A third-view multi-target spacecraft engineering status monitoring method applicable to the surface of extraterrestrial bodies

Abstract

The invention discloses a method for monitoring the engineering status of multi-target spacecrafts from a third-perspective on the surface of an extraterrestrial body, and belongs to the technical field of deep space exploration. First, a monitoring system applied to the method for monitoring the engineering status of multi-target spacecrafts from a third-perspective is established; then, monitoring system parameters are determined according to requirements and a camera field of view model is constructed, a spacecraft geometric model is constructed according to the structural dimensions of the spacecraft, and a space illumination environment of the surface of the celestial body is established according to the local time; imaging composition and timing are designed to obtain the positional relationship between each spacecraft and the camera and the relative posture of each spacecraft and the camera; finally, according to the space illumination environment of the surface of the celestial body, an imaging effect image of all spacecrafts in the camera field of view is obtained, and real-time monitoring of the engineering status of all spacecrafts is achieved according to the image; the invention can monitor and take group photos of the engineering status of multiple spacecrafts on the surface of an extraterrestrial body by using a completely independent third-perspective method for local and panoramic imaging.

Description

Technical Field

[0001] The present invention belongs to the technical field of deep space exploration, and in particular relates to a method for monitoring the engineering status of multi-target spacecrafts from a third-view angle applicable to the surface of an extraterrestrial body. Background Art

[0002] A. Significance and Background of Spacecraft Engineering Condition Monitoring

[0003] In deep space exploration missions, understanding the engineering status of a space probe after landing on the surface of an extraterrestrial body is usually a very important part of the mission. Using optical monitoring technology to transmit images of the probe's on-orbit working status after landing can clearly and intuitively display the actual status of the probe and its working environment, realize the monitoring and feedback of the engineering status, and effectively reflect the execution actions of the engineering mission and key parts. It is an important way to display the results of the mission. In addition, the intuitive visual display can improve the public's awareness of the exploration mission, lift the veil of mystery of the universe, and deepen the public's understanding of extraterrestrial bodies and even the universe. The imaging effect and method of its optical monitoring technology determine the level of mission display and the ability to touch the public. Therefore, optical monitoring not only needs to meet the basic imaging requirements in system design, but also the imaging method and the displayed imaging content are very important elements.

[0004] B. Presentation Methods for Early Tasks

[0005] At present, the photography of space probes landing on the surface of extraterrestrial bodies mainly adopts the methods of self-portrait and mutual photography of two devices. Self-portrait is to use the monitoring cameras installed on the mast, extension arm and specific bracket of the spacecraft to realize the photography and monitoring of specific parts; mutual photography of two devices is usually to use the cameras carried by the lander and the rover to take pictures of each other, respectively obtain the working status of the two devices in orbit, and show the working environment and mission actions of each device. The above common methods are not sufficient and comprehensive for the monitoring and display of the relationship between spacecraft and multiple devices and the overall mission, and also have certain limitations in the visual cognition brought to the public.

[0006] In addition, from the perspective of lighting, the monitoring and shooting tasks that use the Selfie and mutual shooting methods have a greater risk of backlit shooting, which leads to the engineering optical monitoring being subject to shooting time window restrictions or the image quality being difficult to meet the requirements due to strong light entering the field of view. The status monitoring details may not be visible due to insufficient exposure, which also brings a large workload to the ground image data processing. Summary of the invention

[0007] In view of this, the present invention provides a third-perspective multi-target spacecraft engineering status monitoring method suitable for the surface of an extraterrestrial body, which can monitor and take group photos of the engineering status of multiple spacecraft on the surface of an extraterrestrial body locally and panoramically using a completely independent third-perspective.

[0008] The present invention is achieved through the following technical solutions:

[0009] A method for monitoring the engineering status of a multi-target spacecraft from a third-view angle on the surface of an extraterrestrial body, wherein the multi-target spacecraft is a spacecraft that lands on the surface of an extraterrestrial body, and includes more than two spacecraft, that is, at least one spacecraft that is movable after landing and one spacecraft that is immovable after landing;

[0010] The monitoring method is:

[0011] Step 1, establishing a monitoring system used by the third-view multi-objective spacecraft engineering status monitoring method;

[0012] Step 2: Determine the monitoring system parameters and build the camera field of view model according to the requirements, build the spacecraft geometry model according to the structure size of the spacecraft, and establish the space lighting environment of the celestial body surface according to the local time;

[0013] Step 3: Design the imaging composition and timing, that is, obtain the positional relationship between each spacecraft and the camera and the relative posture of each spacecraft and the camera according to the set field of view margin of the camera;

[0014] Step 4: According to the space lighting environment on the surface of the celestial body, determine the imaging time of all spacecrafts, and then obtain the imaging effect image of all spacecrafts in the camera field of view, and realize real-time monitoring of the engineering status of all spacecrafts based on this image.

[0015] Further, in step 1, the monitoring system used in the third-view multi-target spacecraft engineering status monitoring method includes: a spacecraft platform wireless control unit and a wireless separated monitoring and shooting probe;

[0016] The spacecraft platform wireless control unit is used to realize the control, data transmission and management of the wireless separated monitoring and shooting probe. It is configured on any spacecraft platform that can work for a long time. The spacecraft platform integrated management system provides it with primary power supply and LVDS data transmission and control management.

[0017] The wireless detachable monitoring and shooting probe is installed on any movable spacecraft platform, and includes: a locking and releasing device, a monitoring and shooting component, a wireless communication module and a self-contained power supply;

[0018] The monitoring and shooting assembly is installed on the movable spacecraft platform through a locking and releasing device, and the locking and releasing device is used to lock or release the monitoring and shooting assembly, that is, before the third-view monitoring mission is implemented, the monitoring and shooting assembly is fixed and installed on the movable spacecraft platform, and when the mission starts, the monitoring and shooting assembly is unlocked and released from the movable spacecraft platform to establish a third view;

[0019] The monitoring and shooting component adopts a binocular navigation camera, which is used to monitor more than two spacecraft, realize monitoring imaging and shooting from a third perspective, and transmit the measured image data to the spacecraft platform wireless control unit through a wireless communication module;

[0020] The wireless communication module is used to transmit the image data to the wireless control unit of the spacecraft platform by wireless transmission, so as to realize data communication and transmission between the wireless detachable monitoring and shooting probe and the wireless control unit of the spacecraft platform; the self-contained power supply is an energy source independent of the spacecraft platform system, which is used to power the monitoring and shooting components and the wireless communication module, so that the wireless detachable monitoring and shooting probe can work independently;

[0021] When establishing a third perspective, after the movable spacecraft platform with the wireless detachable monitoring and shooting probe moves from the initial position to the specified location, the wireless detachable monitoring and shooting probe is unlocked and released from the movable spacecraft platform. After the wireless detachable monitoring and shooting probe is fixed at the specified location, the movable spacecraft platform returns to the initial position. At this time, the wireless detachable monitoring and shooting probe establishes a third perspective to monitor more than two spacecraft.

