Test method, device and electronic equipment for star open-loop pointing

Abstract

The application discloses a star open-loop pointing test method and device and electronic equipment. The device coordinate systems and the conversion relationship between the device coordinate systems are calibrated. First orbit attitude data of a first satellite corresponding to a laser terminal and second orbit attitude data of a second satellite are acquired, and the laser link information of the first satellite and the second satellite is determined. A star map corresponding to a target star is projected by a star simulator based on the laser link information and the conversion relationship between the device coordinate systems, so that the laser terminal simulates star open-loop pointing test based on the star map. Thus, the equivalent, conversion and unified relationship between each space coordinate system involved in the laser terminal in-orbit link star open-loop pointing environment and each device coordinate system in the ground test simulation environment can be established. Based on this, the star map is corrected in deviation, the spatial accuracy of indoor star open-loop pointing test is obtained, and more accurate and reliable test results are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite communication, in particular to a method and device for testing star open-loop pointing and an electronic device. BACKGROUND

[0002] With the increasing demand for high-speed data transmission, laser communication with the advantages of high bandwidth, strong anti-interference, low power consumption, etc. gradually begins to be applied in the field of satellite communication.

[0003] The narrow-beam characteristics of laser communication put higher requirements on the star open-loop pointing technology of the precision optical terminal. The star open-loop pointing calibration uses the star sensor coaxial with the terminal to take real-time photos of the star, provides high-precision attitude reference, corrects the pointing target accuracy in real time, eliminates the large pointing difference caused by factors such as in-orbit gravity release, thermal deformation, and long-term orbit extrapolation error of the laser terminal, and provides reliable guarantee for realizing long-term stability and rapid reconnection of the inter-satellite laser link. However, the current ground star open-loop pointing calibration has large differences with the on-orbit star open-loop pointing scene, and the verification environment has low equivalence; and the outdoor test scene is greatly limited by weather conditions, and it is difficult to realize high-precision and high-reliability ground verification.

[0004] In view of the problem that the above ground star open-loop pointing calibration cannot achieve high precision and high reliability, no effective solution has been proposed so far. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a method and device for testing star open-loop pointing, which can realize spatial equivalence between space orbits and star environments and ground simulation environments, and obtain more accurate and reliable test results.

[0006] The first aspect of the present specification provides a method for testing star open-loop pointing, applied to a star open-loop pointing test system, wherein the star open-loop pointing test system at least includes a turntable, a laser terminal installed on the turntable, and a star simulator. The method comprises:

[0007] Calibrating the coordinate systems of each device and the conversion relationship between the coordinate systems of each device, wherein the coordinate systems of each device at least include a reference coordinate system of the turntable, a zero-point coordinate system of the turntable, a coordinate system of the laser terminal, a coordinate system of the star simulator, and a star map coordinate system;

[0008] Obtaining and determining first orbit attitude data of a first satellite corresponding to the laser terminal and second orbit attitude data of a second satellite according to the laser link information of the first satellite and the second satellite;

[0009] Projecting a star map corresponding to a target star based on the laser link information and the conversion relationship between the coordinate systems of each device by using the star simulator, so that the laser terminal simulates star open-loop pointing test based on the star map.

[0010] In some embodiments of the present disclosure, the star map projected by the star simulator is a star background of a laser link direction sky area of the first satellite and the second satellite.

[0011] In some embodiments of the present disclosure, calibrating the position and direction of each device coordinate system and the conversion relationship between the device coordinate systems comprises:

[0012] calibrating the position and direction of each device coordinate system and the coordinate system deviation between the device coordinate systems;

[0013] determining the deviation correction amount between the device coordinate systems based on the coordinate system deviation between the device coordinate systems as the conversion relationship between the device coordinate systems.

[0014] In some embodiments of the present disclosure, calibrating the position and direction of each device coordinate system and the coordinate system deviation between the device coordinate systems comprises:

[0015] installing a zero point measurement tool at a zero point position of the turntable, representing a reference coordinate system of the turntable through a first cube mirror installed at a reference position of the turntable, and representing a zero point coordinate system of the turntable through a second cube mirror;

[0016] optically measuring the first cube mirror and the second cube mirror by using the theodolite to determine a first coordinate system deviation between the first cube mirror and the second cube mirror;

[0017] installing the laser terminal at the zero point position of the turntable, representing the zero point coordinate system of the turntable through a third cube mirror installed on the laser terminal, and representing a coordinate system of the star simulator through a fourth cube mirror installed on the star simulator;

[0018] defining a star map coordinate system projected by the star simulator, optically measuring the first cube mirror and the third cube mirror, the first cube mirror and the fourth cube mirror, and the fourth cube mirror and the star map coordinate system by using the theodolite to determine a second coordinate system deviation between the first cube mirror and the third cube mirror, a third coordinate system deviation between the first cube mirror and the fourth cube mirror, and a fourth coordinate system deviation between the fourth cube mirror and the star map coordinate system.

[0019] In some embodiments of the present disclosure, determining the deviation correction amount between the device coordinate systems based on the coordinate system deviation between the device coordinate systems comprises:

[0020] based on each coordinate system deviation, determining a direction cosine corresponding to each coordinate system deviation as the deviation correction amount between the corresponding device coordinate systems;

[0021] determine a third deviation correction quantity between the zero-point coordinate system and the laser terminal coordinate system based on a first deviation correction quantity between the reference coordinate system and the zero-point coordinate system and a second deviation correction quantity between the reference coordinate system and a coordinate system of the laser terminal;

[0022] determine a sixth deviation correction quantity between the star map coordinate system and the laser terminal coordinate system based on a fourth deviation correction quantity between the reference coordinate system and a coordinate system of the star simulator, a fifth deviation correction quantity between the coordinate system of the star simulator and the star map coordinate system, and the second deviation correction quantity.

[0023] In some embodiments of the present specification, the first track attitude data and / or the second track attitude data at least include: track position data in an inertial coordinate system, velocity data of a satellite, Euler angles, and quaternions.

[0024] In some embodiments of the present specification, the laser link information of the first satellite and the second satellite is determined according to the first track attitude data of the first satellite corresponding to the laser terminal and the second track attitude data of the second satellite, including:

[0025] determine first position data of the first satellite in an inertial coordinate system and second position data of the second satellite in the inertial coordinate system based on the first track attitude data and the second track attitude data;

[0026] determine a pointing vector of the first satellite to the second satellite in the inertial coordinate system as the laser link information based on the second position data and the second position data.

[0027] In some embodiments of the present specification, a star map corresponding to a target star is projected by a star simulator based on the laser link information and a conversion relationship between coordinate systems of devices, including:

[0028] determine a star map projection control quantity of the star simulator for projecting the star map based on the laser link information and the conversion relationship between coordinate systems of devices;

[0029] project the star map in a laser link direction sky region of the first satellite and the second satellite by the star simulator based on the star map projection control quantity.

[0030] In some embodiments of the present specification, the star map projection control quantity of the star simulator for projecting the star map is determined based on the laser link information and the conversion relationship between coordinate systems of devices, including:

[0031] The pointing vector from the first satellite to the second satellite in the laser link information in the inertial coordinate system is converted to the target direction vector in the star map coordinate system based on the conversion relationship between the coordinate systems of the devices, and the target direction vector is obtained.

[0032] A rotation quaternion of the central optical axis of the star map coordinate system is determined to the target direction vector, and the rotation quaternion is used as the star map projection control quantity.

[0033] In some embodiments of the present specification, the star map projection control quantity is determined by the following formula:

[0034] ;

[0035] Wherein q represents the rotation quaternion of the star map coordinate system, representing the star map projection control quantity; represents the pointing vector from the first satellite to the second satellite in the laser link information in the star map coordinate system; represents the pointing vector from the first satellite to the second satellite in the laser link information in the star map coordinate system, and V1 represents the unit vector of the central optical axis of the star map coordinate system, represents the pointing vector from the first satellite to the second satellite in the laser link information in the inertial coordinate system, C M4 represents the conversion relationship from the star map coordinate system to the star simulator, C 14 represents the conversion relationship from the reference coordinate system to the star simulator, C 12 represents the conversion relationship from the reference coordinate system to the zero point coordinate system.

[0036] In some embodiments of the present specification, after determining the rotation quaternion of the central optical axis of the star map coordinate system to the target direction vector, the method further comprises:

[0037] The rotation quaternion is normalized, and the normalized rotation quaternion is used as the star map projection control quantity.

[0038] In some embodiments of the present specification, the star open-loop pointing test system further comprises a timing device and a data processing end, and the method further comprises:

[0039] The laser terminal, the turntable and the star simulator are respectively subjected to corresponding time alignment processing by using the timing device.

