A high-fidelity visual simulation system and method for landmark navigation in deep space exploration

Abstract

A high-fidelity visual simulation system and method for landmark navigation in deep space exploration. The high-fidelity visual simulation system includes a mission management and visualization subsystem, a 3D mesh editing and optimization subsystem, an environment configuration and update subsystem, a visual image rendering subsystem, and a data input / output subsystem. It is applied in the preliminary design and verification process of the deep space exploration visual navigation system, can provide high-quality simulation images for the whole stage, realize precise pinpoint landing in Mars exploration through the obtained simulation images, can render images of most deep space celestial bodies, and has expandability and adaptability to various deep space exploration tasks.

Description

Technical Field

[0001] The present invention relates to a high-fidelity visual simulation system and method for deep space exploration landmark navigation, belonging to the field of spacecraft autonomous navigation. Background Art

[0002] Autonomous navigation using visual information is a key approach to achieving precise landing targets on Mars. However, due to the remoteness of Mars and the high cost of developing rovers, a high-fidelity simulation environment must be established to simulate the image sequences during approach, descent, and landing. This allows for the pre-design and verification of visual navigation systems, accelerating development and reducing costs.

[0003] Semi-physical simulation can simulate a highly realistic system environment, including a scaled target celestial body model, sensor system, and control system. However, it also has many limitations, such as: (1) Due to the influence of system errors, it is impossible to accurately determine the true position and motion state of the probe relative to the target, making it difficult to effectively verify and correctly evaluate the navigation system; (2) The development of the simulation platform is difficult, costly, and time-consuming, and the operation is complex and requires calibration. In contrast, mathematical simulation can simulate the sequence of images required for navigation in each stage under a real-scale environment, and accurately provide reference information such as the true position and motion state of the probe relative to the target, thereby ensuring reliable verification and comprehensive evaluation of the navigation system. However, the existing image simulation systems still have some shortcomings, including: (1) the image quality cannot meet the requirements or the operating efficiency is low; (2) the maximum image resolution is low, and the sequence of images of the final landing stage cannot be simulated; (3) the system integration is not high, and there is a lack of a simple and unified user interface, which makes it inconvenient to use and difficult to operate. Summary of the Invention

[0004] The technical problem solved by the present invention is: in response to the shortcomings of the current existing technology, a high-fidelity visual simulation system for deep space exploration landmark navigation is proposed, which can provide high-fidelity simulation images at all stages for the design and verification of the visual navigation system, which is conducive to shortening its research and development cycle.

[0005] The present invention solves the above technical problems by the following technical solutions:

[0006] A high-fidelity visual simulation system for deep space exploration landmark navigation includes a task management and visualization subsystem, a 3D mesh editing and optimization subsystem, an environment configuration and update subsystem, a visual image rendering subsystem, and a data input and output subsystem, wherein:

[0007] Task Management and Visualization Subsystem: Used to manage and control image simulation tasks, and at the same time output the current running information on the display and interact with users;

[0008] 3D Mesh Editing and Optimization Subsystem: Used to edit and optimize the environmental element models participating in the simulation;

[0009] Environmental Configuration and Update Subsystem: Configure the corresponding simulation environment for specific image simulation tasks, and update it according to the input parameters to prepare for subsequent image rendering;

[0010] Visual Image Rendering Subsystem: Render the images observed by the camera according to the currently configured environmental parameters;

[0011] Data Input / Output Subsystem: Used to read external data to configure the parameters of the image simulation environment and the simulation process, and save the simulation results to the specified path.

[0012] The said Task Management and Visualization Subsystem includes a control module, a communication module, and a display module. The control module manages and controls according to the current image simulation task, interacts with users through the communication module, and displays the current task running information through the display module.

[0013] The said 3D Mesh Editing and Optimization Subsystem includes a model reading module, a model saving module, and a model editing and optimization module. The model reading module reads the environmental elements participating in the simulation, the model saving module saves the read model, and performs editing and optimization through the model editing and optimization module, and conducts user interaction and display through the Task Management and Visualization Subsystem.

[0014] The said Environmental Configuration and Update Subsystem includes a target celestial body model module, a detector model module, a stellar ephemeris module, a lighting module, a camera module, and a parameter setting module. The target celestial body model module and the detector model module perform model simulation according to the types of environmental elements read by the model reading module, configure the corresponding simulation environment for the current image simulation task through the stellar ephemeris module, the lighting module, and the camera module, and perform parameter update through the parameter setting module.

