Method and device for measuring and calibrating attitude of spacecraft ground full-physical simulation system

Abstract

The invention discloses a spacecraft ground full-physical simulation system attitude measurement calibration method and device, and belongs to the technical field of spacecraft measurement. The objective of the invention is to solve the problem of real-time measurement of the attitude of a spacecraft ground full-physical simulation system. A cross laser generator, a concentric circular ring coding target, a monocular camera and a processing unit are fixedly installed on a three-axis air bearing table, the monocular camera is fixedly arranged on one side of the cross laser generator, and the monocular camera is connected with the processing unit. Laser emitted by the cross laser generator vertically irradiates the plane of the concentric circular ring coding target, the concentric circular ring coding target adopts a concentric circular ring coding array design, and each group of concentric circular ring coding units is composed of a plurality of hollow circular rings which are concentrically arranged. And generating a code ID of each group of concentric circular ring coding units through radius proportion combination of the adjacent hollow circular rings. The method is stable in long-term operation precision, greatly reduces the workload of element installation and calibration, does not need a complex field calibration process, and is flexible in installation and deployment.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft measurement technology, specifically relating to a method and apparatus for attitude measurement and calibration of a spacecraft ground-based full physical simulation system. Background Technology

[0002] Currently, three-degree-of-freedom air-bearing tables have become the main ground simulation equipment. Existing measurement methods for three-axis air-bearing tables require the addition of complex mechanical and sensor systems, resulting in complex structures.

[0003] The invention patent application number 202211330537.5, entitled "A Monocular Vision Attitude Measurement Device and Working Method Suitable for Air-Floating Platforms," ​​proposes a monocular vision attitude measurement device and working method suitable for air-floating platforms. This method uses a cooperative target made of an infrared lamp array to provide a group of feature points; then, a camera system is used to acquire image information; the image information is sent to a computer on the platform for image preprocessing to extract the coordinates of the feature points in the pixel coordinate system, and further, the SoftPOSIT algorithm is used to iteratively solve for the attitude information of the air-floating platform; finally, the attitude information is sent to a host computer for real-time display via a communication system. However, the SoftPOSIT algorithm used in this method is relatively complex and computationally intensive. Summary of the Invention

[0004] The problem to be solved by this invention is to achieve real-time and accurate measurement of the attitude of a spacecraft ground-based full physical simulation system, and to propose a method and device for attitude measurement and calibration of a spacecraft ground-based full physical simulation system.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A spacecraft ground-based full physical simulation system attitude measurement and calibration device includes a cross laser generator, a concentric ring coded target, a monocular camera, and a processing unit;

[0007] The cross laser generator, concentric ring coded target, monocular camera, and processing unit are fixedly mounted on a three-axis air-bearing platform. The monocular camera is fixedly set on one side of the cross laser generator and connected to the processing unit. The laser emitted by the cross laser generator is perpendicularly irradiated onto the plane of the concentric ring coded target. The concentric ring coded target adopts a concentric ring coded array design. Each group of concentric ring coded units consists of several concentrically arranged hollow rings. The coded ID of each group of concentric ring coded units is generated by combining the radius ratios of adjacent hollow rings.

[0008] Furthermore, the center point of each set of concentric ring coding units of the concentric ring coding target is calibrated by a coordinate measuring machine to obtain the three-dimensional coordinates in the world coordinate system, and pre-stored in the coding library of the processing unit.

[0009] Furthermore, a rigid transformation model of the laser plane of the cross-shaped laser emitter is constructed, including the first laser plane. Second laser plane ;

[0010] The normal vector of the first laser plane is The center point of the cross laser generator installation The plane equation of the first laser plane is: , The coordinates of a three-dimensional point in the three-axis air-bearing platform body coordinate system;

[0011] The normal vector of the second laser plane is The center point of the cross laser generator installation The equation of the plane is ;

[0012] Set the inherent constraints as follows ,and ;

[0013] Let the initial rotation matrix from the body coordinate system to the world coordinate system of the three-axis air-bearing platform be: Initial translation vector The equations for transforming the two laser planes to the world coordinate system are:

[0014]

[0015] in, For the first in the world coordinate system A laser plane equation, Let j be the normal vector of the j-th laser plane. These are the coordinates of a three-dimensional point in the world coordinate system.

