Orbit-based laser link dynamic acquisition and tracking link establishment ground verification device and method

Abstract

The embodiment of the application provides a kind of based on track laser link dynamic capture and follow-up chain ground verification device and method, it is related to satellite communication technical field, the device includes laser platform, two-dimensional rotary table, rotary table controller, laser terminal, terminal ground inspection, laser terminal is installed on two-dimensional rotary table;Laser platform includes collimator and control computer;Collimator provides the far-field environment of inter-satellite laser link light beam;Control computer sends orbit data to terminal ground inspection and rotary table controller;Rotary table controller calculates the target control variable of two-dimensional rotary table using orbit data, and drives two-dimensional rotary table to rotate to the position corresponding to target control variable;Terminal ground inspection broadcasts orbit data to laser terminal;Laser terminal calculates inter-satellite pointing vector using orbit data, and according to inter-satellite pointing vector, the light beam of laser terminal is driven to point to the opposite end, and emits light beam to the opposite end.The scheme can fully verify the inter-satellite capture and follow-up chain capability of laser terminal and laser link stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite communication, in particular to a ground verification device and method for dynamic laser link capture and tracking based on orbits. BACKGROUND

[0002] In the continuous development of satellite communication technology, laser communication technology plays a crucial role. Compared with microwave communication, there are three main difficulties in laser communication: first, the beam divergence angle of the laser terminal is narrow, there are many interference factors affecting the link establishment, which makes it difficult for the laser link terminals to capture and track in orbit. The beam divergence angle of the laser terminal is usually only a few tens of microradians. In the low-orbit satellites with a distance of several thousand kilometers, the establishment of laser link requires the laser terminal to have extremely high pointing and tracking accuracy, and the laser link terminals to have matching capture and tracking strategies and parameters, so that the laser link can be established under the action of various link interference factors and maintained stable. The interference factors affecting the capture and tracking of the laser terminal and the stability of the link include orbit and attitude disturbance, orbit extrapolation accuracy, inter-satellite laser pointing error, satellite micro-vibration, etc. Second, there is currently a lack of effective simulation conditions for laser in-orbit link establishment environment and link interference factors, and the ground verification of the capture and tracking and stability of the laser link is insufficient. The matching degree of the capture and tracking strategy and parameters is poor, and a lot of time is usually spent on in-orbit adjustment and measurement, which is not conducive to large-scale laser in-orbit rapid link establishment and networking. Third, the effective simulation conditions for laser in-orbit link establishment environment and link interference factors are missing, and a ground parallel fault diagnosis system for laser link cannot be established, which is not conducive to the rapid diagnosis and elimination of laser link in-orbit faults and the long-term stability of the laser link.

[0003] To ensure that the laser terminal can quickly establish a laser link after being launched into orbit with the satellite, and maintain long-term stability of the link, a high-fidelity orbit, attitude and interference factor simulation environment needs to be established on the ground to fully verify the inter-satellite link capture and tracking capability and link stability of the laser terminal. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a ground verification device and method for dynamic laser link capture and tracking based on orbits, to establish a unified verification environment in time and space, to simulate the key factors of laser terminal in-orbit link establishment and stability with high fidelity, to dynamically verify the inter-satellite laser link capture and tracking process, to fully test the inter-satellite laser link capture and tracking capability, to optimize the inter-satellite laser link capture and tracking strategy and parameters, and to support the realization of laser terminal in-orbit rapid link establishment and long-term stability of the laser link. The specific technical solutions are as follows:

[0005] In a first aspect, the embodiments of the present application provide a ground verification device for dynamic tracking and link establishment of a laser link based on an orbit, comprising: a laser platform, a two-dimensional turntable, a turntable controller, a laser terminal, and a terminal ground detector, wherein the laser terminal is installed on the two-dimensional turntable; the laser platform comprises a collimator and a control computer;

[0006] The collimator is configured to provide a far-field environment for an inter-satellite laser link beam.

[0007] The control computer is configured to obtain orbit data of a satellite, and send the orbit data to the terminal ground detector and the turntable controller in advance by a first preset frequency and for a preset time period, relative to a time stamp carried by the orbit data.

[0008] The turntable controller is configured to calculate a target control quantity of the two-dimensional turntable by using the orbit data, and send the target control quantity to the two-dimensional turntable, wherein the target control quantity comprises a control quantity of a pitch angle and a control quantity of an azimuth angle.

[0009] The two-dimensional turntable is configured to drive the two-dimensional turntable to move to a given position corresponding to the target control quantity according to the target control quantity, so as to provide a dynamic orbit simulation environment.

[0010] The terminal ground detector is configured to broadcast the orbit data to the laser terminal.

[0011] The laser terminal is configured to calculate an inter-satellite pointing vector by using the orbit data, and drive a beam emitted by the laser terminal to point to a peer terminal according to the inter-satellite pointing vector, so as to emit the beam to the peer terminal and establish a laser link with the peer terminal.

[0012] In some embodiments, the control computer is specifically configured to send one frame of orbit data to the terminal ground detector in advance by the first preset frequency and for the preset time period, relative to the time stamp carried by the orbit data.

[0013] The terminal ground detector is specifically configured to broadcast the orbit data to the laser terminal by the first preset frequency when the time stamp carried by the orbit data is reached.

[0014] In some embodiments, the control computer is specifically configured to send multiple frames of orbit data to the turntable controller in advance by the first preset frequency and for the preset time period, relative to the time stamp carried by the orbit data.

[0015] The turntable controller is specifically configured to send a target control quantity to the two-dimensional turntable by a second preset frequency when the time stamp carried by the orbit data is reached.

[0016] In some embodiments, the turntable controller is specifically configured to:

[0017] According to the track data and a coordinate system transformation matrix from the laser terminal coordinate system to a two-dimensional turntable zero point coordinate system, an intersatellite pointing vector is calculated; and according to the intersatellite pointing vector and the zero point coordinate of the two-dimensional turntable, a target control quantity of a motion angle of the two-dimensional turntable is calculated.

[0018] In some embodiments, the turntable controller is specifically used for:

[0019] According to the intersatellite pointing vector and the zero point coordinate of the two-dimensional turntable, an initial control quantity of a motion angle of the two-dimensional turntable is calculated; and according to the initial control quantity and a pointing deviation analog quantity, a target control quantity of a motion angle of the two-dimensional turntable is calculated.

[0020] In some embodiments, the target control quantity includes a correction quantity of an azimuth angle and a correction quantity of a pitch angle of the two-dimensional turntable.

[0021] In some embodiments, the coordinate system transformation matrix is an angle deviation between the laser terminal coordinate and the two-dimensional turntable coordinate when the two-dimensional turntable is in a zero point coordinate state.

[0022] In some embodiments, the laser terminal is further used for: after the laser link is established, waiting for a preset time, cutting off the laser link, and re-executing the step of emitting a light beam to the opposite end to establish a laser link with the opposite end.

[0023] In some embodiments, when the two-dimensional turntable is in a zero point coordinate position, two axes of the two-dimensional turntable are coplanar with a camera of the collimator, and an optical axis of the laser terminal is coaxial with a camera optical axis of the collimator.

[0024] The laser terminal is specifically used for emitting a light beam to the opposite end through the collimator.

[0025] In some embodiments, a preset vibration spectrum is applied in an optical path of the collimator.

[0026] In some embodiments, the laser platform further includes a collimator camera.

[0027] The collimator is further used for focusing a light spot to the collimator camera.

[0028] The collimator camera is used for calculating a centroid position of the light spot and displaying the light spot in real time.

[0029] In some embodiments, the device further includes a time system device.

[0030] The time system device is used for aligning times of the control computer, the terminal ground station, the turntable controller and the laser terminal.

[0031] In some embodiments, the time system device is specifically configured to send a time code to the control computer.

[0032] In some embodiments, the time system device is specifically configured to send a time code, a 10M / 100M rate signal and a 1PPS pulse signal to the terminal ground station.

[0033] In some embodiments, the time system device is specifically configured to send a time code to the turntable controller.

[0034] In some embodiments, the time system device is specifically configured to send a 10M / 100M rate signal and a 1PPS pulse signal to the laser terminal.

[0035] In a second aspect, the embodiments of the present application provide a ground verification method for dynamic tracking and link establishment of a laser link based on an orbit, applied to any device provided in the first aspect, the device comprising a laser platform, a two-dimensional turntable, a turntable controller, a laser terminal, and a terminal ground station, the laser terminal being installed on the two-dimensional turntable, the laser platform comprising a collimator and a control computer; the method comprising:

[0036] The control computer acquires orbit data of a satellite, and sends the orbit data to the terminal ground station and the turntable controller in advance by a first preset frequency and a preset time length relative to a time stamp carried by the orbit data.