[0022] Further, in step 2, based on the performance parameters of the camera's field of view angle, focal length, and phase element number in the third-view multi-target spacecraft engineering status monitoring system proposed in step 1, a camera field of view model is established; the camera field of view model is a camera visible space range constructed by the camera field of view angle, and uses the camera focal length and phase element number to project objects in the camera visible space onto the phase element plane to form a simulated imaging effect, and the imaging effect includes the spacecraft in the field of view and the background environment in the field of view;

[0023] According to the structural dimensions of each spacecraft, a corresponding spacecraft geometric model is established. The spacecraft geometric model is a model established based on the layout of the main equipment on the spacecraft, the size and structure of each product;

[0024] A spatial lighting environment on the surface of a celestial body where the spacecraft is located is established based on local time, wherein the local time is the local time formed by sunrise and sunset on the landing planet; the spatial lighting environment is the lighting condition formed based on the relationship between the sun's position and the local time.

[0025] Further, in step 3, based on the camera field of view model established in step 2, the field of view margin of the third-view camera is set, so as to obtain an effective and safe camera field of view model in which the spacecraft mission implementation status can be completely photographed, and the field of view margin is obtained based on the camera optical axis deviation and the position deviations of two or more spacecrafts;

[0026] Based on the geometric models of the two or more spacecraft established in step 2, a safety distance that needs to be retained for the two or more spacecraft to work in orbit is set, and a distance linkage coupling relationship between the two or more spacecraft is obtained according to the set safety distance;

[0027] The geometric models of the two or more spacecraft with linkage coupling relationship are brought into the effective safety camera field of view model, and the space occupied by each spacecraft in different placement positions in the camera field of view, as well as the mutual occlusion relationship of all spacecraft in the field of view, are analyzed by simulation to obtain the positional relationship between each spacecraft and the camera;

[0028] The relative attitudes of each spacecraft and camera are obtained by taking the frontal display of the spacecraft's iconic products as the standard.

[0029] Furthermore, in step 4, based on the positional relationship between each spacecraft and the camera obtained in step 3, and the relative posture of each spacecraft and the camera, a group photo composition of all spacecraft in the camera of the third perspective is formed, and on this basis, according to the spatial lighting environment of the celestial body surface established in step 2, the imaging time of all spacecraft is determined, and then the imaging effect image of all spacecraft in the camera field of view is obtained, and the real-time monitoring of the engineering status of all spacecraft is realized based on the image.

[0030] Furthermore, the locking and releasing device of the wireless detachable monitoring and shooting probe in step 1 is replaced with an unfolding mechanism; the monitoring and shooting component adopts an unfolding camera;

[0031] The camera is installed on any movable spacecraft platform through a deployment mechanism, and the deployment mechanism is used to deploy the camera, that is, before the third-view monitoring mission is implemented, the camera is fixed and installed on the movable spacecraft platform, and when the mission begins, the camera is deployed to establish a third-viewing angle;

[0032] When establishing a third perspective, more than three spacecraft are required, including at least one movable spacecraft. After the movable spacecraft platform with a wireless detachable monitoring and shooting probe moves from an initial position to a specified location, the camera of the wireless detachable monitoring and shooting probe is unfolded. At this time, the wireless detachable monitoring and shooting probe establishes a third perspective to monitor the other two or more spacecraft.

[0033] Furthermore, when the number of spacecraft is two, the two spacecraft are the landing platform N1 and the rover N2;

[0034] The size of the space occupied by the spacecraft in the camera field of view is measured by the angle formed by the spacecraft in the camera field of view. The angles of the landing platform N1 and the rover N2 in the camera field of view are obtained by the following formula:

[0035]

[0036] Among them, θ N1 is the angle formed by the landing platform N1 in the camera, R N1 L is the maximum outer envelope radius of the landing platform N1, N1 is the distance from the geometric projection center of landing platform N1 to the geometric projection center of the camera lens;

[0037]

[0038] Among them, θ N2 is the opening angle formed by the patroller N2 in the camera, R N2 is the maximum outer envelope radius of patroller N2, L N2 is the distance from the geometric projection center of rover N2 to the geometric projection center of the camera lens;

[0039] The opening angles of the two spacecraft in the camera satisfy the following relationship:

[0040]

[0041] Where Φ is the maximum field of view of the camera, θ x is the field of view margin; the sum of the field of view margins of each spacecraft on both sides of the imaging object on the camera is greater than or equal to 10%; and when the camera is imaging, it is ensured that the imaging object is still within the field of view when the camera pitches and rolls at least 10°.

[0042] Furthermore, the positional relationship between the spacecraft and the camera satisfies the following conditions:

[0043] L N1 >L N2

[0044] That is, the distance between the landing platform N1 and the camera is greater than the distance between the rover N2 and the camera;

[0045] At the same time, it should also meet the following requirements:

[0046]

[0047]

[0048] When the distance between the landing platform N1 and the camera and the distance between the rover N2 and the camera satisfy the above relationship, the angle formed by the landing platform N1 in the camera and the angle formed by the rover N2 in the camera on the adjacent side have a collinear relationship.

[0049] Furthermore, based on the maximum field of view of the camera, the maximum envelope size of the spacecraft, and their relative positions, the relationship between the wireless data transmission rate, the camera's shooting frame rate, and the camera's phase element and focal length is established:

[0050] M≥1.2×P×f(μ)

[0051] Where M is the wireless data transmission rate, P is the camera frame rate, and f(μ) is the size of each image obtained based on the phase element;

[0052] At the same time, the focal length F of the camera satisfies:

[0053]

[0054] Where μ is the number of phase elements, s is the phase element size, and Φ is the maximum field of view of the camera.

