacecraft always points towards the Earth's center; for example, a servicing spacecraft uses an Earth-oriented control mode during the communication phase to point its antenna towards the Earth. The Sun-oriented control mode refers to a control mode that ensures the normal to the spacecraft's solar panels points towards the Sun; for example, a servicing spacecraft uses a sun-oriented control mode during the charging phase to maximize the solar panels' illumination. The inertial orientation control mode refers to a control mode that maintains a fixed attitude and pointing direction for the spacecraft in inertial space; for example, a space telescope uses an inertial orientation control mode during the observation phase to keep its lens pointing towards the target star.

[0086] Calculate the bending and torsional vibration modes of a large flexible solar panel structure, and calculate the dynamic response during deployment and the thermoelastic deformation caused by the temperature gradient.

[0087] Large flexible solar panel structures refer to solar panels or antenna structures with large areas and low stiffness, exhibiting significant vibration characteristics; for example, a flexible solar panel with an area of ​​30m² on each side of a spacecraft, with a fundamental frequency of 0.5Hz. Bending vibration modes refer to the vibration patterns of a structure in the direction perpendicular to the neutral plane, corresponding to specific frequencies and mode shapes; for example, the first-order bending vibration mode of a solar panel has a frequency of 0.5Hz, and the mode shape is the maximum displacement at the ends. Torsional vibration modes refer to the vibration patterns of a structure twisting about its own axis; for example, the first-order torsional vibration mode of a solar panel has a frequency of 1.2Hz, and the mode shape is opposite twisting at both ends.

[0088] Dynamic response refers to the change of displacement, velocity, and acceleration of a structure over time under external excitation; for example, under the excitation of the reaction torque of a robotic arm, the dynamic response of the end of the solar panel exhibits a damped oscillation with an amplitude of 0.1m. Space thermal deformation effect refers to the thermal expansion or contraction deformation of a spacecraft structure under extreme temperature changes in space; for example, when a servicing spacecraft enters or exits Earth's shadow, the truss structure experiences a thermal deformation of 0.5mm due to a temperature difference of 100℃.

[0089] The finite element method and modal superposition technology were used to calculate the deformation and vibration characteristics of the space truss structure under the action of gravity gradient torque, thermal stress, and contact force.

[0090] Among them, a space truss structure refers to a spatial grid structure formed by connecting members through nodes, used to construct the skeleton of large spacecraft; for example, a square space truss structure with a side length of 10m is composed of carbon fiber members and alloy A nodes. The finite element method refers to a numerical method that discretizes a continuous structure into a finite number of elements and analyzes the structural mechanical response by solving a system of equations; for example, dividing a truss structure into 1000 beam elements and 500 nodes, and calculating the deformation of each node. Modal superposition technology refers to representing the vibration response of a structure as a linear superposition of various mode shapes, used for rapid calculation of dynamic response; for example, calculating the first 20 modes of a truss, and superimposing the responses under contact force excitation to obtain the total deformation.

[0091] It should be noted that the finite element analysis was completed offline beforehand, extracting the mode shape vectors, modal masses, and modal stiffness of the first 30 modes. In the real-time simulation, based on the current contact force, gravity gradient moment, and thermal stress distribution, the coordinate response of each mode was quickly calculated through modal superposition, and then the structural deformation and vibration were obtained through mode shape superposition. To ensure real-time performance, only the first 10 dominant modes were calculated, and higher-order modes were considered as residual flexibility and included in the calculation using a static correction method.

[0092] The deformation and vibration characteristics under the action of gravitational gradient torque refer to the structural deformation and vibration patterns caused by the torque generated when a spacecraft's center of mass does not coincide with the center of gravity in a non-uniform gravitational field. For example, in a servicing spacecraft orbiting at 400 km, the gravitational gradient torque causes a static bending deformation of 0.2 mm and a vibration of 0.05 mm at the truss end. The deformation and vibration characteristics under the action of thermal stress refer to the deformation and vibration patterns caused by thermal stress generated within the structure due to uneven temperature distribution. For example, a temperature difference of 150°C between the sunlit and shaded sides causes thermal stress that results in a 0.3 mm warping deformation and a 1 Hz flutter in the truss. The deformation and vibration characteristics under the action of contact force refer to the structural deformation and vibration patterns caused by the contact force generated when the end of a robotic arm contacts an object in the environment. For example, when a robotic arm grasps a truss, a contact force of 10 N causes a local deformation of 0.05 mm and a vibration of 0.2 Hz on the servicing spacecraft platform.