[0016] Furthermore, the laser plane intersection constraint equation is constructed, and the calculation expression is as follows:

[0017]

[0018] in, For monocular camera projection mapping, For the first The equation of the intersection line between the laser plane and the target plane Term coefficient, No. The equation of the intersection line between the laser plane and the target plane Term coefficient, No. The constant term coefficients of the equation of the intersection line between the laser plane and the target plane. World coordinate system target plane Points on For the first The pixel straight line equation of the center line of the bright band Term coefficient, For the first The pixel straight line equation of the center line of the bright band Term coefficient, For the first The constant term coefficients of the pixel straight line equation for the center line of the bright band. A point in a pixel coordinate system.

[0019] Furthermore, an online self-calibration mechanism based on a sliding window is set up to utilize the absolute position reference provided by the concentric ring coded target, and jointly solve the installation center point of the cross laser generator, the normal vector of the first laser plane and the normal vector of the second laser plane with the pose parameters of the three-axis air-bearing platform to compensate for parameter drift in real time.

[0020] A method for attitude measurement and calibration of a spacecraft ground-based full physical simulation system includes the following steps:

[0021] S1. Install the attitude measurement and calibration device for a spacecraft ground-based full physical simulation system;

[0022] S2. Perform a one-time pre-calibration and initialization on the attitude measurement and calibration device of the spacecraft ground full physical simulation system;

[0023] S3. The monocular camera acquires planar images of the concentric ring coded target in real time and transmits them synchronously to the processing unit for image preprocessing;

[0024] S4. For the preprocessed image obtained in step S3, identify the world coordinates and corresponding pixel coordinates of the centers of multiple concentric rings, and use the least squares method to fit the laser bright band region in the preprocessed image to obtain the pixel line equations of the center lines of the two bright bands.

[0025] S5. Based on the world coordinates and corresponding pixel coordinates of the multiple sets of concentric ring centers obtained in step S4, solve for the initial pose of the three-axis air-bearing platform;

[0026] S6. Online self-calibration of the attitude of the spacecraft ground-based full physical simulation system is performed using an online self-calibration mechanism based on a sliding window;

[0027] S7. Iterate the online self-calibration results of the spacecraft ground-based full physical simulation system attitude obtained in step S6 to achieve continuous real-time attitude measurement and online self-calibration.

[0028] Furthermore, the specific implementation method of step S2 includes the following steps:

[0029] S2.1. For a monocular camera, solve for the camera intrinsic parameter matrix using Zhang's calibration method. and distortion coefficient;

[0030] S2.2. Rigid body transformation model of the laser plane based on the cross laser emitter, calibrating the fixed transformation relationship between the camera coordinate system and the three-axis air-bearing platform body coordinate system. , ,in, This is the rotation matrix for transforming from the body coordinate system to the camera coordinate system. This is the translation vector used to transform the body coordinate system to the camera coordinate system;

[0031] S2.3. Generate the code for each group of concentric ring coding units for the concentric ring coding target, and calibrate the world coordinates of the center of each group of concentric rings using a coordinate measuring machine. Establish the correspondence between the encoding and world coordinates.

[0032] Furthermore, the image preprocessing method in step S3 is to use an improved Sauvola algorithm to perform adaptive binarization of the planar image of the concentric ring coded target.

[0033] Furthermore, the specific implementation method of step S6 includes the following steps:

[0034] S6.1. Maintain a sliding window of fixed length, and include the initial pose of the three-axis air-bearing platform of the current frame, the world coordinates and corresponding pixel coordinates of the centers of multiple concentric rings, and the equation of the laser bright band line into the window. If the window is full, remove the earliest frame.

[0035] S6.2. Integrate the fixed parameters of the cross laser generator to be calibrated online with the pose parameters of the air-bearing platform in all frames within the window into a global optimization unknown vector. :

[0036]

[0037] in, For the first The three-axis Euler angles of the three-axis air-bearing platform. For the first Translation vector of the origin of the three-axis air-bearing platform in the world coordinate system. This represents the total number of frames within the sliding window.