[0037] The turntable controller calculates a target control amount of the two-dimensional turntable by using the orbit data, and sends the target control amount to the two-dimensional turntable, the target control amount comprising a control amount of a pitch angle and a control amount of an azimuth angle.

[0038] The two-dimensional turntable drives the two-dimensional turntable to move to a given position corresponding to the target control amount, so as to provide a dynamic orbit simulation environment.

[0039] The terminal ground station broadcasts the orbit data to the laser terminal.

[0040] The laser terminal calculates an inter-satellite pointing vector by using the orbit data, and drives a light beam emitted by the laser terminal to point to a peer terminal according to the inter-satellite pointing vector, so as to emit the light beam to the peer terminal, and establish a laser link with the peer terminal.

[0041] The embodiments of the present application have the following beneficial effects:

[0042] In the technical scheme provided by the embodiment of the application, the control computer included in the laser platform sends track data to the terminal ground station and the turntable controller, the turntable controller drives the two-dimensional turntable to move by using the track data, so as to establish a track movement scene and provide a dynamic track simulation environment; the terminal ground station sends the track data to the laser terminal, so as to drive the laser terminal to establish a dual-satellite link in the track movement scene, ensure the stability of the posture and track of the laser terminal in the simulation test process, and realize high-fidelity verification of a dynamic capture and tracking link establishment process and data of the laser terminal. The device provided by the embodiment of the application is an open-loop control system, the system is more simplified, the response speed is higher, large-scale parallel processing can be performed, the inter-satellite laser link capture and tracking link establishment process is dynamically verified, the inter-satellite laser link capture and tracking link establishment capability is fully tested, the inter-satellite laser link capture and tracking link establishment strategy and parameters are optimized, the laser terminal in-orbit rapid link establishment and long-term stability of the laser link are supported to be realized, the capture and tracking link establishment verification efficiency is improved, and the capture and tracking precision of the laser terminal is improved.

[0043] Of course, implementing any product or method of the present application does not necessarily require all the advantages described above to be achieved simultaneously. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other embodiments can also be obtained by those skilled in the art based on these drawings.

[0045] Figure 1 The first schematic diagram of the laser link dynamic capture and tracking link establishment ground verification device (single end) provided by the embodiment of the present application is shown in FIG. 1.

[0046] Figure 2a The first schematic diagram of the laser link dynamic capture and tracking link establishment ground verification device (single end) provided by the embodiment of the present application is shown in FIG. 1.

[0047] Figure 2b The first schematic diagram of the laser link dynamic capture and tracking link establishment ground verification device (single end) provided by the embodiment of the present application is shown in FIG. 1.

[0048] Figure 3 The first schematic diagram of the laser link dynamic capture and tracking link establishment ground verification device (single end) provided by the embodiment of the present application is shown in FIG. 1.

[0049] Figure 4 The second schematic diagram of the laser link dynamic capture and tracking link establishment ground verification device (single end) provided by the embodiment of the present application is shown in FIG. 2.

[0050] Figure 5 The second schematic diagram of the laser link dynamic capture and tracking link establishment ground verification device (single end) provided by the embodiment of the present application is shown in FIG. 2.

[0051] Figure 6 A first flowchart of a ground verification method for orbit-based dynamic acquisition and tracking of a laser link according to an embodiment of the present application is shown in FIG. 1.

[0052] Figure 7 A second flowchart of a ground verification method for orbit-based dynamic acquisition and tracking of a laser link according to an embodiment of the present application is shown in FIG. 2. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to 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 of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0054] In the prior art, a closed-loop control mode is used to directly provide the absolute position of a two-dimensional turntable to a laser terminal, and the laser terminal is controlled to make a reverse compensation. This mode does not simulate the real orbit environment of laser link acquisition and tracking, nor does it simulate the key factors affecting the in-orbit acquisition and tracking of the laser terminal. The simulation fidelity is low, and it is a static verification, which has little reference significance for optimizing the acquisition and tracking strategy of the inter-satellite laser link and the in-orbit acquisition and tracking of the laser terminal.

[0055] To solve the above problems, an orbit-based dynamic acquisition and tracking ground verification device for a laser link is provided according to an embodiment of the present application, as shown in FIG. 1. The device comprises a laser platform 101, a terminal ground detector 102, a turntable controller 103, a two-dimensional turntable 104, and a laser terminal 105. The laser terminal 105 is installed on the two-dimensional turntable 104. The laser platform 101 comprises a collimator 1011 and a control computer 1012. Figure 1

[0056] The collimator 1011 is used to provide a far-field environment of an inter-satellite laser link beam.

[0057] The control computer 1012 is used to acquire orbit data of a satellite, and send the orbit data to the terminal ground detector 102 and the turntable controller 103.

[0058] The turntable controller 103 is used to calculate a target control quantity of the two-dimensional turntable 104 by using the orbit data, and send the target control quantity to the two-dimensional turntable 104.

[0059] The two-dimensional turntable 104 is used to drive the two-dimensional turntable 104 to move according to the target control quantity, so as to provide a dynamic orbit simulation environment.

[0060] The terminal ground detector 102 is used to broadcast the orbit data to the laser terminal 105. ​

[0061] The laser terminal 105 is configured to calculate an inter-satellite pointing vector by using the orbit data, and drive a light beam emitted by the laser terminal 105 to point to a peer terminal according to the inter-satellite pointing vector, so as to establish a laser link with the peer terminal.

[0062] In the technical scheme provided in the embodiments of the present application, the control computer 1012 sends the orbit data to the terminal ground station and the turntable controller, the turntable controller drives the two-dimensional turntable to move by using the orbit data, so as to establish an orbit motion scene and provide a dynamic orbit simulation environment; and the terminal ground station broadcasts the orbit data to the laser terminal, so as to drive the laser terminal to establish a dual-satellite link in the orbit motion scene, ensure the stability of the laser terminal in the simulation test process, and realize high-fidelity verification of a dynamic capture and tracking link establishment process and data of the laser terminal. The device provided in the embodiments of the present application is an open-loop control system, the system is more simplified, has higher response speed, can perform large-scale parallel processing, verifies the capture and tracking link establishment process of the inter-satellite laser link dynamically, fully tests the capture and tracking link establishment capability of the inter-satellite laser link, optimizes the capture and tracking link establishment strategy and parameters of the inter-satellite laser link, supports realization of rapid link establishment of the laser terminal in orbit and long-term stability of the laser link, improves the capture and tracking link establishment verification efficiency, and improves the capture and tracking precision of the laser terminal.

[0063] In the embodiments of the present application, the control computer 1012 can also be referred to as a laser engineering data workstation. A user can select orbit data of a test period, such as orbit data of a continuous orbit period (about 108 minutes), convert the orbit data of the test period into a format file (such as a CSV / TXT file) that can be recognized by the laser platform 101 (that is, the control computer 1012), and write the CSV / TXT file into the control computer 1012. Then, the control computer 1012 obtains the orbit data from the CSV / TXT file. The orbit data is short for orbit and attitude data, and can be simulation orbit data or satellite in-orbit data. The orbit data can include but is not limited to system real-time time broadcast, J2000 position, velocity and time stamp of the satellite and the peer satellite, attitude quaternion and roll, pitch and yaw attitude angle, angular velocity and time stamp (including T0, T0+250 ms, T0+500 ms, T0+750 ms four groups of attitude data) of the satellite, and does not include terminal star-sensitive attitude data, and a sun vector. The orbit data can have a time stamp, and T0 is a start time stamp of the orbit data.

[0064] The control computer 1012 sends the track data to the terminal ground station 102 and the turntable controller 103 according to a data broadcasting protocol after obtaining the track data. The data broadcasting protocol can include a transmission protocol and a file format, etc. The transmission protocol can be a User Datagram Protocol (UDP) or other transmission protocols, and the file format can be a CSV / TXT file format or other file formats. The data broadcasting protocol can also include a broadcasting advance (i.e., a preset time length) and a broadcasting frequency (such as a first preset frequency and a second preset frequency). The second preset frequency can be the frequency of the track data, and the first preset frequency is less than the second frequency.

[0065] The broadcasting advance can be determined according to the transmission delay between the control computer 1012 and the terminal ground station 102, and the transmission delay between the control computer 1012 and the turntable controller 103, for example, the broadcasting advance can be 1 second (s), 2s, etc. The broadcasting frequency is determined according to the interval of the time stamp (i.e., a given time stamp) carried by the track data. For example, if the interval of the given time stamp is 0.1s, the first preset frequency can be 1Hz, i.e., one frame of track data is sent every 1s, and the second preset frequency can be 10Hz, i.e., one frame of track data is sent every 0.1s.

[0066] For the terminal ground station 102, the control computer 1012 can send the track data to the terminal ground station 102 in any of the following ways.