[0055] Furthermore, the photo-taking moment is confirmed by the local sun position, and the sun does not enter the camera field of view to satisfy the following relationship:

[0056] θ SN1C <90°

[0057] θ SN2C <90°

[0058] Among them, θ SN1C is the angle between the sun, the landing platform N1 and the camera C, θ SN2C is the angle formed by the sun's rays, the landing platform N2 and the camera C;

[0059] The solar altitude angle should satisfy the following relationship:

[0060]

[0061] Among them, θ H is the solar altitude angle of the extraterrestrial landing mission execution point, θ CL is the angle between the camera's optical axis and the horizon.

[0062] Beneficial effects:

[0063] (1) The present invention proposes for the first time a method for monitoring the engineering status of spacecraft, which can be used for the third-perspective collaborative group imaging monitoring task of multiple spacecraft on the surface of an extraterrestrial body. The method uses a completely independent third-perspective method to monitor the engineering status of multiple spacecraft on the surface of an extraterrestrial body and to perform group imaging. The method comprehensively considers the coupling relationship of multiple factors such as camera parameters, landing background, lighting conditions, surrounding environment, layout of multiple devices, and camera position, and achieves an imaging result in which multiple devices do not interfere with each other, the scene light is uniform, dynamic and static are combined, and the imaging object is stable within the field of view. The method can not only solve the problems of overexposure and backlight shooting existing in the current monitoring shooting method, but also solve the problem of imaging objects being out of the frame due to factors such as path planning and camera release posture, and at the same time, it can take into account the dynamic imaging effect of multiple spacecraft from local details to overall display. On the basis of ensuring the on-orbit shooting task, it combines science and art to further demonstrate the engineering implementation process.

[0064] (2) The present invention establishes a third-perspective multi-target spacecraft engineering status monitoring system, which includes a spacecraft platform wireless control unit and a wireless detachable monitoring and shooting probe. The third field of view is established through wireless transmission and unlocking separation, the wireless control unit is used to interact with the spacecraft platform, and the third field of view monitoring and shooting probe is self-sustaining through its own power supply; the third-perspective camera field of view can be obtained by separating and releasing the monitoring camera and using wireless transmission technology; the monitoring system and the multi-target shooting method can realize local and overall photo monitoring of the operating status of key parts of the detector on the surface of an extraterrestrial body, the execution status of key actions, etc. The acquired images directly and effectively support the ground measurement and control station to control the operating status of the detector and the coordinated working status of multiple devices, provide visual support for the implementation of the task, and at the same time improve the display effect of the task to the public. Therefore, the monitoring system fully guarantees the safe implementation of the engineering task and the complete and good display of the imaging shooting effect during the imaging process.

[0065] (3) The present invention establishes the relationship between camera parameters and camera field of view model based on the monitoring system, establishes a spacecraft geometric model according to the structure size of the spacecraft, and establishes a spatial lighting environment according to the local time; obtains an effective and safe camera field of view model according to the camera field of view model based on the field of view margin of deviation analysis; obtains a multi-spacecraft geometric model with safety distance linkage between multiple spacecrafts based on the safety distance of the deviation analysis according to multiple spacecraft geometric models; obtains the unobstructed and maximized position relationship calculation of the imaging target through repeated iterative calculation of the effective safety field of view model of the field of view margin and the multi-spacecraft geometric model with safety distance linkage coupling relationship, and obtains the system solution determination of the implementation plan and the camera parameter linkage; obtains the posture relationship calculation of multiple spacecraft and the shooting camera based on the analysis of the front display of the iconic product; therefore, the present invention proposes to take the safety distance as the linkage coupling relationship between multiple spacecraft as the basis, and repeatedly iterates the inclusion relationship between the camera field of view model and the spacecraft geometric model, and provides a method for determining the position and posture of the fully and completely displayed collaborative work of multiple spacecraft; under the premise of ensuring the maximum imaging shooting of the target spacecraft group, the problem of the imaging object exceeding the field of view caused by the optical axis deviation during the mission implementation can be effectively avoided, and a multi-factor determination method for the linkage of multiple camera parameters and tasks is realized.

[0066] (4) The present invention obtains the composition of the engineering monitoring group photo based on the positional relationship and attitude relationship between each spacecraft and the camera, and obtains the imaging time of the on-orbit spacecraft according to the analysis of the lighting environment of the celestial body surface, and then obtains the imaging effect diagram in the field of view of the spacecraft camera; after the spacecraft and camera attitude determined by the method of the present invention are implemented, the shooting and monitoring process can present the image information of a single device or key components and actions according to the method, and can also present the relationship between the collaborative work of multiple devices. The dynamic task execution process of the main imaging target in the background of other spacecraft can be realized, and the collaborative work relationship between multiple devices is brought in while greatly improving the display of the task. The film shooting technique of low-angle upward lens / high-angle downward lens is applied to engineering optical monitoring, so as to express more execution details of the extraterrestrial body detection mission, and present the task from the local to the whole, from large to small, so that it has a strong sense of visual impact and a sense of description of the implementation of the task.

[0067] (5) The size of the space occupied by the spacecraft of the present invention in the camera's field of view is measured by the angular span formed by the spacecraft in the camera's field of view. Based on the size of the camera's field of view and the geometric envelope of the immovable spacecraft after landing and the movable spacecraft after landing, various error factors during the mission implementation are taken into consideration, and the spatial geometric position relationship between the camera and the immovable spacecraft after landing and the movable spacecraft after landing is determined with the aim of maximizing the shooting target and stabilizing the shooting target in the field of view. Based on this, the process status monitoring and group photo imaging are carried out in consideration of comprehensive lighting conditions, so that a group photo of multiple devices in a working state after landing on an extraterrestrial body can be achieved.