[0038] Satisfying orthogonal constraints Unit vector constraint ;

[0039] S6.3. Establish a dual-constraint joint optimization objective function to ensure that the optimization result simultaneously satisfies the geometric constraints of the intersection line between the absolute position reference and the laser plane:

[0040]

[0041] in, No. Frame, First The intersection line of the laser plane and the target plane in the world coordinate system. For the first Frame, First A laser-bright band of pixels in a straight line. These are the weighting coefficients. This represents the number of valid ring groups extracted from a single image frame. For the first in the target The known coordinates of the center of the annulus in the world coordinate system. For the first The first frame extracted from the image Subpixel-level center coordinates of the annulus;

[0042] S6.4. Using the LM nonlinear optimization algorithm, substituting the dual-constraint joint optimization objective function and constraints, the unknown vector is solved iteratively. The residual change must be less than 1e. -6 Alternatively, it can stop iterating after reaching the maximum number of iterations.

[0043] Furthermore, the specific implementation method of step S7 is to fix the laser parameters after this calibration as the initial optimization value for the next round of process step S6; and to use the optimal pose output this time as the auxiliary reference for the initial pose of the next round of process step S5, returning to the image acquisition stage of step S3 to complete the closed loop of the whole process and realize continuous real-time attitude measurement and online self-calibration.

[0044] The beneficial effects of this invention are:

[0045] The attitude measurement and calibration device for a spacecraft ground-based full physical simulation system described in this invention features a highly robust target with absolute position reference. The concentric ring coded target can provide global absolute coordinates corresponding to a unique ID, solving the problems of traditional passive targets having no reference and being prone to misidentification. It has strong rotation / scale invariance and is resistant to partial occlusion, providing a stable global reference for the system.

[0046] The attitude measurement and calibration device for a spacecraft ground-based full physical simulation system described in this invention has the capability of online self-calibration of all parameters, eliminating the need for offline calibration of laser parameters. It incorporates the installation position and laser plane normal vector into online optimization, and can compensate for parameter drift caused by vibration and temperature drift in real time. It maintains stable accuracy during long-term operation and significantly reduces the workload of component installation and calibration.

[0047] The attitude measurement and calibration device for a spacecraft ground-based full physical simulation system described in this invention has a simple structure and is easy to deploy. It only requires a single fixed camera, a fixed target, and a cross laser generator mounted on an air-bearing platform. It does not require multi-camera coordination or complex on-site calibration procedures, and its installation and deployment are flexible. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the attitude measurement and calibration device for a spacecraft ground-based full physical simulation system according to the present invention;

[0049] Figure 2 This is a schematic diagram of the structure of the concentric ring coded target of the present invention;

[0050] Figure 3 This is a flowchart of an attitude measurement and calibration method for a spacecraft ground-based full physical simulation system, as described in this invention. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described specific embodiments are merely a part of the embodiments of the invention, and not all of them. The components of the specific embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations, and the invention may also have other embodiments.

[0052] Therefore, the following detailed description of specific embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected specific embodiments of the invention. All other specific embodiments obtained by those skilled in the art based on these specific embodiments without inventive effort are within the scope of protection of this invention.

[0053] To further understand the invention's content, features, and effects, the following specific embodiments are provided, along with accompanying drawings. Figure 1 -Appendix Figure 3 Detailed explanation is as follows:

[0054] Example 1:

[0055] A spacecraft ground-based full physical simulation system attitude measurement and calibration device includes a cross laser generator, a concentric ring coded target, a monocular camera, and a processing unit;

[0056] The cross laser generator, concentric ring coded target, monocular camera, and processing unit are fixedly mounted on a three-axis air-bearing platform. The monocular camera is fixedly set on one side of the cross laser generator and connected to the processing unit. The laser emitted by the cross laser generator is perpendicularly irradiated onto the plane of the concentric ring coded target. The concentric ring coded target adopts a concentric ring coded array design. Each group of concentric ring coded units consists of several concentrically arranged hollow rings. The coded ID of each group of concentric ring coded units is generated by combining the radius ratios of adjacent hollow rings.

[0057] Furthermore, each set of concentric rings has a ratio of 1:a:b:c:d, and the corresponding code ID is abcd. Different combinations of radius ratios correspond to different unique identifiers, with no coding conflicts.

[0058] The design of the concentric ring coded target is as follows:

[0059] ① Rotation invariance: No matter how the air-bearing platform rotates, the ring always maintains an elliptical shape in the camera image, which can be stably identified through ellipse detection and is not affected by the attitude of the air-bearing platform;

[0060] ② Scale invariance: The radius ratio of the ring does not change with the camera shooting distance or angle, and accurate decoding can still be completed under long distance and large angle shooting.