[0015] The said Visual Image Rendering Subsystem performs camera image rendering processing through a 3D image rendering module according to the environmental parameters configured by the Environmental Configuration and Update Subsystem.

[0016] The said Data Input / Output Subsystem includes a data reading module and a data saving module. The data reading module is used to read external data into the memory and process its format to prepare for the configuration of the simulation environment, and the data saving module is used to save the simulation results to the specified path according to the corresponding format.

[0017] A high-fidelity visual simulation method for deep space exploration landmark navigation, the steps are as follows:

[0018] (1) The task management and visualization subsystem reads the simulation configuration file through the data input and output subsystem and loads it into the computer memory, performs unified scheduling, sends all simulation configuration files to the corresponding subsystems for configuration, and displays the currently executed image simulation task and related parameters;

[0019] (2) Before image simulation, the three-dimensional grid editing and optimization subsystem receives the three-dimensional grid model of the target celestial body sent by the task management and visualization subsystem, characterizes its surface terrain features, interpolates the three-dimensional grid near the landing area and adds terrain details, sets the minimum spatial resolution required for image simulation at any position of the landing trajectory, and reduces the interpolated data to reduce the memory required by the simulation task hardware;

[0020] (3) The environment configuration and update subsystem receives the system parameters from the task management and visualization subsystem and the multi-scale grid model of the target celestial body output by the three-dimensional grid editing and optimization subsystem, configures the simulation environment, sets its initial attitude according to the direction of the spin axis of the target celestial body in the inertial space, adds a parallel light source and sets its direction and intensity, adds a camera and sets its internal parameter matrix, and sets the ambient light and shadow mode;

[0021] (4) The visual image rendering subsystem receives the state parameters from the task management and visualization subsystem and the configured simulation environment of the environment configuration and update subsystem, and starts the image rendering process, and loops through the image rendering process until a simulation image of the complete landing trajectory of the three-dimensional grid model of the target celestial body is obtained.

[0022] In the step (1), the simulation configuration file includes the detector trajectory, attitude sequence state parameters, light direction and intensity, and camera internal parameter matrix parameters, and is sent to the detector model module, parameter setting module, lighting module, and camera module respectively.

[0023] In the step (4), the specific image rendering process is as follows:

[0024] Among the state parameters sent by the task management and visualization subsystem, read a state node, call the environment configuration and update subsystem to update the position and attitude of the target celestial body and the position and attitude parameters of the detector, and call the three-dimensional image rendering engine to render the scene, and send the simulation image to the task management and visualization subsystem and the data input and output subsystem for real-time display and data saving.

[0025] The high-fidelity visual simulation system for deep-space exploration landmark navigation, which consists of a task management and visualization subsystem, a 3D mesh editing and optimization subsystem, an environment configuration and update subsystem, a visual image rendering subsystem, and a data input and output subsystem, can perform all-weather image simulation processing.

[0026] The advantages of the present invention compared with the prior art are as follows:

[0027] (1) A high-fidelity visual simulation system for deep-space exploration landmark navigation provided by the present invention designs a task management and visualization subsystem, which provides an integrated solution for the image simulation problem of deep-space exploration visual navigation. At the same time, a 3D mesh editing and optimization subsystem is designed to express the terrain features of the target surface at multiple scales, minimizing the data volume of environmental elements on the basis of meeting the minimum spatial resolution required for image simulation, reducing the requirements of the simulation system for computer hardware, and achieving the goal of performing image simulation in the whole stage by the VSS;

[0028] (2) The high-fidelity visual simulation system and simulation method provided by the present invention design a visual image rendering subsystem, taking into account environmental parameters such as lighting, atmosphere, albedo of the celestial body surface, and shadows, enabling the VSS to render images of most deep-space celestial bodies, thus having expandability and adaptability to various deep-space exploration tasks. Through clear and logical method steps, the complete acquisition of the rendered images can be achieved, assisting in obtaining the simulation images of the entire landing trajectory. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the high-fidelity visual simulation system provided by the invention;

[0030] Figure 2 Schematic diagram of the high-fidelity visual simulation method provided by the invention; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] A high-fidelity visual simulation system and method for deep-space exploration landmark navigation are applied in the preliminary design and verification process of a deep-space exploration visual navigation system, and can provide high-quality simulation images in the whole stage, namely the approach stage, the orbiting stage, the descent stage, and the landing stage. Precise landing at a fixed point on Mars can be achieved through the obtained simulation images. The high-fidelity visual simulation system for deep-space exploration landmark navigation mainly includes a task management and visualization subsystem, a 3D mesh editing and optimization subsystem, an environment configuration and update subsystem, a visual image rendering subsystem, and a data input and output subsystem, wherein:

[0032] Task management and visualization subsystem: used to manage and control image simulation tasks, and at the same time output the current running information on the display and interact with the user;

[0033] The task management and visualization subsystem includes a control module, a communication module, and a display module. The control module manages and controls according to the current image simulation task, interacts with users through the communication module, and displays the current task running information through the display module;

[0034] 3D mesh editing and optimization subsystem: used to edit and optimize the environmental element models participating in the simulation;

[0035] The 3D mesh editing and optimization subsystem includes a model reading module, a model saving module, and a model editing and optimization module. The model reading module reads the environmental elements participating in the simulation, the model saving module saves the read model, and performs editing and optimization through the model editing and optimization module, and performs user interaction and display through the task management and visualization subsystem;

[0036] Environmental configuration and update subsystem: Configure the corresponding simulation environment for a specific image simulation task and update it according to the input parameters to prepare for subsequent image rendering;

[0037] The environmental configuration and update subsystem includes a target celestial body model module, a detector model module, a stellar ephemeris module, a lighting module, a camera module, and a parameter setting module. The target celestial body model module and the detector model module perform model simulation according to the environmental element types read by the model reading module, configure the corresponding simulation environment for the current image simulation task through the stellar ephemeris module, the lighting module, and the camera module, and perform parameter update through the parameter setting module;

[0038] Visual image rendering subsystem: Render the image observed by the camera according to the currently configured environmental parameters;

[0039] The visual image rendering subsystem performs camera image rendering processing through the 3D image rendering module according to the environmental parameters configured by the environmental configuration and update subsystem;

[0040] Data input and output subsystem: used to read external data to configure the parameters of the image simulation environment and the simulation process, and save the simulation results to a specified path;

[0041] The data input and output subsystem includes a data reading module and a data saving module. The data reading module is used to read external data into the memory and perform format processing on it to prepare for the configuration of the simulation environment. The data saving module is used to save the simulation results to a specified path according to the corresponding format.

[0042] A high-fidelity visual simulation method for deep space exploration landmark navigation that can be adopted by a high-fidelity visual simulation system for deep space exploration landmark navigation is as follows:

[0043] (1) The task management and visualization subsystem reads the simulation configuration file by calling the data input and output subsystem, loads it into the computer memory, performs unified scheduling, sends all simulation configuration files to the corresponding subsystems for configuration, and displays the current image simulation task and related parameters.

[0044] The simulation configuration files include detector trajectories, attitude sequence state parameters, lighting direction and intensity, and camera internal parameter matrix parameters, which are sent to the detector model module, parameter setting module, lighting module, and camera module respectively.

[0045] (2) Before image simulation, the 3D mesh editing and optimization subsystem receives the 3D mesh model of the target celestial body sent by the task management and visualization subsystem, characterizes its surface terrain features, interpolates the 3D mesh near the landing area and adds terrain details, sets the minimum spatial resolution required for image simulation at any position of the landing trajectory, and reduces the interpolated data to reduce the memory required by the simulation task hardware.

[0046] (3) The environment configuration and update subsystem receives the system parameters from the task management and visualization subsystem and the multi-scale mesh model of the target celestial body output by the 3D mesh editing and optimization subsystem, configures the simulation environment, sets its initial attitude according to the direction of the spin axis of the target celestial body in the inertial space, adds a parallel light source and sets its direction and intensity, adds a camera and sets its internal parameter matrix, and sets the ambient light and shadow mode.

[0047] (4) The visual image rendering subsystem receives the state parameters from the task management and visualization subsystem and the configured simulation environment from the environment configuration and update subsystem, and starts the image rendering process, which loops until a simulation image of the complete landing trajectory of the 3D mesh model of the target celestial body is obtained. Specifically, the image rendering process is as follows:

[0048] From the state parameters sent by the task management and visualization subsystem, read a state node, call the environment configuration and update subsystem to update the position and attitude of the target celestial body and the position and attitude parameters of the detector, and call the 3D image rendering engine to render the scene. Send the simulation image to the task management and visualization subsystem and the data input and output subsystem for real-time display and data saving.

[0049] The high-fidelity visual simulation system for deep space exploration landmark navigation composed of the task management and visualization subsystem, 3D mesh editing and optimization subsystem, environment configuration and update subsystem, visual image rendering subsystem, and data input and output subsystem can perform all-weather image simulation processing.