[0093] In the above-mentioned optional methods, reaction flywheels, thrusters and magnetic torquers are further used as attitude actuators to support multiple control modes such as three-axis stabilization, ground orientation, sun orientation and inertial orientation. The bending and torsional vibration modes of large flexible panels and the dynamic response and thermal deformation effects during the deployment process are calculated to realize the simulation of the deformation and vibration characteristics of space trusses under the action of gravity gradient torque, thermal stress and contact force.

[0094] In one alternative approach, the robotic arm dynamics subsystem is specifically used for: Using the Lagrange method or the Newton-Euler method, dynamic equations for the joint space and the operating space are established based on the mass distribution of the connecting rod, joint friction, and flexibility effects.

[0095] The dynamic equations in joint space refer to the differential equations describing the relationship between the joint torques, joint angles, angular velocities, and angular accelerations of the robotic arm. For example, the dynamic equations in joint space state that the joint torque vector equals the mass matrix multiplied by the angular acceleration vector, plus the Coriolis force term and the gravity term. The dynamic equations in maneuver space refer to the equations describing the relationship between the forces and accelerations of the robotic arm's end effector in Cartesian space. For example, the dynamic equations in maneuver space state that the end effector force vector equals the inertia matrix multiplied by the end effector acceleration vector, plus the nonlinear velocity term and the gravity term.

[0096] Position control strategy, impedance control strategy and force-position hybrid control strategy are adopted to calculate the free space motion process, the constrained surface contact process and the load handling operation process.

[0097] Among them, position control strategy refers to a control method that uses joint torque to bring the end effector of the robotic arm to a target position; for example, the position control strategy sets the target end effector position as [1.0m, 0.5m, 0.2m], and the proportional-integral-derivative controller calculates the joint torque to make the end effector approach the target. Impedance control strategy refers to a control method that adapts to environmental contact by controlling the dynamic relationship (inertia, damping, stiffness) between the force and position of the end effector of the robotic arm; for example, the impedance control strategy sets the end effector stiffness to 500N / m and the damping to 50N·s / m, and the end effector passively retracts when the contact force exceeds the threshold. Force-position hybrid control strategy refers to a composite control method that performs position control in some directions and force control in other directions; for example, the force-position hybrid control strategy performs force control (maintaining a 5N clamping force) in the gripping direction and position control in the vertical direction.

[0098] The free-space motion process refers to the motion process where the end effector of the robotic arm does not contact any environmental objects; for example, during the process of the robotic arm moving from its initial position to the target truss gripping point, the end effector moves in free space and is not subject to external forces. The constrained surface contact process refers to the motion process where the end effector of the robotic arm maintains contact with an environmental surface and applies forces; for example, after the robotic arm's grippers contact the truss surface, they slide along the truss surface to find the optimal gripping point, maintaining a constant normal force. The load handling operation process refers to the motion process where the robotic arm grips and moves an object; for example, the robotic arm grips a 50kg truss module and moves it from its storage location to its installation location, considering the load's inertial force and gravitational gradient.

[0099] Perform multi-arm cooperative motion planning, load distribution algorithm and collision detection.

[0100] Multi-arm cooperative motion planning refers to the planning of motion trajectories for two or more robotic arms to collaboratively complete a task on the same platform; for example, the left and right arms simultaneously grasp both ends of a large truss and coordinate their motion to install the truss onto a space station node. Load distribution algorithms refer to algorithms that distribute load forces or torques to each robotic arm according to a certain strategy during multi-arm cooperative operation; for example, a load distribution algorithm might allocate 40% of a 100kg load to the left arm and 60% to the right arm to balance joint torques. Collision detection refers to the calculation process of determining whether the robotic arm body, end effector, or load causes geometric interference with environmental objects; for example, a collision detection algorithm might calculate the distance between the robotic arm links and the spacecraft surface in real time, issuing an alarm and stopping movement when the distance is less than 0.01m.

[0101] In the above-mentioned optional methods, the dynamic equations of the joint space and operation space of the robotic arm are further established based on the Lagrange method or the Newton-Euler method, supporting position control, impedance control and force-position hybrid control strategies, realizing multi-arm cooperative motion planning, load distribution algorithm and collision detection function for free space motion, constrained surface contact and load handling operations.