[0067] a1, inject at a first preset frequency.

[0068] In the embodiments of the present application, the track data carries a time stamp. The control computer 1012 is specifically configured to send one frame of track data to the terminal ground station 102 at a first preset frequency and a preset time length relative to the time stamp carried by the track data. In this case, the terminal ground station 102 is specifically configured to broadcast the track data to the laser terminal 105 at a first preset frequency when the time stamp carried by the track data is reached.

[0069] Wherein, the preset time length can be determined according to the transmission delay between the control computer 1012 and the terminal ground station 102, for example, the preset time length can be 1 second (s), 2s, etc. In one example, the preset time length is greater than or equal to the transmission delay between the control computer 1012 and the terminal ground station 102, to ensure that the terminal ground station 102 can broadcast the track data to the laser terminal 105 when the time stamp carried by the track data is reached, such as ensuring that the terminal ground station 102 can broadcast the track data with T0 time stamp to the laser terminal 105 at T0 moment.

[0070] The time stamp of the orbit data is from T0. The control computer 1012 triggers the orbit data to be broadcast to the terminal ground station 102 according to the time stamp of the orbit data at a first preset frequency. For example, the first preset frequency is 1 Hz, and the control computer 1012 broadcasts a frame of orbit data to the terminal ground station 102 every 1 s. The time stamps of two frames of orbit data played in succession are separated by 1 s, and the time stamp of each frame of orbit data is later than the preset time length at the time of sending. Similarly, the terminal ground station 102 also triggers a frame of orbit data to be broadcast to the laser terminal 105 according to the time stamp of the orbit data, so that the terminal ground station 102 broadcasts orbit data to the laser terminal 105 at the same frequency as the control computer 1012 broadcasts orbit data to the terminal ground station 102, that is, the first preset frequency.

[0071] Taking the first preset frequency as 1 Hz and the preset time length as 1 s as an example.

[0072] As shown in the orbit data broadcast schematic diagram shown in Figure 2a and Figure 2b , the control computer 1012 can broadcast a frame of orbit data including time, orbit, sun vector, attitude, etc. to the terminal ground station 102 at a frequency of 1 Hz and 1 s in advance. For example, as shown in Figure 2a , for the orbit data at 0 s (time stamp 0 s), the control computer 1012 broadcasts the orbit data to the terminal ground station 102 at-1 s; for the orbit data at 1 s (time stamp 1 s), the control computer 1012 broadcasts the orbit data to the terminal ground station 102 at 0 s; and so on, which will not be repeated. The time delay △t of the control computer 1012 processing the orbit data is less than 20 milliseconds (ms).

[0073] After receiving the orbit data, the terminal ground station 102 packages and unpackages the orbit data according to the on-orbit working format, triggers according to the time stamp, and pushes the orbit data to the laser terminal 105 at a frequency of 1 Hz. For example, as shown in Figure 2b , for the orbit data at 0 s (time stamp 0 s), the terminal ground station 102 broadcasts the orbit data to the laser terminal 105 at 0 s; for the orbit data at 1 s (time stamp 1 s), the terminal ground station 102 broadcasts the orbit data to the laser terminal 105 at 1 s; and so on, which will not be repeated. The time delay △t of the terminal ground station 102 processing the orbit data is less than 20 ms. If the orbit data includes four sets of attitude data of T0, T0+250 ms, T0+500 ms and T0+750 ms, the terminal ground station 102 broadcasts attitude data to the laser terminal 105 once every 250 ms within 1 s.

[0074] Method a2, one-time injection.

[0075] In the embodiment of the present application, the track data is provided with a time stamp. The control computer 1012 is specifically configured to inject the track data into the terminal ground detector once. In this case, the terminal ground detector 102 is specifically configured to broadcast the track data to the laser terminal 105 at the first preset frequency when the time stamp provided by the track data is reached.

[0076] In the embodiment of the present application, before the simulation test, the control computer 1012 can inject the entire track data of a test period into the terminal ground detector 102 once. After the terminal ground detector 102 receives the track data, the terminal ground detector 102 can unpack and pack the track data according to the on-board working format, and according to the time stamp, push a frame of track data to the laser terminal 105 at the first preset frequency when the time stamp provided by the track data is reached, as shown in FIG. 3. Figure 2b

[0077] In the embodiment of the present application, the control computer 1012 can broadcast the track data to the terminal ground detector 102 according to the actual demand by using mode a1 or mode a2. For example, for the terminal ground detector 102 requiring an advance time (i.e., a preset time length) greater than 1 s, the control computer 1012 broadcasts the track data to the terminal ground detector 102 by using mode a2; for the terminal ground detector 102 requiring an advance time (i.e., a preset time length) less than or equal to 1 s, the control computer 1012 broadcasts the track data to the terminal ground detector 102 by using mode a1.

[0078] For the turntable controller 103, the control computer 1012 can broadcast the track data to the turntable controller 103 by using the following mode: the control computer 1012 can specifically be configured to send multiple frames of track data to the turntable controller 103 at the first preset frequency and with a preset time length in advance relative to the time stamp provided by the track data; and the turntable controller 103 can specifically be configured to send the target control quantity to the two-dimensional turntable 104 at the second preset frequency when the time stamp provided by the track data is reached.

[0079] In the embodiment of the present application, the track data is provided with a time stamp. To simplify the operation of the control computer 1012 and reduce the burden of the control computer 1012, the control computer 1012 broadcasts multiple frames of track data to the turntable controller 103 and the terminal ground detector 102 at the first preset frequency. The time stamp interval of the track data broadcast to the turntable controller 103 is less than the time stamp interval of the track data broadcast to the terminal ground detector 102.

[0080] In the embodiment of the present application, the time stamp provided by the track data starts from T0. When the sending time is reached, the control computer 1012 sends multiple frames of track data to the turntable controller 103 at the first preset frequency, where the time length from the time stamp to the current time is greater than or equal to the preset time length and less than twice the preset time length. ​

[0081] In addition, the turntable controller 103 triggers the broadcasting of the target control quantity to the two-dimensional turntable 104 according to the time stamp of the track data, and accordingly, the frequency (e.g., the second preset frequency) at which the turntable controller 103 broadcasts the control quantity to the two-dimensional turntable 104 can be determined according to the interval between the time stamps of adjacent two track data. For example, if the interval between the time stamps of adjacent two track data is 0.1 s, the second preset frequency can be 1 / 0.1 s = 10 Hz.

[0082] For example, the first preset frequency is 1 Hz, the interval between the time stamps of adjacent two track data is 0.1 s, and the preset time length is 1 s.

[0083] The control computer 1012 can broadcast multiple frames of track data including time, track, sun vector, and attitude, etc. to the turntable controller 103 in advance at a frequency of 1 Hz and 1 s in advance. Each time of broadcasting includes 10 frames of track data, and the interval between the time stamps of the 10 frames of track data is 100 ms. The turntable controller 103 calculates the target control quantity of the two-dimensional turntable corresponding to each frame of track data according to each frame of track data, and triggers the sending of the target control quantity to the two-dimensional turntable 104 according to the time stamp of the track data, starting from T0, at a frequency of 10 Hz according to the time stamp of the track data, to drive the two-dimensional turntable 104 to move, so that the two-dimensional turntable 104 reaches the given position corresponding to the target control quantity, realizes the simulation of the real track environment of the laser link chain establishment, compensates the beam pointing of the laser terminal 105 in the reverse direction, and realizes the simulation of the relative angular reverse motion of the double stars. Here, the closed-loop control period of the two-dimensional turntable 104 can be less than or equal to 0.12 ms.

[0084] In the embodiments of the present application, the control computer 1012 can also send the track data broadcasted by the turntable controller 103 in other ways. For example, before the simulation test, the control computer 1012 can inject an entire package of track data of a test period to the turntable controller 103 at one time. This is not limited.

[0085] In some embodiments, the turntable controller 103 can be specifically configured to: calculate an inter-satellite pointing vector according to the track data and the coordinate system transformation matrix; and calculate a target control quantity of a motion angle of the two-dimensional turntable according to the inter-satellite pointing vector. The inter-satellite pointing vector is a double-star theoretical pointing vector, and the target control quantity can include a correction quantity of an azimuth angle and a correction quantity of a pitch angle of the two-dimensional turntable.

[0086] In the embodiments of the present application, the control computer 1012 pre-calibrates the zero point coordinates of the two-dimensional turntable 104, the coordinate system transformation relationship between the two-dimensional turntable 104 and the laser terminal 105, to unify the space reference, that is, the coordinate system transformation relationship between the two-dimensional turntable 104 and the laser terminal 105 (i.e., the above-mentioned coordinate system transformation matrix), which can also be understood as the coordinate system transformation matrix from the laser terminal coordinate system to the two-dimensional turntable zero point coordinate system.

