A method and system for rapid simulation of spacecraft system based on closed loop of image model

Abstract

A method and system for rapid simulation of a spacecraft system based on an image model closed loop, comprising: establishing a three-dimensional digital model of a spacecraft, wherein the size of the spacecraft is adjustable and the characteristic load of the spacecraft is configurable; setting the space environment and environmental information of the simulation scene; retrieving the observation area according to the sensor installation configuration to obtain an ideal image of the observation area; establishing an image sensor model to simulate the imaging effect of the optical system and degrade the ideal image of the observation area; degrading the optical simulation image by the circuit system to obtain an observed simulated degraded image; processing the observed simulated degraded image; simulating the digital interface of the imaging sensor, saving and generating the simulation image, and saving or transmitting the data that meets the electrical characteristics and timing characteristics of the sensor electronic circuit interface to a subsequent processing unit; connecting the simulation closed loop of the spacecraft control system through a standardized data interface, and solving, storing and displaying the simulation results through the master control scheduling.

Description

Technical Field

[0001] The invention relates to a method and system for rapid simulation of a spacecraft system based on an image model closed loop, and belongs to the technical field of spacecraft simulation. Background Art

[0002] With the diversification of detection targets and requirements, spacecraft control systems are becoming increasingly complex. In addition to conventional attitude sensors, many spacecraft are also equipped with image sensors with autonomous perception and control capabilities, which are suitable for different needs such as space patrol, relative measurement, autonomous navigation, and environmental perception. The perception categories are diverse and the scenes are complex. During the ground development stage, it is necessary to introduce the perception image into the control system and conduct closed-loop simulation verification of perception fusion algorithms such as image processing, navigation, and obstacle recognition. However, ground physical tests are difficult to simulate the real space environment, and the on-orbit measured data is limited. In order to enhance the test coverage and reduce the test cost, it is necessary to model the perception imaging link through digital simulation and generate image data that can be introduced into the closed loop of the control system. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and solve the problem of image perception verification of spacecraft control systems.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A method for rapid simulation of a spacecraft system based on a closed loop of an image model, comprising:

[0006] Establish a three-dimensional digital model of the spacecraft, the size of the spacecraft can be adjusted, and the characteristic load of the spacecraft can be configured; set the simulation scene space environment and environmental information;

[0007] According to the sensor installation configuration, the observation area is retrieved to obtain the ideal image of the observation area; an image sensor model is established to simulate the imaging effect of the optical system, and the ideal image of the observation area is degraded to obtain the observed optical simulation image; the circuit system degrades the optical simulation image to obtain the observed simulated degraded image;

[0008] Processing the observed simulated degraded image;

[0009] Simulate the digital interface of the imaging sensor, save and generate the simulated image, and save or transmit the generated image to the subsequent processing unit in accordance with the data of the electrical characteristics and timing characteristics of the sensor electronic circuit interface;

[0010] Through the standardized data interface, the spacecraft control system simulation closed loop is connected, and the solution, simulation result storage and display are carried out through the general control scheduling.

[0011] Preferably, the spacecraft includes one or more combinations of near-Earth satellites, space stations, and deep space probes.

[0012] Preferably, the analog sensor uses a filtering algorithm to preprocess the simulated image, and then performs image feature extraction, target / obstacle detection, and relative pose estimation.

[0013] Preferably, the orthophoto of the visible range in the simulation scene and the albedo of each point in the area are retrieved according to the installation position, field of view range and imaging resolution of the image sensor.

[0014] Preferably, the degradation effect of the simulated optical simulation system on the ideal image includes: observation range deviation caused by focal length deviation of the optical system; image blur degradation caused by focal length, entrance pupil position, entrance pupil diameter, object distance, optical system modulation transfer function, and dispersion factors; image blur caused by high-speed movement and vibration of the platform; image degradation caused by optical system transmittance, optical system spectral range, and center wavelength drift; optical system distortion; stray light interference, that is, image brightness changes caused when the incident direction of sunlight is greater than the solar suppression angle of the optical system.

[0015] Preferably, the analog circuit system produces a degradation effect on the optical simulation image, and the degradation types include: simulation of electrical characteristics of imaging devices; influence of exposure mode and integration time on imaging; simulation of influence of ambient temperature on imaging; system noise simulation; and image data transmission bit error rate simulation.