[0102] In one alternative approach, the ROS2 bridging unit employs a hierarchical communication architecture, including: The underlying layer uses ROS2's DDS data distribution service to achieve real-time communication between simulation nodes; the upper layer uses the rosbridge_suite bridging component and WebSocket full-duplex asynchronous communication mechanism to achieve cross-platform remote connection with external algorithm platforms. The ROS2 bridging unit uses a TCP / IP protocol stack for network transmission; the ROS2 bridging unit publishes the encapsulated ROS2 standard messages according to the quality of service (QoS) policy configuration, which includes reliable transmission mode and best-effort transmission mode; the ROS2 bridging unit has a co-simulation interface with MATLAB and a co-simulation interface with Simulink.

[0103] WebSocket full-duplex asynchronous communication mechanism refers to a communication protocol that provides bidirectional real-time data transmission over a single TCP connection, supporting asynchronous message sending and receiving. For example, when a simulation platform establishes a WebSocket connection with an external algorithm platform, both parties can send and receive data simultaneously without blocking each other. Quality of Service (QoS) policy configuration refers to setting parameters such as reliability, history, and depth for ROS2 message transmission to adapt to the needs of different data types. For example, configuring a reliable transmission mode and a queue depth of 10 for sensory data topics, and configuring a best-effort transmission mode for control command topics.

[0104] Among them, reliable transmission mode refers to a transmission strategy that ensures messages are successfully received by the other party, and retransmits if lost; for example, joint control commands use reliable transmission mode to ensure that each command is received by the dynamics part, avoiding loss of motion control. Best-effort transmission mode refers to a transmission strategy that does not guarantee reliable message reception, but sends messages with the lowest possible delay; for example, visible light image data uses best-effort transmission mode, allowing occasional frame drops in exchange for real-time performance.

[0105] Among the above optional methods, data transmission is further implemented based on the WebSocket full-duplex asynchronous communication mechanism and the TCP / IP protocol. Service quality strategies are configured according to reliable transmission mode and best-effort transmission mode, and joint simulation interfaces with MATLAB and Simulink are provided to ensure real-time data interaction capabilities with external algorithm platforms.

[0106] An interactive, high-fidelity simulation platform for assembling large spacecraft in space is developed based on a high-performance graphics workstation. It uses the Windows operating system as its underlying support platform and Unreal Engine as its core simulation engine, with secondary development to achieve deterministic simulation cycles and high-precision physical calculations. This embodiment of the system comprises three main parts: a visual simulation module, a high-precision dynamics simulation module, and a cross-platform remote communication and simulation control module. The visual simulation module provides an immersive visualization environment and multi-source sensing data generation capabilities for space assembly missions. The high-precision dynamics simulation module enables multi-scale dynamic calculations from the orbital level to the joint level. The cross-platform remote communication and simulation control module enables data interaction and real-time control under a distributed architecture. These three modules together provide end-to-end simulation support for space construction missions, from scene construction and physical calculations to virtual-real interaction.

[0107] The visual simulation module is built upon the real-time rendering capabilities of Unreal Engine. For example... Figure 2As shown, the visual simulation module 101 architecture encompasses three layers: space environment modeling, spacecraft platform modeling, and sensor modeling. In terms of space environment modeling, the system constructs a complete deep space scene representation system, including a high-resolution starry sky background environment, a solar and solar illumination model, an Earth model, a lunar model, and a Mars model. The starry sky background environment generates star distribution and brightness levels based on real star surface data. The solar illumination model automatically calculates the sun's position according to the mission time, with light intensity and color temperature decreasing with distance, and simulates the alternating changes between Earth's shadow and illuminated areas. The Earth model uses high-precision terrain and texture data, including atmospheric scattering, cloud dynamics, and surface light reflection effects. The lunar and Mars models are constructed based on digital elevation model data and image textures acquired during the exploration mission. Regarding spacecraft platform modeling, the system has a built-in parametric model library, including a basic satellite platform model, a modular truss connection structure, and a space robotic arm model. The satellite platform model supports customizable body dimensions, mass characteristics, and surface materials. The modular truss connection structure is used to simulate the space station construction process, supporting truss splicing, deployment, and locking state switching. The space robotic arm model features a seven-degree-of-freedom configuration, supporting parametric configuration of link lengths, joint types, and range of motion. For sensor modeling, the system constructs models for a visible light camera, a time-of-flight camera, a lidar system, an inertial measurement unit (IMU), a global navigation satellite system (GNSS) receiver, and a sun sensor. The visible light camera model supports various focal lengths and field-of-view configurations, simulating real camera distortion, depth of field, and exposure effects, outputting physically accurate image data. The time-of-flight camera model simulates depth measurement principles, generating point cloud data containing distance information. The lidar model supports different scanning methods and angular resolution configurations, outputting 3D environment scanning results. The IMU model simulates the measurement characteristics of accelerometers and gyroscopes, including drift and noise error models. The GNSS receiver model simulates the navigation signal reception and positioning calculation processes. The sun sensor model outputs solar azimuth measurement data for attitude determination reference.