[0068] (6) The timing of the group photo imaging of the present invention is confirmed by the local sun position so that the sun does not enter the field of view of the camera. Taking into account the lighting environment on the surface of the celestial body, a method for determining the range of the optimal time for imaging illumination and interference with engineering monitoring caused by the sun not entering the field of view is provided. This method can prevent the sun from entering the field of view to cause backlighting and cause unclear targets in the imaging image, and effectively support the good display of engineering status monitoring tasks. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 This is the implementation step of the third perspective multi-objective spacecraft engineering status monitoring method of the present invention;

[0070] Figure 2 It is a schematic diagram of the composition of the multi-objective spacecraft engineering status monitoring system from a third perspective of the present invention;

[0071] Figure 3 This is a structural composition diagram of a wireless detachable monitoring and shooting probe of a third-view multi-target spacecraft engineering status monitoring system of the present invention;

[0072] Figure 4 It is a schematic diagram of the process of the position and posture confirmation method of the present invention;

[0073] Figure 5 It is a schematic diagram of the relative position planning of multiple spacecraft on orbit according to the present invention;

[0074] Figure 6 This is a working principle diagram of the wireless detachable monitoring and shooting probe of this embodiment 4;

[0075] Figure 7 This is a schematic diagram of the relative position of the sun at the time of extraterrestrial photography in Example 4;

[0076] Figure 8 This is the working implementation process of the spacecraft and the camera of this embodiment 4;

[0077] Fig. 9 This is a schematic diagram of a simulated group photo shoot for monitoring engineering status of multiple spacecraft involved in Example 4;

[0078] Fig.10 This is a diagram showing the specific implementation effect of Example 4 in China's first Mars exploration mission.

[0079] Among them, 1-locking and releasing device, 2-monitoring and shooting component, 3-wireless communication module, 4-self-contained power supply. DETAILED DESCRIPTION

[0080] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0081] Embodiment 1:

[0082] This embodiment provides a method for monitoring the engineering status of a multi-target spacecraft from a third-view angle on the surface of an extraterrestrial body. The multi-target spacecraft is a spacecraft that lands on the surface of an extraterrestrial body, including two or more spacecraft, that is, at least one spacecraft that can move after landing (usually referred to as a rover) and one spacecraft that cannot move after landing (usually referred to as a landing platform).

[0083] See attached Figure 1 , the monitoring method is: firstly, establish a monitoring system applied by the third-view multi-target spacecraft engineering status monitoring method, further determine the monitoring system parameters according to the requirements and construct a camera field of view model, further construct a spacecraft geometric model according to the spacecraft structure size design result, further design the imaging composition and timing, and finally determine the third-view multi-target spacecraft monitoring solution result;

[0084] The specific steps of the monitoring method are as follows:

[0085] Step 1: Establish a monitoring system for the third-view multi-objective spacecraft engineering status monitoring method, see Appendix Figure 2 , the monitoring system comprises: a wireless control unit of a spacecraft platform and a wireless detachable monitoring and shooting probe; data is transmitted between the wireless control unit of the spacecraft platform and the wireless detachable monitoring and shooting probe via wireless communication;

[0086] The spacecraft platform wireless control unit is used to realize the control, data transmission and management of the wireless separated monitoring and shooting probe. It is configured on any spacecraft platform that can work for a long time. The spacecraft platform integrated management system provides it with primary power supply and LVDS data transmission and control management.

[0087] See attached Figure 3 The wireless detachable monitoring and shooting probe is installed on any movable spacecraft platform, and includes: a locking and releasing device 1, a monitoring and shooting component 2, a wireless communication module 3 and a self-contained power supply 4;

[0088] The monitoring and shooting component 2 is installed on the movable spacecraft platform through the locking and releasing device 1. The locking and releasing device 1 is used to lock or release the monitoring and shooting component 2, that is, before the third-view monitoring task is implemented, the monitoring and shooting component 2 is fixed and installed on the movable spacecraft platform. When the task starts, the monitoring and shooting component 2 is unlocked and released from the movable spacecraft platform to establish a third view.

[0089] The monitoring and shooting component 2 uses a binocular navigation camera (hereinafter referred to as the camera), which is used to monitor more than two spacecraft, realize monitoring imaging and shooting from a third perspective, and transmit the measured image data to the spacecraft platform wireless control unit through the wireless communication module 3;

[0090] The wireless communication module 3 is used to transmit the image data to the wireless control unit of the spacecraft platform by wireless transmission, so as to realize data communication and transmission between the wireless detachable monitoring and shooting probe and the wireless control unit of the spacecraft platform; the self-contained power supply 4 is an energy source independent of the spacecraft platform system, and is used to power the monitoring and shooting component 2 and the wireless communication module 3, so that the wireless detachable monitoring and shooting probe can work independently;

[0091] When establishing the third viewing angle, after the movable spacecraft platform with the wireless detachable monitoring and shooting probe moves from the initial position to the specified location, the wireless detachable monitoring and shooting probe is unlocked and released from the movable spacecraft platform, and after the wireless detachable monitoring and shooting probe is fixed at the specified location, the movable spacecraft platform returns to the initial position. At this time, the wireless detachable monitoring and shooting probe establishes the third viewing angle to monitor more than two spacecraft;

[0092] Step 2, based on the performance parameters such as the field of view angle, focal length, and phase element number of the camera in the third-perspective multi-target spacecraft engineering status monitoring system proposed in step 1, a camera field of view model is established, wherein the coordinate system of the camera field of view model is a coordinate system centered on the spacecraft that cannot be moved after landing; the camera field of view model is a camera visible space range constructed by the camera field of view angle, and the objects in the camera visible space are projected onto the phase element plane using the camera focal length and the phase element number to form a simulated imaging effect, wherein the imaging effect includes the spacecraft in the field of view and the background environment in the field of view;

[0093] According to the structural dimensions of each spacecraft, a corresponding spacecraft geometric model is established. The spacecraft geometric model is a model established based on the layout of the main equipment on the spacecraft, the size and structure of each product;

[0094] A spatial lighting environment on the surface of a celestial body where the spacecraft is located is established based on local time, wherein the local time is the local time formed by sunrise and sunset on the landing planet; the spatial lighting environment is the lighting condition formed based on the relationship between the sun's position and the local time.