[0087] In the embodiments of the present application, based on the zero point coordinates of the collimator 1011 (such as the zero point coordinates (X0, Y0) of the collimator camera shown in FIG. 1), the zero point coordinates of the two-dimensional turntable 104 and the zero point coordinates of the laser terminal 105 are calibrated, and the coordinate system of the two-dimensional turntable 104 (such as the two-dimensional turntable reference coordinate system X1Y1Z1 shown in FIG. 1), the zero point coordinate system of the two-dimensional turntable 104 (such as the two-dimensional turntable zero point coordinate system X2Y2Z2 shown in FIG. 1), and the coordinate system of the laser terminal 105 (such as the laser terminal coordinate system X3Y3Z3 shown in FIG. 1) are determined. Figure 3 Figure 3 Figure 3 Figure 3 Among them, the coordinate system of the two-dimensional turntable is the reference coordinate system, and the coordinate system transformation relationship between the two-dimensional turntable 104 and the laser terminal 105 is obtained through the coordinate system of the two-dimensional turntable 104, that is, the coordinate system transformation matrix from the laser terminal 105 coordinate system to the two-dimensional turntable 104 zero point coordinate system. In addition, the X2 axis of the zero point coordinate system of the two-dimensional turntable is parallel to the X axis of the satellite orbit coordinate system, the Y2 axis of the zero point coordinate system of the two-dimensional turntable is parallel to the Y axis of the satellite orbit coordinate system, the Z2 axis of the zero point coordinate system of the two-dimensional turntable is parallel to the Z axis of the satellite orbit coordinate system, and the two-dimensional turntable zero point coordinate system X2Y2Z2 is equivalent to the satellite orbit coordinate system XYZ. In combination with the coordinate system transformation matrix, the relationship between the coordinate systems of each device and the satellite orbit coordinate system is obtained.

[0088] In the case of obtaining the orbit data (i.e., double-star position vector telemetry or simulation data), the turntable controller 103 can calculate the pointing vector V i =[X j -X i , Y j -Y i , Z j -Z i ] and V j =[X i -X j , Y i -Y j , Z i -Z j ] according to the orbit data, where V i represents the pointing vector of the star i, V j represents the pointing vector of the other star j (i.e., the target star), (X​​​i , Y i , Z i ) represents the coordinates of the target star j, and (X j , Y j , Z j ) represents the coordinates of the target star j. According to the conversion matrix R WX of the J2000 coordinate system to the satellite body coordinate system, the conversion matrix R ZD of the terminal coordinate system, and the matrix R RPY formed by the roll and pitch angles of the satellite, the antenna controller 103 can calculate the unit pointing vector V ZD in the terminal coordinate system as follows: V ZD = R ZD × R RPY × R WX × V i_e , V ZD_X is the X-axis component of the unit vector V ZD , V ZD_Y is the Y-axis component of the unit vector V ZD , V ZD_Z is the Z-axis component of the unit vector V ZD , and V i_e is the pointing vector of the target star j in the J2000 coordinate system.

[0089] According to the theodolite measurement, the coordinate system conversion matrix of the terminal coordinate system to the two-dimensional turntable zero point coordinate system is C 12 (C 13 ) -1 , C 12 (C 13 ) -1 is the angle deviation between the laser terminal coordinates and the two-dimensional turntable coordinates when the two-dimensional turntable is in the zero point coordinate state. Then, after the coordinate conversion correction, the interstellar pointing vector of the target star calculated by the antenna controller 103 is: =C 12 (C 13 ) -1 × R ZD × R RPY × R WX × V i_e。

[0090] The antenna controller 103 can convert the interstellar pointing vector to the azimuth pointing angle and the pitch pointing angle by using the following formula (1).

[0091] (1)

[0092] In formula (1), θ AZ represents the azimuth pointing angle of the target star in the laser terminal coordinate system, and the unit is radian (rad); θEL represents the elevation pointing angle of the target star in the laser terminal coordinate system, in radian (rad); represents three components of the interstellar pointing vector .

[0093] Since the two-dimensional turntable 104 and the laser terminal 105 move in opposite directions, the azimuth pointing angle and the elevation pointing angle of the two-dimensional turntable 104 are actually -θ AZ and -θ EL , respectively. Therefore, the theoretical control quantity of the two-dimensional turntable can be determined by formula (2):

[0094] (2)

[0095] wherein E ZD is the theoretical control quantity of the elevation angle without introducing pointing deviation, A ZD is the theoretical control quantity of the azimuth angle without introducing pointing deviation, A0 is the azimuth zero point coordinate of the two-dimensional turntable 104, and E0 is the elevation zero point coordinate of the two-dimensional turntable 104.

[0096] In the embodiment of the present application, in order to further improve the simulation accuracy of the dynamic orbit simulation environment, the turntable controller 103 calculates the theoretical control quantity of the two-dimensional turntable 104, such as E ZD and A ZD , by using the orbit data, the satellite attitude (i.e., the coordinate system transformation matrix between the satellite orbit coordinate system and the satellite body coordinate system), and the coordinate system transformation matrix between the two-dimensional turntable and the laser terminal. The turntable controller 103 calculates (E ZD +E0) and (A ZD +A0) to constitute the initial control quantity of the two-dimensional turntable 104. A0 is the azimuth zero point coordinate of the two-dimensional turntable 104, E0 is the elevation zero point coordinate of the two-dimensional turntable 104, (E ZD +E0) is the initial control quantity of the elevation pointing angle without introducing interference factor data, and (A ZD +A0) is the initial control quantity of the azimuth pointing angle without introducing interference factor data.

[0097] The turntable controller 103 can take the above-mentioned initial control quantity of the two-dimensional turntable 104 as the target control quantity of the two-dimensional turntable 104, drive the two-dimensional turntable 104 to rotate to a given position corresponding to the target control quantity, so as to simulate the reverse motion of the double-star orbit, simulate the real orbit environment of the laser chain establishment, ensure the stable operation of the laser terminal 105, and then accurately carry out the long-term stable chain test of the laser terminal 105.

[0098] The communication gear between the laser terminals 105 can be set according to the test requirements to monitor the number of times of break-link recapturing, the longest capturing time, the shortest capturing time, the tracking accuracy, and the communication error rate and the like indexes.

[0099] In some embodiments, the turntable controller 103 can be specifically configured to: calculate an initial control quantity of a motion angle of the two-dimensional turntable 104 according to the inter-satellite pointing vector; and calculate a target control quantity of the motion angle of the two-dimensional turntable according to the initial control quantity and a pointing deviation analog quantity.

[0100] The determination of the initial control quantity can refer to the determination manners of (E ZD +E0) and (A ZD +A0) described above, which will not be repeated here. The pointing deviation analog quantity is an embodiment of the chain establishment interference factor data, and the pointing deviation analog quantity can be a disturbance quantity artificially introduced, including a pointing deviation analog quantity △A of the azimuth angle and a pointing deviation analog quantity △E of the elevation angle. The pointing deviation analog quantity is an embodiment of the chain establishment interference factor data, and the pointing deviation analog quantity can also be referred to as Sqrt(△A 2 +△E 2 )=1mrad, so as to simulate a pointing deviation of 1mrad. Sqrt(△A 2 +△E 2 ) can also be other values, so as to simulate a pointing deviation of other angles (i.e. the chain establishment interference factor data).

[0101] The turntable controller 103 can calculate the target control quantity of the motion angle of the two-dimensional turntable 104 by using the following formula in combination with the initial control quantity and the pointing deviation analog quantity.

[0102] E ZD '=E ZD +△E+A0

[0103] A ZD '=A ZD +△A+E0

[0104] Wherein, E ZD ' is the target control quantity of the elevation angle, A ZD ' is the target control quantity of the azimuth angle, E ZD is the theoretical control quantity of the elevation angle, (E ZD +E0) is the initial control quantity of the elevation angle, A ZD is the theoretical control quantity of the azimuth angle, (A ZD +A0) is the initial control quantity of the azimuth angle, △A is the pointing deviation analog quantity of the azimuth angle, △E is the pointing deviation analog quantity of the elevation angle, A0 is the azimuth zero point coordinate of the two-dimensional turntable 104, and E0 is the elevation zero point coordinate of the two-dimensional turntable 104.

[0105] The turntable controller 103 drives the two-dimensional turntable 104 to rotate to a given position corresponding to the target control quantity, so that the two-dimensional turntable 104 simulates the reverse motion of the double-star orbit, simulates the real orbit environment of laser chain building, ensures the stable operation of the laser terminal 105, and then accurately carries out long-term stable chain testing of the laser terminal 105.