[0108] The high-precision dynamics simulation module constructs accurate mathematical models that conform to the laws of space physics. For example... Figure 3As shown, the multibody dynamics coupling relationship encompasses three core components: the orbital dynamics subsystem, the attitude dynamics subsystem, and the robotic arm operation dynamics subsystem. The orbital dynamics subsystem supports loading standard-format satellite orbital data, calculating the satellite's position and velocity in the J2000 inertial frame based on a high-precision orbital propagator, considering major perturbation factors such as Earth's non-spherical gravitational perturbation, atmospheric drag, solar radiation pressure, and third-body gravity. The orbital dynamics subsystem simulates orbital maneuvers under pulsed or continuous thrust, including orbital lifting, plane correction, phase adjustment, and rendezvous and docking trajectory planning, outputting key parameters such as satellite orbital elements, geocentric distance, velocity vector, and nadir trajectory in real time. For space assembly missions, the orbital dynamics subsystem supports relative motion modeling of multiple spacecraft, enabling relative orbital dynamics simulation during formation flying, close-range operations, and docking. The attitude dynamics subsystem establishes a rigid-body and flexible coupled attitude motion model, simulating the working characteristics of actuators such as reaction wheels, thrusters, and magnetic torquers, supporting three-axis stable control mode, Earth-oriented control mode, Sun-oriented control mode, and inertial orientation control mode. The attitude dynamics subsystem calculates the bending and torsional vibration modes of a large flexible solar panel structure, simulating the dynamic response and space thermal deformation effects during deployment. For space truss structures, the attitude dynamics subsystem uses the finite element method and modal superposition technology to calculate the deformation and vibration characteristics under gravitational gradient torque, thermal stress, and contact force. The robotic arm dynamics subsystem implements a complete modeling chain from kinematics to dynamics, supporting forward and inverse kinematics solutions. It uses the Lagrangian method or the Newton-Euler method to establish the joint space dynamics equations and the operational space dynamics equations, taking into account link mass distribution, joint friction, and flexibility effects. The robotic arm dynamics subsystem supports position-based proportional-integral-derivative control strategies, force-based impedance control strategies, and force-position hybrid control strategies to simulate free space motion processes, constrained surface contact processes, and load handling processes. For multi-branch robot systems, the robotic arm dynamics subsystem executes multi-arm cooperative motion planning, load distribution algorithms, and collision detection. Figure 4 As shown, the space robotic arm dynamics simulation interface displays the angles, angular velocities, torques, end-effector poses, and contact force information of each joint of the robotic arm in real time, forming a complete control closed-loop verification environment.