[0095] Step 3, see attached Figure 4 , based on the camera field of view model established in step 2, the field of view margin of the third-view camera is set to ensure that the photographed object (i.e., all spacecraft, i.e., the imaging object) is within the field of view under any circumstances, so as to obtain an effective and safe camera field of view model in which the spacecraft mission implementation status can be completely photographed, and the field of view margin is obtained based on the camera optical axis deviation and the position deviations of two or more spacecraft; wherein, the camera optical axis deviation is obtained based on the mechanical movement deviation of the camera release process and the surface morphology and stone distribution at the camera release location; the spacecraft position deviation is obtained based on the travel and turning deviation and slippage of the movable spacecraft during the path driving process;

[0096] Based on the geometric models of the two or more spacecraft established in step 2, a safe distance that needs to be retained by the two or more spacecraft when working in orbit is set, and a distance linkage coupling relationship between the two or more spacecraft is obtained according to the set safe distance; the safe distance is obtained based on errors such as the navigation positioning accuracy of the camera and the movement and rotation accuracy of the movable spacecraft;

[0097] The geometric models of the two or more spacecraft with linkage coupling relationship are brought into the effective safety camera field of view model considering field of view margin, and the space occupied by each spacecraft in the camera field of view at different placement positions and the mutual occlusion relationship of all spacecraft in the field of view are analyzed through simulation, with the aim of maximizing the imaging target and fully and completely displaying the spacecraft, the positional relationship between each spacecraft and the camera is obtained;

[0098] The relative postures of the various spacecraft and cameras are obtained by taking the front display of the iconic product of the spacecraft as a standard. The front display of the iconic product may be a national flag, a trademark, or a front display of a probe.

[0099] Step 4: Based on the positional relationship between each spacecraft and the camera obtained in step 3, and the relative posture of each spacecraft and the camera, a group photo composition of all spacecraft in the camera of the third perspective is formed. On this basis, according to the spatial lighting environment of the celestial body surface established in step 2, the imaging time of all spacecraft is determined, and then the imaging effect image of all spacecraft in the camera field of view is obtained, and the real-time monitoring of the engineering status of all spacecraft is realized according to the image;

[0100] Among them, the space lighting environment comprehensively considers factors such as the sun not entering the camera's field of view, the sun being relative to the spacecraft and on the same side as the camera, avoiding mirror reflections of light sources, and the imaging object being more obvious in the background environment. Preferably, a larger solar altitude angle is selected.

[0101] Embodiment 2:

[0102] In this embodiment, based on the embodiment 1, the locking and releasing device of the wireless detachable monitoring and shooting probe in step 1 is replaced by an unfolding mechanism; the monitoring and shooting component adopts an unfolding camera;

[0103] The camera is installed on any movable spacecraft platform through a deployment mechanism, and the deployment mechanism is used to deploy the camera, that is, before the third-view monitoring mission is implemented, the camera is fixed and installed on the movable spacecraft platform, and when the mission begins, the camera is deployed to establish a third-viewing angle;

[0104] When establishing the third perspective, more than three spacecraft are required, including at least one movable spacecraft among the three or more spacecraft. After the movable spacecraft platform with the wireless detachable monitoring and shooting probe moves from the initial position to the specified location, the camera of the wireless detachable monitoring and shooting probe is unfolded. At this time, the wireless detachable monitoring and shooting probe establishes the third perspective to monitor the other two or more spacecraft.

[0105] Embodiment 3:

[0106] In this embodiment, based on Embodiment 1 and Embodiment 2, two spacecraft are taken as an example to describe in detail:

[0107] The two spacecrafts mentioned above are specifically targeted at the most representative landing platform N1 (spacecraft that cannot be moved after landing) and rover N2 (spacecraft that can be moved after landing) in extraterrestrial landing missions;

[0108] In step 3, see the Figure 5 , the space occupied by the spacecraft in the camera field of view is measured by the angle formed by it in the camera field of view. The angles of the landing platform N1 and the rover N2 in the camera field of view are obtained by the following formula:

[0109]

[0110] Among them, θ N1 is the angle formed by the landing platform N1 in the camera, R N1 L is the maximum outer envelope radius of the landing platform N1, N1 is the distance from the geometric projection center of landing platform N1 to the geometric projection center of the camera lens;

[0111]

[0112] Among them, θ N2 is the opening angle formed by the patroller N2 in the camera, R N2 is the maximum outer envelope radius of patroller N2, L N2 is the distance from the geometric projection center of rover N2 to the geometric projection center of the camera lens;

[0113] The opening angles of the two spacecraft in the camera satisfy the following relationship:

[0114]

[0115] Where Φ is the maximum field of view of the camera, θ x is the field of view margin; at the same time, in order to prevent image distortion from having a significant impact on monitoring imaging, when selecting the maximum field of view angle Φ of the camera, the image distortion should not exceed 30% within the full field of view angle Φ.

[0116] Preferably, in the imaging image, the sum of the field margins on both sides of the imaging object should be greater than or equal to 10% to prevent the imaging object from being out of the frame due to the deflection of the optical axis of the camera for third-angle imaging.

[0117] The posture of the camera takes into account the influence of the error deviation of the optical axis during the unlocking and releasing or unfolding process. For the camera after unlocking and releasing in Example 1, the optical axis error deviation factors include but are not limited to the release separation position, angle error, and the error caused by the uneven landing point caused by the surface slope of the celestial body at the separation point, surface stones, etc. For the unfolded camera in Example 2, the optical axis error deviation factors include but are not limited to the rotation error of the unfolding mechanism; preferably, when the camera performs imaging planning, it should be considered that the imaging object is still within the field of view under the condition of at least 10° pitch and roll.

[0118] The positional relationship between the spacecraft and the camera satisfies the following conditions:

[0119] L N1 >L N2

[0120] That is, the distance between the landing platform N1 and the camera is greater than the distance between the rover N2 and the camera;

[0121] At the same time, it should also meet the following requirements:

[0122]

[0123]

[0124] When the distance between the landing platform N1 and the camera and the distance between the rover N2 and the camera satisfy the above relationship, the angle formed by the landing platform N1 in the camera and the adjacent side of the angle formed by the rover N2 in the camera have a collinear relationship, thereby ensuring that the landing platform N1 and the rover N2 do not block each other in the camera field of view and facilitating the maximum display of the imaging object; the postures of the landing platform N1 and the rover N2 are determined according to the front display of their respective iconic products; preferred iconic products may be national flags, display trademarks, and the front of spacecraft, etc.