[0106] In the embodiment of the application, when the control computer 1012 sends the orbit data to the turntable controller 103, the coordinate system transformation matrix and the pointing error simulation quantity between the two-dimensional turntable 104 and the laser terminal 105 can also be sent to the turntable controller 103, and the coordinate system transformation matrix and the pointing error simulation quantity between the two-dimensional turntable 104 and the laser terminal 105 can also be pre-configured in the turntable controller 103, which is not limited.

[0107] The communication gear between the laser terminals 105 can be set according to the testing needs to monitor the number of chain breaking and recapturing, the longest capture time, the shortest capture time, the tracking accuracy, and the communication error rate and other indicators.

[0108] In the embodiment of the application, by introducing the coordinate system transformation matrix and the pointing error between the laser terminal and the two-dimensional turntable, the assembly error, the satellite launch vibration, the satellite platform attitude jitter, the orbit accuracy and other factors are simulated to interfere with the pointing and tracking of the laser terminal 105, and the accuracy of the capture and tracking chain building process verification is further improved.

[0109] In the embodiment of the application, the target control quantity can also be determined in other ways, such as generating the target control quantity of the two-dimensional turntable 104 from the double-star aiming angles A and E in the orbit data, which is not limited.

[0110] The turntable controller 103 can convert the target control quantity into format data recognizable by the two-dimensional turntable 104, such as CSV data, and inject the CSV data into the two-dimensional turntable 104.

[0111] The two-dimensional turntable 104 is a platform that can rotate in the pitch axis (rotation around the Y axis) and the azimuth axis (rotation around the Z axis). The laser terminal 105 is a laser terminal that needs to be installed on a satellite. The laser terminal 105 is installed on the two-dimensional turntable 104, the two-dimensional turntable 104 can drive the laser terminal 105, and the laser terminal 105 can also rotate relative to the two-dimensional turntable 104.

[0112] To more accurately verify the capture and tracking chain building process of the laser terminal, the laser terminal 105 can also be used to: after establishing the laser link, waiting for a preset time, cutting off the laser link, and then re-executing the steps of emitting a light beam to the opposite end to establish a laser link with the opposite end. The opposite end is another laser terminal.

[0113] In the embodiments of the present application, the preset time can be set according to actual needs. For example, the preset time can be 5 minutes, 10 minutes, etc.

[0114] In some embodiments, when the two-dimensional turntable 104 is at the zero coordinate position, the two axes of the two-dimensional turntable 104 are coplanar with the camera of the collimator 1011, and the optical axis of the laser terminal 105 is coaxial with the camera optical axis of the collimator 1011; the laser terminal 105 can be specifically used to emit a light beam to the opposite end through the collimator 1011. In order to improve the realism of the simulation, a preset vibration spectrum, such as the NASDA vibration spectrum, can be applied to the optical path of the collimator 1011 to simulate satellite micro-vibration. The optical path of the collimator 1011 can be generated by the laser link single branch docking equipment shown in the figure. Figure 3

[0115] In order to improve the accuracy of the simulation, the zero point of the laser terminal 105 and the two-dimensional turntable 104 can be calibrated before the simulation to determine the zero coordinate of the laser terminal 105 and the two-dimensional turntable 104, and the position of the collimator 1011, as follows:

[0116] 1) Install the laser terminal 105 on the two-dimensional turntable 104, set the working parameters of the laser terminal 105 and the two-dimensional turntable 104, such as camera exposure time, transmit-receive wavelength, polarization, etc., and adjust the collimator 1011 to the corresponding position for parameter setting;

[0117] 2) Turn on the laser of the collimator 1011 and the laser of the laser terminal 105, adjust the two axes (pitch axis and azimuth axis) of the two-dimensional turntable 104 to the coplanar position with the camera of the collimator 1011, at this time, the azimuth angle A0 and the pitch angle E0 of the two-dimensional turntable 104 are the zero coordinates of the two-dimensional turntable 104;

[0118] 3) Adjust the azimuth angle and the pitch angle of the laser terminal 105, so that the optical axis of the laser terminal 105 is coaxial with the camera optical axis of the collimator 1011, at this time, the laser terminal 105 and the focal plane camera of the collimator 1011 can simultaneously observe a complete and regular circular light spot, and the light spot is located at the central (X0, Y0) point of the camera field of view, at this time, the azimuth angle A0' and the pitch angle E0' of the laser terminal 105 are the zero coordinates of the laser terminal 105.

[0119] Calibrate the coordinate relationship between the laser terminal 105 and the two-dimensional turntable 104: adopt the coordinate precision measurement method, first calibrate the coordinate deviation between the two-dimensional turntable coordinate precision measurement cube and the zero point calibration cube (i.e. the coordinate system relationship between the zero point calibration cube and the two-dimensional turntable coordinate precision measurement cube in the zero static state); then calibrate the coordinate deviation between the laser terminal precision measurement cube and the zero point calibration cube (i.e. the coordinate system relationship between the zero point calibration cube and the laser terminal precision measurement cube in the zero static state).​

[0120] Wherein, the two-dimensional turntable reference coordinate system (i.e. two-dimensional turntable coordinate precision measuring cube) is defined as X1Y1Z1; the zero point of the two-dimensional turntable is calibrated by using the zero point measuring tool, at this time the two-dimensional turntable zero point coordinate system (i.e. zero point calibration cube) is defined as X2Y2Z2, the zero point is defined as the (X0, Y0) point formed on the collimator camera after the light beam emitted by the optical fiber received by the collimator and reflected by the zero point calibration cube, the (X0, Y0) point corresponds to the maximum power point received by the optical fiber; the zero point measuring tool is removed, the laser terminal is installed to the two-dimensional turntable, the two-dimensional turntable is maintained at the zero point position, the laser terminal coordinate system (i.e. laser terminal precision measuring cube) is defined as X3Y3Z3, and each coordinate system satisfies the right-hand rule.

[0121] The specific positions of the three cubes installed on the two-dimensional turntable, the zero point measuring tool and the laser terminal can be seen in the cube at the origin of the corresponding coordinate system shown in Figure 3 .

[0122] Since the laser terminal and the zero point measuring tool cannot be installed at the same time, the coordinate system transformation relationship is transmitted through the two-dimensional turntable reference coordinate system. In the embodiment of the application, the coordinate system transformation relationship between the laser terminal coordinate system and the two-dimensional turntable zero point coordinate system (i.e. the coordinate system transformation matrix from the laser terminal coordinate system to the two-dimensional turntable zero point coordinate system) can be obtained by three measurements, and the specific steps are as follows:

[0123] a) Measurement determines the two-dimensional turntable zero point coordinate system X2Y2Z2. The two-dimensional turntable zero point precision measuring tool (i.e. zero point measuring tool) is installed on the two-dimensional turntable, the two-dimensional turntable 104 zero point when the two-dimensional turntable coordinate precision measuring cube and the collimator camera are coplanar is calibrated, the light spot (X0, Y0) is obtained, and the (X0, Y0) alignment position is the maximum power point received by the optical fiber received by the collimator;

[0124] b) Measurement determines the coordinate system transformation matrix C 12 between the two-dimensional turntable zero point coordinate system X2Y2Z2 and the two-dimensional turntable reference coordinate system X1Y1Z1;

[0125] c) Measurement determines the transformation matrix C 13 between the laser terminal coordinate system X3Y3Z3 and the two-dimensional turntable reference coordinate system X1Y1Z1;

[0126] d) The position vector of the two-dimensional turntable reference coordinate system is = (r i , r j , r k ), r i , r j , r k are unit vectors on three axes, and the position vector of the two-dimensional turntable zero point coordinate system is = (r I , r J , r K ), r I , r J , r K are unit vectors on three axes, and the position vector of the laser terminal coordinate system is = (r I ', r J ', r K ), r I ', r J ', r K ' are unit vectors on three axes; the transformation relationship between the two-dimensional turntable reference coordinate system, the two-dimensional turntable zero-point coordinate system and the laser terminal coordinate system is as follows:

[0127]

[0128] wherein, represents the position vector of the two-dimensional turntable reference coordinate system; represents the position vector of the two-dimensional turntable zero-point coordinate system; C 12 represents the direction cosine matrix from the two-dimensional turntable reference coordinate system to the two-dimensional turntable zero-point coordinate system.

[0129]

[0130] wherein, represents the position vector of the two-dimensional turntable reference coordinate system; represents the position vector of the laser terminal coordinate system; C 13 represents the direction cosine matrix from the two-dimensional turntable reference coordinate system to the laser terminal coordinate system.

[0131] Based on the above two formulas, the following formula can be obtained.

[0132]

[0133] Thus, the coordinate system transformation relationship from the two-dimensional turntable zero-point coordinate system to the laser terminal coordinate system is obtained. Based on this, the coordinate system transformation matrix from the laser terminal coordinate system to the two-dimensional turntable zero-point coordinate system is .