[0109] The cross-platform remote communication and simulation control module breaks down the barriers between the simulation platform and user algorithms and hardware devices. For example... Figure 5As shown, the cross-platform communication architecture is built on ROS2 and rosbridge_suite. The simulation platform runs native ROS2 nodes in an Ubuntu 24.04 environment, achieving real-time communication between modules through DDS; rosbridge_suite acts as a protocol adaptation layer, serializing ROS2 messages into JSON format and transmitting them to the Windows workstation via WebSocket. WebSocket's full-duplex feature supports concurrent transmission of simulation data uplink (sensor data, status feedback) and control commands downlink (joint control, mode switching), while the TCP / IP protocol stack ensures connection reliability in both LAN and WAN environments. The data communication architecture employs a publish-subscribe mechanism to achieve efficient data exchange between multiple nodes. The simulation platform, as the data publisher, broadcasts key information in real time, including spacecraft orbital attitude information, robotic arm joint status, raw sensor data and processing results, simulation timestamps, and system status flags. The data format conforms to the Robot Operating System Version 2 standard message type. The simulation platform, as the subscriber, listens for control commands published by the user, covering satellite attitude and orbit control commands, robotic arm joint control commands, and end effector operation commands. All communication is based on the TCP / IP protocol, supporting remote connections in both LAN and WAN environments. The simulation control function offers three operating modes: manual control, program control, and batch processing. In manual control mode, the operator directly intervenes in the simulation process through a graphical interface, adjusting the spacecraft's attitude or teaching the robotic arm's movement in real time. In program control mode, the platform receives control command sequences generated by the user-defined algorithm, executes them frame-by-frame according to the simulation step size, and provides feedback on the results, supporting single-step operation, continuous operation, and breakpoint debugging. In batch processing mode, the platform loads predefined task scripts, automatically executes simulation experiments with multiple parameter combinations, and generates batch result data for algorithm performance evaluation and statistical analysis. The platform adopts a modular plug-in architecture design, supporting the import of custom spacecraft models and sensor parameter configuration files, embedding user-developed control algorithm dynamic link libraries, co-simulation interfaces with MATLAB / Simulink, and providing a Python-based scripting interface.

[0110] An interactive, high-fidelity simulation platform for assembling large spacecraft in space offers three key benefits. For example... Figure 6As shown, the simulation system's interactive interface is built upon a visual simulation environment using Unreal Engine. Through real-time ray tracing and physically based material rendering technologies, changes in sunlight, transitions in Earth's shadow zones, and the reflective properties of thermal control materials on spacecraft surfaces are accurately rendered. The platform supports a dual-mode workflow, allowing users to call parametric model libraries and import local computer-aided design models. Users can complete the construction of complex on-orbit construction scenarios involving multiple spacecraft formations, large flexible truss structures, and multi-degree-of-freedom robotic arms within minutes. Figure 7 As shown, real-time images from a visible light camera simulate real lens distortion and depth-of-field effects; a time-of-flight camera and lidar generate point cloud data with noise characteristics; and an inertial measurement unit and a global navigation satellite system receiver model inject measurement noise that conforms to actual error statistics, providing crucial support for the verification of intelligent algorithms. Figure 8 As shown, the real-time linear and angular velocity monitoring interface during the robotic arm's motion demonstrates the multi-scale dynamic coupling simulation effect. Through a three-layer architecture of track-attitude-robotic arm, the platform accurately describes the complex physical phenomena during on-orbit assembly: the platform's center of mass shift and reaction torque caused by the robotic arm's motion are fed back to the attitude control system in real time; the angular acceleration generated by attitude maneuvers is transmitted to the robotic arm's dynamic model as a base excitation; and the changes in the microgravity environment caused by track perturbations and maneuvers synchronously affect the contact dynamics calculations. The unity of high fidelity and real-time performance allows the control algorithm to be fully validated under conditions close to the real on-orbit environment. Figure 9 As shown, the simulation process, including the user-end node subscription and remote control of the robotic arm's motion status interface, demonstrates the effectiveness of the cross-platform communication development architecture. The platform adopts a Windows-ROS Bridge-Linux cross-platform communication architecture, connecting the Unreal Engine high-fidelity simulation environment with the Robot Operating System Version 2 (ROS 2) algorithm development environment. Based on the WebSocket full-duplex asynchronous communication mechanism, simulation data is transmitted to the user end in real-time using the ROS 2 standard message format. Control commands are reliably sent to the simulation platform after being configured with a Quality of Service (QoS) policy, supporting both reliable and best-effort transmission modes to adapt to the real-time requirements of different data types. Algorithm developers can debug algorithms using the ROS 2 toolchain in a native Linux environment without needing to adapt to a closed simulation software environment. The platform supports control algorithms written in multiple languages ​​such as MATLAB / Simulink, Python, and C++ through a unified interface for verification, greatly reducing algorithm migration costs. The distributed architecture supports multi-user collaborative development; different modules such as task planning, path planning, and control law design can be integrated and verified in parallel within the simulation environment.