[0040] The orbit and attitude data with timestamps are sent to the turntable and the laser terminal at a first time point in advance by a data processing end, so that the turntable and the laser terminal simulate the orbit and attitude of the first satellite and the second satellite in orbit link establishment based on the orbit and attitude data, and simulate the star open loop pointing test based on the star map projected by the star simulator at a target time point in the process of movement; wherein the first orbit and attitude data and the second orbit and attitude data of the target time point are included in the orbit and attitude data.

[0041] The second aspect of the present specification provides a star open loop pointing test device, applied to a star open loop pointing test system, wherein the star open loop pointing test system at least includes a turntable, a laser terminal installed on the turntable, and a star simulator, and the device includes:

[0042] A calibration module is configured to calibrate device coordinate systems and conversion relationships between the device coordinate systems, wherein the device coordinate systems at least include a reference coordinate system of the turntable, a zero-point coordinate system of the turntable, a coordinate system of the laser terminal, a coordinate system of the star simulator, and a star map coordinate system.

[0043] A processing module is configured to obtain and determine first orbit and attitude data of a first satellite corresponding to the laser terminal and second orbit and attitude data of a second satellite, and determine laser link information of the first satellite and the second satellite;

[0044] A test module is configured to project a star map corresponding to a target star based on the laser link information and the conversion relationships between the device coordinate systems by the star simulator, so that the laser terminal simulates the star open loop pointing test based on the star map.

[0045] The third aspect of the present specification provides an electronic device, including a processor and a memory for storing processor-executable instructions, and the processor executes the instructions to implement the steps of the method of the first aspect.

[0046] The fourth aspect of the present specification provides a computer storage medium, which stores computer program instructions, and the computer program instructions are executed by a processor to implement the steps of the method of the first aspect.

[0047] The fifth aspect of the present specification provides a computer program product, which contains a computer program, and the computer program is executed by a processor to implement the steps of the method of the first aspect.

[0048] The star open-loop pointing test method, device and electronic equipment provided in the embodiments of the present specification calibrate the device coordinate systems and the conversion relationship between the device coordinate systems; obtain and determine the first satellite and the second satellite first track attitude data corresponding to the laser terminal, and the second track attitude data of the second satellite, to determine the laser link information of the first satellite and the second satellite; and project the star map corresponding to the target star based on the laser link information and the conversion relationship between the device coordinate systems by using the star simulator, so that the laser terminal simulates the star open-loop pointing test based on the star map. Through the calibration of the device coordinate systems and the conversion relationship between the device coordinate systems, the equivalent, conversion and unified relationship between each space coordinate system involved in the laser terminal in the on-orbit link star open-loop pointing environment and each device coordinate system in the ground test simulation environment can be established, and based on this, the star map can be corrected in deviation when projecting the star map by combining the conversion relationship between the device coordinate systems and the laser link information between the simulated satellites, so as to ensure the spatial accuracy of the indoor star open-loop pointing test, and obtain more accurate and reliable test results. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0050] Figure 1 A schematic diagram of a star open-loop pointing test method provided by the embodiments of the present specification is shown;

[0051] Figure 2 A schematic diagram of a star open-loop pointing test system provided by the embodiments of the present specification is shown;

[0052] Figure 3 A schematic diagram of a coordinate system deviation determination method provided by the embodiments of the present specification is shown;

[0053] Figure 4 A schematic diagram of a deviation correction amount determination method provided by the embodiments of the present specification is shown;

[0054] Figure 5 A schematic diagram of a device coordinate system provided by the embodiments of the present specification is shown;

[0055] Figure 6 A schematic diagram of a device coordinate system and a satellite orbit coordinate system provided by the embodiments of the present specification is shown;

[0056] Figure 7A schematic diagram of internal coordinate system relationship of a star simulator is shown.

[0057] Figure 8 A schematic diagram of a star open-loop pointing test device is shown.

[0058] Figure 9 A schematic diagram of an electronic device is shown. DETAILED DESCRIPTION

[0059] In order to enable persons skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should fall within the scope of protection of the present application.

[0060] It should be noted that the terms "first", "second", and the like in the description and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, device, product or apparatus that includes a series of steps or units does not necessarily have to be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or apparatus.

[0061] The present specification provides method operation steps as described in the embodiments or flowcharts, but can include more or fewer operation steps based on routine or non-creative labor. The order of steps listed in the embodiments is only one of the many execution orders of the steps, and does not represent the only execution order. In actual system or device product execution, the method order shown in the embodiments or drawings can be executed in sequence or in parallel.

[0062] It should be noted that the information (including but not limited to user terminal device information, user personal information, etc.) involved in the present application is all information and data authorized by the user or authorized by all parties, and the acquisition, transmission, storage, use and processing of the relevant data comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0063] It should be noted that in the embodiments of the present specification, some industry solutions such as certain software, components, models, etc. may be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility in the implementation of the technical solutions of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0064] The star open-loop pointing is that the laser terminal uses the star sensor on the laser terminal to take pictures of the stars in the link pointing sky region in real time during the link maintaining process, solves the star sensor attitude quaternion in real time, and then solves the pointing difference of the laser terminal. The core of the attitude solution is to match the direction vector of the photographed star in the star sensor and the direction vector of the star in the inertial coordinate system in theory by taking the star in the link pointing sky region by the star sensor, to solve the rotation matrix from the satellite body coordinate system to the inertial coordinate system, so as to obtain the attitude quaternion. The star sensor on the laser terminal follows the pointing change of the link, and the pointing difference of the laser terminal is contained in the solved attitude quaternion. The pointing difference of the laser terminal can be solved by combining the CPA theory of the laser terminal, the actual pointing position, the star sensor solved attitude quaternion, and the installation matrix. When the star open-loop pointing is verified on the ground, it is crucial to have a verification environment that effectively simulates the satellite orbit, attitude motion, and dynamic change of the star map of the link pointing sky region following the orbit.

[0065] In some implementation scenarios, the state of the satellite and the state of the ground operation and control center are simulated on the ground when the laser communication payload is calibrated on orbit. A target star is selected, the selected star position is framed and broadcast to the laser payload by the simulation center machine, the laser payload points to the target star on the ground, and the star calibration is performed. However, the method has a large difference between the laser terminal in the geostationary coordinate system and the orbit, the link pointing sky region, and the dynamic star background, and cannot effectively simulate the orbit, the attitude, and the dynamic star map background of the pointing sky region. In addition, since the verification is performed outdoors, it is limited and uncontrollable by weather conditions, and the verification accuracy and reliability are difficult to guarantee.

[0066] In view of the problems in the above implementation scenarios, the embodiments of the present application establish an equivalent, transformation, and unified relationship between each spatial coordinate system involved in the laser terminal on-orbit link star open-loop pointing environment and each coordinate system in the ground test simulation environment, to provide a spatial reference for indoor equivalent simulation of the laser on-orbit star open-loop pointing environment, and to realize the laser terminal star open-loop pointing process and precision verification.

[0067] Based on this, the embodiments of the present specification provide a star open-loop pointing test method, which can be applied to a star open-loop pointing test system, wherein the star open-loop pointing test system at least comprises a laser terminal, a turntable (such as a two-dimensional turntable, etc.), and a star simulator. Figure 1 A schematic diagram of a star open-loop pointing test method provided by the embodiments of the present specification is shown. As shown in Figure 1As shown, the star open-loop pointing test method can include:

[0068] S101: calibrate each device coordinate system and the conversion relationship between each device coordinate system, wherein the device coordinate system at least includes the reference coordinate system of the turntable, the zero point coordinate system of the turntable, the coordinate system of the laser terminal, the coordinate system of the star simulator, and the star map coordinate system.

[0069] Correspondingly, the conversion relationship between each device coordinate system can include: the conversion relationship between the reference coordinate system and the zero point coordinate system, the conversion relationship between the reference coordinate system and the coordinate system of the laser terminal, the conversion relationship between the reference coordinate system and the coordinate system of the star simulator, the conversion relationship between the coordinate system of the star simulator and the star map coordinate system, the conversion relationship between the zero point coordinate system and the coordinate system of the laser terminal, and the conversion relationship between the coordinate system of the laser terminal and the coordinate system of the star simulator.

[0070] S102: Obtain and determine the laser link information of the first satellite and the second satellite according to the first track attitude data of the first satellite corresponding to the laser terminal and the second track attitude data of the second satellite.

[0071] It can be understood that the star open-loop pointing test can include the pointing process of the laser terminal of the laser terminal corresponding to the target star, the pointing deviation correction, the corrected star open-loop pointing accuracy and other test links. Among them, the laser terminal corresponding to the star can be used as the measured laser terminal, which can be simulated through the laser terminal in step S102. The star in the embodiment of the present specification is the first satellite, and the corresponding target star is the second satellite, and the laser terminal in step S102 is the laser terminal corresponding to the first satellite. Of course, in other embodiments, the first satellite can also be the target star, and the second satellite can be the star, and the corresponding laser terminal of the second satellite is the laser terminal in step S102.