[0134] In some embodiments, in order to improve the accuracy of the laser terminal capture link verification, as shown in Figure 4 , the above ground verification device can further include a time synchronization device 106; the time synchronization device 106 is used to align the time of the control computer 1012, the terminal ground detector 102, the turntable controller 103 and the laser terminal 105.

[0135] In the embodiments of the present application, the control computer 1012, the terminal ground detector 102, the turntable controller 103 and the laser terminal 105 are respectively connected with the time system device 106, the time system device 106 provides time for the control computer 1012, the terminal ground detector 102, the turntable controller 103 and the laser terminal 105 to provide a unified clock source, establish a time-unified measurement environment, and further improve the accuracy of the laser terminal capture tracking link verification.

[0136] The time system device 106 provides time in different ways for different devices to achieve time synchronization, so as to achieve the purpose of time alignment of the control computer 1012, the terminal ground detector 102, the turntable controller 103 and the laser terminal 105.

[0137] 1) The time system device can send time code to the control computer 1012.

[0138] 2) The time system device can send time code, 10M / 100M rate signal and 1PPS pulse signal to the terminal ground detector 102.

[0139] 3) The time system device can send time code to the turntable controller 103.

[0140] 4) The time system device can send 10M / 100M rate signal and 1PPS pulse signal to the laser terminal 105.

[0141] The time system device 106 provides the same starting time reference for the terminal ground detector 102, ensures that the two ends (two laser terminals) are synchronized to start pointing calculation, and moves according to the calculation; the time system device 106 provides PPS second pulse signal to the laser terminal 105 to simulate the integrated electronics on the satellite, realizes attitude broadcast synchronization; the time system device 106 provides time code to the terminal ground detector 102 to generate satellite time broadcast information.

[0142] The time system device 106 aligns the time of the control computer 1012, the terminal ground detector 102, the turntable controller 103 and the laser terminal 105, avoids data processing errors caused by inconsistent time, ensures the synchronous rotation of the two-dimensional turntable 104 and the laser terminal 105, and improves the accuracy of the laser terminal capture tracking link verification.

[0143] In some embodiments, the laser platform 101 can further include a collimator camera.

[0144] In this case, the collimator 1011 is also used to focus the light spot to the collimator camera; the collimator camera is used to calculate the centroid position of the light spot and display the light spot in real time for capture tracking monitoring.

[0145] In this embodiment, the collimator 1011 focuses the captured light spot onto the collimator camera. The collimator camera can display the light spot in real time. The light spot displayed by the collimator camera allows for a direct observation of the laser link tracking status, thereby determining the inter-satellite tracking and link establishment capability of the laser terminal and the stability of the laser link.

[0146] For example, if the light spot displayed by the collimator camera disappears, it indicates that the laser link is interrupted, the laser link is unstable, and does not meet the stability requirements.

[0147] For example, after the laser terminal 105 starts link establishment, the collimator camera displays the light spot very quickly. If the light spot is displayed within the preset time, it indicates that the laser terminal has good inter-satellite tracking and link establishment capabilities and meets the tracking and link establishment capability requirements.

[0148] In addition, the collimator camera can calculate the centroid position of the light spot, thereby determining the distance between the centroid position of the light spot and the zero-point coordinates of the collimator. By measuring the distance between the centroid position of the light spot and the zero-point coordinates of the collimator, the inter-satellite tracking and linking capability of the laser terminal can be quantitatively determined, facilitating subsequent optimization of inter-satellite tracking and linking strategies and parameters.

[0149] The following is combined Figure 5 The capture and chain-building test system shown, and Figure 6 The illustrated flow chart of the orbit-based laser link dynamic tracking and link establishment ground verification method describes the ground verification device provided in this application embodiment. This tracking and link establishment test system includes two ground verification devices: a first ground verification device 51 and a second ground verification device 52. The first ground verification device 51 and the second ground verification device 52 share a timing device 511. The first ground verification device 51 further includes a first control computer 512, a first terminal ground detector 513, a first turntable controller 514, a first two-dimensional turntable 515, a first laser terminal 516, and a first collimator 517. The second ground verification device 52 further includes a second control computer 522, a second terminal ground detector 523, a second turntable controller 524, a second two-dimensional turntable 525, a second laser terminal 526, and a second collimator 527. The first collimator 517 and the second collimator 527 are connected via optical fiber; the connection relationships between other devices are described below. Figure 5 Connections between devices.

[0150] Step S601: Calibrate the zero-point coordinates of the laser terminal and the two-dimensional turntable.

[0151] In this embodiment, the first laser terminal 516 is mounted on the first two-dimensional turntable 515. The first laser terminal 516 is aligned with the first collimator 517, and the zero-point coordinates (such as azimuth angle A) of the first two-dimensional turntable 515 are calibrated. 01 and pitch angle E 01) and the zero point coordinates (such as azimuth angle A 01 and pitch angle E 01 ) of the first laser terminal 516, and specifically can be:

[0152] 1) The first laser terminal 516 is installed on the first two-dimensional turntable 515, the working parameters of the first laser terminal 516 and the first two-dimensional turntable 515 are set, and the first collimator 517 is adjusted to the corresponding position for parameter setting;

[0153] 2) The laser of the first collimator 517 and the laser of the first laser terminal 516 are turned on, and the two axes of the first two-dimensional turntable 515 are adjusted to the coplanar position with the camera of the first collimator 517. At this time, the azimuth angle A 01 and the pitch angle E 01 of the first two-dimensional turntable 515 are the zero point coordinates of the first two-dimensional turntable 515;

[0154] 3) The azimuth angle and the pitch angle of the first laser terminal 516 are adjusted so that the optical axis of the first laser terminal 516 and the camera optical axis of the first collimator 517 are coaxial. At this time, the first laser terminal 516 and the focal plane camera of the first collimator 517 can simultaneously observe a complete and regular circular light spot, and the light spot is located in the central field of view of the camera. At this time, the azimuth angle A 01 and the pitch angle E 01 of the first laser terminal 516 are the zero point coordinates of the first laser terminal 516.

[0155] Similarly, the second laser terminal 526 is installed on the second two-dimensional turntable 525, the second laser terminal 526 is aligned with the second collimator 527, and the zero point coordinates (such as azimuth angle A 02 and pitch angle E 02 ) of the second two-dimensional turntable 525 and the zero point coordinates (such as azimuth angle A 02 and pitch angle E 02 ) of the second laser terminal 526 are calibrated.

[0156] Step S602, calibrate the coordinate system conversion matrix between the laser terminal and the two-dimensional turntable. That is, calibrate the coordinate system conversion matrix between the first laser terminal 516 and the first two-dimensional turntable 515, and calibrate the coordinate system conversion matrix between the second laser terminal 526 and the second two-dimensional turntable 525 to unify the space reference.

[0157] Step S603, align the time of the time synchronization device. That is, the first control computer 512, the first terminal ground detector 513, the first turntable controller 514, the first laser terminal 516, the second control computer 522, the second terminal ground detector 523, the second turntable controller 524, and the second laser terminal 526 are aligned in time using the time synchronization device 511.

[0158] Step S604, inject the orbit data with the time stamp into the control computer.

[0159] In the embodiment, the orbit data of one satellite in a continuous orbit period is injected into the first control computer 512, and the orbit data of another satellite in the continuous orbit period is injected into the second control computer 522. The starting time stamp of the continuous orbit period can be T0, the orbit data is saved in a CSV / TXT file in a protocol format, and the orbit and attitude disturbance (i.e., the link establishment interference factor data) is added by the injected data.

[0160] In the embodiment, the panel time of the time system device 511 can be T0 minus a specified time length, so as to leave a preparation time for the ground verification device. The specified time length can be set according to actual needs, for example, the specified time length can be 5 minutes, 6 minutes, or 8 minutes, etc.

[0161] Step S605, the control computer sends the orbit data to the turntable controller and the terminal ground inspection and broadcasting.

[0162] Taking the time stamp interval of the orbit and attitude data as 100 ms, the first preset frequency as 1 Hz, and the preset time length (i.e., the broadcasting advance amount) as 1 s as an example.

[0163] The first control computer 512 sends 10 frames of orbit data to the first turntable controller 514 at a frequency of 1 Hz by using UDP to advance the time stamp of the orbit data by 1 s, and the time interval between adjacent two frames of orbit data is 100 ms. The first control computer 512 sends one frame of orbit data to the first terminal ground inspection 513 at a frequency of 1 Hz by using UDP to advance the time stamp of the orbit data by 1 s.

[0164] Similarly, the second control computer 522 sends 10 frames of orbit data to the second turntable controller 524 at a frequency of 1 Hz by using UDP to advance the time stamp of the orbit data by 1 s. The second control computer 522 sends one frame of orbit data to the second terminal ground inspection 523 at a frequency of 1 Hz by using UDP to advance the time stamp of the orbit data by 1 s.