[0050] The following is further described in combination with specific embodiments:

[0051] In the current embodiment, as Figure 1 、 Figure 2 shown, for the design and verification of the deep space exploration visual navigation system, considering its urgent need for high-quality, full-stage simulation images, a high-fidelity visual simulation system VSS is proposed. Adhering to the idea of modular design, a simulation system including five subsystems, namely, a task management and visualization subsystem, a 3D mesh editing and optimization subsystem, an environment configuration and update subsystem, a visual image rendering subsystem, and a data input / output subsystem, is designed. Using VSS, high-fidelity simulation images for the full stage can be provided for the design and verification of the visual navigation system. Specifically:

[0052] (1) Task Management and Visualization Subsystem

[0053] It includes a control module, a communication module, and a display module, which are used to manage and control image simulation tasks, and at the same time output the current running information on the display and interact with the user.

[0054] (2) 3D Mesh Editing and Optimization Subsystem

[0055] It includes a model reading module, a model saving module, a model editing and optimization module, a communication module, and a display module, which are used to edit and optimize environmental elements participating in the simulation, such as the target celestial body model and the detector model, so as to improve the quality of the simulation image and reduce the system's requirements for computer hardware.

[0056] (3) Environment Configuration and Update Subsystem

[0057] It includes a target celestial body model (including an atmosphere model), a detector model, a stellar ephemeris module, a lighting module, a camera module, a communication module, a display module, and a parameter setting module, which are used to configure the corresponding simulation environment for a specific task and update it according to the input parameters, so as to prepare for the subsequent image rendering subsystem.

[0058] (4) Visual Image Rendering Subsystem

[0059] It includes a target celestial body model (including an atmosphere model), a detector model, a stellar ephemeris module, a lighting module, a camera module, a communication module, a display module, and a 3D image rendering module, which are used to render the image observed by the camera according to the currently configured environmental parameters.

[0060] (5) Data Input / Output Subsystem

[0061] It includes a data reading and saving module and corresponding formats, a data analysis and processing module, a communication module, and a display module, which are used to read external data to configure the parameters of the image simulation environment and the simulation process, and save the simulation results to a specified path.

[0062] The high-fidelity visual simulation method proposed according to the above system is as follows:

[0063] In the first step, the task management and visualization subsystem reads the simulation configuration file by calling the data input / output subsystem and loads it into the computer memory. This configuration file includes: state parameters such as the trajectory and attitude sequence of the detector, system parameters such as the 3D mesh models of the target celestial body and the detector, the target spin axis / period, the 3D position of the landing point, the illumination direction / intensity, and the internal parameter matrix of the navigation camera. These data will be uniformly scheduled by the task management and visualization subsystem and sent to other subsystems to achieve specific functions, and at the same time, the currently executed tasks and related parameters will be displayed on the output device to facilitate the interaction between the operator and the system;

[0064] In the second step, before implementing the image simulation, the 3D mesh editing and optimization subsystem receives the 3D mesh model of the target celestial body from the task management and visualization subsystem, and performs multi-scale expression of its surface terrain features, performs multi-scale interpolation on the 3D mesh near the landing area and adds terrain details to make it meet the minimum spatial resolution required for image simulation at any position of the landing trajectory, and at the same time minimizes the interpolation data to reduce the requirements of the simulation system for computer hardware such as memory, CPU, and GPU;

[0065] In the third step, the environment configuration and update subsystem receives the system parameters from the task management and visualization subsystem and the multi-scale mesh model of the target celestial body output by the 3D mesh editing and optimization subsystem, and starts to configure the simulation environment, that is: set its initial attitude according to the direction of the spin axis of the target celestial body in the inertial space, add a parallel light source and set its direction and intensity, add a camera and set its internal parameter matrix, set the ambient light, shadow mode, etc.;

[0066] In the fourth step, the visual image rendering subsystem receives the state parameters from the task management and visualization subsystem and the simulation environment configured by the environment configuration and update subsystem, and starts the image rendering process. This subsystem first reads a state node from the state parameter sequence, then calls the environment configuration and update subsystem to update parameters such as the position and attitude (spin angle) of the target celestial body and the position and attitude of the detector, then calls the 3D image rendering engine to render the scene, and finally sends the simulation image to the task management and visualization subsystem and the data input / output subsystem for real-time display and data saving. Repeating the above process can obtain the simulation images of the entire landing trajectory.

[0067] A high-fidelity visual simulation system and method for deep space exploration landmark navigation can achieve multi-scale expression of the terrain features of the target surface, minimize the data volume of environmental elements, reduce the requirements of the simulation system for computer hardware, and have scalability and adaptability to various deep space exploration tasks, and can render images of most deep space celestial bodies.