[0072] It can be understood that the first track attitude data and the second track attitude data can be track attitude data with a time stamp, and the first track attitude data and the second track attitude data can correspond to the same time stamp, and the first satellite under the first track attitude data and the second satellite under the second track attitude data can be captured and maintained through the laser communication link of the laser terminal.

[0073] S103: Project the star map corresponding to the target star based on the laser link information and the conversion relationship between each device coordinate system using the star simulator, so that the laser terminal simulates the star open-loop pointing test based on the star map.

[0074] In the embodiments of the present specification, through the calibration of each device coordinate system and the conversion relationship between each device coordinate system, the various space coordinate systems involved in the laser terminal in-orbit link star open-loop pointing environment and the various device coordinate systems in the ground test simulation environment can be established equivalent, transformed and unified relationship. Based on this, when projecting the star map, the star map can be corrected in combination with the conversion relationship between the device coordinate systems and the laser link information between the simulated satellites, so as to ensure the spatial accuracy of the indoor star open-loop pointing test and obtain more accurate and reliable test results.

[0075] The star open-loop pointing test system in the embodiments of the present specification can be a system deployed on the ground indoors for simulating the in-orbit star open-loop pointing verification environment of a satellite and performing star open-loop pointing tests. Figure 2 As shown in the drawings, the star open-loop pointing test system provided by the embodiments of the present specification can at least include a turntable (for example, a two-dimensional turntable), a star simulator, a laser terminal and the like.

[0076] Among them, the turntable, the star simulator and the laser terminal can be deployed with corresponding protocol rules, such as UDP (User Datagram Protocol, User Datagram Protocol) protocol and the like. The star simulator can be arranged corresponding to the laser terminal.

[0077] Among them, the turntable can be used to simulate the orbit and attitude motion of the star during the star open-loop pointing test process, and the laser terminal is arranged on the turntable and can be used to simulate the motion of the laser load on the target satellite during the star calibration process; the star simulator can be used to simulate the target star during the star calibration process. The laser terminal can be specifically provided with a laser generator, a laser receiver, a star sensor (or a star sensor). The star simulator can be specifically provided with a star map projection unit for projecting a star map and the like. In specific implementation, the turntable control quantity can be determined based on the obtained orbit and attitude data to drive the motion of the turntable, and a dynamic orbit simulation environment can be provided; the laser terminal can obtain and calculate the pointing vector based on the orbit and attitude data. Further, since the motion of the driven turntable cannot accurately simulate the orbit and attitude data of the star, the satellite orbit motion can be compensated in real time by the laser terminal and pointed to the target star under the unified time reference, so as to provide a basis for subsequent star open-loop pointing tests.

[0078] In some embodiments of the present specification, the star open-loop pointing test system further comprises a time system device and a data processing end, and the method further comprises: using the time system device to perform corresponding time alignment processing on the laser terminal, the turntable and the star simulator; using the data processing end to send the orbit and attitude data with time stamps to the turntable and the laser terminal at a first advance time point, so that the turntable and the laser terminal simulate the orbit and attitude of the first satellite and the second satellite in orbit link establishment based on the orbit and attitude data, and simulate the star open-loop pointing test based on the star map projected by the star simulator at the target time point in the process of movement; wherein the orbit and attitude data include the first orbit and attitude data and the second orbit and attitude data at the target time point.

[0079] Specifically, the star open-loop pointing test system can further comprise a time system device, a laser engineering data workstation, a terminal ground detector, and a turntable controller (for example, a two-dimensional state controller).

[0080] The time system device can be connected to the laser engineering data workstation, the terminal ground detector, the turntable, the turntable controller and the laser terminal through wired or wireless means. The laser engineering data workstation can be connected to the terminal ground detector and the turntable controller, and the laser engineering data workstation, the laser terminal, the terminal ground detector, the turntable and the turntable controller can also be deployed with corresponding protocol rules. The turntable controller can be connected to the turntable. The terminal ground detector can be connected to the laser terminal.

[0081] The laser engineering data workstation can be used to obtain or generate the orbit and attitude data of the first satellite and the second satellite, and send the orbit and attitude data of the first satellite to the turntable controller and the orbit and attitude data of the first satellite and the second satellite to the terminal ground detector according to the broadcast protocol of the orbit and attitude data. Further, the orbit and attitude data sent to the turntable controller can also be fused with disturbance data, which can include but is not limited to orbit and attitude disturbance, orbit extrapolation error, and inter-satellite laser pointing error. The disturbance data can be simulated by the turntable. The turntable controller can be used to drive the turntable according to the orbit and attitude data of the first satellite to provide a dynamic orbit simulation environment; the terminal ground detector can be used to broadcast the orbit and attitude data of the first satellite and the second satellite to the laser terminal, so that the laser terminal compensates the current orbit and attitude of the laser terminal, and can calculate the pointing vector according to the orbit and attitude data of the two satellites to correct the star open-loop pointing. The time system device can be used to provide a unified clock source for the laser engineering data workstation, the turntable controller, the terminal ground detector and the laser terminal.

[0082] In some embodiments of the present disclosure, a user can select orbit and attitude data of a test period, such as orbit and attitude data of a continuous orbit period, convert the orbit and attitude data of the test period into a format file recognizable by the laser engineering data workstation, such as a CSV / TXT file, and write the file into the laser engineering data workstation. In turn, the laser engineering data workstation can obtain the orbit and attitude data from the file. The orbit and attitude data can be simulation orbit and attitude data, or in-orbit data of the first satellite and the second satellite, and the orbit and attitude data can include, but is not limited to, system real-time time broadcast, J2000 position, velocity and timestamp of the present star and other stars, present star attitude quaternion and roll, pitch, yaw attitude angle, angular velocity and timestamp (including T0, T0+250 milliseconds (ms), T0+500 ms, T0+750 ms four sets of attitude data), solar vector, etc. The orbit and attitude data have a timestamp (i.e., a given timestamp), and T0 is the starting timestamp (i.e., the initial time point) of the orbit and attitude data.

[0083] It can be understood that the orbit and attitude data have a given timestamp. The format of the orbit and attitude data with the given timestamp specified in the broadcast protocol can include a transmission protocol and a file format, etc. The transmission protocol can be a User Datagram Protocol (UDP) or other transmission protocol, and the file format can be a CSV / TXT file format or other file format. The first advance time point can be determined according to the transmission delay between the laser engineering data workstation and the terminal ground station, and the transmission delay between the laser engineering data workstation and the turntable controller, for example, the first advance time point can be 1 second (s), 2 s, etc. The preset broadcast frequency can be determined according to the interval of the given timestamp of the orbit and attitude data. For example, if the interval of the given timestamp is 1 s, the preset broadcast frequency can be 1 / 1 s = 1 Hz; if the interval of the given timestamp is 0.1 s, the preset broadcast frequency can be 1 / 0.1 s = 10 Hz.

[0084] In some embodiments of the present disclosure, the time alignment processing of the data processing end, the laser terminal, the ground station terminal, the turntable, the turntable controller, and the star simulator, etc. by the time system device can include: sending a preset time code to the data processing end, sending a preset trigger signal to the turntable, sending a preset time code and a preset trigger signal to the turntable controller, sending a preset time code, a preset trigger signal and a preset transmission configuration signal to the ground station terminal, and sending a preset trigger signal and a preset transmission configuration signal to the laser terminal.

[0085] It can be understood that the preset trigger signal can be specifically a 1PPS signal. 1PPS (1 Pulse Per Second) can specifically refer to one pulse per second. In specific implementation, the corresponding synchronization triggering can be performed using the preset trigger signal. The preset transmission configuration signal can be specifically 10M / 100M. The 10M / 100M signal is used to define that the upper limit of the speed of data transmission is 10 Mbps (Megabit per second) or 100 Mbps. In specific implementation, the preset transmission configuration signal can be used, and the communication efficiency and network performance are taken into account at the same time, so as to ensure the communication quality based on the laser link. The time code can be specifically used to unify the time reference of different devices in the star open-loop pointing test system.

[0086] In the embodiments of the present specification, by using the time code, the preset trigger signal, the preset transmission configuration signal, and combining the track and attitude data carrying the timestamp, the time alignment processing for the star open-loop pointing test system can be accurately and comprehensively completed, so that the error caused by the time delay and the like in the subsequent test process can be avoided.