[0061] ③ Anti-occlusion capability: Even if some rings are occluded, as long as the effective radius ratio of the remaining rings can be calculated, decoding and center coordinate matching can be completed.

[0062] Furthermore, the center point of each set of concentric ring coding units of the concentric ring coding target is calibrated by a coordinate measuring machine to obtain the three-dimensional coordinates in the world coordinate system, and pre-stored in the coding library of the processing unit.

[0063] Furthermore, the core coordinate system is defined as follows:

[0064] (1) World coordinate system :origin Located at the preset reference point on the target plane, The axis is perpendicular to the target plane and points outwards. , Orthogonal within the target plane, the target plane is fixed as follows. flat;

[0065] (2) Coordinate system of air-floating platform :origin Located at the center of mass of the triaxial air-float platform, , The axes are two horizontal orthogonal axes of the air-floating platform. The axis is the vertical axis of the air-float platform;

[0066] (3) Camera coordinate system :origin Located at the camera's optical center, The axis moves forward along the camera's optical axis. , The axes are parallel to the horizontal and vertical axes of the image coordinate system;

[0067] (4) Image pixel coordinate system :origin Located in the top left corner of the image, axis, The axes are distributed along the horizontal and vertical axes of the image, with units of pixels.

[0068] Furthermore, a rigid transformation model of the laser plane of the cross-shaped laser emitter is constructed, including the first laser plane. Second laser plane ;

[0069] The normal vector of the first laser plane is The center point of the cross laser generator installation The plane equation of the first laser plane is: , The coordinates of a three-dimensional point in the three-axis air-bearing platform body coordinate system;

[0070] The normal vector of the second laser plane is The center point of the cross laser generator installation The equation of the plane is ;

[0071] Set the inherent constraints as follows ,and ;

[0072] Let the initial rotation matrix from the body coordinate system to the world coordinate system of the three-axis air-bearing platform be: Initial translation vector The equations for transforming the two laser planes to the world coordinate system are:

[0073]

[0074] in, For the first in the world coordinate system A laser plane equation, Let j be the normal vector of the j-th laser plane. These are the coordinates of a three-dimensional point in the world coordinate system.

[0075] Furthermore, the laser plane intersection constraint equation is constructed, and the calculation expression is as follows:

[0076]

[0077] in, For monocular camera projection mapping, For the first The equation of the intersection line between the laser plane and the target plane Term coefficient, No. The equation of the intersection line between the laser plane and the target plane Term coefficient, No. The constant term coefficients of the equation of the intersection line between the laser plane and the target plane. World coordinate system target plane Points on For the first The pixel straight line equation of the center line of the bright band Term coefficient, For the first The pixel straight line equation of the center line of the bright band Term coefficient, For the first The constant term coefficients of the pixel straight line equation for the center line of the bright band. A point in a pixel coordinate system.

[0078] Furthermore, the laser plane With the target plane They intersect, forming a straight line in space, which will Substituting the laser plane equation into the world coordinate system, we obtain the intersection line equation after expansion:

[0079]

[0080] The coefficients are:

[0081]

[0082] Based on the pinhole camera projection model, the intersection line in the world coordinate system remains a straight line when projected onto the image pixel coordinate system. Let the pixel line equation of the laser bright band center line extracted through image processing be: The core constraint is: the line of intersection in the world coordinate system, after being projected by the camera projection model, completely coincides with the line extracted from the image.

[0083] Furthermore, an online self-calibration mechanism based on a sliding window is set up to utilize the absolute position reference provided by the concentric ring coded target, and jointly solve the installation center point of the cross laser generator, the normal vector of the first laser plane and the normal vector of the second laser plane with the pose parameters of the three-axis air-bearing platform to compensate for parameter drift in real time.