[0111] Figure 10This diagram illustrates a flowchart of an embodiment of a spacecraft assembly scene modeling and dynamics simulation method provided by the present invention. This method employs the spacecraft assembly scene modeling and dynamics simulation system 100 provided by the present invention. Figure 10 As shown, the method includes the following steps: S1. Calculate the orbital motion of the spacecraft under perturbation and output orbital data; calculate the attitude motion of the rigid body coupled with the flexible structure and output attitude data; calculate the forward and inverse kinematics and dynamics of the robotic arm and output joint state data and end contact force data; couple and solve the orbital data, attitude data and joint state data to obtain the spacecraft body pose and robotic arm end pose data. S2. Drive the satellite platform model, the truss structure model, and the space robotic arm model to move according to the attitude of the spacecraft body, and generate sensing data of the visible light camera model, the time-of-flight camera model, the lidar model, the inertial measurement unit model, the global navigation satellite system receiver model, and the sun sensor model; S3. Receive control command topics published by an external algorithm platform, convert the control command topics into drive commands, and encapsulate the sensing data, the orbit data, the attitude data, the joint state data, and the end contact force data into ROS2 standard messages before publishing them to the external algorithm platform; control the operation mode of the simulation process, the operation mode including manual control mode, program control mode, and batch processing mode.

[0112] It should be noted that the beneficial effects of the space assembly spacecraft scene modeling and dynamics simulation method provided in the above embodiments are the same as those of the space assembly spacecraft scene modeling and dynamics simulation system 100 described above, and will not be repeated here. Furthermore, the method and system embodiments provided in the above embodiments belong to the same concept, and their specific implementation process is detailed in the system embodiments, and will not be repeated here.

[0113] The space assembly spacecraft scene modeling and dynamics simulation system 100 of the present invention can be a computer program (including program code) running on a computer device. For example, the space assembly spacecraft scene modeling and dynamics simulation system 100 of the present invention is an application software that can be used to execute the corresponding steps in the space assembly spacecraft scene modeling and dynamics simulation method of the present invention.

[0114] In some embodiments, the space assembly spacecraft scene modeling and dynamics simulation system 100 of the present invention can be implemented in a combination of hardware and software. As an example, the space assembly spacecraft scene modeling and dynamics simulation system 100 of the present invention can be a processor in the form of a hardware decoding processor, which is programmed to execute the space assembly spacecraft scene modeling and dynamics simulation method of the present invention. For example, the processor in the form of a hardware decoding processor can be one or more application specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), or other electronic components.

[0115] The modules described in the embodiments of this invention can be implemented in software or hardware. The names of the modules are not, in some cases, limiting the scope of the module itself.

[0116] An electronic device according to an embodiment of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any of the above-mentioned methods for modeling and simulating the space assembly spacecraft scene. That is, an electronic device according to an embodiment of the present invention may include, but is not limited to: a processor and a memory; the memory is used to store the computer program; the processor is used to execute the method for modeling and simulating the space assembly spacecraft scene according to any embodiment of the present invention by calling the computer program.

[0117] In one alternative embodiment, an electronic device is provided, such as Figure 11 As shown, Figure 11 The illustrated electronic device 4000 includes a processor 4001 and a memory 4003. The processor 4001 and the memory 4003 are connected, for example, via a bus 4002. Optionally, the electronic device 4000 may further include a transceiver 4004, which can be used for data interaction between the electronic device and other electronic devices, such as sending and / or receiving data. It should be noted that in practical applications, the transceiver 4004 is not limited to one type, and the structure of the electronic device 4000 does not constitute a limitation on the embodiments of the present invention.

[0118] Processor 4001 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this invention. Processor 4001 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0119] Bus 4002 may include a path for transmitting information between the aforementioned components. Bus 4002 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Bus 4002 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 11 The bus 4002 is represented by only one thick line, but this does not mean that there is only one bus or one type of bus.

[0120] The memory 4003 may be ROM (Read Only Memory) or other types of static storage devices capable of storing static information and instructions, RAM (Random Access Memory) or other types of dynamic storage devices capable of storing information and instructions, or EEPROM (Electrically Erasable Programmable Read Only Memory), CD-ROM (Compact Disc Read Only Memory) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto.

[0121] The memory 4003 stores application code (computer program) for executing the present invention, and its execution is controlled by the processor 4001. The processor 4001 executes the application code stored in the memory 4003 to implement the content shown in the foregoing method embodiments.

[0122] Among them, electronic devices can also be terminal devices. A terminal device can be any terminal device that can install applications and access web pages through applications, including at least one of smartphones, tablets, laptops, desktop computers, smart speakers, smartwatches, smart TVs, and smart in-vehicle devices.