[0087] In specific implementation, the process of implementing the star open-loop pointing verification by using the star open-loop pointing test system is as follows: the star open-loop pointing test system simulates the on-orbit chain building of the satellite-borne laser terminal, the orbits and attitudes of double stars, and the star background of the link pointing sky area, so as to provide the spatial environment equivalent to the on-orbit star open-loop pointing for the laser terminal. The turntable simulates the satellite orbit and attitude movement. The star simulator simulates the dynamic change of the star background of the link pointing sky area according to the input double star coordinates, and the irradiance meets the star rating requirement. The measured laser terminal is installed on the turntable. Under the unified time reference, the laser terminal compensates the attitude and orbit in real time. The laser terminal star sensor aligns the star simulator to start shooting the star and calculate the laser terminal pointing difference in real time, so as to develop the indoor star open-loop pointing verification.

[0088] In some embodiments of the present specification, the star chart projected by the star simulator is the star background of the laser link direction sky area of the first satellite and the second satellite.

[0089] It can be understood that after the device coordinate systems and the conversion relationship between the device coordinate systems are calibrated, the star map coordinate system is an initial coordinate system of the star map, the coordinate origin of the initial coordinate system is defined at the center of the exit pupil of the optical system of the star simulator, the Z-axis direction is the exit direction of the optical axis (at this time, the initial optical axis coincides with the Z-axis of the inertial coordinate system), and the X-axis and the Y-axis are two orthogonal axes perpendicular to the optical axis and determined by the right-hand rule. When the star simulator projects the star map, the central optical axis of the projected star map needs to be determined. In order to make the center of the projected star map in the direction of the optical axis of the laser terminal, the central optical axis of the star map coordinate system needs to be rotated to the direction of the optical axis of the laser terminal, that is, the direction of the laser link. At this time, the star map coordinate system is rotated relative to the initial coordinate system, and the projected star map is the star map (that is, the star background) of the sky area in the direction of the double-star laser link.

[0090] In some embodiments of the present specification, calibrating the device coordinate systems and the conversion relationship between the device coordinate systems includes: calibrating the position and direction of each device coordinate system and the coordinate system deviation between the device coordinate systems; and determining the deviation correction amount between the device coordinate systems as the conversion relationship between the device coordinate systems based on the coordinate system deviation between the device coordinate systems.

[0091] It can be understood that the position and direction of the device coordinate system can be represented by a position vector, for example, can include the position vector of the reference coordinate system of the turntable, the position vector of the zero-point coordinate system of the turntable, the position vector of the coordinate system of the laser terminal, the position vector of the coordinate system of the star simulator, and the position vector of the initial coordinate system of the star map. Then, when determining the coordinate system deviation between the coordinate systems, the position vectors of the device coordinate systems can be calibrated, and the deviations between the position vectors, such as the direction deviation, can be calibrated at the same time. Then, the deviation correction amount between the device coordinate systems can be determined based on the deviation of the position vectors. Further, since the deviation of the position vectors of some coordinate systems cannot be directly measured and calibrated, the deviation correction amount between the device coordinate systems can be obtained by transformation based on the measured and calibrated deviation, so as to realize the unification of the spatial reference between the devices.

[0092] Reference Figure 3 In some embodiments of the present specification, calibrating the position and direction of each device coordinate system and the coordinate system deviation between the device coordinate systems can include:

[0093] S301: installing a zero-point measuring tool at the zero-point position of the turntable, representing the reference coordinate system of the turntable by a first cube mirror installed at the reference position of the turntable, and representing the zero-point coordinate system of the turntable by a second cube mirror;

[0094] S302: optically measuring the first cube mirror and the second cube mirror by using the theodolite to determine the first coordinate system deviation between the first cube mirror and the second cube mirror;

[0095] S303: install the laser terminal on the zero point position of the turntable, represent the zero point coordinate system of the turntable through a third cube mirror installed on the laser terminal, and represent the coordinate system of the star simulator through a fourth cube mirror installed on the star simulator;

[0096] S304: define the coordinate system of the star map projected by the star simulator, and perform optical measurement on the first cube mirror and the third cube mirror, the first cube mirror and the fourth cube mirror, and the fourth cube mirror and the coordinate system of the star map by using the theodolite to determine a second coordinate system deviation between the first cube mirror and the third cube mirror, a third coordinate system deviation between the first cube mirror and the fourth cube mirror, and a fourth coordinate system deviation between the fourth cube mirror and the coordinate system of the star map.

[0097] It can be understood that the zero point coordinate system of the turntable can be equivalent to the orbit coordinate system of the spaceborne laser terminal in orbit, the laser terminal coordinate system can be equivalent to the coordinate system of the spaceborne laser terminal, and the coordinate system of the star simulator can be equivalent to the coordinate system of the star in orbit. The coordinate system deviation can be used to represent the overall system deviation relative to the true star open-loop pointing correction of the satellite in orbit when the simulated star open-loop pointing test is performed on the ground by using the star open-loop pointing test system, and then, based on the determined coordinate system deviation, the deviation correction amount between the coordinate systems can be further determined to establish an equivalent, transformation and unified relationship between the various spatial coordinate systems (including the J2000 inertial coordinate system, the satellite orbit coordinate system, and the laser terminal coordinate system) involved in the laser terminal in-orbit link star open-loop pointing environment and the coordinate systems (the turntable coordinate system, the laser terminal coordinate system, and the star map coordinate system) in the ground test simulation environment, to realize the indoor equivalent simulation of the laser in-orbit star open-loop pointing environment, and to provide a spatial reference for the laser terminal star open-loop pointing process and precision verification.

[0098] Reference Figure 4 As shown in the drawings, in some embodiments of the present application, the deviation correction amount between the device coordinate systems is determined based on the coordinate system deviation between the device coordinate systems, which includes:

[0099] S401: based on the coordinate system deviation, the direction cosine corresponding to the coordinate system deviation is determined as the deviation correction amount between the corresponding device coordinate systems;

[0100] S402: based on the first deviation correction amount between the reference coordinate system and the zero point coordinate system, and the second deviation correction amount between the reference coordinate system and the coordinate system of the laser terminal, the third deviation correction amount between the zero point coordinate system and the coordinate system of the laser terminal is determined;

[0101] S403: determining a sixth deviation correction amount between the star map coordinate system and the laser terminal coordinate system based on a fourth deviation correction amount between the reference coordinate system and the coordinate system of the star simulator, a fifth deviation correction amount between the coordinate system of the star simulator and the star map coordinate system, and the second deviation correction amount.

[0102] It can be understood that since the relationship between the coordinate system of the laser terminal and the zero point coordinate system of the turntable, and the relationship between the coordinate system of the laser terminal and the coordinate system of the star simulator cannot be accurately obtained, the conversion relationship between the coordinate system of the laser terminal and the zero point coordinate system of the turntable, and the conversion relationship between the coordinate system of the laser terminal and the coordinate system of the star simulator can be determined by defining the reference coordinate system of the turntable and calibrating the conversion relationship between the reference coordinate system and the coordinate system of each device, thereby providing a basis for subsequent unification of the space reference.

[0103] In some embodiments of the present specification, the process of calibrating each device coordinate system and the conversion relationship between each device coordinate system can be as follows:

[0104] Referring to Figure 5 , the orbit coordinate system of the target satellite is defined as XYZ, X points to the orbit advancing direction, Z direction points to the center of the earth, and Y direction is the right-hand direction of X and Z. The zero point coordinate system X2Y2Z2 of the turntable is equivalent to the satellite orbit coordinate system XYZ, which is represented by a cube mirror 2 placed on the zero point measurement tool of the turntable, wherein X2 / / X, Y2 / / Y, and Z2 / / Z are consistent in direction, and the position vector of the cube mirror 2 is ; the coordinate system X3Y3Z3 of the laser terminal is represented by a cube mirror 3 thereon, and the position vector of the cube mirror 3 is ; the reference coordinate system X1Y1Z1 of the turntable is represented by a cube mirror 1 installed on the side surface of the turntable, and the position vector of the cube mirror 1 is , which is used to calibrate the initial coordinate relationship of the laser terminal and the zero point coordinate system of the turntable. Referring to Figure 6 , the coordinate system of the star simulator is established by installing a cube mirror 4 on the star simulator, which is defined as X4Y4Z4, and the position vector of the cube mirror 4 is . The initial coordinate system of the star map is defined as X5’Y5’Z5’, which is equivalent to the inertial (i.e. J2000) coordinate system XJ2000YJ2000ZJ2000, wherein X5’ / / XJ2000, Y5’ / / YJ2000, and Z5’ / / ZJ2000 are consistent in direction; the star map coordinate system of the projected star map is defined as X5Y5Z5, wherein X5 is the long side of the star map projection plate, Y5 is the short side of the star map projection plate, and Z5 is the direction of the terminal pointed by the simulated target star. Each coordinate system satisfies the right-hand rule.