[0084] Example 2:

[0085] An attitude measurement and calibration method for a spacecraft ground-based full physical simulation system, as described in Embodiment 1, includes the following steps:

[0086] S1. Install the attitude measurement and calibration device for a spacecraft ground-based full physical simulation system;

[0087] S2. Perform a one-time pre-calibration and initialization on the attitude measurement and calibration device of the spacecraft ground full physical simulation system;

[0088] Furthermore, the specific implementation method of step S2 includes the following steps:

[0089] S2.1. For a monocular camera, solve for the camera intrinsic parameter matrix using Zhang's calibration method. and distortion coefficient;

[0090] S2.2. Rigid body transformation model of the laser plane based on the cross laser emitter, calibrating the fixed transformation relationship between the camera coordinate system and the three-axis air-bearing platform body coordinate system. , ,in, This is the rotation matrix for transforming from the body coordinate system to the camera coordinate system. This is the translation vector used to transform the body coordinate system to the camera coordinate system;

[0091] S2.3. Generate the code for each group of concentric ring coding units for the concentric ring coding target, and calibrate the world coordinates of the center of each group of concentric rings using a coordinate measuring machine. Establish the correspondence between the encoding and world coordinates.

[0092] S3. The monocular camera acquires planar images of the concentric ring coded target in real time and transmits them synchronously to the processing unit for image preprocessing;

[0093] Furthermore, the image preprocessing method in step S3 is to use an improved Sauvola algorithm to perform adaptive binarization of the planar image of the concentric ring coded target.

[0094] S4. For the preprocessed image obtained in step S3, identify the world coordinates and corresponding pixel coordinates of the centers of multiple concentric rings, and use the least squares method to fit the laser bright band region in the preprocessed image to obtain the pixel line equations of the center lines of the two bright bands.

[0095] Furthermore, the specific implementation method of step S4 includes fitting the elliptical contours in the binarized image based on the least squares ellipse fitting method, selecting concentric ellipse groups, and extracting the sub-pixel-level center coordinates of each ellipse group. The radius ratio of the concentric ellipse group is substituted into the formula for generating the ID of the concentric annulus radius ratio code. The ID of the annulus group is calculated and matched with the pre-stored code library to obtain the world coordinate system coordinates of the corresponding annulus center. Ultimately, this yields one-to-one point pairs of "3D world coordinates - 2D pixel coordinates";

[0096] S5. Based on the world coordinates and corresponding pixel coordinates of the multiple sets of concentric ring centers obtained in step S4, solve for the initial pose of the three-axis air-bearing platform;

[0097] Furthermore, the specific implementation method of step S5 includes using the world coordinates and corresponding pixel coordinates of at least four sets of valid concentric ring centers identified in step S4 to construct a mapping equation:

[0098]

[0099] in, The camera intrinsic parameters calibrated in step S2, , The pose from the world coordinate system to the camera coordinate system is the coordinate system to be solved.

[0100] The initial pose of the air-bearing platform is solved using the EPnP algorithm to obtain the initial rotation matrix. With translation vector .

[0101] S6. Online self-calibration of the attitude of the spacecraft ground-based full physical simulation system is performed using an online self-calibration mechanism based on a sliding window;

[0102] Furthermore, the specific implementation method of step S6 includes the following steps:

[0103] S6.1. Maintain a sliding window of fixed length, and include the initial pose of the three-axis air-bearing platform of the current frame, the world coordinates and corresponding pixel coordinates of the centers of multiple concentric rings, and the equation of the laser bright band line into the window. If the window is full, remove the earliest frame.

[0104] S6.2. Integrate the fixed parameters of the cross laser generator to be calibrated online with the pose parameters of the air-bearing platform in all frames within the window into a global optimization unknown vector. :

[0105]

[0106] in, For the first The three-axis Euler angles of the three-axis air-bearing platform. For the first Translation vector of the origin of the three-axis air-bearing platform in the world coordinate system. This represents the total number of frames within the sliding window.

[0107] Satisfying orthogonal constraints Unit vector constraint ;

[0108] S6.3. Establish a dual-constraint joint optimization objective function to ensure that the optimization result simultaneously satisfies the geometric constraints of the intersection line between the absolute position reference and the laser plane:

[0109]

[0110] in, No. Frame, First The intersection line of the laser plane and the target plane in the world coordinate system. For the first Frame, First A laser-bright band of pixels in a straight line. These are the weighting coefficients. This represents the number of valid ring groups extracted from a single image frame. For the first in the target The known coordinates of the center of the annulus in the world coordinate system. For the first The first frame extracted from the image Subpixel-level center coordinates of the annulus;

[0111] S6.4. Using the LM nonlinear optimization algorithm, substituting the dual-constraint joint optimization objective function and constraints, the unknown vector is solved iteratively. The residual change must be less than 1e. -6 Alternatively, it can stop iterating after reaching the maximum number of iterations.