[0123] It should be noted that, Figure 11 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0124] It should be understood that the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0125] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-disclosed concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this invention.

[0126] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and represent a limitation on a specific order or sequence. Where appropriate, the order of use for similar objects can be interchanged so that the embodiments of this application described herein can be implemented in an order other than that shown or described.

[0127] Those skilled in the art will recognize that this invention can be implemented as a system, method, or computer program product. Therefore, this invention can be specifically implemented in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "circuit," "module," or "system." Furthermore, in some embodiments, this invention can also be implemented as a computer program product contained in one or more computer-readable media, which includes computer-readable program code.

[0128] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A spacecraft assembly scene modeling and dynamics simulation system, characterized in that, include: Visual simulation module, dynamics simulation module, and cross-platform communication control module; The dynamics simulation module includes an orbital dynamics subsystem, an attitude dynamics subsystem, and a robotic arm dynamics subsystem; the orbital dynamics subsystem calculates the spacecraft's orbital motion under perturbation and outputs orbital data; The attitude dynamics subsystem calculates the attitude motion of the rigid body coupled with the flexible structure and outputs attitude data; the robotic arm dynamics subsystem calculates the forward and inverse kinematics and dynamics of the robotic arm and outputs joint state data and end-effector contact force data. The dynamics simulation module couples and solves the orbital data, the attitude data, and the joint state data to obtain the spacecraft body pose and the robotic arm end pose data, and outputs the spacecraft body pose to the visual simulation module. The visual simulation module constructs a 3D scene of the space assembly mission based on Unreal Engine. The 3D scene includes a satellite platform model, a truss structure model, a space robotic arm model, a visible light camera model, a time-of-flight camera model, a lidar model, an inertial measurement unit model, a global navigation satellite system receiver model, and a sun sensor model. The visual simulation module drives the movement of the satellite platform model, the truss structure model, and the space robotic arm model according to the spacecraft's pose, and generates perception data for the visible light camera model, the time-of-flight camera model, the lidar model, the inertial measurement unit model, the global navigation satellite system receiver model, and the sun sensor model. The cross-platform communication control module is built on the ROS2 communication framework and includes a ROS2 bridging unit and a simulation control unit. The ROS2 bridging unit receives control command topics published by an external algorithm platform, converts the control command topics into drive commands executed by the dynamics simulation module, and encapsulates the sensing data, trajectory data, attitude data, joint state data, and end-effector contact force data into ROS2 standard messages before publishing them to the external algorithm platform. The simulation control unit controls the operation mode of the simulation process, which includes manual control mode, program control mode, and batch processing mode.

2. The space assembly spacecraft scene modeling and dynamics simulation system according to claim 1, characterized in that, The three-dimensional scene also includes a starry sky background model, a sunlight model, an Earth model, a Moon model, and a Mars model; The star background model is generated using star distribution and brightness levels based on real star catalog data; The solar illumination model automatically calculates the sun's position based on the mission time. The light intensity in the solar illumination model decreases with distance, and the solar illumination model includes the alternating changes between the Earth's shadow area and the illuminated area. The Earth model uses high-precision terrain and texture data, and includes atmospheric scattering, cloud dynamics, and surface illumination reflection. The lunar model and the Mars model are constructed based on digital elevation model data and image textures from the exploration mission.

3. The space assembly spacecraft scene modeling and dynamics simulation system according to claim 1, characterized in that, The satellite platform model has the functions of customizing the body size, customizing the mass characteristics, and customizing the surface material; The truss structure model is used to simulate the construction process of the space station. The truss structure model has the functions of switching between truss splicing state, truss deployment state, and truss locking state. The space robotic arm model has a basic configuration with seven degrees of freedom. The space robotic arm model has parameterized configuration functions for the length of each link, the type of each joint, and the range of motion.

4. The space assembly spacecraft scene modeling and dynamics simulation system according to claim 1, characterized in that, The visible light camera model has multiple focal length configuration functions and multiple field of view configuration functions. The visible light camera model includes the distortion characteristics, depth of field characteristics and exposure characteristics of a real camera. The time-of-flight camera model generates point cloud data containing distance information based on the depth measurement principle; The lidar model has configuration functions for different scanning modes and different angular resolutions, and outputs three-dimensional environment scanning results. The inertial measurement unit model simulates the measurement characteristics of an accelerometer and a gyroscope, and includes a drift error model and a noise error model. The global navigation satellite system receiver model simulates the navigation signal reception process and the positioning calculation process. The solar sensor model outputs solar azimuth measurement data.