[0105] Further, the calibration of the conversion relationship between the coordinate systems of the devices can include: calibration of the relationship between the zero point coordinate system of the turntable and the reference coordinate system of the turntable, calibration of the relationship between the laser terminal coordinate system and the reference coordinate system of the turntable, calibration of the relationship between the star simulator coordinate system and the reference coordinate system of the turntable, and calibration of the relationship between the star simulator coordinate system and the initial coordinate system of the star map.

[0106] In some embodiments of the present specification, the calibration of the relationship between the zero point coordinate system of the turntable and the reference coordinate system of the turntable can specifically include: when the inter-satellite laser terminal performs link establishment at both ends, the light source of the receiving optical fiber originates from the collimator, and therefore the parallelism of the plane formed by the collimator camera and the two axes of the two-dimensional turntable needs to be calibrated. Specifically, the light emitted by the receiving optical fiber and the collimator is reflected backward by the zero point cube mirror 2 of the turntable, and a light spot is presented on the camera of the collimator. The calibration device is used to make the light spot at the best optical fiber coupling position (X0, Y0) of the collimator camera, and the azimuth pointing angle and the elevation pointing angle (A0, E0) corresponding to this position are the zero point position of the turntable, which is also the spatial zero point of the alignment of the turntable and the simulated track. The theodolite is used to calibrate the zero point cube mirror 2 of the turntable and the reference cube mirror 1 of the turntable, and the measurement is shown in Figure 5 The position vector of the reference coordinate system of the turntable is The position vector of the zero point coordinate system of the turntable is and the mutual conversion relationship (for example, it can be represented as a conversion matrix C 12 from the reference coordinate system to the zero point coordinate system of the turntable) is obtained. The collimator can be arranged corresponding to the cube mirror 2.

[0107] In some embodiments of the present specification, the calibration of the relationship between the laser terminal coordinate system and the reference coordinate system of the turntable can specifically include: the laser terminal to be measured is fixedly installed on the turntable; the collimator and the laser of the laser terminal are turned on to emit light at both ends and point to each other; the azimuth pointing angle and the elevation pointing angle of the laser terminal are adjusted to make the optical axis of the laser terminal and the optical axis of the collimator coaxial, which is specifically embodied in that the laser terminal and the focal plane camera of the collimator simultaneously observe a complete and regular circular light spot, and the light spot is located in the center of the field of view of the camera. The azimuth pointing angle and the elevation pointing angle A0' and E0' of the laser terminal at this time are recorded as the zero point of the laser terminal. The theodolite is used to calibrate the cube mirror 3 corresponding to the laser terminal and the reference cube mirror 1 of the turntable, as shown in Figure 6 The position vector of the reference coordinate system of the turntable is The position vector of the laser terminal coordinate system is and the mutual conversion relationship (for example, it can be represented as a conversion matrix C 13). Further, based on the conversion relationship between the zero point coordinate system of the turntable and the reference coordinate system of the turntable, the conversion relationship between the coordinate system of the laser terminal and the zero point coordinate system of the turntable can be calculated. The collimator can be arranged corresponding to the laser terminal.

[0108] In some embodiments of the present specification, the relationship between the star simulator coordinate system and the reference coordinate system of the turntable can specifically include: placing the turntable and the laser terminal at the initial position of the orbit (i.e. the zero point position), keeping the zero point position. Install the star simulator in front of the terminal, the star simulator projects the calibration star map, adjust the star simulator tool to the star sensitive of the laser terminal, the star map can be captured and the four-element number can be successfully solved, and when the visual light axis deflection angle is less than or equal to 3°, it is determined as the alignment position. After the four-element number is solved, the turntable is returned to the zero point, and the theodolite is used to accurately measure the corresponding cube mirror 4 of the star simulator and the cube mirror 1 of the turntable, as shown in Figure 6 , the position vector of the reference coordinate system of the turntable is obtained as , and the position vector of the star simulator is , and the mutual conversion relationship (for example, which can be represented as a conversion matrix C 14 from the reference coordinate system to the coordinate system of the star simulator) is Further, combined with the conversion relationship between the zero point coordinate system of the turntable and the reference coordinate system of the turntable, the conversion relationship between the coordinate system of the star simulator and the zero point coordinate system of the turntable can be calculated.

[0109] In some embodiments of the present specification, the initial coordinate system of the star map is equivalent to the inertial coordinate system, so that the conversion relationship between the star simulator coordinate system and the initial coordinate system of the star map can be calibrated by measuring the conversion relationship between the cube mirror 4 and the inertial coordinate system. Specifically, the non-contact optical measurement of the cube mirror 4 and the cube mirror representing the inertial coordinate system can be used to determine the direction cosine between them as the conversion relationship between the star simulator coordinate system and the initial coordinate system of the star map. The coordinate system position vector of the star simulator measured by the theodolite is , and the position vector of the initial coordinate system of the star map is , and the mutual conversion relationship (for example, which can be represented as a conversion matrix C M4 from the reference coordinate system to the coordinate system of the laser terminal) is

[0110] The conversion relationship between the above-mentioned coordinate systems of each device can be as follows: the measurement matrix C 12 is measured and determined between the zero point coordinate system X2Y2Z2 of the turntable and the reference coordinate system X1Y1Z1 of the turntable; the measurement matrix C14 is measured and determined between the coordinate system X4Y4Z4 of the star simulator and the reference coordinate system X1Y1Z1 of the turntable; and the measurement matrix C 13; the measurement matrix C of the coordinate system X4Y4Z4 of the star simulator and the initial coordinate system X5'Y5'Z5' of the star map M4 . Then, the coordinate conversion relationship is as shown below:

[0111] Formula (1)

[0112] Formula (2)

[0113] Formula (3)

[0114] Formula (4)

[0115] From the conversion relationship between the above-mentioned coordinate systems, the direction vector of the laser terminal pointing and the projected star map direction vector represented by the zero point coordinate system of the turntable can be derived:

[0116] Formula (5)

[0117] Formula (6)

[0118] In some embodiments of the present specification, the first track attitude data and / or the second track attitude data at least include: track position data in an inertial coordinate system, velocity data of the satellite, Euler angles, and quaternions.

[0119] Based on the foregoing star open-loop pointing test system, before projecting the star map, orbit dynamic simulation of the target star and / or the target star (including the target star and the target star) needs to be performed, and then during the orbit dynamic simulation, the target star can be simulated to build a chain of satellites, and based on a unified time reference, the star map is projected, the target star pointing difference is calculated, corrected, and the correction accuracy is tested.

[0120] In some embodiments of the present specification, based on the foregoing established unified space reference, the orbit dynamic simulation can be realized by sending the orbit and attitude data of the target star in the inertial coordinate system and the orbit position data of the target star to the laser terminal and the turntable.

[0121] Specifically, the data used in the orbit dynamic simulation can include the orbit position, velocity, Euler angles and quaternions of the target star in the J2000 inertial coordinate system. The position vectors of the target star A and the target star B in the inertial coordinate system (i.e. J2000 system) can be set as (X1, Y1, Z1) and (X2, Y2, Z2) respectively, and the pointing vector of the target star A to the target star B is:

[0122] Formula (7)

[0123] The pointing vector is converted to the orbit coordinate system VVLH under the Euler angle measured at J2000 (the default orbit coordinate system coincides with the target satellite body coordinate system, 312 rotation sequence), and the attitude conversion matrix used is R 312 The pointing vector in the inertial coordinate system is converted to the orbit coordinate system, which can be expressed as:

[0124] Formula (8)

[0125] Where, r VVLH The position vector of the reference coordinate system of the turntable can be equivalent to Based on the conversion matrix in the foregoing, the pointing vector in the orbit coordinate system can be converted to the coordinate system of the laser terminal, which can be expressed as:

[0126] Formula (9)

[0127] The azimuth pointing angle θ Az and the pitch pointing angle θ El of the laser terminal can be calculated based on the pointing vector in the laser terminal coordinate system, which can be calculated by the following formula:

[0128] Formula (10)

[0129] Since the turntable and the laser terminal move in opposite directions, the azimuth pointing angle and the pitch pointing angle of the turntable are-θ Az and-θ El Therefore, the control quantity of the turntable can be expressed as:

[0130] Formula (11)

[0131] Where, A can represent the azimuth pointing angle of the state, and E can represent the pitch pointing angle of the turntable.

[0132] Further, the turntable controller can drive the turntable to move based on the control quantity of the turntable, so as to realize orbit dynamic simulation.