[0112] S7. Iterate the online self-calibration results of the spacecraft ground-based full physical simulation system attitude obtained in step S6 to achieve continuous real-time attitude measurement and online self-calibration.

[0113] Furthermore, the specific implementation method of step S7 is to fix the laser parameters after this calibration as the initial optimization value for the next round of process step S6; and to use the optimal pose output this time as the auxiliary reference for the initial pose of the next round of process step S5, returning to the image acquisition stage of step S3 to complete the closed loop of the whole process and realize continuous real-time attitude measurement and online self-calibration.

[0114] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0115] Although this application has been described above with reference to specific embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of this application. In particular, as long as there is no structural conflict, the features in the specific embodiments disclosed in this application can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A spacecraft ground-based full physical simulation system attitude measurement and calibration device, characterized in that, Includes a cross-shaped laser generator, a concentric ring coded target, a monocular camera, and a processing unit; The cross laser generator, concentric ring coded target, monocular camera, and processing unit are fixedly mounted on a three-axis air-bearing platform. The monocular camera is fixedly set on one side of the cross laser generator and connected to the processing unit. The laser emitted by the cross laser generator is perpendicularly irradiated onto the plane of the concentric ring coded target. The concentric ring coded target adopts a concentric ring coded array design. Each group of concentric ring coded units consists of several concentrically arranged hollow rings. The coded ID of each group of concentric ring coded units is generated by combining the radius ratios of adjacent hollow rings.

2. The attitude measurement and calibration device for a spacecraft ground-based full physical simulation system according to claim 1, characterized in that, The center point of each set of concentric ring coding units of the concentric ring coding target is calibrated by a coordinate measuring machine to obtain the three-dimensional coordinates in the world coordinate system, and then pre-stored in the coding library of the processing unit.

3. The attitude measurement and calibration device for a spacecraft ground-based full physical simulation system according to claim 2, characterized in that, Construct a rigid transformation model of the laser plane of the cross-shaped laser emitter, including the first laser plane. Second laser plane ; The normal vector of the first laser plane is The center point of the cross laser generator installation The plane equation of the first laser plane is: , The coordinates of a three-dimensional point in the three-axis air-bearing platform body coordinate system; The normal vector of the second laser plane is The center point of the cross laser generator installation The equation of the plane is ; Set the inherent constraints as follows ,and ; Let the initial rotation matrix from the body coordinate system to the world coordinate system of the three-axis air-bearing platform be: Initial translation vector The equations for transforming the two laser planes to the world coordinate system are: in, The first in the world coordinate system A laser plane equation, Let j be the normal vector of the j-th laser plane. These are the coordinates of a three-dimensional point in the world coordinate system.

4. The attitude measurement and calibration device for a spacecraft ground-based full physical simulation system according to claim 3, characterized in that, Construct the laser plane intersection constraint equation, and calculate the expression as follows: in, For monocular camera projection mapping, For the first The equation of the intersection line between the laser plane and the target plane Term coefficient, No. The equation of the intersection line between the laser plane and the target plane Term coefficient, No. The constant term coefficients of the equation of the intersection line between the laser plane and the target plane. Target plane in world coordinate system The point on, For the first The pixel straight line equation of the center line of the bright band Term coefficient, For the first The pixel straight line equation of the center line of the bright band Term coefficient, For the first The constant term coefficients of the pixel straight line equation for the center line of the bright band. It is a point in the pixel coordinate system.

5. The attitude measurement and calibration device for a spacecraft ground-based full physical simulation system according to claim 4, characterized in that, The online self-calibration mechanism based on a sliding window is set up by using the absolute position reference provided by the concentric ring coded target, and jointly solving the installation center point of the cross laser generator, the normal vector of the first laser plane and the normal vector of the second laser plane with the pose parameters of the three-axis air-bearing platform to compensate for parameter drift in real time.