[0016] A spacecraft system rapid simulation system based on an image model closed loop, comprising: a spacecraft and space environment modeling module, an image sensor imaging simulation module, an image data processing simulation module, an imaging sensor digital interface simulation module, and a simulation scheduling and storage display module;

[0017] The spacecraft and space environment modeling module is used to build a three-dimensional digital model of the spacecraft, with adjustable spacecraft size and configurable characteristic payload; and to set the simulation scene space environment and environmental information;

[0018] Image sensor imaging simulation module, used to retrieve the observation area according to the sensor installation configuration to obtain the ideal image of the observation area; used for optical system imaging simulation and circuit system imaging simulation;

[0019] Image data processing simulation module, used for image processing;

[0020] An imaging sensor digital interface simulation module is used for simulating the imaging sensor digital interface, saving and generating a simulation image, and saving or transmitting the generated image to a subsequent processing unit with data that conforms to the electrical characteristics and timing characteristics of the sensor electronic circuit interface;

[0021] The simulation scheduling and storage display module is connected to the spacecraft control system simulation closed loop through a standardized data interface to perform calculations in each module and store and display simulation results.

[0022] Preferably, the orthophoto of the visible range in the simulation scene and the albedo of each point in the area are retrieved according to the installation position, field of view range and imaging resolution of the image sensor.

[0023] Preferably, in the optical system imaging simulation, the degradation effect of the optical simulation system on the ideal image is simulated, and the degradation types include: observation range deviation caused by the focal length deviation of the optical system; image blur degradation caused by focal length, entrance pupil position, entrance pupil diameter, object distance, optical system modulation transfer function, and dispersion factors; image blur caused by high-speed movement and vibration of the platform; image degradation caused by optical system transmittance, optical system spectral range, and central wavelength drift; optical system distortion; stray light interference, that is, the change in image brightness when the incident direction of sunlight is greater than the solar suppression angle of the optical system.

[0024] Preferably, in the circuit system imaging simulation, the simulated circuit system produces a degradation effect on the optical simulation image, and the degradation types include: simulation of the electrical characteristics of the imaging device; the influence of the exposure method and the integration time on the imaging; simulation of the influence of the ambient temperature on the imaging; system noise simulation; and image data transmission bit error rate simulation.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention has an imaging sensor parameter configuration interface, which can configure internal and external parameters such as sensor installation, field of view, focal length, sampling period, etc., and can be extended to various imaging sensors to meet multi-task requirements;

[0027] (2) The present invention can simulate the optical system model and the circuit system model to degrade the perceived image, approximate the measurement characteristics of the real sensor, and simulate various types of noise and environmental interference to verify the robustness of the perception algorithm;

[0028] (3) The present invention establishes a digital interface simulation for imaging sensors, which can not only save simulated images, but also save or transmit the generated images to subsequent processing units in accordance with the electrical characteristics and timing characteristics of the sensor electronic circuit interface, support multi-channel output, and can be quickly introduced into the closed loop of spacecraft control system simulation;

[0029] (4) The present invention connects the spacecraft control system simulation closed loop through a standardized data interface to form an image in-loop control data flow, which facilitates the joint simulation of image processing related algorithms and other control processing algorithms to fully verify the control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure is a flow chart of the steps of the method of the present invention. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] A fast simulation method for spacecraft system based on closed loop of image model, such as Figure 1 As shown, the specific implementation steps are as follows:

[0033] (1) Spacecraft and space environment modeling: Taking near-Earth satellites, space stations, and deep space probes (landers) as representatives, a three-dimensional digital model of the spacecraft is established. The size of the spacecraft can be adjusted, and characteristic payloads such as sails and antennas can be configured. According to different mission stages and verification requirements such as near-Earth orbit, space rendezvous, deep space cruise, planetary landing, and star surface inspection, the simulation scene space environment is set, including characteristic environments such as starry sky background, planetary background, and extraterrestrial star surface. The scene lighting and other environmental information are set according to the mission time and ephemeris calculation results. The position and attitude information of the spacecraft in the simulation scene is driven by the calculation data from the environment and dynamics simulation system. According to the vibration parameter configuration, the three-axis flutter effect can be mixed to simulate the impact of installation errors on the imaging of image sensors under high-speed motion.

[0034] (2) Imaging simulation of image sensors: The image sensor retrieves the observation area based on the position and attitude information of the spacecraft and the installation configuration of the sensor on the spacecraft. The data returned in the field of view include the orthographic image and the albedo of each point in the area, and the ideal image of the observation area is obtained. An image sensor model is established to simulate the imaging effect. The ideal image is degraded according to the optical system model and the circuit system model to obtain the simulated image observed by the landing navigation sensor.