[0133] Further, in the process of orbit dynamic simulation, the laser link between the two satellites can be simulated, at this time, the real-time dynamic star map, that is, the dynamic star map simulation, can be projected by the star simulator, so that the laser terminal star sensor can be aligned with the star simulator to start shooting stars and calculate the pointing difference of the laser terminal in real time, and the indoor star open-loop pointing verification can be carried out. In the process of dynamic star map simulation, the laser link information of the two stars, such as the laser link direction, needs to be determined, and then the star map initial coordinate system is rotated to the laser link direction, so that the center of the projected star map is in the optical axis direction of the laser terminal, and then the real-time dynamic star map is projected based on the rotated star map coordinate system, so as to realize dynamic star map simulation.

[0134] Specifically, determining the laser link information of the first satellite and the second satellite according to the first orbit and attitude data of the first satellite corresponding to the laser terminal and the second orbit and attitude data of the second satellite can include: determining first position data of the first satellite in an inertial coordinate system and second position data of the second satellite in the inertial coordinate system based on the first orbit and attitude data and the second orbit and attitude data; and determining, as the laser link information, a pointing vector of the first satellite to the second satellite in the inertial coordinate system based on the second position data and the second position data.

[0135] It can be understood that the pointing vector in the embodiments of the present specification can be expressed as the pointing vector of the star A to the target star B in the inertial coordinate system in the foregoing as r AB The calculation process of the pointing vector in the inertial coordinate system can be implemented by using the control software corresponding to the data processing terminal, the laser terminal, and the star simulator in the foregoing star open-loop pointing test system. In the case of calculating the pointing vector by using the devices such as the data terminal and the laser terminal, the pointing vector in the inertial coordinate system can be sent to the control software of the star simulator based on the broadcast protocol established between the devices. Then, the control software of the star simulator can determine the control signal of the star simulator projection star map, such as the star map projection control quantity, based on the pointing vector in the inertial coordinate system and the conversion relationship between the coordinate systems of the devices, and send the control signal to the star simulator to drive the star simulator to project the real-time dynamic star map.

[0136] In a specific implementation scenario, the turntable controller can start from the time T0 (i.e., the initial time point) and send the corresponding control quantity to the turntable at 10 Hz to control the turntable to rotate to simulate the relative angular negative direction motion of the double stars, and the closed-loop control period of the turntable is less than or equal to 0.12 ms. The data processing terminal can inject the orbit and position data at a first advance time point (for example, 1 second before the initial time point) into the terminal ground station at 1 Hz through the UDP protocol. After the terminal ground station receives the data, the terminal ground station frames and broadcasts the data to the laser terminal according to the on-board format to drive the laser terminal to compensate for the satellite orbit motion and point to the corresponding laser terminal of the target star. The data processing terminal can load the position data in the J2000 coordinate system of the star A and the target star B (the conversion matrix between the turntable zero-point coordinate system and the star simulator coordinate system can be superimposed on the position data) into the star simulator control software, so that the star simulator control software determines the star map projection control quantity based on the received orbit and position data. The star simulator software is installed in the data processing terminal, reads the system time in real time, and sends the star map projection control quantity to the star simulator at a frequency of 20 Hz, so that the star simulator can project the dynamic star map based on the star map projection control quantity.

[0137] In some embodiments of the present disclosure, projecting a star map corresponding to a target star based on the laser link information and the conversion relationship between the coordinate systems of the devices can include: determining a star map projection control quantity of the star simulator for projecting the star map based on the laser link information and the conversion relationship between the coordinate systems of the devices; and projecting the star map in the laser link direction sky region of the first satellite and the second satellite based on the star map projection control quantity by using the star simulator.

[0138] In some embodiments of the present disclosure, determining a star map projection control quantity of the star simulator for projecting the star map based on the laser link information and the conversion relationship between the coordinate systems of the devices can include: converting a pointing vector from the first satellite to the second satellite in the laser link information in the inertial coordinate system to a target direction vector in the star map coordinate system based on the conversion relationship between the coordinate systems of the devices; and determining a rotation quaternion of a central optical axis of the star map coordinate system to the target direction vector, and taking the rotation quaternion as the star map projection control quantity.

[0139] Specifically, based on the foregoing formula (6) and formula (8), the conversion relationship between the pointing vector in the star map initial coordinate system and the inertial coordinate system can be obtained, which can be represented by the following formula:

[0140] Formula (12)

[0141] wherein, represents a pointing vector from the first satellite to the second satellite in the laser link information in the inertial coordinate system, C M4 represents a conversion relationship from the star map coordinate system to the star simulator, C 14 represents a conversion relationship from the reference coordinate system to the star simulator, C 12 represents a conversion relationship from the reference coordinate system to the zero point coordinate system.

[0142] After obtaining the target vector, the optical axis of the star map initial coordinate system needs to be rotated to the bidirectional chain building direction to obtain the star map projection control quantity. Specifically, the star map projection control quantity can be determined by the following formula:

[0143] Formula (13)

[0144] wherein, q represents a rotation quaternion of the star map coordinate system, representing the star map projection control quantity. V1 represents the direction vector corresponding to the pointing vector from the first satellite to the second satellite in the laser link information under the star map coordinate system, and V1 represents the unit vector of the central optical axis of the star map coordinate system. Specifically, the initial optical axis in the star map is defined to coincide with the Z-axis of the J2000 coordinate system, and its unit vector V1 = [0; 0; 1].

[0145] In some embodiments of this specification, after determining the rotation quaternion from the central optical axis of the star map coordinate system to the target direction vector, the method may further include: normalizing the rotation quaternion and using the normalized rotation quaternion as the star map projection control quantity.

[0146] Specifically, the normalization of rotation quaternions can be achieved using the following formula:

[0147] Formula (14)

[0148] in, |q|| can represent the normalized rotation quaternion, and ||q|| can represent the Euclidean norm of the rotation quaternion.

[0149] Reference Figure 7 As shown in the figure, the internal coordinate relationship of a star simulator provided in this embodiment can be represented by the pointing vector characterizing the binary star linking direction. The coordinates are transformed to the cube mirror 4 coordinate system (i.e., the star simulator coordinate system), and then from the cube mirror 4 coordinate system to the initial coordinate system of the star map X5'Y5'Z5'. After calculating the rotation quaternion, the initial coordinate system of the star map can be rotated to the coordinate system X5Y5Z5 to obtain the star map under the digital micromirror device (DMD). The star simulator can project the star map based on the rotation quaternion and the determined positions of each star in the field of view of the laser terminal.

[0150] In some embodiments of this specification, when generating a star map, it is also necessary to determine the position of each star in the star map. Specifically, based on the star catalog, each star is determined to have a corresponding position in the J2000 coordinate system, using right ascension α. s and declination δ s If expressed in terms of direction, then the direction vector of each star in the J2000 coordinate system is:

[0151] Formula (15)

[0152] Further, an angle between a direction vector of each star in an inertial coordinate system and a pointing vector corresponding to the double star chain building direction can be calculated, and then the positions of each star in the star map are determined, and images or image identifiers of each star are generated at the corresponding positions in the star coordinate system. When projecting the star map, the rotation quaternion or the normalized rotation quaternion can be input into the star simulator. The star simulator projects the dynamic sky area of the double star chain building direction (i.e., the real-time dynamic star map) based on the rotation quaternion or the normalized rotation quaternion and the generated star map. The projection of the real-time dynamic star map can be performed by time alignment of each device through the time terminal, and the real-time dynamic star map corresponding to the chain building direction is projected while the double star chain tracking is performed under the unified time reference.

[0153] In a specific implementation, after the star simulator projects the real-time dynamic star map of the chain building direction, the star sensor of the laser terminal can be aligned with the star map to start star shooting and calculate the laser terminal pointing difference in real time, and indoor star open-loop pointing verification is performed. Specifically, the pointing difference calculation, the pointing deviation correction amount calculation, the laser terminal pointing correction, the pointing correction accuracy based on the corrected pointing deviation, and the like can be included.

[0154] The space coordinate equivalence method in the embodiments of the present specification can be applied to indoor verification of star open-loop pointing, and can achieve space equivalence of the space orbit and the star environment and the ground simulation environment. Further, based on the unified space reference, a space environment with high-fidelity simulated satellite orbit attitude and dynamic star background can be established. By superimposing the coordinate system correction amount obtained through precise measurement and coordinate transformation on the double star orbit data input into the star simulator control software, the correction from the turntable zero point coordinate to the star module coordinate system can be achieved, and the coordinate deviation correction accuracy can be ensured, thereby providing a basis for the space accuracy of the indoor star open-loop pointing verification. Further, by unifying the chain building sky area and the central optical axis direction of the star simulator, the orbit attitude can be simulated with high fidelity, and the indoor star open-loop pointing verification can be achieved.