6. A method for attitude measurement and calibration of a spacecraft ground-based full physical simulation system, characterized in that, Includes the following steps: S1. Install the attitude measurement and calibration device for a spacecraft ground-based full physical simulation system as described in any one of claims 1-5; S2. Perform a one-time pre-calibration and initialization on the attitude measurement and calibration device of the spacecraft ground full physical simulation system; S3. The monocular camera acquires planar images of the concentric ring coded target in real time and transmits them synchronously to the processing unit for image preprocessing; S4. For the preprocessed image obtained in step S3, identify the world coordinates and corresponding pixel coordinates of the centers of multiple concentric rings, and use the least squares method to fit the laser bright band region in the preprocessed image to obtain the pixel line equations of the center lines of the two bright bands. S5. Based on the world coordinates and corresponding pixel coordinates of the multiple sets of concentric ring centers obtained in step S4, solve for the initial pose of the three-axis air-bearing platform; S6. Online self-calibration of the attitude of the spacecraft ground-based full physical simulation system is performed using an online self-calibration mechanism based on a sliding window; S7. Iterate the online self-calibration results of the spacecraft ground-based full physical simulation system attitude obtained in step S6 to achieve continuous real-time attitude measurement and online self-calibration.

7. The attitude measurement and calibration method for a spacecraft ground-based full physical simulation system according to claim 6, characterized in that, The specific implementation method of step S2 includes the following steps: S2.

1. For a monocular camera, solve for the camera intrinsic parameter matrix using Zhang's calibration method. and distortion coefficient; S2.

2. Rigid body transformation model of the laser plane based on the cross laser emitter, calibrating the fixed transformation relationship between the camera coordinate system and the three-axis air-bearing platform body coordinate system. , ,in, This is the rotation matrix for transforming from the body coordinate system to the camera coordinate system. This is the translation vector used to transform the body coordinate system to the camera coordinate system; S2.

3. Generate the code for each group of concentric ring coding units for the concentric ring coding target, and calibrate the world coordinates of the center of each group of concentric rings using a coordinate measuring machine. Establish the correspondence between the encoding and world coordinates.

8. The attitude measurement and calibration method for a spacecraft ground-based full physical simulation system according to claim 7, characterized in that, The image preprocessing method in step S3 is to use the improved Sauvola algorithm to perform adaptive binarization of the planar image of the concentric ring coded target.

9. The attitude measurement and calibration method for a spacecraft ground-based full physical simulation system according to claim 8, characterized in that, The specific implementation method of step S6 includes the following steps: S6.

1. Maintain a sliding window of fixed length, and include the initial pose of the three-axis air-bearing platform of the current frame, the world coordinates and corresponding pixel coordinates of the centers of multiple concentric rings, and the equation of the laser bright band line into the window. If the window is full, remove the earliest frame. S6.

2. Integrate the fixed parameters of the cross laser generator to be calibrated online with the pose parameters of the air-bearing platform in all frames within the window into a global optimization unknown vector. : in, For the first The three-axis Euler angles of the three-axis air-bearing platform. For the first Translation vector of the origin of the three-axis air-bearing platform in the world coordinate system. This represents the total number of frames within the sliding window. Satisfying orthogonal constraints Unit vector constraint ; S6.

3. Establish a dual-constraint joint optimization objective function to ensure that the optimization result simultaneously satisfies the geometric constraints of the intersection line between the absolute position reference and the laser plane: in, No. Frame, First The intersection line of the laser plane and the target plane in the world coordinate system. For the first Frame, First A laser-bright band of pixels in a straight line. These are the weighting coefficients. This represents the number of valid ring groups extracted from a single image frame. For the first in the target The known coordinates of the center of the annulus in the world coordinate system. For the first The first frame extracted from the image Subpixel-level center coordinates of the annulus; S6.

4. Using the LM nonlinear optimization algorithm, substituting the dual-constraint joint optimization objective function and constraints, the unknown vector is solved iteratively. The residual change must be less than 1e. -6 Alternatively, it can stop iterating after reaching the maximum number of iterations.

10. The attitude measurement and calibration method for a spacecraft ground-based full physical simulation system according to claim 9, characterized in that, The specific implementation method of step S7 is to fix the laser parameters after this calibration as the initial optimization value of the next process step S6; and use the optimal pose output this time as the auxiliary reference for the initial pose of the next process step S5, and return to the image acquisition stage of step S3 to complete the closed loop of the whole process and realize continuous real-time attitude measurement and online self-calibration.

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