[0035] (3) Image data processing simulation: Image data processing simulates the image processing function inside the sensor. According to the actual function of the image sensor to be simulated, relevant image processing algorithms are integrated, including the use of filtering algorithms for simulation image preprocessing, image feature extraction, target / obstacle detection, relative pose estimation, etc.

[0036] (4) Imaging sensor digital interface simulation: Imaging sensor digital interface simulation, the simulation image and the image data processing algorithm calculation results are saved or transmitted to the subsequent processing unit by the simulation scheduling and storage display module as data that conforms to the electrical characteristics and timing characteristics of the sensor electronic circuit interface;

[0037] (5) Simulation scheduling and storage display: Through standardized data interfaces, the spacecraft control system simulation closed loop is connected, including the environment and spacecraft dynamics simulation module, image sensor model, spacecraft controller model, and non-image sensor and actuator models, to form the image control data flow in the loop. Through simulation scheduling, each module is solved according to the solution order and solution cycle, and the simulation results are stored and displayed according to user needs.

[0038] Furthermore, in step (2), the imaging simulation of the image sensor includes the following steps:

[0039] (2.1) Observation area retrieval: According to the installation position, field of view interval, and imaging resolution of the image sensor, the orthophoto image of the visible range in the simulation scene and the albedo of each point in the area are retrieved. The input data includes: the three-dimensional coordinates of the optical center of the image sensor in the reference coordinate system, the vector direction of the main optical axis in the reference coordinate system, and the sensor field of view angle; using the deep search method, the possible intersection points of the ray starting from the pixel of the image and passing through the optical center of the sensor and the object are estimated, and the intersection point closest to the optical center is selected to form an image in the sensor; according to the simulation requirements, three imaging models can be used: hemispherical reflection model, Lommel-Seeliger reflection model, and Lambert-Lommel-Seeliger reflection model;

[0040] (2.2) Optical system imaging simulation: Load the optical system simulation configuration parameters to simulate the degradation effect of the optical simulation system on the ideal image; the degradation types include: ① the observation range deviation caused by the focal length deviation of the optical system; ② the image blur degradation caused by factors such as focal length, entrance pupil position, entrance pupil diameter, object distance, optical system modulation transfer function, dispersion, etc.; ③ the image blur caused by high-speed movement and vibration of the platform; ④ the image degradation caused by factors such as optical system transmittance, optical system spectral range, and central wavelength drift; ⑤ optical system distortion (including principal point displacement and radial distortion); ⑥ stray light interference, that is, the image brightness change caused when the incident direction of sunlight is greater than the solar suppression angle of the optical system (light shield);

[0041] (2.3) Circuit system impact simulation: Load the circuit system simulation configuration parameters to simulate the degradation effect of the circuit system on the optical simulation image; the degradation types include: ① simulation of the electrical characteristics of the imaging device; ② the impact of the exposure method and integration time on the imaging; ③ simulation of the impact of the ambient temperature on the imaging; ④ system noise simulation; ⑤ image data transmission bit error rate simulation;

[0042] Furthermore, in step (3), the image data processing simulation may include algorithms such as image preprocessing function simulation, image feature extraction and detection algorithm, image feature matching, and relative pose estimation according to the specific simulation task verification requirements;

[0043] In the step (4), the imaging sensor digital interface simulation includes a simulation software interface and a hardware data communication interface; the software interface uses the interface function specification of the dynamic link library and the data retrieval format of the external simulation system; the hardware interface uses a network interface to transmit data using the TCP protocol.

[0044] In the step (5), the simulation scheduling and storage display work mode is: connecting the environment and dynamics simulation system, the spacecraft onboard computer processing simulation system, and the image sensor model simulation system constructed in steps (2), (3), and (4) to form a control system closed loop, triggering the image simulation and image processing links with instructions, and feeding back the image simulation results or image processing results to the onboard computer and the master control storage module, forming a complete spacecraft control system simulation closed loop that introduces the image.