[0155] Based on the above star open-loop pointing test method, the present specification further provides a star open-loop pointing test device. It can be understood that the device can be applied to a star open-loop pointing test system, wherein the star open-loop pointing test system at least includes a turntable, a laser terminal installed on the turntable, and a star simulator. Figure 8 As shown, the star open-loop pointing test device can include: Figure 8 As shown, the star open-loop pointing test device can include:

[0156] The calibration module 801 is configured to calibrate the coordinate systems of each device and the conversion relationship between the coordinate systems of each device, wherein the coordinate systems of each device at least include a reference coordinate system of the turntable, a zero point coordinate system of the turntable, a coordinate system of the laser terminal, a coordinate system of the star simulator, and a star map coordinate system.

[0157] The processing module 802 is configured to acquire first orbit and attitude data of a first satellite corresponding to the laser terminal and second orbit and attitude data of a second satellite, and determine laser link information of the first satellite and the second satellite.

[0158] The test module 803 is configured to project a star map corresponding to a target star based on the laser link information and a conversion relationship between coordinate systems of devices by using a star simulator, so that the laser terminal simulates star open-loop pointing test based on the star map.

[0159] In some embodiments of the present specification, the star map projected by the star simulator is a star background in a laser link direction sky area of the first satellite and the second satellite.

[0160] In some embodiments of the present specification, the calibration module 801 can be specifically configured to calibrate positions and directions of the coordinate systems of devices and coordinate system deviation amounts between the coordinate systems of devices, and determine a conversion relationship between the coordinate systems of devices as a deviation correction amount between the coordinate systems of devices based on the coordinate system deviation amounts between the coordinate systems of devices.

[0161] In some embodiments of the present specification, when calibrating the positions and directions of the coordinate systems of devices and the coordinate system deviation amounts between the coordinate systems of devices, the calibration module 801 can be specifically configured to install a zero-point measuring tool at a zero-point position of the turntable, represent a reference coordinate system of the turntable by a first cube mirror installed at a reference position of the turntable, and represent a zero-point coordinate system of the turntable by a second cube mirror, perform optical measurement on the first cube mirror and the second cube mirror by using a theodolite, and determine a first coordinate system deviation amount between the first cube mirror and the second cube mirror, install the laser terminal at the zero-point position of the turntable, represent the zero-point coordinate system of the turntable by a third cube mirror installed on the laser terminal, represent a coordinate system of the star simulator by a fourth cube mirror installed on the star simulator, define a star map coordinate system projected by the star simulator, perform optical measurement on the first cube mirror and the third cube mirror, the first cube mirror and the fourth cube mirror, and the fourth cube mirror and the star map coordinate system by using the theodolite, and determine a second coordinate system deviation amount between the first cube mirror and the third cube mirror, a third coordinate system deviation amount between the first cube mirror and the fourth cube mirror, and a fourth coordinate system deviation amount between the fourth cube mirror and the star map coordinate system.

[0162] In some embodiments of the present specification, when the calibration module 801 determines the offset correction amount between the device coordinate systems based on the coordinate system offset amount between the device coordinate systems, the calibration module 801 can be specifically configured to: determine, based on the coordinate system offset amount, the direction cosine corresponding to the coordinate system offset amount as the offset correction amount between the corresponding device coordinate systems; determine, based on the first offset correction amount between the reference coordinate system and the zero-point coordinate system, the second offset correction amount between the reference coordinate system and the coordinate system of the laser terminal, a third offset correction amount between the zero-point coordinate system and the coordinate system of the laser terminal; and determine, based on the fourth offset correction amount between the reference coordinate system and the coordinate system of the star simulator, the fifth offset correction amount between the coordinate system of the star simulator and the star map coordinate system, and the second offset correction amount, a sixth offset correction amount between the star map coordinate system and the coordinate system of the laser terminal.

[0163] In some embodiments of the present specification, the first track attitude data and / or the second track attitude data at least includes: track position data in an inertial coordinate system, velocity data of the satellite, Euler angles, and quaternions.

[0164] In some embodiments of the present specification, the processing module 802 can be specifically configured to: determine, based on the first track attitude data and the second track attitude data, first position data of the first satellite in an inertial coordinate system and second position data of the second satellite in the inertial coordinate system; and determine, based on the second position data and the second position data, a pointing vector of the first satellite to the second satellite in the inertial coordinate system as the laser link information.

[0165] In some embodiments of the present specification, the test module 803 can be specifically configured to: determine, based on the laser link information and the conversion relationship between the device coordinate systems, a star map projection control amount used by the star simulator to project the star map; and project, by the star simulator, the star map in the laser link direction sky area of the first satellite and the second satellite based on the star map projection control amount.

[0166] In some embodiments of the present specification, when the test module 803 determines, based on the laser link information and the conversion relationship between the device coordinate systems, a star map projection control amount used by the star simulator to project the star map, the test module 803 can be specifically configured to: convert, based on the conversion relationship between the device coordinate systems, the pointing vector from the first satellite to the second satellite in the laser link information in the inertial coordinate system to the star map coordinate system to obtain a target direction vector; and determine a rotation quaternion of the central optical axis of the star map coordinate system rotating to the target direction vector, and take the rotation quaternion as the star map projection control amount.

[0167] In some embodiments of the present specification, the star map projection control quantity is determined by the following formula:

[0168]

[0169] wherein q represents a rotation quaternion of the star map coordinate system, to represent the star map projection control quantity; represents a pointing vector of the first satellite to the second satellite in the star map coordinate system; represents a direction vector corresponding to the pointing vector of the first satellite to the second satellite in the star map coordinate system, and V1 represents a unit vector of a central optical axis of the star map coordinate system, represents a pointing vector of the first satellite to the second satellite in the inertial coordinate system, and C M4 represents a conversion relationship from the star map coordinate system to the star simulator, and C 14 represents a conversion relationship from the reference coordinate system to the star simulator, and C 12 represents a conversion relationship from the reference coordinate system to the zero point coordinate system.

[0170] In some embodiments of the present specification, the test module 803 can also be configured to normalize the rotation quaternion and take the normalized rotation quaternion as the star map projection control quantity.

[0171] In some embodiments of the present specification, the star open-loop pointing test system further comprises a timing device and a data processing end, and the device can further comprise a sending module configured to perform corresponding time alignment processing on the laser terminal, the turntable and the star simulator by using the timing device; and send the orbit and attitude data with timestamps to the turntable and the laser terminal at a first advance time point by using the data processing end, so that the turntable and the laser terminal simulate the orbit and attitude of the first satellite and the second satellite for on-orbit link establishment based on the orbit and attitude data, and simulate the star open-loop pointing test in the process of movement based on the star map projected by the star simulator at a target time point; wherein the orbit and attitude data comprise the first orbit and attitude data and the second orbit and attitude data at the target time point.

[0172] The description and functions of the above modules can be understood by referring to the content of the star open-loop pointing test method, which will not be repeated here.

[0173] In an embodiment of the present application, an electronic device is also provided, such as Figure 9 ​As shown, disposed on a satellite, the electronic device 901 can include one or more processors 902, such as one or more central processing units (CPUs), each of which can implement one or more hardware threads. The electronic device 901 can also include any memory 903 for storing any kind of information, such as code, settings, data, etc. Without limitation, for example, the memory 903 can include any one or combination of: any type of RAM, any type of ROM, a flash memory device, a hard disk, an optical disk, etc. More generally, any memory can use any technology for storing information. Further, any memory can provide volatile or non-volatile retention of information. Further, any memory can represent a fixed or removable component of the electronic device 901. In one case, the electronic device 901 can perform any operation of the associated instructions when executed by the processor 902 stored in any memory or combination of memories. The electronic device 901 also includes one or more drive mechanisms 904 for interacting with any memory, such as a hard disk drive mechanism, an optical disk drive mechanism, etc.

[0174] The electronic device 901 can also include one or more network interfaces 905 for exchanging data with other devices via one or more communication links 906. One or more communication buses 907 couple the above-described components together.

[0175] The communication links 906 can be implemented in any manner, such as through a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication links 906 can include any combination of hardwired links, wireless links, routers, gateway functionality, name servers, etc., governed by any protocol or combination of protocols.

[0176] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program, and the computer program is run by a processor to execute the steps of the above method.

[0177] The embodiments of the present application also provide a computer readable instruction, wherein when the processor executes the instruction, the program in the processor executes the method of any of the above embodiments.

[0178] It should be understood that the size of the sequence number of each process described above in various embodiments of the present application does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0179] It should also be understood that, in the embodiments of the present application, the term "and / or" merely describes an associated relationship with associated objects, and indicates that there can be three relationships. For example, A and / or B can represent three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0180] Those skilled in the art can understand that the units and algorithm steps of the examples described in combination with the embodiments disclosed in the present application can be realized in electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of the examples have been described in general terms in the above description. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0181] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0182] In several embodiments provided by the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can also be electrical, mechanical or other forms of connection.