[0125] Based on the maximum field of view of the above cameras, the maximum envelope size of the spacecraft and their relative positions, the relationship between the wireless data transmission rate, the camera's shooting frame rate, and the camera's phase element and focal length is established:

[0126] M≥1.2×P×f(μ)

[0127] Where, M is the wireless data transmission rate, unit Mpbs, P is the camera frame rate, unit fps, f(μ) is the size of each image obtained according to the phase element, unit Mb;

[0128] At the same time, the focal length F of the camera satisfies:

[0129]

[0130] Where μ is the number of phase elements, s is the phase element size, and Φ is the maximum field of view of the camera.

[0131] After obtaining the relative position and attitude relationship between the landing platform N1, the rover N2 and the camera, the camera can realize engineering status monitoring including but not limited to a single spacecraft from local to overall, and collaborative engineering status monitoring of multiple spacecraft, and can present mission displays from large to small and from near to far.

[0132] In step 4, the group photo imaging time is confirmed by the local sun position, and the sun does not enter the camera field of view to satisfy the following relationship:

[0133] θ SN1C <90°

[0134] θ SN2C <90°

[0135] Among them, θ SN1C is the angle between the sun, the landing platform N1 and the camera C, θ SN2C is the angle formed by the sunlight, the landing platform N2 and the camera C. The above relationship can ensure a better imaging effect and prevent the sun from entering the field of view.

[0136] The solar altitude angle should satisfy the following relationship:

[0137]

[0138] Among them, θ H is the solar altitude angle at the extraterrestrial landing mission execution point (i.e., where the spacecraft is located), θ CL is the angle between the optical axis of the camera and the horizon; the above relationship can determine the optimal illumination range when the solar altitude angle is large, so as to obtain high-quality imaging images.

[0139] Embodiment 4:

[0140] This embodiment is based on the embodiment 3, and takes the Mars WIFI separate shooting probe main camera shooting the Mars landing platform (i.e., the landing platform N1 in the embodiment 3) and the Mars rover (i.e., the rover N2 in the embodiment 3) as an example, and is described in detail according to the above steps:

[0141] Step 1: Establish a monitoring system for the third-view multi-objective spacecraft engineering status monitoring method, see Appendix Figure 6 , the monitoring system comprises: a wireless control unit of a spacecraft platform and a wireless detachable monitoring and shooting probe; data is transmitted between the wireless control unit of the spacecraft platform and the wireless detachable monitoring and shooting probe via wireless communication;

[0142] The spacecraft platform wireless control unit is preferably a WIFI unit, and the wireless detachable monitoring and shooting probe is preferably a WIFI detachable shooting probe;

[0143] The wireless communication method proposed in this embodiment is not limited to the WIFI communication method. The construction of a third perspective after the wireless detachable monitoring and shooting probe is separated from the spacecraft platform includes but is not limited to unlocking, releasing and landing, and it can also be the flight release and landing of the wireless detachable monitoring and shooting probe.

[0144] Step 2: Establish the camera's field of view angle, focal length, number of phase elements and other performance parameters, build the camera field of view model, and follow Figure 5 Establish the camera field of view model of camera C and the spacecraft geometry models of the Mars landing platform and the Mars rover, and determine the field of view angle of the relevant photo-taking spacecraft in the imaging camera;

[0145]

[0146]

[0147] Step 3: Based on the model established in step 2, the specific relationship between the camera, the Mars landing platform and the Mars rover is determined taking into account the safe distance between the spacecraft, the integrity of the photographed object and the presentation of the imaging effect;

[0148] Preferably, the distance between the spacecraft (Mars landing platform and Mars rover) is greater than 1 meter;

[0149] Preferably, the optical axis of the camera lens is parallel to the normal direction of the front of the iconic product (the front of the national flag on the Mars landing platform) to achieve the front display of the national flag;

[0150] Preferably, the imaging object (Mars landing platform and Mars rover) is in the center of the camera field of view as a whole, and a total of 10° field of view margin is reserved on the left and right sides. When a 5° field of view margin is reserved on each side, the imaging effect of the imaging object in the camera field of view is optimal. At this time, the expression formula is as follows:

[0151]

[0152]

[0153] Preferably, considering that the camera is tilted 10° due to other external factors, the imaging object is still within the field of view; that is, the imaging object is in the center of the camera field of view as a whole, and a total of 10° field of view margin is reserved on the upper and lower sides. When a 5° field of view margin is reserved on the upper and lower sides, the imaging effect of the imaging object in the camera field of view is optimal. At this time, the expression formula is as follows:

[0154]

[0155]

[0156] Preferably, the positional relationship between the Mars landing platform, the Mars rover and the camera satisfies the following conditions:

[0157]

[0158]

[0159] At the same time, the angle formed by the Mars landing platform in the camera is collinear with the angle formed by the Mars rover in the camera on one side, thereby ensuring that the Mars landing platform and the Mars rover do not block each other in the camera's field of view.

[0160] Based on the field of view of the aforementioned cameras, the maximum envelope size of the spacecraft, and their relative positions, the relationship between the data transmission rate, the shooting frame rate, the phase element, and the focal length is established:

[0161] Preferably, under the condition of the farthest imaging position, the data transmission rate is greater than 1.2 times the camera data generation rate, so as to fully meet the data generation and transmission affected by complex factors on orbit;

[0162] M≥1.2×P×f(μ)

[0163] Preferably, the shooting condition where the focal length of the camera is greater than the imaging distance that retains the field of view margin is:

[0164]

[0165] Step 4: According to the positional relationship between the spacecraft and the camera established in Steps 2 and 3 and the composition of the group photo of the spacecraft on orbit formed based on this positional relationship, the time point of the group photo of the spacecraft on orbit is determined with the requirement that the sun does not enter the field of view of the camera and the sun is on the same side relative to the spacecraft and the camera:

[0166] θ SN1C <90°

[0167] θ SN2C <90°

[0168] The sun altitude angle should satisfy:

[0169]

[0170] After reaching the surface of Mars, the unlockable and detachable camera is used to take third-person perspective photos. According to the method of this embodiment, the position and posture of the Mars landing platform, the Mars rover, and the camera can be obtained. Figure 8 , and gives the angles of the two spacecraft in the field of view:

[0171]

[0172]

[0173] Among them, θ platform is the angle formed by the Mars landing platform in the camera, R platform is the maximum outer envelope radius of the Mars landing platform, L platform is the distance from the geometric projection center of the Mars landing platform to the geometric projection center of the camera lens;

[0174] θ rover is the angle formed by the rover in the camera, R rover is the maximum outer envelope radius of the Mars rover, L rover is the distance from the rover's geometric projection center to the camera lens' geometric projection center;

[0175] Comparing the camera's field of view, the angles of the Mars landing platform and the Mars rover in the camera's field of view satisfy the following relationship:

[0176]

[0177]

[0178] At the same time, the position relationship of the spacecraft also satisfies the following relationship:

[0179]

[0180]

[0181] In addition, the data transmission rate, shooting frame rate, phase element, and focal length are determined according to the imaging mission plan and meet the third-person perspective multi-target spacecraft engineering status monitoring needs.

[0182] In dynamic video shooting mode:

[0183] (10Mbps=)M≥1.2×P×f(μ)(=1.2×5×1024×1024÷1E6=8Mbps)

[0184] In still shooting mode:

[0185] (10Mbps=)M≥1.2×P×f(μ)(=1.2×2×2048×2048÷1E6=10Mbps)

[0186] Focal length meets:

[0187]

[0188] In order to achieve a higher imaging effect, the height and azimuth of the sun are taken into account during the imaging process, such as Figure 7 Image capture was performed before 11:24 PM on the Martian day:

[0189] The determined time point for group photo imaging of on-orbit spacecraft meets the following angle requirements:

[0190] θ sun-platform-camera <90°

[0191] θ sun-rover-camera <90°

[0192] Among them, θ sun-platform-camera is the angle between the sun's rays and the Mars landing platform and camera, θ sun-rover-camera the angle between the sun's rays and the rover and camera;

[0193] Sun altitude angle at the selected time:

[0194] 80°>θ H >65°

[0195] Considering the angle between the camera optical axis and the horizon is 10°, the solar altitude angle at the selected moment satisfies the following relationship to achieve low-angle upward shooting or high-angle downward shooting:

[0196]

[0197] Step 5. Through the simulation of steps 1-4, it can be seen that the Mars landing platform and the Mars rover do not interfere with each other in the field of view of the camera. The imaging is maximized based on the comprehensive coupling factors such as the spacecraft maintaining a safe distance, the iconic product is displayed positively, the imaging object needs to retain a margin on both sides of the image to avoid being out of the field of view, the imaging object is kept in the field of view within the pitch and roll error range of the camera attitude, and the lighting conditions are optimized. The group photo image is located on both sides of the center of the field of view. Fig. 9 The actual on-orbit implementation effect is as follows Fig.10 , which is consistent with the results of field of view analysis.

[0198] In summary, the third-perspective multi-target spacecraft engineering status monitoring method for the surface of extraterrestrial bodies is correct.

[0199] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for monitoring the engineering status of multi-target spacecraft from a third-view angle on the surface of an extraterrestrial body, wherein the multi-target spacecraft is a spacecraft that lands on the surface of an extraterrestrial body, and includes more than two spacecraft, that is, at least one spacecraft that can move after landing and one spacecraft that cannot move after landing; It is characterized in that The monitoring method is: Step 1, establishing a monitoring system used by the third-view multi-objective spacecraft engineering status monitoring method; Step 2: Determine the monitoring system parameters and build the camera field of view model according to the requirements, build the spacecraft geometry model according to the spacecraft structure size, and establish the space lighting environment of the celestial body surface according to the local time; Step 3: Design the imaging composition and timing, that is, obtain the positional relationship between each spacecraft and the camera and the relative posture of each spacecraft and the camera according to the set field of view margin of the camera; Step 4: Determine the imaging time of all spacecrafts according to the space illumination environment of the celestial body surface, and then obtain the imaging effect image of all spacecrafts in the camera field of view, and realize real-time monitoring of the engineering status of all spacecrafts according to the image; In step 1, the monitoring system used in the third-view multi-target spacecraft engineering status monitoring method includes: a spacecraft platform wireless control unit and a wireless separated monitoring and shooting probe; The spacecraft platform wireless control unit is used to realize the control, data transmission and management of the wireless separated monitoring and shooting probe. It is configured on any spacecraft platform that can work for a long time. The spacecraft platform integrated management system provides it with primary power supply and LVDS data transmission and control management. The wireless detachable monitoring and shooting probe is installed on any movable spacecraft platform, and includes: a locking and releasing device, a monitoring and shooting component, a wireless communication module and a self-contained power supply; The monitoring and shooting assembly is installed on the movable spacecraft platform through a locking and releasing device, and the locking and releasing device is used to lock or release the monitoring and shooting assembly, that is, before the third-view monitoring mission is implemented, the monitoring and shooting assembly is fixed and installed on the movable spacecraft platform, and when the mission starts, the monitoring and shooting assembly is unlocked and released from the movable spacecraft platform to establish a third view; The monitoring and shooting component adopts a binocular navigation camera, which is used to monitor more than two spacecraft, realize monitoring imaging and shooting from a third perspective, and transmit the measured image data to the spacecraft platform wireless control unit through a wireless communication module; The wireless communication module is used to transmit the image data to the wireless control unit of the spacecraft platform by wireless transmission, so as to realize data communication and transmission between the wireless detachable monitoring and shooting probe and the wireless control unit of the spacecraft platform; the self-contained power supply is an energy source independent of the spacecraft platform system, which is used to power the monitoring and shooting components and the wireless communication module, so that the wireless detachable monitoring and shooting probe can work independently; When establishing the third viewing angle, after the movable spacecraft platform with the wireless detachable monitoring and shooting probe moves from the initial position to the specified location, the wireless detachable monitoring and shooting probe is unlocked and released from the movable spacecraft platform, and after the wireless detachable monitoring and shooting probe is fixed at the specified location, the movable spacecraft platform returns to the initial position. At this time, the wireless detachable monitoring and shooting probe establishes the third viewing angle to monitor more than two spacecraft; In step 2, based on the performance parameters of the camera's field of view angle, focal length, and phase element number in the third-view multi-target spacecraft engineering status monitoring system proposed in step 1, a camera field of view model is established; the camera field of view model is a camera visible space range constructed by the camera field of view angle, and uses the camera focal length and phase element number to project objects in the camera visible space onto the phase element plane to form a simulated imaging effect, and the imaging effect includes the spacecraft in the field of view and the background environment in the field of view; According to the structural dimensions of each spacecraft, a corresponding spacecraft geometric model is established. The spacecraft geometric model is a model established based on the layout of the main equipment on the spacecraft, the size and structure of each product; Establishing a space lighting environment on the surface of the celestial body where the spacecraft is located according to the local time, wherein the local time is the local time formed by the sunrise and sunset of the landing planet; the space lighting environment is the lighting condition formed according to the position of the sun corresponding to the local time; In step 3, based on the camera field of view model established in step 2, the field of view margin of the third-view camera is set to obtain an effective and safe camera field of view model in which the spacecraft mission implementation status can be completely photographed, and the field of view margin is obtained based on the camera optical axis deviation and the position deviations of two or more spacecrafts; Based on the geometric models of the two or more spacecraft established in step 2, a safety distance that needs to be retained for the two or more spacecraft to work in orbit is set, and a distance linkage coupling relationship between the two or more spacecraft is obtained according to the set safety distance; The geometric models of the two or more spacecraft with linkage coupling relationship are brought into the effective safety camera field of view model, and the space occupied by each spacecraft in different placement positions in the camera field of view, as well as the mutual occlusion relationship of all spacecraft in the field of view, are analyzed by simulation to obtain the positional relationship between each spacecraft and the camera; Taking the frontal display of the spacecraft's iconic products as the standard, the relative attitudes of each spacecraft and camera are obtained; In step 4, based on the positional relationship between each spacecraft and the camera obtained in step 3, as well as the relative posture of each spacecraft and the camera, a group photo composition of all spacecraft in the camera of the third perspective is formed. On this basis, according to the spatial lighting environment of the celestial body surface established in step 2, the imaging time of all spacecraft is determined, and then the imaging effect image of all spacecraft in the camera field of view is obtained, and the real-time monitoring of the engineering status of all spacecraft is realized based on the image.