5. The space assembly spacecraft scene modeling and dynamics simulation system according to claim 1, characterized in that, The orbital dynamics subsystem is specifically used for: Using a high-precision orbital propagator and incorporating the perturbations of Earth's non-spherical gravitational force, atmospheric drag, solar radiation pressure, and third-body gravity as perturbation factors, the position and velocity of the satellite in the J2000 inertial frame were calculated. Calculate the orbital maneuvering process under pulsed thrust or continuous thrust, wherein the orbital maneuvering process includes orbit lifting, plane correction, phase adjustment and rendezvous and docking trajectory planning; It also performs relative motion modeling for multiple spacecraft and calculates relative orbital dynamics during formation flying, close-range operations, and docking.

6. The space assembly spacecraft scene modeling and dynamics simulation system according to claim 5, characterized in that, The attitude dynamics subsystem is specifically used for: It employs a reaction flywheel, thruster, and magnetic torque generator as actuators, and adopts three-axis stabilization control mode, ground orientation control mode, sun orientation control mode, and inertial orientation control mode; Calculate the bending and torsional vibration modes of a large flexible solar panel structure, and calculate the dynamic response and thermoelastic deformation caused by temperature gradient during the deployment process; The finite element method and modal superposition technology were used to calculate the deformation and vibration characteristics of the space truss structure under the action of gravity gradient torque, thermal stress, and contact force.

7. The space assembly spacecraft scene modeling and dynamics simulation system according to claim 1, characterized in that, The robotic arm dynamics subsystem is specifically used for: Using the Lagrange method or the Newton-Euler method, dynamic equations for the joint space and the operating space are established based on the mass distribution of the connecting rod, joint friction, and flexibility effects. The free space motion process, the constrained surface contact process, and the load handling process are calculated by employing position control strategy, impedance control strategy, and force-position hybrid control strategy. Perform multi-arm cooperative motion planning, load distribution algorithm and collision detection.

8. The space assembly spacecraft scene modeling and dynamics simulation system according to claim 1, characterized in that, The ROS2 bridging unit adopts a hierarchical communication architecture, including: The underlying layer uses ROS2's DDS data distribution service to achieve real-time communication between simulation nodes; the upper layer uses the rosbridge_suite bridging component and WebSocket full-duplex asynchronous communication mechanism to achieve cross-platform remote connection with external algorithm platforms. The ROS2 bridging unit uses a TCP / IP protocol stack for network transmission; the ROS2 bridging unit publishes the encapsulated ROS2 standard messages according to the quality of service (QoS) policy configuration, which includes reliable transmission mode and best-effort transmission mode; the ROS2 bridging unit has a co-simulation interface with MATLAB and a co-simulation interface with Simulink.

9. A method for modeling and simulating the dynamics of a spacecraft assembly scene, employing the spacecraft assembly scene modeling and dynamics simulation system as described in any one of claims 1 to 8, characterized in that, include: The system calculates the orbital motion of the spacecraft under perturbation and outputs orbital data; calculates the attitude motion of the rigid body coupled with the flexible structure and outputs attitude data; calculates the forward and inverse kinematics and dynamics of the robotic arm and outputs joint state data and end-effector contact force data; couples and solves the orbital data, attitude data, and joint state data to obtain the spacecraft body pose and robotic arm end-effector pose data; drives the satellite platform model, truss structure model, and space robotic arm model to move according to the spacecraft body pose, and generates sensing data for the visible light camera model, time-of-flight camera model, lidar model, inertial measurement unit model, global navigation satellite system receiver model, and sun sensor model; The system receives control command topics published by an external algorithm platform, converts the control command topics into drive commands, and encapsulates the sensing data, the orbit data, the attitude data, the joint state data, and the end contact force data into ROS2 standard messages before publishing them to the external algorithm platform; it controls the operation mode of the simulation process, which includes manual control mode, program control mode, and batch processing mode.

10. An electronic device, characterized in that, The electronic device includes a processor coupled to a memory, the memory storing at least one computer program, which is loaded and executed by the processor to enable the electronic device to implement the space assembly spacecraft scene modeling and dynamic simulation method as described in claim 9.

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