[0165] The first control computer 512 opens the vibration spectrum for the first parallel light pipe 517, and the second control computer 522 opens the vibration spectrum for the second parallel light pipe 527.

[0166] Step S606, the turntable controller calculates the target control amount of the two-dimensional turntable by using the orbit data, and controls the rotation of the two-dimensional turntable.

[0167] The first turntable controller 514 calculates the target control amount of the motion angle of the first two-dimensional turntable 515 by using the following formula.

[0168] EZD1 '=E ZD1 +△E1+E 01

[0169] A ZD1 '=A ZD1 +△A1+A 01

[0170] wherein, E ZD1 ' is a target control quantity of the elevation angle of the first two-dimensional turntable 515, A ZD1 ' is a target control quantity of the azimuth angle of the first two-dimensional turntable 515, E ZD1 is a theoretical control quantity of the elevation angle of the first two-dimensional turntable 515, A ZD1 is a theoretical control quantity of the azimuth angle of the first two-dimensional turntable 515, △A1 is a pointing deviation analog quantity of the azimuth angle, △E1 is a pointing deviation analog quantity of the elevation angle, and △A1 and △E1 can be artificial introduction quantities.

[0171] Taking 10 Hz as the second preset frequency as an example. The first turntable controller 514 calculates the target control quantity corresponding to each frame of track data by using each frame of track data and the pointing deviation analog quantity, and then broadcasts the target control quantity corresponding to the track data (i.e., the target control quantity of the movement angle of the first two-dimensional turntable 515) to the first two-dimensional turntable 515 at the time stamp of each frame of track data, that is, the target control quantity corresponding to the track data (i.e., the target control quantity of the movement angle of the first two-dimensional turntable 515) is broadcast to the first two-dimensional turntable 515 at a frequency of 10 Hz, so as to control the first two-dimensional turntable 515 to rotate the target control quantity corresponding to the track data at the corresponding time stamp, so as to simulate the dynamic track environment.

[0172] Similarly, the second turntable controller 524 calculates the target control quantity of the movement angle of the second two-dimensional turntable 525 by using the following formula.

[0173] E ZD2 '=E ZD2 +△E2+E 02

[0174] A ZD2 '=A ZD2 +△A2+A 02

[0175] wherein, E ZD2 ' is a target control quantity of the elevation angle of the second two-dimensional turntable 525, A ZD2 ' is a target control quantity of the azimuth angle of the second two-dimensional turntable 525, E ZD2 is a theoretical control quantity of the elevation angle of the second two-dimensional turntable 525, A ZD2A2 is the pointing error analog quantity of the azimuth angle, and AE2 is the pointing error analog quantity of the elevation angle.

[0176] Taking 10Hz as the second preset frequency, the second turntable controller 524 calculates the target control quantity corresponding to each track data by using each track data and the pointing error analog quantity, and then broadcasts the target control quantity corresponding to the track data (i.e., the target control quantity of the movement angle of the second two-dimensional turntable 525) to the second two-dimensional turntable 525 at the time stamp of each track data, that is, the target control quantity corresponding to the track data (i.e., the target control quantity of the movement angle of the second two-dimensional turntable 525) is broadcast to the second two-dimensional turntable 525 at a frequency of 10Hz, so as to control the second two-dimensional turntable 525 to rotate the target control quantity corresponding to the track data at the corresponding time stamp, so as to simulate the dynamic track environment.

[0177] The first two-dimensional turntable 515 and the second two-dimensional turntable 525 are respectively driven by the first turntable controller 514 and the second turntable controller 524, so as to realize the simulation of the inter-satellite link building track movement.

[0178] In step S607, the terminal ground station broadcasts the track data to the laser terminal.

[0179] The first terminal ground station 513 self-unpacks and packs according to the on-board working format, and pushes the track data to the first laser terminal 516 triggered by the time stamp. The second terminal ground station 523 self-unpacks and packs according to the on-board working format, and pushes the track data to the second laser terminal 526 triggered by the time stamp.

[0180] In step S608, the test device is started, and the dynamic capture and tracking link building capability and process verification of the laser link are carried out.

[0181] Starting from a given time stamp T0, the test device is started, and under the dynamic simulation conditions of the double-satellite track movement and the link building interference factors, the double-end laser terminal (i.e., the first laser terminal 516 and the second laser terminal 526) points to the opposite end according to the track data, one end is gazed, and one end is scanned, so as to establish a laser link with the opposite end, and then the dynamic open-loop pointing and capture and tracking link building test is carried out, and the inter-satellite capture and tracking link building capability and the laser link stability process verification of the laser terminal are carried out. The laser terminal or other user equipment can record the capture time, capture probability, tracking accuracy, communication error rate and other indexes.

[0182] After the link is successfully built, the link is maintained stable for more than 5 minutes, and the double-end laser terminal actively breaks the link for the next capture and tracking link building.

[0183] After the inter-satellite capture and tracking link establishment capability and laser link stability process verification based on orbit data guidance is completed, long-term stable link testing is carried out on demand, the communication gear is set according to the testing requirements, and the indexes such as the number of times of link breakage and recapture, the longest capture time, the shortest capture time, tracking accuracy, communication error rate and the like are monitored.

[0184] In the embodiments of the application, the laser terminal can also be used to optimize the inter-satellite capture and tracking link establishment strategy and parameters according to the ground verification results (such as the indexes of the number of times of link breakage and recapture, the longest capture time, the shortest capture time, tracking accuracy, communication error rate and the like monitored above). The ground verification results reflect the inter-satellite capture and tracking link establishment capability and laser link stability of the laser terminal. By using the ground verification results, the inter-satellite capture and tracking link establishment strategy and parameters can be accurately optimized in the direction of shortening the in-orbit capture and tracking link establishment time of the laser terminal. The laser terminal establishes a laser link with the opposite end by using the optimized inter-satellite capture and tracking link establishment strategy and parameters, which can greatly shorten the in-orbit capture and tracking link establishment time of the laser terminal.

[0185] In the embodiments of the application, the capture and tracking link establishment test system is an open-loop control system. Based on the open-loop control system, the system is more simplified and the response speed is higher, large-scale parallel processing can be performed, and the capture and tracking link establishment verification efficiency is improved; the ground verification is performed based on real orbit data and link establishment interference factors, which is closer to the actual application scene and improves the reliability of the verification; stable pointing and capture are realized under the open-loop condition, and the robustness to the ground environment interference is stronger; for the inter-orbit link and access link scenes, the maximum, minimum and average angular velocities of the two satellites can be traversed in the test, and the capture and tracking link establishment capability of the laser terminal is fully investigated.

[0186] In the technical scheme provided by the embodiments of the application, the control computer included in the laser platform sends orbit data to the terminal ground detector and the turntable controller, the turntable controller drives the two-dimensional turntable to move by using the orbit data, an orbit motion scene and a link establishment interference factor simulation environment are established, and the terminal ground detector broadcasts the orbit data to the laser terminal to drive the laser terminal to establish a laser link between the two satellites in the orbit motion scene, so as to ensure the attitude and orbit stability of the laser terminal in the simulation test process and realize high-fidelity and high-reliability verification of the dynamic capture and tracking link establishment and long-term stable link establishment capability of the laser terminal.

[0187] The device provided by the embodiments of the application is an open-loop control system, the system is more simplified, the response speed is higher, large-scale parallel processing can be performed, the inter-satellite laser link capture and tracking link establishment process is dynamically verified, the inter-satellite laser link capture and tracking link establishment capability is fully tested, the inter-satellite laser link capture and tracking link establishment strategy and parameters are optimized, and the in-orbit rapid link establishment of the laser terminal and the long-term stability of the laser link are supported, which will improve the in-orbit capture and tracking link establishment verification efficiency and the link stability of the laser terminal.

[0188] Corresponding to the ground verification device for dynamic capture and tracking of laser link and chain establishment described above, the embodiment of the application provides a ground verification method for dynamic capture and tracking of laser link and chain establishment, as shown in Figure 7 The device comprises a laser platform, a two-dimensional turntable, a turntable controller, a laser terminal, and a terminal ground detector. The laser terminal is installed on the two-dimensional turntable. The laser platform comprises a collimator and a control computer. The collimator provides a far-field environment for an inter-satellite laser link beam. The method comprises the following steps:

[0189] In step S701, the control computer obtains orbit data of a satellite and sends the orbit data to the terminal ground detector and the turntable controller.

[0190] In step S702, the turntable controller calculates a target control quantity of the two-dimensional turntable by using the orbit data and sends the target control quantity to the two-dimensional turntable.