[0183] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. they can be located in one place, or distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0184] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or software functional unit.

[0185] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or the whole or part of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing an electronic device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0186] The principles and implementation manners of the present application are described in the specific embodiments in the present application. The above embodiment descriptions are only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed. In summary, the content of the present description should not be understood as a limitation of the present application.

Claims

1. A method of testing for stellar open-loop pointing, characterized by, The method is applied to a star open-loop pointing test system, and the star open-loop pointing test system at least comprises a turntable, a laser terminal installed on the turntable, and a star simulator. The method comprises: Calibrating each device coordinate system and a conversion relationship between each device coordinate system, wherein the device coordinate system at least comprises a reference coordinate system of the turntable, a zero-point coordinate system of the turntable, a coordinate system of the laser terminal, a coordinate system of the star simulator, and a star map coordinate system; Obtaining first orbit attitude data of a first satellite corresponding to the laser terminal and second orbit attitude data of a second satellite, and determining laser link information of the first satellite and the second satellite based on the first orbit attitude data and the second orbit attitude data; 2. The method of testing for stellar open-loop pointing according to claim 1, wherein, Projecting a star map corresponding to a target star based on the laser link information and the conversion relationship between each device coordinate system by using the star simulator, so that the laser terminal simulates star open-loop pointing test based on the star map.

3. The method of testing for stellar open-loop pointing according to claim 1, wherein, The star map projected by the star simulator is a star background in a direction of a laser link of the first satellite and the second satellite. Calibrating each device coordinate system and a conversion relationship between each device coordinate system comprises: Calibrating a position and a direction of each device coordinate system, and a coordinate system deviation amount between each device coordinate system; 4. The method of testing for stellar open-loop pointing according to claim 3, wherein, Determining a deviation correction amount between each device coordinate system based on the coordinate system deviation amount between each device coordinate system as the conversion relationship between each device coordinate system. Calibrating a position and a direction of each device coordinate system, and a coordinate system deviation amount between each device coordinate system comprises: Installing a zero-point measuring tool at a zero-point position of the turntable, representing the reference coordinate system of the turntable by a first cube mirror installed at a reference position of the turntable, and representing the zero-point coordinate system of the turntable by a second cube mirror; Optically measuring the first cube mirror and the second cube mirror by using a theodolite to determine a first coordinate system deviation amount between the first cube mirror and the second cube mirror; Installing the laser terminal at the zero-point position of the turntable, representing the zero-point coordinate system of the turntable by a third cube mirror installed on the laser terminal, and representing the coordinate system of the star simulator by a fourth cube mirror installed on the star simulator; 5. The method of testing for stellar open-loop pointing according to claim 4, wherein, Defining a star map coordinate system projected by the star simulator, and optically measuring the first cube mirror and the third cube mirror, the first cube mirror and the fourth cube mirror, and the fourth cube mirror and the star map coordinate system by using the theodolite to determine a second coordinate system deviation amount between the first cube mirror and the third cube mirror, a third coordinate system deviation amount between the first cube mirror and the fourth cube mirror, and a fourth coordinate system deviation amount between the fourth cube mirror and the star map coordinate system. Determining a deviation correction amount between each device coordinate system based on the coordinate system deviation amount between each device coordinate system comprises: Based on each coordinate system deviation amount, determining a direction cosine corresponding to each coordinate system deviation amount as the deviation correction amount between the corresponding device coordinate systems; Based on a first deviation correction amount between the reference coordinate system and the zero-point coordinate system, and a second deviation correction amount between the reference coordinate system and the coordinate system of the laser terminal, determining a third deviation correction amount between the zero-point coordinate system and the coordinate system of the laser terminal; Determine a sixth deviation correction amount between the star map coordinate system and the laser terminal coordinate system based on a fourth deviation correction amount between the reference coordinate system and the coordinate system of the star simulator, a fifth deviation correction amount between the coordinate system of the star simulator and the star map coordinate system, and the second deviation correction amount.

6. The method of testing for stellar open-loop pointing according to claim 1, wherein, The first track attitude data and / or the second track attitude data at least include: track position data in an inertial coordinate system, velocity data of the satellite, Euler angles, and quaternions.

7. The method of testing for stellar open-loop pointing according to claim 1 or 6, characterized in that, Determine laser link information of the first satellite and the second satellite based on the first track attitude data of the first satellite corresponding to the laser terminal and the second track attitude data of the second satellite, including: Determine first position data of the first satellite in an inertial coordinate system and second position data of the second satellite in the inertial coordinate system based on the first track attitude data and the second track attitude data; Determine a pointing vector of the first satellite to the second satellite in the inertial coordinate system as the laser link information based on the second position data and the second position data.

8. The method of testing for open-loop stellar pointing according to claim 1, wherein, Project a star map corresponding to a target star based on the laser link information and the conversion relationship between the coordinate systems of each device using the star simulator, including: Determine a star map projection control amount for the star simulator to project the star map based on the laser link information and the conversion relationship between the coordinate systems of each device; Project the star map in the laser link direction sky region of the first satellite and the second satellite based on the star map projection control amount using the star simulator.

9. The method of testing for stellar open-loop pointing according to claim 8, wherein, Determine a star map projection control amount for the star simulator to project the star map based on the laser link information and the conversion relationship between the coordinate systems of each device, including: Convert the pointing vector from the first satellite to the second satellite in the laser link information in the inertial coordinate system to the star map coordinate system based on the conversion relationship between the coordinate systems of each device to obtain a target direction vector; Determine a rotation quaternion of the central optical axis of the star map coordinate system rotating to the target direction vector, and take the rotation quaternion as the star map projection control amount.

10. The method of testing for stellar open-loop pointing according to claim 8 or 9, characterized in that, The star map projection control amount is determined by the following formula: ； wherein q represents a rotation quaternion of the star map coordinate system, to represent the star map projection control quantity; represents a pointing vector from the first satellite to the second satellite in the star map coordinate system under the star map coordinate system. represents a pointing vector from the first satellite to the second satellite in the star map coordinate system under the star map coordinate system, V1 represents a unit vector of a central optical axis of the star map coordinate system, represents a pointing vector from the first satellite to the second satellite in the star map coordinate system under the star map coordinate system, V1 represents a unit vector of a central optical axis of the star map coordinate system, M4 represents a conversion relationship from the star map coordinate system to the star simulator, C 14 represents a conversion relationship from the reference coordinate system to the star simulator, C 12 represents a conversion relationship from the reference coordinate system to the zero point coordinate system.

11. The method of testing for stellar open-loop pointing according to claim 9, wherein, After determining the rotation quaternion of the central optical axis of the star map coordinate system to the target direction vector, further including: Normalize the rotation quaternion, and take the normalized rotation quaternion as the star map projection control amount.

12. The method of testing for open-loop stellar pointing according to claim 1, wherein, The star simulator open-loop pointing test system further includes a timing device and a data processing end, and the method further includes: Use the timing device to perform corresponding time alignment processing on the laser terminal, the turntable, and the star simulator respectively; At a first advance time point, use the data processing end to send track and attitude data with timestamps to the turntable and the laser terminal, so that the turntable and the laser terminal simulate the track and attitude of the first satellite and the second satellite in orbit based on the track and attitude data, and simulate the star simulator open-loop pointing test based on the star map projected by the star simulator at the target time point in the process of movement; wherein the track and attitude data include the first track attitude data and the second track attitude data at the target time point.

13. A test device for star open loop pointing, characterized in that The device is applied to a star open-loop pointing test system, wherein the star open-loop pointing test system at least comprises a turntable, a laser terminal installed on the turntable, and a star simulator, and the device comprises: a calibration module configured to calibrate device coordinate systems and conversion relationships between the device coordinate systems, wherein the device coordinate systems at least include a reference coordinate system of the turntable, a zero-point coordinate system of the turntable, a coordinate system of the laser terminal, a coordinate system of the star simulator, and a star map coordinate system; a processing module configured to acquire first orbit and attitude data of a first satellite corresponding to the laser terminal and second orbit and attitude data of a second satellite, and determine laser link information of the first satellite and the second satellite; a test module configured to project a star map corresponding to a target star based on the laser link information and the conversion relationships between the device coordinate systems by using the star simulator, so that the laser terminal simulates star open-loop pointing test based on the star map.

14. An electronic device, comprising: The computer storage medium stores computer program instructions, and the computer program instructions are executed by the processor to implement the steps of the method in any one of claims 1 to 12.

15. A computer storage medium, comprising, The computer storage medium stores computer program instructions, and the computer program instructions are executed by the processor to implement the steps of the method in any one of claims 1 to 12.

16. A computer program product, characterised in that, The computer program is executed by the processor to implement the steps of the method in any one of claims 1 to 12.

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