[0068] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0069] The content not detailedly described in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. A high-fidelity visual simulation system for deep space exploration landmark navigation, characterized in that: It includes a task management and visualization subsystem, a 3D mesh editing and optimization subsystem, an environment configuration and update subsystem, a visual image rendering subsystem, and a data input / output subsystem, where: The task management and visualization subsystem: used to manage and control image simulation tasks, and at the same time output the current running information on the display and interact with the user; The 3D mesh editing and optimization subsystem: used to edit and optimize the environmental element models participating in the simulation; The environment configuration and update subsystem: configures the corresponding simulation environment for specific image simulation tasks and updates it according to the input parameters to prepare for subsequent image rendering; The visual image rendering subsystem: renders the images observed by the camera according to the currently configured environmental parameters; The data input / output subsystem: used to read external data to configure the parameters of the image simulation environment and the simulation process, and save the simulation results to the specified path; The task management and visualization subsystem includes a control module, a communication module, and a display module. The control module manages and controls according to the current image simulation task, interacts with the user through the communication module, and displays the current task running information through the display module; The 3D mesh editing and optimization subsystem includes a model reading module, a model saving module, and a model editing and optimization module. The model reading module reads the environmental elements participating in the simulation, the model saving module saves the read models, and performs editing and optimization through the model editing and optimization module, and performs user interaction and display through the task management and visualization subsystem; The environment configuration and update subsystem includes a target celestial body model module, a detector model module, a stellar ephemeris module, a lighting module, a camera module, and a parameter setting module. The target celestial body model module and the detector model module perform model simulation according to the types of environmental elements read by the model reading module, configure the corresponding simulation environment for the current image simulation task through the stellar ephemeris module, the lighting module, and the camera module, and perform parameter update through the parameter setting module; The visual image rendering subsystem performs camera image rendering processing through a 3D image rendering module according to the environmental parameters configured by the environment configuration and update subsystem; The data input / output subsystem includes a data reading module and a data saving module. The data reading module is used to read external data into the memory and perform format processing on it to prepare for the configuration of the simulation environment. The data saving module is used to save the simulation results to the specified path according to the corresponding format; The following interaction steps are included among the foregoing subsystems: (1) The task management and visualization subsystem reads the simulation configuration file by calling the data input / output subsystem and loads it into the computer memory, performs unified scheduling, sends all simulation configuration files to the corresponding subsystems for configuration, and displays the currently executed image simulation task and related parameters; (2) Before performing image simulation, the three-dimensional mesh editing and optimization subsystem receives the three-dimensional mesh model of the target celestial body sent by the mission management and visualization subsystem, characterizes its surface terrain features, interpolates the three-dimensional mesh near the landing area and adds terrain details, sets the minimum spatial resolution required for image simulation at any position on the landing trajectory, and reduces the interpolated data to reduce the memory required by the simulation task hardware; (3) The environment configuration and update subsystem receives the system parameters from the mission management and visualization subsystem and the multi-scale mesh model of the target celestial body output by the three-dimensional mesh editing and optimization subsystem, configures the simulation environment, sets its initial attitude according to the direction of the spin axis of the target celestial body in the inertial space, adds a parallel light source and sets its direction and intensity, adds a camera and sets its internal parameter matrix, and sets the ambient light and shadow mode; (4) The visual image rendering subsystem receives the state parameters from the mission management and visualization subsystem and the simulation environment configured by the environment configuration and update subsystem, and starts the image rendering process, and loops through the image rendering process until the simulation image of the complete landing trajectory of the three-dimensional mesh model of the target celestial body is obtained; In step (1), the simulation configuration file includes the detector trajectory, attitude sequence state parameters, light direction and intensity, and camera internal parameter matrix parameters, which are sent to the detector model module, parameter setting module, lighting module, and camera module respectively; In step (4), the specific image rendering process is as follows: From the state parameters sent by the mission management and visualization subsystem, read a state node, call the environment configuration and update subsystem to update the position and attitude of the target celestial body and the position and attitude parameters of the detector, and call the three-dimensional image rendering engine to render the scene, and send the simulation image to the mission management and visualization subsystem and the data input / output subsystem for real-time display and data storage; The high-fidelity visual simulation system for deep space exploration landmark navigation composed of the mission management and visualization subsystem, three-dimensional mesh editing and optimization subsystem, environment configuration and update subsystem, visual image rendering subsystem, and data input / output subsystem can perform all-weather image simulation processing.

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