[0191] In step S703, the two-dimensional turntable drives the two-dimensional turntable to move according to the target control quantity to provide a dynamic orbit simulation environment.

[0192] In step S704, the terminal ground detector broadcasts the orbit data to the laser terminal.

[0193] In step S705, the laser terminal calculates an inter-satellite pointing vector by using the orbit data and drives a beam emitted by the laser terminal to point to a peer terminal according to the inter-satellite pointing vector to emit the beam to the peer terminal to establish a laser link with the peer terminal.

[0194] In the technical scheme provided by the embodiment of the application, the control computer of the laser platform sends the orbit data to the terminal ground detector and the turntable controller. The turntable controller drives the two-dimensional turntable to move by using the orbit data to establish an orbit motion scene and provide a dynamic orbit simulation environment. The terminal ground detector broadcasts the orbit data to the laser terminal to drive the laser terminal to establish a two-satellite link in the orbit motion scene, ensure the stability of the laser terminal in the simulation test process, and realize high-fidelity verification of a dynamic capture and tracking chain establishment process and data of the laser terminal. The device provided by the embodiment of the application is an open-loop control system. The system is more simplified, has a higher response speed, can perform large-scale parallel processing, verifies an inter-satellite laser link capture and tracking chain establishment process dynamically, fully tests the inter-satellite laser link capture and tracking chain establishment capability, optimizes the inter-satellite laser link capture and tracking chain establishment strategy and parameters, supports realization of rapid chain establishment of the laser terminal in orbit and long-term stability of the laser link, improves the capture and tracking chain establishment verification efficiency, and improves the capture and tracking precision of the laser terminal.

[0195] In the embodiments described above, all or some of the steps can be implemented by hardware, software, firmware or any combination thereof. When implemented by software, all or some of the steps can be implemented in the form of one or more computer programs or program elements. The computer programs reside (at least temporarily) in a memory of a computer during execution. The memory can be a RAM memory, a flash memory, a ROM memory, an EPROM memory, or any other suitable memory. The memory can be integral to or separate from the computer. The computer programs can be written in any suitable programming language, such as C, C++, Java, Visual Basic, etc. The computer programs can be written in assembly or machine language, if desired. The computer programs can be distributed over network coupled file servers, or can be distributed by any other suitable means.

[0196] It is to be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily implying any actual relationship or order between such entities or actions. Also, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. In addition, terms such as "first" and "second" are used herein only to distinguish one entity from another without necessarily implying any actual relationship or order between such entities.

[0197] Each of the embodiments described in the present specification is described in an associated manner, and the same or similar parts among the embodiments can be referred to each other. Each of the embodiments mainly describes the difference from other embodiments. In particular, for the method embodiments, since they are basically similar to the device embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the description of the device embodiments.

[0198] The above merely provides the preferred embodiment of the present application, and not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A ground verification apparatus for dynamic acquisition and link establishment of a laser link based on a track, characterized in that The device comprises a laser platform, a two-dimensional turntable, a turntable controller, a laser terminal, and a terminal ground detector, wherein the laser terminal is installed on the two-dimensional turntable; the laser platform comprises a collimator and a control computer; the collimator is used to provide a far-field environment for an inter-satellite laser link beam; the control computer is used to obtain orbit data of a satellite, and send the orbit data to the terminal ground detector and the turntable controller in advance by a first preset frequency and for a preset time period relative to a time stamp carried by the orbit data; the turntable controller is used to calculate a target control quantity of the two-dimensional turntable by using the orbit data, and send the target control quantity to the two-dimensional turntable, wherein the target control quantity comprises a control quantity of a pitch angle and a control quantity of an azimuth angle; the two-dimensional turntable is used to drive the two-dimensional turntable to move to a given position corresponding to the target control quantity according to the target control quantity, so as to provide a dynamic orbit simulation environment; the terminal ground detector is used to broadcast the orbit data to the laser terminal; the laser terminal is used to calculate an inter-satellite pointing vector by using the orbit data, and drive a beam emitted by the laser terminal to point to a peer according to the inter-satellite pointing vector, so as to emit the beam to the peer and establish a laser link with the peer.

2. The device according to claim 1, wherein the control computer is specifically configured to send one frame of orbit data to the terminal ground detector in advance by the first preset frequency and for the preset time period relative to the time stamp carried by the orbit data; and the terminal ground detector is specifically configured to broadcast the orbit data to the laser terminal by the first preset frequency when the time stamp carried by the orbit data is reached.

3. The device according to claim 1, wherein the control computer is specifically configured to send multiple frames of orbit data to the turntable controller in advance by the first preset frequency and for the preset time period relative to the time stamp carried by the orbit data; and the turntable controller is specifically configured to send a target control quantity to the two-dimensional turntable by a second preset frequency when the time stamp carried by the orbit data is reached. The turntable controller is specifically configured to: calculate an inter-satellite pointing vector according to the orbit data and a coordinate system transformation matrix from a laser terminal coordinate system to a zero-point coordinate system of the two-dimensional turntable; calculate a target control quantity of a movement angle of the two-dimensional turntable according to the inter-satellite pointing vector and a zero-point coordinate of the two-dimensional turntable. The turntable controller is specifically configured to: calculate an initial control quantity of the movement angle of the two-dimensional turntable according to the inter-satellite pointing vector and the zero-point coordinate of the two-dimensional turntable; 4. The apparatus of claim 1, wherein, calculate a target control quantity of the movement angle of the two-dimensional turntable according to the initial control quantity and a pointing deviation simulation quantity. The target control quantity comprises a correction quantity of an azimuth angle and a correction quantity of a pitch angle of the two-dimensional turntable. The coordinate system transformation matrix is an angle deviation between the laser terminal coordinate and the two-dimensional turntable coordinate when the two-dimensional turntable is in a zero-point coordinate state.

5. The apparatus of claim 4, wherein, The laser terminal is further configured to: ​ ​ 6. The apparatus of claim 4, wherein, ​ 7. The device of any one of claims 4-6, wherein, ​ 8. The apparatus of claim 1, wherein, ​ After the laser link is established, a preset time is waited, the laser link is cut off, and the step of transmitting a light beam to the opposite end to establish a laser link with the opposite end is re-executed.

9. The apparatus of claim 1, wherein, When the two-dimensional turntable is at a zero coordinate position, two axes of the two-dimensional turntable are coplanar with a camera of the collimator, and an optical axis of the laser terminal is coaxial with an optical axis of the camera of the collimator. The laser terminal is specifically configured to transmit a light beam to the opposite end through the collimator.

10. The apparatus of claim 9, wherein, A preset vibration spectrum is applied to an optical path of the collimator.

11. The apparatus of claim 1, wherein, The laser platform further comprises a collimator camera. The collimator is further configured to focus a light spot to the collimator camera. The collimator camera is configured to calculate a centroid position of the light spot and display the light spot in real time.

12. The apparatus of claim 1, wherein, The device further comprises a time system device. The time system device is configured to align times of the control computer, the terminal ground detector, the turntable controller and the laser terminal.

13. The apparatus of claim 12, wherein, The time system device is specifically configured to send a time code to the control computer.

14. The apparatus of claim 12, wherein, The time system device is specifically configured to send a time code, a 10M / 100M rate signal and a 1PPS pulse signal to the terminal ground detector.

15. The apparatus of claim 12, wherein, The time system device is specifically configured to send a time code to the turntable controller.

16. The apparatus of claim 12, wherein, The time system device is specifically configured to send a 10M / 100M rate signal and a 1PPS pulse signal to the laser terminal.

17. A method for ground verification of orbit-based laser link dynamic acquisition and tracking link establishment, characterized in that, The device comprises a laser platform, a two-dimensional turntable, a turntable controller, a laser terminal, and a terminal ground detector, the laser terminal is installed on the two-dimensional turntable, the laser platform comprises a collimator and a control computer, the collimator provides a far-field environment of an inter-satellite laser link light beam, and the method comprises: The control computer acquires orbit data of a satellite, and sends the orbit data to the terminal ground detector and the turntable controller in advance by a first preset frequency and for a preset time period relative to a time stamp carried by the orbit data; The turntable controller calculates a target control amount of the two-dimensional turntable by using the orbit data, and sends the target control amount to the two-dimensional turntable, the target control amount comprises a control amount of a pitch angle and a control amount of an azimuth angle; The two-dimensional turntable drives the two-dimensional turntable to move to a given position corresponding to the target control amount to provide a dynamic orbit simulation environment; The terminal ground detector broadcasts the orbit data to the laser terminal; The laser terminal calculates an inter-satellite pointing vector by using the orbit data, and drives a light beam emitted by the laser terminal to point to the opposite end according to the inter-satellite pointing vector, transmits the light beam to the opposite end to establish a laser link with the opposite end.

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