[0045] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

[0046] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may 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 modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for rapid simulation of a spacecraft system based on a closed loop of an image model, characterized in that: include: Establish a three-dimensional digital model of the spacecraft, the size of the spacecraft can be adjusted, and the characteristic load of the spacecraft can be configured; Set the simulation scene space environment and environmental information; According to the sensor installation configuration, the observation area is retrieved to obtain the ideal image of the observation area; an image sensor model is established to simulate the imaging effect of the optical system, and the ideal image of the observation area is degraded to obtain the observed optical simulation image; the circuit system degrades the optical simulation image to obtain the observed simulated degraded image; Processing the observed simulated degraded image; The analog imaging sensor digital interface stores or transmits the processed observed simulated degraded image to a subsequent processing unit as data that conforms to the electrical characteristics and timing characteristics of the sensor electronic circuit interface; Through standardized data interfaces, the spacecraft systems are connected to form a closed-loop simulation, and through master control scheduling, solutions are solved, and simulation results are stored and displayed.

2. The method for rapid simulation of a spacecraft system according to claim 1, characterized in that: The spacecraft includes one or more combinations of near-Earth satellites, space stations, and deep-space probes.

3. The method for rapid simulation of a spacecraft system according to claim 1, characterized in that: The analog sensor uses a filtering algorithm to preprocess the simulated image, and then performs image feature extraction, target / obstacle detection, and relative pose estimation.

4. The method for rapid simulation of a spacecraft system according to claim 1, characterized in that: According to the installation position, field of view and imaging resolution of the image sensor, the orthophoto image of the visible range in the simulation scene and the albedo of each point in the area are retrieved.

5. The method for rapid simulation of a spacecraft system according to claim 1, characterized in that: The degradation effects of the simulated optical simulation system on the ideal image include: observation range deviation caused by focal length deviation of the optical system; image blur degradation caused by focal length, entrance pupil position, entrance pupil diameter, object distance, optical system modulation transfer function, and dispersion factors; image blur caused by high-speed platform movement and vibration; image degradation caused by optical system transmittance, optical system spectral range, and center wavelength drift; optical system distortion; stray light interference, that is, the change in image brightness when the incident direction of sunlight is greater than the solar suppression angle of the optical system.

6. The method for rapid simulation of a spacecraft system according to claim 1, characterized in that: The analog circuit system produces degradation effects on the optical simulation image. The degradation types include: simulation of the electrical characteristics of the imaging device; the impact of exposure mode and integration time on imaging; simulation of the impact of ambient temperature on imaging; simulation of system noise; and simulation of the bit error rate of image data transmission.

7. A spacecraft system rapid simulation system based on image model closed loop, characterized in that: include: Spacecraft and space environment modeling module, image sensor imaging simulation module, image data processing simulation module, imaging sensor digital interface simulation module, simulation scheduling and storage display module; The spacecraft and space environment modeling module is used to build a three-dimensional digital model of the spacecraft, with adjustable spacecraft size and configurable characteristic payload; and to set the simulation scene space environment and environmental information; Image sensor imaging simulation module, used to retrieve the observation area according to the sensor installation configuration to obtain the ideal image of the observation area; used for optical system imaging simulation and circuit system imaging simulation; Image data processing simulation module, used for image processing; An imaging sensor digital interface simulation module is used for imaging sensor digital interface simulation, and saves or transmits the image processed by the image data processing simulation module to a subsequent processing unit as data that conforms to the electrical characteristics and timing characteristics of the sensor electronic circuit interface; The simulation scheduling and storage display module connects the spacecraft system through a standardized data interface to form a closed-loop simulation, and performs calculations on each module and stores and displays simulation results.

8. The spacecraft system rapid simulation system according to claim 7, characterized in that: According to the installation position, field of view and imaging resolution of the image sensor, the orthophoto image of the visible range in the simulation scene and the albedo of each point in the area are retrieved.

9. The spacecraft system rapid simulation system according to claim 7, characterized in that: In the optical system imaging simulation, the degradation effect of the optical simulation system on the ideal image is simulated. The degradation types include: observation range deviation caused by the focal length deviation of the optical system; image blur degradation caused by focal length, entrance pupil position, entrance pupil diameter, object distance, optical system modulation transfer function, and dispersion factors; image blur caused by high-speed platform movement and vibration; image degradation caused by optical system transmittance, optical system spectral range, and central wavelength drift; optical system distortion; stray light interference, that is, the change in image brightness when the incident direction of sunlight is greater than the solar suppression angle of the optical system.

10. The spacecraft system rapid simulation system according to claim 7, characterized in that: In the circuit system imaging simulation, the simulated circuit system produces degradation effects on the optical simulation image. The degradation types include: simulation of the electrical characteristics of the imaging device; the influence of the exposure method and integration time on imaging; simulation of the influence of ambient temperature on imaging; system noise simulation; and image data transmission bit error rate simulation.

Images