2. A method for monitoring the engineering status of a spacecraft from a third-view angle and multiple targets on the surface of an extraterrestrial body as claimed in claim 1, characterized in that: The locking and releasing device of the wireless detachable monitoring and shooting probe in step 1 is replaced with an unfolding mechanism; the monitoring and shooting component adopts an unfolding camera; The camera is installed on any movable spacecraft platform through a deployment mechanism, and the deployment mechanism is used to deploy the camera, that is, before the third-view monitoring mission is implemented, the camera is fixed and installed on the movable spacecraft platform, and when the mission begins, the camera is deployed to establish a third-viewing angle; When establishing a third perspective, more than three spacecraft are required, including at least one movable spacecraft. After the movable spacecraft platform with a wireless detachable monitoring and shooting probe moves from an initial position to a specified location, the camera of the wireless detachable monitoring and shooting probe is unfolded. At this time, the wireless detachable monitoring and shooting probe establishes a third perspective to monitor the other two or more spacecraft.

3. A method for monitoring the engineering status of a spacecraft from a third-view angle on the surface of an extraterrestrial body as claimed in claim 1, characterized in that: When the number of spacecraft is two, the two spacecraft are landing platform N1 and rover N2; The size of the space occupied by the spacecraft in the camera field of view is measured by the angle formed by the spacecraft in the camera field of view. The angles of the landing platform N1 and the rover N2 in the camera field of view are obtained by the following formula: Among them, θ N1 is the angle formed by the landing platform N1 in the camera, R N1 L is the maximum outer envelope radius of the landing platform N1, N1 is the distance from the geometric projection center of landing platform N1 to the geometric projection center of the camera lens; Among them, θ N2 is the opening angle formed by the patroller N2 in the camera, R N2 is the maximum outer envelope radius of patroller N2, L N2 is the distance from the geometric projection center of rover N2 to the geometric projection center of the camera lens; The opening angles of the two spacecraft in the camera satisfy the following relationship: Where Φ is the maximum field of view of the camera, is the field of view margin; the sum of the field of view margins of each spacecraft on both sides of the imaging object on the camera is greater than or equal to 10%; and when the camera is imaging, it is ensured that the imaging object is still within the field of view when the camera pitches and rolls at least 10°.

4. A method for monitoring the engineering status of a spacecraft from a third-view angle and multiple targets on the surface of an extraterrestrial body as claimed in claim 3, characterized in that: The positional relationship between the spacecraft and the camera satisfies the following conditions: That is, the distance between the landing platform N1 and the camera is greater than the distance between the rover N2 and the camera; At the same time, it should also meet the following requirements: When the distance between the landing platform N1 and the camera and the distance between the rover N2 and the camera satisfy the above relationship, the angle formed by the landing platform N1 in the camera and the angle formed by the rover N2 in the camera on the adjacent side have a collinear relationship.

5. A method for monitoring the engineering status of a multi-target spacecraft from a third-view angle on the surface of an extraterrestrial body as claimed in claim 3 or 4, characterized in that: Based on the maximum field of view of the camera, the maximum envelope size of the spacecraft, and their relative positions, the relationship between the wireless data transmission rate, the camera's shooting frame rate, and the camera's phase element and focal length is established: Where M is the wireless data transmission rate, P is the camera frame rate, is the size of each image obtained according to the phase element; At the same time, the focal length F of the camera satisfies: In the formula is the number of phase elements, s is the phase element size, and Φ is the maximum field of view of the camera.

6. A method for monitoring the engineering status of a spacecraft from a third-view angle and multiple targets on the surface of an extraterrestrial body as claimed in claim 3 or 4, characterized in that: The photo-taking moment is determined by the local sun position, and the sun does not enter the camera field of view to satisfy the following relationship: Among them, θ SN1C is the angle between the sun, the landing platform N1 and the camera C, θ SN2C is the angle formed by the sun's rays and rover N2 and camera C; The solar altitude angle should satisfy the following relationship: Among them, θ H is the solar altitude angle of the extraterrestrial landing mission execution point, θ CL is the angle between the camera's optical axis and the horizon.

Images